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1.  Comparison of the lung function change in patients with COPD and bronchial asthma before and after treatment with budesonide/formoterol 
Journal of Thoracic Disease  2012;4(6):583-587.
This study investigated the rapid onset of bronchodilation effect and compared lung function changes following budesonide/formoterol (Symbicort Turbuhaler®) inhalation in Chinese patients with moderate-severe chronic obstructive pulmonary disease (COPD) and bronchial asthma.
In this open-label, parallel-group clinical study, patients eligible for study were divided into COPD group (n=62, mean age 68.16±8.75 years) and asthma group (n=30, mean age 45.80±12.35 years). Lung function tests (include FEV1, FVC, FEV1/FVC, and IC) were performed at baseline (t=0 min time point, value before inhalation of budesonide/formoterol), and then eligible patients received two inhalations of budesonide/formoterol (160/4.5 μg). Lung function tests were reassessed at t=3, 10 and 30 min time point. The primary end-point was lung function change 3 min after drug inhalation, and the secondary end-points were comparison of the gas flow rate (ΔFEV1) and volume responses (ΔFVC, ΔIC) between COPD and asthma patients after inhalation of budesonide/formoterol.
Compared with the baseline, all patients significantly improved their lung function (included FEV1, FVC, FEV1/FVC, and IC) at 3 min (P<0.05). Greater bronchodilation efficacy was found in the asthma group compared with the COPD group (P<0.05). In the asthmatic patients, the curves of FEV1, FVC, FEV1/FVC, IC, showed improvement with an ascending trend at all time points from 3 to 30 min. Whereas in the COPD patients, only the curves of FEV1, FVC, IC showed similar pattern. We found that ΔFVC was significantly higher than ΔFEV1 in both groups (P<0.05), but no significant difference between ΔIC and ΔFEV1 (P>0.05). Compared with COPD group, asthma group had higher level of ΔFEV1 and ΔIC (P<0.05), but no significant difference for ΔFVC can be found.
Budesonide/formoterol has a fast onset of bronchodilation effect in patients with moderate-severe COPD and asthma. Greater efficacy was found in the asthma group compared with the COPD group. The gas flow rate and volume responses in patients with COPD differ from those with asthma after inhalation of Budesonide/formoterol.
PMCID: PMC3506807  PMID: 23205282
Budesonide/formoterol; chronic obstructive pulmonary disease; bronchial asthma; lung function test
2.  Body Mass Index and Phenotype in Mild-to-Moderate Persistent Asthma 
While obesity has been hypothesized to worsen asthma, data from studies of well-characterized asthmatics are lacking.
Evaluate the relationship between body mass index (BMI), asthma impairment and response to therapy.
BMI (kg/m2) and asthma phenotypic and treatment response data were extracted from Asthma Clinical Research Network (ACRN) studies. The cross-sectional relationship between BMI and asthma impairment was analyzed, as was the longitudinal relationship between BMI and response to asthma controller therapies.
1,265 subjects with mild-to-moderate persistent asthma were evaluated. Analyses of lean vs. overweight/obese asthmatics demonstrated small differences in FEV1 (3.05 vs. 2.91 L, p=0.001), FEV1/FVC (mean 83.5% vs. 82.4%, p=0.01), rescue albuterol use (1.1 vs. 1.2 puffs/day, p=0.03) and asthma-related quality of life (5.77 vs. 5.59, p=0.0004). Overweight/obese asthmatics demonstrated a smaller improvement in exhaled nitric oxide with inhaled corticosteroid (ICS) treatment than did lean asthmatics (3.6 vs. 6.5ppb, p=0.04). With ICS/long-acting beta agonist treatment, overweight/obese asthmatics demonstrated smaller improvements in lung function than lean asthmatics, with an 80mL (p=0.04) and 1.7% (p=0.02) lesser improvement in FEV1 and FEV1/FVC ratio, respectively. Significant differences in therapeutic response to leukotriene modifiers between BMI categories were not observed.
Elevated BMI is not associated with clinically-significant worsening of impairment in patients with mild-to-moderate persistent asthma. There is a modest association between elevated BMI and reduced therapeutic effect of ICS-containing regimens in this patient population. Prospective studies evaluating the impact of overweight and obesity on treatment response in asthma are warranted.
Clinical Implications
In individuals with mild to moderate persistent asthma, being overweight or obese does not appear to modify indices of asthma-related impairment. Elevated body mass index may reduce response to inhaled corticosteroid-containing treatment regimens.
PMCID: PMC2743451  PMID: 19501235
Asthma; obesity; treatment; severity
3.  Clinical Predictors and Outcomes of Consistent Bronchodilator Response in the Childhood Asthma Management Program 
Among asthmatics, bronchodilator response (BDR) to inhaled ß2- adrenergic agonists is variable, and the significance of a consistent response over time is unknown.
We assessed baseline clinical variables and determined the clinical outcomes associated with a consistently positive BDR over 4 years in children with mild-moderate persistent asthma.
In the 1,041 participants in the Childhood Asthma Management Program (CAMP), subjects with a change in FEV1 of 12% or greater (and 200mLs) after inhaled ß2 agonist at each of their yearly follow-up visits (consistent BDR) were compared with those who did not have a consistent BDR.
We identified 52 children with consistent BDR over the 4-year trial. Multivariable logistic regression modeling demonstrated that baseline pre-bronchodilator FEV1 (OR=0.71, p<0.0001), log 10 IgE level (OR=1.97, p=0.002), and lack of treatment with inhaled corticosteroids (OR=0.31, p=0.009) were associated with a consistent BDR. Individuals who had a consistent BDR had more hospital visits (p=0.007), required more prednisone bursts (p=0.0007), had increased nocturnal awakenings due to asthma (p<0.0001), and missed more days of school (p=0.03) than non-responders during the 4-year follow-up.
We have identified predictors of consistent BDR and determined that this phenotype is associated with poor clinical outcomes.
PMCID: PMC2947830  PMID: 18848350
asthma; consistent bronchodilator response; outcomes
4.  Effects of Time, Albuterol, and Budesonide on Shape of the Flow-Volume Loop in Children with Asthma 
Assessment of asthma via spirometry in children is challenging due to often normal FEV1 values.
We used Mead’s slope ratio ( (dV•∕dV)∕(V•∕V) ) to analyze the shape of the flow volume loop.
We analyzed the effects of time, albuterol, and budesonide on FEV1, FEV1/FVC, FEF25-75%, and Mead’s slope ratio, early (between 75% and 50% of FVC, SR61) and late (between 75% and 50% of FVC, SR35) in exhalation, in the Childhood Asthma Management Program cohort at baseline, 4 months, and end of study in participants who received either inhaled placebo or budesonide BID.
In the placebo group, both SR61 and SR35 improved over time. Bronchodilator consistently improved both SR61 and SR35, without change in degree of improvement over time. Similarly, in the budesonide group, time and bronchodilator each independently improved both SR61 and SR35. At 4 months and end of study, budesonide patients had significant improvements in SR61 relative to placebo patients, independent of bronchodilator effect. Budesonide and placebo were not different with respect to pre or post-bronchodilator SR35.
Budesonide-treated patients have less concave flow-volume loops when compared to placebo-treated patients. Time and bronchodilator also make the flow-volume loop less concave. Furthermore, it appears that there are discrete bronchodilator responsive and corticosteroid responsive components of airflow obstruction in pediatric asthma.
Clinical Implications
Changes in flow-volume loop shape in children with asthma may reflect changes in airflow for which slope ratio may be more sensitive than conventional measures.
PMCID: PMC2881659  PMID: 19014770
Spirometry; Slope Ratio; Asthma; Pediatric; Children
5.  Effects of formoterol-budesonide on airway remodeling in patients with moderate asthma 
Acta Pharmacologica Sinica  2010;32(1):126-132.
To evaluate the effect of inhaled formoterol-budesonide on airway remodeling in adult patients with moderate asthma.
Thirty asthmatic patients and thirty control subjects were enrolled. Asthmatic subjects used inhaled Symbicort 4.5/160 μg twice daily for one year. The effect of formoterol-budesonide on airway remodeling was assessed with comparing high-resolution computer tomography (HRCT) images of asthmatic patients and controls, as well as expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness.
The differences in age and gender between the two groups were not significant. However, differences in FVC %pred, FEV1 %pred, and PC20 between the two groups were significant. After treatment with formoterol-budesonide, the asthma patients' symptoms were relieved, and their lung function was improved. The WT and WA% of HRCT images in patients with asthma was increased, whereas treatment with formoterol-budesonide caused these values to decrease. The expression of MMP-9, TIMP-1, and TGF-β1 in induced sputum samples increased in patients with asthma and decreased dramatically after treatment with formoterol-budesonide. The WT and WA% are correlated with the expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness, while these same values are correlated negatively with FEV1/FVC and FEV1%.
Formoterol-budesonide might interfere in chronic inflammation and airway remodeling in asthmatic patients. HRCT can be used to effectively evaluate airway remodeling in asthmatic patients.
PMCID: PMC4003310  PMID: 21170080
asthma; hyper-responsiveness; airway remodeling; high-resolution computer tomography; formoterol-budesonide; induced sputum; single-center, open-label study
6.  The Effect of Obesity Degree on Childhood Pulmonary Function Tests 
Balkan Medical Journal  2014;31(3):235-238.
Childhood obesity has become a global epidemic. It is related to several chronic diseases such as essential hypertension, type 2 diabetes mellitus, and renal disease. The relationship between the degree of obesity and lung functions is well defined in adults, but limited information is available about the childhood period.
This study aims to determine the impact of the degree of obesity on the pulmonary functions of school children and adolescents.
Study Design:
Cross sectional study.
Included in the study were a total of 170 school children and adolescents (9–17 years old) referred to our paediatric outpatient clinic. Of these subjects, 42 were lean and non-obese (BMI % <85), 30 subjects were overweight (BMI % >85, <95), 34 subjects were obese (BMI % >95, <97), and 64 subjects were morbidly obese (BMI % >97). Anthropometric measurements were taken and spirometry was performed on all subjects. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced vital capacity 25–75 (FEV25–75) and peak expiratory flow (PEF) were used to measure the ventilatory functions for all the subjects.
The groups showed no significant differences in age or gender. Despite no statistically significant differences in FEV1, FVC, or FEV1/FVC, there were significant reductions in PEF (p<0.001) and FEV25–75 (p<0.001) in the overweight, obese and morbidly obese subjects, when compared with those who were non-obese.
Overweight, obese and morbidly obese children have no obstructive abnormalities compared with healthy lean subjects.
PMCID: PMC4204752  PMID: 25337419
Adolescent; obesity; respiratory function tests; school children
7.  The utility of forced expiratory flow between 25% and 75% of vital capacity in predicting childhood asthma morbidity and severity 
The Journal of Asthma  2012;49(6):586-592.
The forced expiratory volume in one second (FEV1), felt to be an objective measure of airway obstruction, is often normal in asthmatic children. The forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) reflects small airway patency and has been found to be reduced in children with asthma. The aim of this study was to determine if FEF25-75 is associated with increased childhood asthma severity and morbidity in the setting of a normal FEV1, and to determine if bronchodilator responsiveness (BDR) as defined by FEF25-75 identifies more childhood asthmatics than does BDR defined by FEV1.
The Children’s Hospital Boston Pulmonary Function Test database was queried and the most recent spirometry result was retrieved for 744 children diagnosed with asthma between 10–18 years of age between October 2000 and October 2010. Electronic medical records in the 1 year prior and the 1 year following the date of spirometry were examined for asthma severity (mild, moderate or severe) and morbidity outcomes for three age, race and gender-matched subgroups: group A (n= 35) had a normal FEV1, FEV1/FVC and FEF25-75; Group B (n= 36) had solely a diminished FEV1/FVC; and Group C (n=37) had a normal FEV1, low FEV1/FVC and low FEF25-75. Morbidity outcomes analyzed included the presence of hospitalization, emergency department visit, intensive care unit admission, asthma exacerbation, and systemic steroid use.
Subjects with a low FEF25-75 (Group C) had nearly 3 times the odds (OR 2.8, p<0.01) of systemic corticosteroid use and 6 times the odds of asthma exacerbations (OR 6.3, p>0.01) compared with those who had normal spirometry (Group A). Using FEF25-75 to define bronchodilator responsiveness identified 53% more subjects with asthma than did using a definition based on FEV1.
A low FEF25-75 in the setting of a normal FEV1 is associated with increased asthma severity, systemic steroid use and asthma exacerbations in children. In addition, using the percent change in FEF25-75 from baseline may be helpful in identifying bronchodilator responsiveness in asthmatic children with a normal FEV1.
PMCID: PMC3398223  PMID: 22742446
spirometry; childhood asthma; FEF25-75; bronchodilator responsiveness
8.  Obesity in Children with Poorly-Controlled Asthma: Sex Differences 
Pediatric pulmonology  2012;48(9):847-856.
Obesity increases asthma risk, and may alter asthma severity. In adults, sex appears to modify the effect of obesity on asthma. Among children, the effect of sex on the relationship between obesity and asthma severity remains less clear, particularly when considering race.
To determine how obesity affects disease characteristics in a diverse cohort of children with poorly controlled asthma, and if obesity effects are altered by sex.
We analyzed 306 children between 6–17 years of age with poorly controlled asthma enrolled in a 6-month trial assessing lansoprazole for asthma control. In this secondary analysis, we determined associations between obesity and symptom severity, spirometry, exacerbation risk, airway biomarkers, bronchial reactivity and airflow perception. We used both a multivariate linear regression and longitudinal mixed-effect model to determine if obesity interacted with sex to affect asthma severity.
Regardless of sex, BMI>95th percentile did not affect asthma control, exacerbation risk or airway biomarkers. Sex changed the effect of obesity on lung function (sex*obesity FEV1%, interaction p-value <.01, sex*obesity FEV1/FVC, interaction p-value=.03). Obese males had significantly worse airflow obstruction compared to non-obese males, while in females there was no obesity effect on airflow obstruction. In females, obesity was associated with significantly greater FEV1 and FVC, and a trend toward reduced airway reactivity.
Obesity did not affect asthma control, airway markers or disease stability; however obesity did affect lung function in a sex-dependent manner. In males, obesity associated with reduced FEV1/FVC, and in females, obesity associated with substantially improved lung function.
PMCID: PMC3578966  PMID: 23143849
Asthma; Obesity; Children; Sex; Body Mass Index; Spirometry
9.  Obesity can influence children’s and adolescents’ airway hyperresponsiveness differently 
Literature is still arguing about a possible relationship between airway hyperresponsiveness (AHR) and body mass index (BMI). This study aimed at evaluating the influence of BMI on AHR and pulmonary function in children and adolescents that performed a methacholine test for suggestive asthma symptoms.
799 consecutive children/adolescents (535 M; mean age: 15 ± 3 yrs; median FEV1% predicted: 101.94% [93.46-111.95] and FEV1/FVC predicted: 91.07 [86.17-95.38]), were considered and divided into underweight, normal, overweight and obese. Different AHR levels were considered as moderate/severe (PD20 ≤ 400 μg) and borderline (PD20 > 400 μg).
536 children/adolescents resulted hyperreactive with a median PD20 of 366 μg [IQR:168–1010.5]; 317 patients were affected by moderate/severe AHR, whereas 219 showed borderline hyperresponsiveness. Obese subjects aged > 13 years showed a lower (p = 0.026) median PD20 (187μg [IQR:110–519]) compared to overweight (377 μg [IQR:204–774]) and normal-weight individuals’ values (370.5 μg [IQR:189–877]). On the contrary, median PD20 observed in obese children aged ≤ 13 years (761 μg [IQR:731–1212]) was higher (p = 0.052) compared to normal-weight children’s PD20 (193 μg [IQR:81–542]) and to obese adolescents’ values (aged > 13 years) (p = 0.019). Obesity was a significant AHR risk factor (OR:2.853[1.037-7.855]; p = 0.042) in moderate/severe AHR adolescents. Females showed a higher AHR risk (OR:1.696[1.046-2.751] p = 0.032) compared to males. A significant relationship was found between BMI and functional parameters (FEV1, FVC, FEV1/FVC) only in hyperreactive females.
Obesity seems to influence AHR negatively in female but not in male adolescents and children. In fact, AHR is higher in obese teenagers, in particular in those with moderate/severe hyperresponsiveness, and may be mediated by obesity-associated changes in baseline lung function.
PMCID: PMC3844670  PMID: 24028436
Airway hyperresponsiveness; Asthma; Body mass index; Children and adolescents; Methacholine test; Obesity
10.  502 Plasminogen Activator Inhibitor-1, Fibrinogen and Lung Function in Adolescents with Asthma and Obesity 
The World Allergy Organization Journal  2012;5(Suppl 2):S176-S177.
Obesity promotes a low-grade systemic inflammatory state that may act on the lung to exacerbate asthma. There is little information on the relationship between systemic inflammation and lung function in children and adolescents.
One hundred and seventy eight adolescents (boys and girls) were involved, 4 groups were divided according to their diagnosis: non-obese and non-asthmatic controls (n = 38), non-obese asthmatics (n = 31), obese non-asthmatics (n = 62), obese asthmatics (n = 47). The levels of PAI-1 and fibrinogen were determined in blood samples. The lung function was evaluated by measuring forced expiratory flow in 1-second (FEV1) and forced vital capacity (FVC1).
Compared to healthy controls, obese adolescents with or without asthma showed higher levels of fibrinogen (328.4 ± 54.9, 324.9 ± 68.9 and 289.2 ± 61.5 mg/dL, respectively) and PAI-1 (36.0 ± 17.3, 53.2 ± 22.3 and 52.6 ± 24.7 ng/mL, respectively) and reduced FEV1/FVC ratio (87.7 ± 7.7, 81.6 ± 8.6 and 81.7 ± 6.9, respectively). In the whole studied subjects, FEV1/FVC ratio showed significant inverse correlation with PAI-1 (r = -0.185), fibrinogen (r = -0.157), BMI (r = -0.303), insulin(r = -0.198) and HOMA (r = -0.173). In the 78 asthmatic subjects, FVC correlated positively with BMI, no significant correlation was observed between FEV1/FVC ratio and BMI, HOMA, PAI-1 or fibrinogen.
Our data demonstrated that the degree of systemic inflammation and the degree of obesity in the whole studied groups correlated to the reduced lung function. Further studies are needed to identify the pathophysiologic mechanism for such association.
PMCID: PMC3513029
11.  Protective effect of budesonide/formoterol compared with formoterol, salbutamol and placebo on repeated provocations with inhaled AMP in patients with asthma: a randomised, double-blind, cross-over study 
Respiratory Research  2010;11(1):66.
The budesonide/formoterol combination is successfully used for fast relief of asthma symptoms in addition to its use as maintenance therapy. The temporarily increased corticosteroid dose during increasing inhaler use for symptom relief is likely to suppress any temporary increase in airway inflammation and may mitigate or prevent asthma exacerbations. The relative contribution of the budesonide and formoterol components to the improved asthma control is unclear.
The acute protective effect of inhaled budesonide was tested in a model of temporarily increased airway inflammation with repeated indirect airway challenges, mimicking an acute asthma exacerbation. A randomised, double-blind, cross-over study design was used. Asthmatic patients (n = 17, mean FEV1 95% of predicted) who previously demonstrated a ≥30% fall in forced expiratory volume in 1 second (FEV1) after inhaling adenosine 5'-monophosphate (AMP), were challenged on four consecutive test days, with the same dose of AMP (at 09:00, 12:00 and 16:00 hours). Within 1 minute of the maximal AMP-induced bronchoconstriction at 09:00 hours, the patients inhaled one dose of either budesonide/formoterol (160/4.5 μg), formoterol (4.5 μg), salbutamol (2 × 100 μg) or placebo. The protective effects of the randomised treatments were assessed by serial lung function measurements over the test day.
In the AMP provocations at 3 and 7 hours after inhalation, the budesonide/formoterol combination provided a greater protective effect against AMP-induced bronchoconstriction compared with formoterol alone, salbutamol and placebo. In addition all three active treatments significantly increased FEV1 within 3 minutes of administration, at a time when inhaled AMP had induced the 30% fall in FEV1.
A single dose of budesonide/formoterol provided a greater protective effect against inhaled AMP-induced bronchoconstriction than formoterol alone, both at 3 and at 7 hours after inhalation. The acute protection against subsequent bronchoconstrictor stimuli such as inhaled AMP and the rapid reversal of airway obstruction supports the use of budesonide/formoterol for both relief and prevention in the treatment of asthma.
Trial Registration number NCT00272753
PMCID: PMC2890647  PMID: 20509942
12.  Genome‐wide linkage analysis of pulmonary function in families of children with asthma in Costa Rica 
Thorax  2006;62(3):224-230.
Although asthma is highly prevalent among certain Hispanic subgroups, genetic determinants of asthma and asthma‐related traits have not been conclusively identified in Hispanic populations. A study was undertaken to identify genomic regions containing susceptibility loci for pulmonary function and bronchodilator responsiveness (BDR) in Costa Ricans.
Eight extended pedigrees were ascertained through schoolchildren with asthma in the Central Valley of Costa Rica. Short tandem repeat (STR) markers were genotyped throughout the genome at an average spacing of 8.2 cM. Multipoint variance component linkage analyses of forced expiratory volume in 1 second (FEV1) and FEV1/ forced vital capacity (FVC; both pre‐bronchodilator and post‐bronchodilator) and BDR were performed in these eight families (pre‐bronchodilator spirometry, n = 640; post‐bronchodilator spirometry and BDR, n = 624). Nine additional STR markers were genotyped on chromosome 7. Secondary analyses were repeated after stratification by cigarette smoking.
Among all subjects, the highest logarithm of the odds of linkage (LOD) score for FEV1 (post‐bronchodilator) was found on chromosome 7q34–35 (LOD = 2.45, including the additional markers). The highest LOD scores for FEV1/FVC (pre‐bronchodilator) and BDR were found on chromosomes 2q (LOD = 1.53) and 9p (LOD = 1.53), respectively. Among former and current smokers there was near‐significant evidence of linkage to FEV1/FVC (post‐bronchodilator) on chromosome 5p (LOD = 3.27) and suggestive evidence of linkage to FEV1 on chromosomes 3q (pre‐bronchodilator, LOD = 2.74) and 4q (post‐bronchodilator, LOD = 2.66).
In eight families of children with asthma in Costa Rica, there is suggestive evidence of linkage to FEV1 on chromosome 7q34–35. In these families, FEV1/FVC may be influenced by an interaction between cigarette smoking and a locus (loci) on chromosome 5p.
PMCID: PMC2117166  PMID: 17099076
13.  Daily versus as-needed inhaled corticosteroid for mild persistent asthma (The Helsinki early intervention childhood asthma study) 
Archives of Disease in Childhood  2007;93(8):654-659.
To compare the effect of inhaled budesonide given daily or as-needed on mild persistent childhood asthma.
Patients, design and interventions:
176 children aged 5–10 years with newly detected asthma were randomly assigned to three treatment groups: (1) continuous budesonide (400 μg twice daily for 1 month, 200 μg twice daily for months 2–6, 100 μg twice daily for months 7–18); (2) budesonide, identical treatment to group 1 during months 1–6, then budesonide for exacerbations as needed for months 7–18; and (3) disodium cromoglycate (DSCG) 10 mg three times daily for months 1–18. Exacerbations were treated with budesonide 400 μg twice daily for 2 weeks.
Main outcome measures:
Lung function, the number of exacerbations and growth.
Compared with DSCG the initial regular budesonide treatment resulted in a significantly improved lung function, fewer exacerbations and a small but significant decline in growth velocity. After 18 months, however, the lung function improvements did not differ between the groups. During months 7–18, patients receiving continuous budesonide treatment had significantly fewer exacerbations (mean 0.97), compared with 1.69 in group 2 and 1.58 in group 3. The number of asthma-free days did not differ between regular and intermittent budesonide treatment. Growth velocity was normalised during continuous low-dose budesonide and budesonide therapy given as needed. The latter was associated with catch-up growth.
Regular use of budesonide afforded better asthma control but had a more systemic effect than did use of budesonide as needed. The dose of ICS could be reduced as soon as asthma is controlled. Some children do not seem to need continuous ICS treatment.
PMCID: PMC2532957  PMID: 17634183
Screening-CT identifies small peripheral lung nodules, some of which may be pre- or early invasive neoplasia. Secondary endpoint analysis of a previous chemoprevention trial in individuals with bronchial dysplasia showed reduction in size of peripheral nodules by inhaled budesonide.
We performed a randomized, double-blind, placebo-controlled phase IIb trial of inhaled budesonide in current and former smokers with CT-detected lung nodules that were persistent for at least one year. A total of 202 individuals received inhaled budesonide 800 µg twice daily or placebo for one year. The primary endpoint was the effect of treatment on target nodule size in a per-person analysis after one year.
The per-person analysis showed no significant difference between the budesonide and placebo arms (response rate 2% and 1%, respectively). Although the per-lesion analysis revealed a significant effect of budesonide on regression of existing target nodules (p=0.02), the appearance of new lesions was similar in both groups and thus the significance was lost in the analysis of all lesions. The evaluation by nodule type revealed a non-significant trend toward regression of non-solid and partially solid lesions after budesonide treatment. Budesonide was well tolerated with no unexpected side effects identified.
Treatment with inhaled budesonide for one year did not significantly affect peripheral lung nodule size. There was a trend toward regression of non-solid and partially solid nodules after budesonide treatment. Since a subset of these nodules is more likely to represent precursors of adenocarcinoma, additional follow-up is needed. ( number, NCT00321893)
PMCID: PMC3017323  PMID: 21163939
chemoprevention; lung cancer; helical CT; budesonide
15.  Genome-Wide Association Analysis in Asthma Subjects Identifies SPATS2L as a Novel Bronchodilator Response Gene 
PLoS Genetics  2012;8(7):e1002824.
Bronchodilator response (BDR) is an important asthma phenotype that measures reversibility of airway obstruction by comparing lung function (i.e. FEV1) before and after the administration of a short-acting β2-agonist, the most common rescue medications used for the treatment of asthma. BDR also serves as a test of β2-agonist efficacy. BDR is a complex trait that is partly under genetic control. A genome-wide association study (GWAS) of BDR, quantified as percent change in baseline FEV1 after administration of a β2-agonist, was performed with 1,644 non-Hispanic white asthmatic subjects from six drug clinical trials: CAMP, LOCCS, LODO, a medication trial conducted by Sepracor, CARE, and ACRN. Data for 469,884 single-nucleotide polymorphisms (SNPs) were used to measure the association of SNPs with BDR using a linear regression model, while adjusting for age, sex, and height. Replication of primary P-values was attempted in 501 white subjects from SARP and 550 white subjects from DAG. Experimental evidence supporting the top gene was obtained via siRNA knockdown and Western blotting analyses. The lowest overall combined P-value was 9.7E-07 for SNP rs295137, near the SPATS2L gene. Among subjects in the primary analysis, those with rs295137 TT genotype had a median BDR of 16.0 (IQR = [6.2, 32.4]), while those with CC or TC genotypes had a median BDR of 10.9 (IQR = [5.0, 22.2]). SPATS2L mRNA knockdown resulted in increased β2-adrenergic receptor levels. Our results suggest that SPATS2L may be an important regulator of β2-adrenergic receptor down-regulation and that there is promise in gaining a better understanding of the biological mechanisms of differential response to β2-agonists through GWAS.
Author Summary
Bronchodilator response (BDR) is an important asthma phenotype that measures reversibility of airway obstruction by comparing lung function before and after the administration of short-acting β2-agonists, common medications used for asthma treatment. We performed a genome-wide association study of BDR with 1,644 white asthmatic subjects from six drug clinical trials and attempted to replicate these findings in 1,051 white subjects from two independent cohorts. The most significant associated variant was near the SPATS2L gene. We knocked down SPATS2L mRNA in human airway smooth muscle cells and found that β2-adrenergic receptor levels increased, suggesting that SPATS2L may be a regulator of BDR. Our results highlight the promise of pursuing GWAS results that do not necessarily reach genome-wide significance and are an example of how results from pharmacogenetic GWAS can be studied functionally.
PMCID: PMC3390407  PMID: 22792082
16.  Effect of Obesity on Asthma Phenotype is Dependent upon Asthma Severity 
We recently reported that obese and non-obese patients with asthma have similar airflow limitation and bronchodilator responsiveness, but obese patients have more symptoms overall. There is limited information on the effect of obesity on asthmatics of varying severity measured by objective physiological parameters. Understanding how obesity affects asthmatics of differing severity can provide insights into the pathogenesis of asthma in the obese and a rationale for the therapeutic approach to such patients.
Participants with asthma from two American Lung Association-Asthma Clinical Research Center studies were grouped by tertiles of airflow obstruction (FEV1% predicted, FEV1/FVC) and methacholine reactivity (PC20FEV1). Within each tertile we examined the independent effect of body mass index (BMI), divided into normal weight, overweight and obese categories, on lung function, airway reactivity and symptoms.
Overall, both FEV1 and FVC decreased and symptoms worsened with increasing BMI; airway reactivity was unchanged. When stratified by the degree of airflow obstruction, higher BMI was not associated with greater airway reactivity to methacholine. Higher BMI was associated with more asthma symptoms only in the least obstructed FEV1/FVC tertile. When stratified by degree of airway reactivity, BMI was inversely associated with FVC in all PC20FEV1 tertiles. BMI was directly associated with asthma symptoms only in those with the least airway reactivity.
Obesity does not influence airway reactivity in patients with asthma and it is associated with more symptoms only in those with less severe disease.
PMCID: PMC4007205  PMID: 21091180
17.  Relationship Between Adiposity and Pulmonary Function in School-Aged Canadian Children 
Reduced lung function has been observed in adults with excess adiposity; however, in children, the relationship between adiposity and lung function is not clearly understood. A sample of 1,583 children, less than 18 years of age, from the Canadian Health Measures Survey (CHMS) was used to examine the associations of various anthropometric and skinfold measures with lung function parameters. The mean age of the sample was 12.15 (0.096). In normal weight boys, body mass index (BMI) was positively associated with forced vital capacity (FVC), FEV0.75 and FEV1; while in overweight or obese boys, waist circumference (WC) and waist-to-hip ratio showed inverse correlations with pulmonary function measures. Similarly, in normal weight girls, BMI and WC had positive associations with lung function measures but no inverse effect of adiposity was observed in overweight or obese girls. Skinfold analysis showed that only triceps skinfold had a significant inverse association with FVC and borderline significant associations with FEV0.75 and FEV1 in normal weight boys; while in overweight or obese boys, all the skinfold indicators displayed inverse correlations with lung function. The best predictor of lung function was triceps skinfold with βstd=−0.3869 for FVC, −0.3496 for FEV0.75 and −0.3668 for FEV1. No inverse correlations between skinfolds and lung function were observed in girls. Adiposity had differing effects on respiratory function that were dependent on sex and BMI group with the most significant effect on the overweight or obese boys. The most important indicator of adiposity in boys with BMI <30 kg/m2 was triceps skinfold. In girls, adiposity was not associated with poor lung function.
PMCID: PMC4170807  PMID: 25276486
18.  Comparing the effects of two inhaled glucocorticoids on allergen-induced bronchoconstriction and markers of systemic effects, a randomised cross-over double-blind study 
Inhaled glucocorticoids are efficient in protecting against asthma exacerbations, but methods to compare their efficacy vs systemic effects have only been attempted in larger multi-centre studies. The aim of the current study was therefore to directly compare the effects of two separate inhaled glucocorticoids, mometasone and budesonide, to compare the effects on the early and late asthmatic responses to inhaled allergen in patients with mild allergic asthma, and sputum eosinophils, and to relate the clinical positive effects to any systemic effects observed.
Twelve patients with documented early and late asthmatic responses (EAR and LAR) to inhaled allergen at a screening visit were randomized in a double-blind fashion to treatment with mometasone (200 μg × 2 or 400 μg × 2), budesonide (400 μg × 2) or placebo in a double-blind crossover fashion for a period of seven days. Challenge with the total allergen dose causing both an EAR and LAR was given on the last day of treatment taken in the morning. Lung function was assessed using FEV1, and systemic glucocorticoid activity was quantified using 24 h urinary cortisol.
Mometasone and budesonide attenuate both EAR and LAR to allergen to a similar degree. No significant dose-related effects on the lung function parameters were observed. Both treatments reduced the relative amount of sputum eosinophils (%) after allergen. At the dose of 800 μg daily, mometasone reduced 24 h urinary cortisol by approximately 35%. Both drugs were well tolerated.
Mometasone and budesonide are equieffective in reducing early and late asthmatic responses induced by inhaled allergen challenge. Mometasone 800 μg given for seven days partially affects the HPA axis.
PMCID: PMC3339360  PMID: 22409907
allergen; asthma; budesonide; mometasone; inflammation
19.  Association of Adenotonsillectomy with Asthma Outcomes in Children: A Longitudinal Database Analysis 
PLoS Medicine  2014;11(11):e1001753.
Rakesh Bhattacharjee and colleagues use data from a US private health insurance database to compare asthma severity measures in children one year before and one year after they underwent adenotonsillectomy with asthma measures in those who did not undergo adenotonsillectomy.
Please see later in the article for the Editors' Summary
Childhood asthma and obstructive sleep apnea (OSA), both disorders of airway inflammation, were associated in recent observational studies. Although childhood OSA is effectively treated by adenotonsillectomy (AT), it remains unclear whether AT also improves childhood asthma. We hypothesized that AT, the first line of therapy for childhood OSA, would be associated with improved asthma outcomes and would reduce the usage of asthma therapies in children.
Methods and Findings
Using the 2003–2010 MarketScan database, we identified 13,506 children with asthma in the United States who underwent AT. Asthma outcomes during 1 y preceding AT were compared to those during 1 y following AT. In addition, 27,012 age-, sex-, and geographically matched children with asthma without AT were included to examine asthma outcomes among children without known adenotonsillar tissue morbidity. Primary outcomes included the occurrence of a diagnostic code for acute asthma exacerbation (AAE) or acute status asthmaticus (ASA). Secondary outcomes included temporal changes in asthma medication prescriptions, the frequency of asthma-related emergency room visits (ARERs), and asthma-related hospitalizations (ARHs). Comparing the year following AT to the year prior, AT was associated with significant reductions in AAE (30.2%; 95% CI: 25.6%–34.3%; p<0.0001), ASA (37.9%; 95% CI: 29.2%–45.6%; p<0.0001), ARERs (25.6%; 95% CI: 16.9%–33.3%; p<0.0001), and ARHs (35.8%; 95% CI: 19.6%–48.7%; p = 0.02). Moreover, AT was associated with significant reductions in most asthma prescription refills, including bronchodilators (16.7%; 95% CI: 16.1%–17.3%; p<0.001), inhaled corticosteroids (21.5%; 95% CI: 20.7%–22.3%; p<0.001), leukotriene receptor antagonists (13.4%; 95% CI: 12.9%–14.0%; p<0.001), and systemic corticosteroids (23.7%; 95% CI: 20.9%–26.5%; p<0.001). In contrast, there were no significant reductions in these outcomes in children with asthma who did not undergo AT over an overlapping follow-up period. Limitations of the MarketScan database include lack of information on race and obesity status. Also, the MarketScan database does not include information on children with public health insurance (i.e., Medicaid) or uninsured children.
In a very large sample of privately insured children, AT was associated with significant improvements in several asthma outcomes. Contingent on validation through prospectively designed clinical trials, this study supports the premise that detection and treatment of adenotonsillar tissue morbidity may serve as an important strategy for improving asthma control.
Please see later in the article for the Editors' Summary
Editors' Summary
The global burden of asthma has been rising steadily over the past few decades. Nowadays, about 200–300 million adults and children worldwide are affected by asthma, a chronic condition caused by inflammation of the airways (the tubes that carry air in and out of the lungs). Although asthma can develop at any age, it is often diagnosed in childhood—asthma is one of the commonest chronic diseases in children. In the US, for example, asthma affects around 7.1 million children under the age of 18 years and is the third leading cause of hospitalization of children under the age of 15 years. In people with asthma, the airways can react very strongly to allergens such as animal fur or to irritants such as cigarette smoke. Exercise, cold air, and infections can trigger asthma attacks, which can be fatal. The symptoms of asthma include wheezing, coughing, chest tightness, and shortness of breath. Asthma cannot be cured, but drugs can relieve its symptoms and prevent acute asthma attacks.
Why Was This Study Done?
Recent studies have found an association between severe childhood asthma and obstructive sleep apnea (OSA). In OSA, airway inflammation promotes hypertrophy (excess growth) of the adenoids and the tonsils, immune system tissues in the upper airway. During sleep, the presence of hypertrophic adenotonsillar tissues predisposes the walls of the throat to collapse, which results in apnea—a brief interruption in breathing. People with OSA often snore loudly and frequently wake from deep sleep as they struggle to breathe. Childhood OSA, which affects 2%–3% of children, can be effectively treated by removal of the adenoids and tonsils (adenotonsillectomy). Given the association between childhood OSA and severe asthma and given the involvement of airway inflammation in both conditions, might adenotonsillectomy also improve childhood asthma? Here, the researchers analyze data from the MarketScan database, a large database of US patients with private health insurance, to investigate whether adenotonsillectomy is associated with improvements in asthma outcomes and with reductions in the use of asthma therapies in children.
What Did the Researchers Do and Find?
The researchers used the database to identify 13,506 children with asthma who had undergone adenotonsillectomy and to obtain information about asthma outcomes among these children for the year before and the year after the operation. Because asthma severity tends to decrease with age, the researchers also used the database to identify 27,012 age-, sex-, and geographically matched children with asthma who did not have the operation so that they could examine asthma outcomes over an equivalent two-year period in the absence of complications related to adenotonsillar hypertrophy. Comparing the year after adenotonsillectomy with the year before the operation, adenotonsillectomy was associated with a 30% reduction in acute asthma exacerbations, a 37.9% reduction in acute status asthmaticus (an asthma attack that is unresponsive to the drugs usually used to treat attacks), a 25.6% reduction in asthma-related emergency room visits, and a 35.8% reduction in asthma-related hospitalizations. By contrast, among the control children, there was only a 2% reduction in acute asthma exacerbations and only a 7% reduction in acute status asthmaticus over an equivalent two-year period. Adenotonsillectomy was also associated with significant reductions (changes unlikely to have occurred by chance) in prescription refills for most types of drugs used to treat asthma, whereas there were no significant reductions in prescription refills among children with asthma who had not undergone adenotonsillectomy. The study was limited by the lack of measures of race and obesity, which are both associated with severity of asthma.
What Do These Findings Mean?
These findings show that in a large sample of privately insured children in the US, adenotonsillectomy was associated with significant improvements in several asthma outcomes. These results do not show, however, that adenotonsillectomy caused a reduction in the severity of childhood asthma. It could be that the children who underwent adenotonsillectomy (but not those who did not have the operation) shared another unknown factor that led to improvements in their asthma over time. To prove a causal link, it will be necessary to undertake a randomized controlled trial in which the outcomes of groups of children with asthma who are chosen at random to undergo or not undergo adenotonsillectomy are compared. However, with the proviso that there are some risks associated with adenotonsillectomy, these findings suggest that the detection and treatment of adenotonsillar hypertrophy may help to improve asthma control in children.
Additional Information
Please access these websites via the online version of this summary at
The US Centers for Disease Control and Prevention provides information on asthma, including videos, games, and links to other resources for children with asthma
The American Lung Association provides detailed information about asthma and a fact sheet on asthma in children; it also has information about obstructive sleep apnea
The National Sleep Foundation provides information on snoring and obstructive sleep apnea in children
The UK National Health Service Choices website provides information (including some personal stories) about asthma, about asthma in children, and about obstructive sleep apnea
The “Global Asthma Report 2014” will be available in October 2014
MedlinePlus provides links to further information on asthma, on asthma in children, on sleep apnea, and on tonsils and adenoids (in English and Spanish)
PMCID: PMC4219664  PMID: 25369282
20.  Genetic Markers of Adult Obesity Risk Are Associated with Greater Early Infancy Weight Gain and Growth 
PLoS Medicine  2010;7(5):e1000284.
Ken Ong and colleagues genotyped children from the ALSPAC birth cohort and showed an association between greater early infancy gains in weight and length and genetic markers for adult obesity risk.
Genome-wide studies have identified several common genetic variants that are robustly associated with adult obesity risk. Exploration of these genotype associations in children may provide insights into the timing of weight changes leading to adult obesity.
Methods and Findings
Children from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort were genotyped for ten genetic variants previously associated with adult BMI. Eight variants that showed individual associations with childhood BMI (in/near: FTO, MC4R, TMEM18, GNPDA2, KCTD15, NEGR1, BDNF, and ETV5) were used to derive an “obesity-risk-allele score” comprising the total number of risk alleles (range: 2–15 alleles) in each child with complete genotype data (n = 7,146). Repeated measurements of weight, length/height, and body mass index from birth to age 11 years were expressed as standard deviation scores (SDS). Early infancy was defined as birth to age 6 weeks, and early infancy failure to thrive was defined as weight gain between below the 5th centile, adjusted for birth weight. The obesity-risk-allele score showed little association with birth weight (regression coefficient: 0.01 SDS per allele; 95% CI 0.00–0.02), but had an apparently much larger positive effect on early infancy weight gain (0.119 SDS/allele/year; 0.023–0.216) than on subsequent childhood weight gain (0.004 SDS/allele/year; 0.004–0.005). The obesity-risk-allele score was also positively associated with early infancy length gain (0.158 SDS/allele/year; 0.032–0.284) and with reduced risk of early infancy failure to thrive (odds ratio  = 0.92 per allele; 0.86–0.98; p = 0.009).
The use of robust genetic markers identified greater early infancy gains in weight and length as being on the pathway to adult obesity risk in a contemporary birth cohort.
Please see later in the article for the Editors' Summary
Editors' Summary
The proportion of overweight and obese children is increasing across the globe. In the US, the Surgeon General estimates that, compared with 1980, twice as many children and three times the number of adolescents are now overweight. Worldwide, 22 million children under five years old are considered by the World Health Organization to be overweight.
Being overweight or obese in childhood is associated with poor physical and mental health. In addition, childhood obesity is considered a major risk factor for adult obesity, which is itself a major risk factor for cancer, heart disease, diabetes, osteoarthritis, and other chronic conditions.
The most commonly used measure of whether an adult is a healthy weight is body mass index (BMI), defined as weight in kilograms/(height in metres)2. However, adult categories of obese (>30) and overweight (>25) BMI are not directly applicable to children, whose BMI naturally varies as they grow. BMI can be used to screen children for being overweight and or obese but a diagnosis requires further information.
Why Was This Study Done?
As the numbers of obese and overweight children increase, a corresponding rise in future numbers of overweight and obese adults is also expected. This in turn is expected to lead to an increasing incidence of poor health. As a result, there is great interest among health professionals in possible pathways between childhood and adult obesity. It has been proposed that certain periods in childhood may be critical for the development of obesity.
In the last few years, ten genetic variants have been found to be more common in overweight or obese adults. Eight of these have also been linked to childhood BMI and/or obesity. The authors wanted to identify the timing of childhood weight changes that may be associated with adult obesity. Knowledge of obesity risk genetic variants gave them an opportunity to do so now, without following a set of children to adulthood.
What Did the Researchers Do and Find?
The authors analysed data gathered from a subset of 7,146 singleton white European children enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) study, which is investigating associations between genetics, lifestyle, and health outcomes for a group of children in Bristol whose due date of birth fell between April 1991 and December 1992. They used knowledge of the children's genetic makeup to find associations between an obesity risk allele score—a measure of how many of the obesity risk genetic variants a child possessed—and the children's weight, height, BMI, levels of body fat (at nine years old), and rate of weight gain, up to age 11 years.
They found that, at birth, children with a higher obesity risk allele score were not any heavier, but in the immediate postnatal period they were less likely to be in the bottom 5% of the population for weight gain (adjusted for birthweight), often termed “failure to thrive.” At six weeks of age, children with a higher obesity risk allele score tended to be longer and heavier, even allowing for weight at birth.
After six weeks of age, the obesity risk allele score was not associated with any further increase in length/height, but it was associated with a more rapid weight gain between birth and age 11 years. BMI is derived from height and weight measurements, and the association between the obesity risk allele score and BMI was weak between birth and age three-and-a-half years, but after that age the association with BMI increased rapidly. By age nine, children with a higher obesity risk allele score tended to be heavier and taller, with more fat on their bodies.
What Do These Findings Mean?
The combined obesity allele risk score is associated with higher rates of weight gain and adult obesity, and so the authors conclude that weight gain and growth even in the first few weeks after birth may be the beginning of a pathway of greater adult obesity risk.
A study that tracks a population over time can find associations but it cannot show cause and effect. In addition, only a relatively small proportion (1.7%) of the variation in BMI at nine years of age is explained by the obesity risk allele score.
The authors' method of finding associations between childhood events and adult outcomes via genetic markers of risk of disease as an adult has a significant advantage: the authors did not have to follow the children themselves to adulthood, so their findings are more likely to be relevant to current populations. Despite this, this research does not yield advice for parents how to reduce their children's obesity risk. It does suggest that “failure to thrive” in the first six weeks of life is not simply due to a lack of provision of food by the baby's caregiver but that genetic factors also contribute to early weight gain and growth.
The study looked at the combined obesity risk allele score and the authors did not attempt to identify which individual alleles have greater or weaker associations with weight gain and overweight or obesity. This would require further research based on far larger numbers of babies and children. The findings may also not be relevant to children in other types of setting because of the effects of different nutrition and lifestyles.
Additional Information
Please access these Web sites via the online version of this summary at
Further information is available on the ALSPAC study
The UK National Health Service and other partners provide guidance on establishing a healthy lifestyle for children and families in their Change4Life programme
The International Obesity Taskforce is a global network of expertise and the advocacy arm of the International Association for the Study of Obesity. It works with the World Health Organization, other NGOs, and stakeholders and provides information on overweight and obesity
The Centers for Disease Control and Prevention (CDC) in the US provide guidance and tips on maintaining a healthy weight, including BMI calculators in both metric and Imperial measurements for both adults and children. They also provide BMI growth charts for boys and girls showing how healthy ranges vary for each sex at with age
The Royal College of Paediatrics and Child Health provides growth charts for weight and length/height from birth to age 4 years that are based on WHO 2006 growth standards and have been adapted for use in the UK
The CDC Web site provides information on overweight and obesity in adults and children, including definitions, causes, and data
The CDC also provide information on the role of genes in causing obesity.
The World Health Organization publishes a fact sheet on obesity, overweight and weight management, including links to childhood overweight and obesity
Wikipedia includes an article on childhood obesity (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
PMCID: PMC2876048  PMID: 20520848
21.  Development of a Pharmacogenetic Predictive Test in asthma: proof of concept 
Pharmacogenetics and genomics  2010;20(2):86-93.
To assess the feasibility of developing a Combined Clinical and Pharmacogenetic Predictive Test, comprised of multiple single nucleotide polymorphisms (SNPs) that is associated with poor bronchodilator response (BDR).
We genotyped SNPs that tagged the whole genome of the parents and children in the Childhood Asthma Management Program (CAMP) and implemented an algorithm using a family-based association test that ranked SNPs by statistical power. The top eight SNPs that were associated with BDR comprised the Pharmacogenetic Predictive Test. The Clinical Predictive Test was comprised of baseline forced expiratory volume in 1 s (FEV1). We evaluated these predictive tests and a Combined Clinical and Pharmacogenetic Predictive Test in three distinct populations: the children of the CAMP trial and two additional clinical trial populations of asthma. Our outcome measure was poor BDR, defined as BDR of less than 20th percentile in each population. BDR was calculated as the percent difference between the prebronchodilator and postbronchodilator (two puffs of albuterol at 180 μg/puff) FEV1 value. To assess the predictive ability of the test, the corresponding area under the receiver operating characteristic curves (AUROCs) were calculated for each population.
The AUROC values for the Clinical Predictive Test alone were not significantly different from 0.50, the AUROC of a random classifier. Our Combined Clinical and Pharmacogenetic Predictive Test comprised of genetic polymorphisms in addition to FEV1 predicted poor BDR with an AUROC of 0.65 in the CAMP children (n= 422) and 0.60 (n= 475) and 0.63 (n= 235) in the two independent populations. Both the Combined Clinical and Pharmacogenetic Predictive Test and the Pharmacogenetic Predictive Test were significantly more accurate than the Clinical Predictive Test (AUROC between 0.44 and 0.55) in each of the populations.
Our finding that genetic polymorphisms with a clinical trait are associated with BDR suggests that there is promise in using multiple genetic polymorphisms simultaneously to predict which asthmatics are likely to respond poorly to bronchodilators.
PMCID: PMC3654515  PMID: 20032818
asthma; bronchodilator response; personalized medicine; pharmacogenetic test; predictive medicine
22.  Effects of BMI, Fat Mass, and Lean Mass on Asthma in Childhood: A Mendelian Randomization Study 
PLoS Medicine  2014;11(7):e1001669.
In this study, Granell and colleagues used Mendelian randomization to investigate causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ years in the Avon Longitudinal Study of Parents and Children (ALSPAC) and found that higher BMI increases the risk of asthma in mid-childhood.
Please see later in the article for the Editors' Summary
Observational studies have reported associations between body mass index (BMI) and asthma, but confounding and reverse causality remain plausible explanations. We aim to investigate evidence for a causal effect of BMI on asthma using a Mendelian randomization approach.
Methods and Findings
We used Mendelian randomization to investigate causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ y in the Avon Longitudinal Study of Parents and Children (ALSPAC). A weighted allele score based on 32 independent BMI-related single nucleotide polymorphisms (SNPs) was derived from external data, and associations with BMI, fat mass, lean mass, and asthma were estimated. We derived instrumental variable (IV) estimates of causal risk ratios (RRs). 4,835 children had available data on BMI-associated SNPs, asthma, and BMI. The weighted allele score was strongly associated with BMI, fat mass, and lean mass (all p-values<0.001) and with childhood asthma (RR 2.56, 95% CI 1.38–4.76 per unit score, p = 0.003). The estimated causal RR for the effect of BMI on asthma was 1.55 (95% CI 1.16–2.07) per kg/m2, p = 0.003. This effect appeared stronger for non-atopic (1.90, 95% CI 1.19–3.03) than for atopic asthma (1.37, 95% CI 0.89–2.11) though there was little evidence of heterogeneity (p = 0.31). The estimated causal RRs for the effects of fat mass and lean mass on asthma were 1.41 (95% CI 1.11–1.79) per 0.5 kg and 2.25 (95% CI 1.23–4.11) per kg, respectively. The possibility of genetic pleiotropy could not be discounted completely; however, additional IV analyses using FTO variant rs1558902 and the other BMI-related SNPs separately provided similar causal effects with wider confidence intervals. Loss of follow-up was unlikely to bias the estimated effects.
Higher BMI increases the risk of asthma in mid-childhood. Higher BMI may have contributed to the increase in asthma risk toward the end of the 20th century.
Please see later in the article for the Editors' Summary
Editors' Summary
The global burden of asthma, a chronic (long-term) condition caused by inflammation of the airways (the tubes that carry air in and out of the lungs), has been rising steadily over the past few decades. It is estimated that, nowadays, 200–300 million adults and children worldwide are affected by asthma. Although asthma can develop at any age, it is often diagnosed in childhood—asthma is the most common chronic disease in children. In people with asthma, the airways can react very strongly to allergens such as animal fur or to irritants such as cigarette smoke, becoming narrower so that less air can enter the lungs. Exercise, cold air, and infections can also trigger asthma attacks, which can be fatal. The symptoms of asthma include wheezing, coughing, chest tightness, and shortness of breath. Asthma cannot be cured, but drugs can relieve its symptoms and prevent acute asthma attacks.
Why Was This Study Done?
We cannot halt the ongoing rise in global asthma rates without understanding the causes of asthma. Some experts think obesity may be one cause of asthma. Obesity, like asthma, is increasingly common, and observational studies (investigations that ask whether individuals exposed to a suspected risk factor for a condition develop that condition more often than unexposed individuals) in children have reported that body mass index (BMI, an indicator of body fat calculated by dividing a person's weight in kilograms by their height in meters squared) is positively associated with asthma. Observational studies cannot prove that obesity causes asthma because of “confounding.” Overweight children with asthma may share another unknown characteristic (confounder) that actually causes both obesity and asthma. Moreover, children with asthma may be less active than unaffected children, so they become overweight (reverse causality). Here, the researchers use “Mendelian randomization” to assess whether BMI has a causal effect on asthma. In Mendelian randomization, causality is inferred from associations between genetic variants that mimic the effect of a modifiable risk factor and the outcome of interest. Because gene variants are inherited randomly, they are not prone to confounding and are free from reverse causation. So, if a higher BMI leads to asthma, genetic variants associated with increased BMI should be associated with an increased risk of asthma.
What Did the Researchers Do and Find?
The researchers investigated causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ years in 4,835 children enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC, a long-term health project that started in 1991). They calculated an allele score for each child based on 32 BMI-related genetic variants, and estimated associations between this score and BMI, fat mass and lean mass (both measured using a special type of X-ray scanner; in children BMI is not a good indicator of “fatness”), and asthma. They report that the allele score was strongly associated with BMI, fat mass, and lean mass, and with childhood asthma. The estimated causal relative risk (risk ratio) for the effect of BMI on asthma was 1.55 per kg/m2. That is, the relative risk of asthma increased by 55% for every extra unit of BMI. The estimated causal relative risks for the effects of fat mass and lean mass on asthma were 1.41 per 0.5 kg and 2.25 per kg, respectively.
What Do These Findings Mean?
These findings suggest that a higher BMI increases the risk of asthma in mid-childhood and that global increases in BMI toward the end of the 20th century may have contributed to the global increase in asthma that occurred at the same time. It is possible that the observed association between BMI and asthma reported in this study is underpinned by “genetic pleiotropy” (a potential limitation of all Mendelian randomization analyses). That is, some of the genetic variants included in the BMI allele score could conceivably also increase the risk of asthma. Nevertheless, these findings suggest that public health interventions designed to reduce obesity may also help to limit the global rise in asthma.
Additional Information
Please access these websites via the online version of this summary at
The US Centers for Disease Control and Prevention provides information on asthma and on all aspects of overweight and obesity (in English and Spanish)
The World Health Organization provides information on asthma and on obesity (in several languages)
The UK National Health Service Choices website provides information about asthma, about asthma in children, and about obesity (including real stories)
The Global Asthma Report 2011 is available
The Global Initiative for Asthma released its updated Global Strategy for Asthma Management and Prevention on World Asthma Day 2014
Information about the Avon Longitudinal Study of Parents and Children is available
MedlinePlus provides links to further information on obesity in children, on asthma, and on asthma in children (in English and Spanish
Wikipedia has a page on Mendelian randomization (note: Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
PMCID: PMC4077660  PMID: 24983943
23.  Bronchodilatory effect of inhaled budesonide/formoterol and budesonide/salbutamol in acute asthma: a double-blind, randomized controlled trial 
BMC Pediatrics  2012;12:21.
There are no published studies that have compared bronchodilatory effect of inhaled budesonide/formoterol combination with budesonide/salbutamol delivered by metered dose inhaler with a spacer in acute exacerbation of asthma in children. We, therefore, compared the bronchodilatory effects of inhaled budesonide/formoterol (dose: 200 μg and 12 μg respectively) combination with budesonide (200 μg)/salbutamol (200 μg) administered by metered dose inhaler and spacer in children of 5-15 years with mild acute exacerbation of asthma [Modified Pulmonary Index Score (MPIS) between 6-8] in this double-blind, randomized controlled trial. The primary outcome was FEV1 (% predicted) in the two groups at 1, 5, 15, 30, 60 min after administration of the study drug.
We did not observe any significant differences in the % predicted FEV1 and MPIS between formoterol and salbutamol at various time points from 1 min to 60 min post drug administration. There was significant improvement in FEV1 (% predicted) from baseline in both the groups as early as 1 min after drug administration.
Salbutamol or formoterol delivered along with inhaled corticosteroid by metered dose inhaler with spacer in children between 5-15 years of age with mild acute exacerbation of asthma had similar bronchodilatory effects.
Trial Registration NCT00900874
PMCID: PMC3324377  PMID: 22394648
Acute asthma; Bronchodilatation; Formoterol; Salbutamol
24.  Effects of inhaled budesonide on spirometric values, reversibility, airway responsiveness, and cough threshold in smokers with chronic obstructive lung disease. 
Thorax  1991;46(5):372-377.
Inhaled corticosteroids are known to reduce respiratory symptoms and airway responsiveness in allergic patients with asthma. The aim of the present randomised, double blind study was to assess the effect of eight weeks' treatment with inhaled budesonide in non-allergic smokers with chronic obstructive lung disease. Twenty four subjects (23 male) entered the study. Their ages ranged from 40 to 70 (mean 57) years, with a mean of 35 (range 9-80) pack years of smoking; the mean FEV1 was 53% (range 32-74%) predicted and geometric mean PC20 (histamine concentration causing a 20% fall in FEV1) 0.96 (range 0.07-7.82) mg/ml. After a two week washout, single blind, placebo period, 12 patients were allocated to treatment with budesonide 1600 microgram/day and 12 to placebo for eight weeks. The only additional drug to be taken was ipratropium bromide "if needed." Twenty one patients completed the study, 10 in the budesonide group and 11 in the placebo group. The standard deviation of the difference between duplicate measurements of PC20 histamine and citric acid cough threshold made two weeks apart was below one doubling dose step. There was a significant reduction in dyspnoea in the budesonide group, but otherwise no change in symptom scores or use of ipratropium bromide over the eight weeks of treatment within or between the two groups. No significant differences in spirometric values, peak expiratory flow, PC20 histamine, or citric acid cough threshold were found between the groups. Although differences were not significant, some of the changes showed a trend in favour of budesonide. Whether a longer observation period would show a significant influence of inhaled corticosteroids in patients with chronic obstructive lung disease remains to be determined.
PMCID: PMC1020969  PMID: 2068695
25.  Fixed airflow obstruction in asthma: a descriptive study of patient profiles and effect on treatment responses 
The Journal of Asthma  2014;51(6):603-609.
The role of fixed airflow obstruction (FAO) in asthma is unclear. Objective: To assess the relationship between FAO and clinical features of asthma and the effect of FAO on treatment response. Methods: Post hoc descriptive analysis of data stratified by FAO category (screening post-albuterol FEV1/FVC
PMCID: PMC4162502  PMID: 24524222
Airflow limitation; airway inflammation; budesonide; combination therapy; formoterol; inhaled corticosteroid; lung function

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