Weight loss and increased physical fitness are established approaches to reduce cardiovascular risk factors. We studied the reduction in BMI z-score associated with improvement in cardiometabolic risk factors in overweight and obese children and adolescents treated with a combined hospital/public health nurse model. We also examined how aerobic fitness influenced the results.
From 2004-2007, 307 overweight and obese children and adolescents aged 7-17 years were referred to an outpatient hospital pediatrics clinic and evaluated by a multidisciplinary team. Together with family members, they were counseled regarding diet and physical activity at biannual clinic visits. Visits with the public health nurse at local schools or at maternal and child health centres were scheduled between the hospital consultations. Fasting blood samples were taken at baseline and after one year, and aerobic fitness (VO2peak) was measured. In the analyses, 230 subjects completing one year of follow-up by December 2008 were divided into four groups according to changes in BMI z-score: Group 1: decrease in BMI z-score≥0.23, Group 2: decrease in BMI z-score≥0.1-< 0.23, Group 3: decrease in/stable BMI z-score≥0.0-< 0.1, Group 4: increase in BMI z-score (>0.00-0.55).
230 participants were included in the analyses (75%). Mean (SD) BMI z-score was reduced from 2.18 (0.30) to 2.05 (0.39) (p < 0.001) in the group as a whole. After adjustment for BMI z-score, waist circumference and gender, the three groups with reduced BMI z-score had a significantly greater reduction in HOMA-IR, insulin, total cholesterol, LDL cholesterol and total/HDL cholesterol ratio than the group with increased BMI z-score. Adding change in aerobic fitness to the model had little influence on the results. Even a very small reduction in BMI z-score (group 3) was associated with significantly lower insulin, total cholesterol, LDL and total/HDL cholesterol ratio. The group with the largest reduction in BMI z-score had improvements in HOMA-IR and aerobic fitness as well. An increase in BMI z-score was associated with worsening of C-peptide and total/HDL cholesterol ratio.
Even a modest reduction in BMI z-score after one year of combined hospital/and public health nurse intervention was associated with improvement in several cardiovascular risk factors.
There is an urgent need to develop and evaluate weight management interventions to address childhood obesity. Recent research suggests that interventions designed for parents exclusively, which have been named parents as agents of change (PAC) approaches, have yielded positive outcomes for managing pediatric obesity. To date, no research has combined a PAC intervention approach with cognitive behavioural therapy (CBT) to examine whether these combined elements enhance intervention effectiveness. This paper describes the protocol our team is using to examine two PAC-based interventions for pediatric weight management. We hypothesize that children with obesity whose parents complete a CBT-based PAC intervention will achieve greater reductions in adiposity and improvements in cardiometabolic risk factors, lifestyle behaviours, and psychosocial outcomes than children whose parents complete a psycho-education-based PAC intervention (PEP).
This study is a pragmatic, two-armed, parallel, single-blinded, superiority, randomized clinical trial. The primary objective is to examine the differential effects of a CBT-based PAC vs PEP-based PAC intervention on children’s BMI z-score (primary outcome). Secondary objectives are to assess intervention-mediated changes in cardiometabolic, lifestyle, and psychosocial variables in children and parents. Both interventions are similar in frequency of contact, session duration, group facilitation, lifestyle behaviour goals, and educational content. However, the interventions differ insofar as the CBT-based intervention incorporates theory-based concepts to help parents link their thoughts, feelings, and behaviours; these cognitive activities are enabled by group leaders who possess formal training in CBT. Mothers and fathers of children (8–12 years of age; BMI ≥85th percentile) are eligible to participate if they are proficient in English (written and spoken) and agree for at least one parent to attend group-based sessions on a weekly basis. Anthropometry, cardiometabolic risk factors, lifestyle behaviours, and psychosocial health of children and parents are assessed at pre-intervention, post-intervention, 6-, and 12-months follow-up.
This study is designed to extend findings from earlier efficacy studies and provide data on the effect of a CBT-based PAC intervention for managing pediatric obesity in a real-world, outpatient clinical setting.
ClinicalTrials.gov identifier: NCT01267097
Obesity; Pediatric; Treatment; Parents; Cognitive behavioral therapy; Canada
A sedentary lifestyle predisposes to cardiometabolic diseases. Lifestyle changes such as increased physical activity improve a range of cardiometabolic risk factors. The objective of this study was to examine whether functional changes in adipose tissue were related to these improvements.
Seventy-three sedentary, overweight (mean BMI 29.9 ± 3.2 kg/m2) and abdominally obese, but otherwise healthy men and women (67.6 ± 0.5 years) from a randomised controlled trial of physical activity on prescription over a 6-month period were included (control n = 43, intervention n = 30). Detailed examinations were carried out at baseline and at follow-up, including fasting blood samples, a comprehensive questionnaire and subcutaneous adipose tissue biopsies for fatty acid composition analysis (n = 73) and quantification of mRNA expression levels of 13 candidate genes (n = 51), including adiponectin, leptin and inflammatory cytokines.
At follow-up, the intervention group had a greater increase in exercise time (+137 min/week) and a greater decrease in body fat mass (−1.5 kg) compared to the control subjects (changes of 0 min/week and −0.5 kg respectively). Circulating concentrations of adiponectin were unchanged, but those of leptin decreased significantly more in the intervention group (−1.8 vs −1.1 ng/mL for intervention vs control, P < 0.05). The w6-polyunsaturated fatty acid content, in particular linoleic acid (18:2w6), of adipose tissue increased significantly more in the intervention group, but the magnitude of the change was small (+0.17 vs +0.02 percentage points for intervention vs control, P < 0.05). Surprisingly leptin mRNA levels in adipose tissue increased in the intervention group (+107% intervention vs −20% control, P < 0.05), but changes in expression of the remaining genes did not differ between the groups.
After a 6-month period of increased physical activity in overweight elderly individuals, circulating leptin concentrations decreased despite increased levels of leptin mRNA in adipose tissue. Otherwise, only minor changes occurred in adipose tissue, although several improvements in metabolic parameters accompanied the modest increase in physical activity.
Adipose tissue; Physical activity; Fatty acid composition; Gene expression
Evaluate cardiovascular risk factors in Portuguese obese children and adolescents and the long-term effects of lifestyle modifications on such risk factors.
Transversal cohort study and longitudinal study.
University Hospital S. João and Children’s Hospital Maria Pia, Porto.
148 obese children and adolescents [81 females (54.7%); mean age of 11.0 years] and 33 controls (sex and age matched) participated in a cross-sectional study. Sixty obese patients agreed to participate in an one year longitudinal study after medical and nutritionist appointments to improve lifestyle modification; a substantial body mass index (BMI) reduction was defined by a decrease in BMI z-score (BMI z-sc) of 0.3 or more over the studied period.
Main Outcome measures:
Lipid profile (triglycerides, cholesterol, HDLc, LDLc, lipoprotein (a), apolipoproteins A and B) and circulating levels of C-reactive protein (CRP), adiponectin, glucose, and insulin.
Compared with the lean children, obese patients demonstrated statistically significantly higher insulin resistance index [Homeostasis model assessment (HOMA)], and triglycerides, LDLc, apolipoprotein (apo) B, insulin and CRP concentrations, whereas their HDLc and apo A levels were significantly lower (cross-sectional study). In the longitudinal study (n=60), a substantial BMI reduction occurred in 17 (28.3%) obese patients which led to a significant reduction in triglycerides, cholesterol, LDLc, apo B, glucose and insulin levels and in HOMA. The ΔBMI values over the studied period correlated inversely and significantly with BMI (P<0.001) and HOMA (P=0.026) values observed at baseline. In multiple linear regression analysis, BMI at baseline remained associated to changes in BMI over the studied period (standardised Beta: -0.271, P=0.05).
Our data demonstrates that small reductions in BMI-zc, imposed by lifestyle modifications in obese children and adolescents, improve the cardiovascular risk profile of such patients. Furthermore, patients with higher BMI and/or insulin resistance seem to experience a greater relative reduction in their BMI after lifestyle improvements.
Lipid profile; insulin resistance; inflammation; childhood obesity; lifestyle modifications.
Introduction. The purpose of this study was to examine levels of physical activity (PA) and screen time (ST) in metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) adolescents and adults. Methods. NHANES data from obese adolescents (12–18 years, BMI z-score ≥ 95th percentile) and adults (19–85 years, BMI ≥ 30 kg/m2) were pooled from 2003–2005 cycles. Metabolic phenotypes were categorized as MHO (0 or 1 cardiometabolic risk factor; triglycerides, HDL-C, blood pressure, or glucose) or MUO (≥2 cardiometabolic risk factors). Logistic regression models estimated associations between phenotype and PA/ST adjusted for age, gender, BMI, race/ethnicity, menopausal status, and NHANES cycle. Results. Among adolescents, PA was not associated with MHO. In contrast, MHO adults 19–44 years were 85% more likely to engage in active transportation and 2.7 times more likely to be involved in light intensity usual daily activity versus sitting. For each minute per day, adults 45–85 years were 36% more likely to have the MHO phenotype with higher levels of moderate PA. ST was not associated with metabolic phenotypes in adolescents or adults. Conclusion. The current study provides evidence that PA, but not ST, differs between MHO and MUO in adults, but not in adolescents. Future studies are needed to confirm results.
To determine the relationship between serum vitamin D levels and cardiometabolic risk factors independent of adiposity in urban schoolchildren.
We assessed the relationships among serum 25-hydroxyvitamin D [25(OH)D], adiposity measured by body mass index (BMI) z-score (BMIz), and 6 cardiometabolic risk factors (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, interleukin-6, and C-reactive protein [CRP]) in a cross-sectional sample of 263 racially and ethnically diverse schoolchildren from the Boston area during late winter. Multivariate regression analyses adjusting for sociodemographic characteristics and BMIz examined associations of 25(OH)D and cardiometabolic risk factors.
Overall, 74.6% of the children were vitamin D deficient [25(OH)D <50 nmol/L; mean, 41.8 ± 13.7 nmol/L]; 45% were overweight or obese (20%and 25%, respectively; BMIz = 0.75 ± 1.1). The 25(OH)D level was not associated with BMIz, but was positively associated with the cardiometabolic risk factor CRP (β = 0.03; P < .05). BMIz was associated with elevated triglycerides (β = 0.13), CRP (β = 0.58), and interleukin-6 (β= 0.14) and low high-density lipoprotein cholesterol (β = −0.09; all P < .01).
Vitamin D deficiency is highly prevalent during the late winter months in urban schoolchildren living in the northeastern United States. This widespread deficiency may contribute to the lack of associations between 25(OH)D and both BMIz and cardiometabolic risk factors. The association between 25(OH)D and CRP warrants further study.
Children and adolescents who have decreased mobility due to spina bifida may be at increased risk for the components of metabolic syndrome, including abdominal obesity, insulin resistance, and dyslipidemia due to low physical activity. Like their nondisabled peers, adolescents with spina bifida that develop metabolic risk factors early in life have set the stage for adult disease. Exercise interventions can improve metabolic dysfunction in nondisabled youth, but the types of exercise programs that are most effective and the mechanisms involved are not known. This is especially true in adolescents with spina bifida, who have impaired mobility and physical function and with whom there have been few well-controlled studies. This paper highlights the current lack of knowledge about the role of physical activity and the need to develop exercise strategies targeting the reduction of cardiometabolic risk and improving quality of life in youth with spina bifida.
Background. Waist girth and BMI are commonly used as markers of cardiometabolic risk. Accumulating data however suggest that sagittal abdominal diameter (SAD) or “abdominal height” may be a better marker of intra-abdominal adiposity and cardiometabolic risk. We aimed to identify cutoffs for SAD using a cardiometabolic risk score. Design. A population-based cross-sectional study. Methods. In 4032 subjects (1936 men and 2096 women) at age 60, different anthropometric variables (SAD, BMI, waist girth, and waist-to-hip ratio) were measured and cardiometabolic risk score calculated. ROC curves were used to assess cutoffs. Results. Among men SAD showed the strongest correlations to the majority of the individual risk factors; whereas in women SAD was equal to that of waist girth. In the whole sample, the area under the ROC curve was highest for SAD. The optimal SAD cutoff for an elevated cardiometabolic risk score in men was ∼22 cm (95%CI; 21.6 to 22.8) and in women ∼20 cm (95%CI; 19.4 to 20.8). These cutoffs were similar if the Framingham risk score was used. Conclusions. These cutoffs may be used in research and screening to identify “metabolically obese” men who would benefit from lifestyle and pharmacological interventions. These results need to be verified in younger age groups.
The objective of this pilot study was to evaluate the effects of exenatide on body mass index (BMI) (primary endpoint) and cardiometabolic risk factors in non-diabetic youth with extreme obesity. Twelve children and adolescents (age 9–16 years old) with extreme obesity (BMI ≥1.2 times the 95th percentile or BMI ≥35 kg/m2) were enrolled in a 6-month, randomized, open-label, crossover, clinical trial consisting of two, 3-month phases: 1) a control phase of lifestyle modification and 2) a drug phase of lifestyle modification plus exenatide. Participants were equally randomized to phase-order (i.e., starting with control or drug therapy) then crossed-over to the other treatment. BMI, body fat percentage, blood pressure, lipids, oral glucose tolerance (OGTT), adipokines, plasma biomarkers of endothelial activation, and endothelial function were assessed at baseline, 3-, and 6-months. The mean change over each 3-month phase was compared between treatments. Compared to control, exenatide significantly reduced BMI (−1.7 kg/m2, 95% CI (−3.0, −0.4), P = 0.01), body weight (−3.9 kg, 95% CI (−7.11, −0.69), P = 0.02), and fasting insulin (−7.5 mU/L, 95% CI (−13.71, −1.37), P = 0.02). Significant improvements were observed for OGTT-derived insulin sensitivity (P = 0.02) and beta cell function (P = 0.03). Compliance with the injection regimen was excellent (≥94%) and exenatide was generally well-tolerated (the most common adverse event was mild nausea in 36%). These preliminary data suggest that exenatide should be evaluated in larger, well-controlled trials for its ability to reduce BMI and improve cardiometabolic risk factors in youth with extreme obesity.
Exenatide; Obesity; Children; Adolescents
BMI percentiles have been routinely and historically used to identify elevated adiposity. This paper aimed to investigate the optimal Centers for Disease Control and Prevention (CDC) body mass index (BMI) percentile that predicts elevated visceral adipose tissue (VAT), fat mass and cardiometabolic risk in a biracial sample of children and adolescents.
Participants and Methods
This cross-sectional analysis included 369 white and African American children (5–18 y). BMI was calculated using height and weight and converted to BMI percentiles based on CDC growth charts. Receiver operating characteristic curve analysis identified the optimal (balance of sensitivity and specificity) BMI percentile to predict the upper quartile of age-adjusted VAT (measured by magnetic resonance imaging), age-adjusted fat mass (measured by dual energy x-ray absorptiometry) and elevated cardiometabolic risk (≥ 2 of high glucose, triglycerides and blood pressure and low high density lipoprotein cholesterol) for each race-by-sex group.
The optimal CDC BMI percentile to predict those in the top quartile of age-adjusted VAT, age-adjusted fat mass and elevated cardiometabolic risk were the 96th, the 96th and the 94th percentiles, respectively, for the sample as a whole. Sensitivity and specificity was satisfactory (> 0.70) for VAT and fat mass. Compared to age-adjusted VAT and age-adjusted fat mass, there was a lower overall accuracy of the optimal percentile in identifying those with elevated cardiometabolic risk.
The present findings support the utility of the 95th CDC BMI percentile as a useful threshold for the prediction of elevated levels of VAT, fat mass and cardiometabolic risk in children and adolescents.
The study is registered at clinicaltrials.gov as NCT01595100.
body mass index; visceral adipose tissue; children; adolescents; Centers for Disease Control and Prevention; body fat
Purpose. The purpose of the study was to examine the independent associations of adiposity and cardiorespiratory fitness with clustered cardiometabolic risk. Methods. A cross-sectional sample of 192 adolescents (118 boys), aged 14–16 years, was recruited from a South Lanarkshire school in the West of Scotland. Anthropometry and blood pressure were measured, and blood samples were taken. The 20 m multistage fitness test was the indicator of cardiorespiratory fitness (CRF). A clustered cardiometabolic risk score was constructed from HDL-C (inverted), LDL-C, HOMA, systolic blood pressure, and triglycerides. Interleukin-6, C-reactive protein, and adiponectin were also measured and examined relative to the clustered cardiometabolic risk score, CRF, and adiposity. Results. Although significant, partial correlations between BMI and waist circumference (WC) and both CRF and adiponectin were negative and weak to moderate, while correlations between the BMI and WC and CRP were positive but weak to moderate. Weak to moderate negative associations were also evident for adiponectin with CRP, IL-6, and clustered cardiometabolic risk. WC was positively associated while CRF was negatively associated with clustered cardiometabolic risk. With the additional adjustment for either WC or CRF, the independent associations with cardiometabolic risk persisted. Conclusion. WC and CRF are independently associated with clustered cardiometabolic risk in Scottish adolescents.
Sleep-disordered breathing is associated with obesity, insulin resistance, and the metabolic syndrome in adults. Similar data in children is limited and conflicting. This pilot study examined the relationships between sleep-disordered breathing, visceral adiposity, and cardiometabolic risk factors in obese adolescents. Twenty obese (body mass index ≥95th percentile), otherwise healthy adolescents (age 14.9 ± 2 years) underwent polysomnogram studies, fasting lipid profile and oral glucose tolerance tests, and measures of body composition (dual-energy X-ray absorptiometry) and visceral adiposity (abdominal computed tomography). The severity of sleep-disordered breathing (as measured by apnea-hypopnea index) was positively associated with visceral adipose tissue (r=0.73, p<0.001) but not with other measures of body composition. After controlling for body mass index, the severity of sleep-disordered breathing was positively associated with markers of insulin resistance (homeostasis model assessment and fasting insulin). Further study to allow for critical assessment of the relationships between sleep-disordered breathing and cardiometabolic risk factors in obese youth remains necessary.
Sleep apnea; insulin resistance; central adiposity; abdominal obesity
To evaluate shifts across BMI categories and associated changes in cardiometabolic risk factors over 2.5 years in an ethnically diverse middle school sample.
As part of HEALTHY, a multisite school-based study designed to mitigate risk for type 2 diabetes, 3993 children participated in health screenings at the start of sixth and end of eighth grades. Assessments included anthropometric measures, blood pressure, and glucose, insulin, and lipids. Students were classified as underweight, healthy weight, overweight, obese, or severely obese. Mixed models controlling for school intervention status and covariates were used to evaluate shifts in BMI category over time and the relation between these shifts and changes in risk factors.
At baseline, students averaged 11.3 (±0.6) years; 47.6% were boys, 59.6% were Hispanic, and 49.8% were overweight or obese. Shifts in BMI category over time were common. For example, 35.7% of youth who were overweight moved to the healthy weight range, but 13% in the healthy weight range became overweight. BMI shifts were not associated with school intervention condition, household education, or youth gender, race/ethnicity, pubertal status, or changes in height. Increases in BMI category were associated with worsening of cardiometabolic risk factors, and decreases were associated with improvements. Boys who increased BMI category were more vulnerable to negative risk factor changes than girls.
There are substantial shifts across BMI categories during middle school that are associated with clinically meaningful changes in cardiometabolic risk factors. Programs to promote decreases in BMI and prevent increases are clearly warranted.
obesity; overweight; obesity trends; BMI; glucose; insulin; blood pressure; lipids
Background. Metabolic risk factors like insulin resistance and dyslipidemia are frequently observed in severly obese children. We investigated the hypothesis that moderate weight reduction by a low-threshold intervention is already able to reduce insulin resistance and cardiovascular risk factors in severely obese children. Methods. A group of 58 severely obese children and adolescents between 8 and 17 years participating in a six-month-long outpatient program was studied before and after treatment. The program included behavioral treatment, dietary education and specific physical training. Metabolic parameters were measured in the fasting state, insulin resistance was evaluated in an oral glucose tolerance test. Results. Mean standard deviation score of the body mass index (SDS-BMI) in the study group dropped significantly from +2.5 ± 0.5 to 2.3 ± 0.6 (P < 0.0001) after participation in the program. A significant decrease was observed in HOMA (6.3 ± 4.2 versus 4.9 ± 2.4, P < 0.03, and in peak insulin levels (232.7 ± 132.4 versus 179.2 ± 73.3 μU/mL, P < 0.006). Significant reductions were also observed in mean levels of hemoglobin A1c, total cholesterol and LDL cholesterol. Conclusions. These data demonstrate that already moderate weight reduction is able to decrease insulin resistance and dyslipidemia in severely obese children and adolescents.
The worldwide prevalence of obesity mandates a widely accessible tool to categorize adiposity that can best predict associated health risks. The body adiposity index (BAI) was designed as a single equation to predict body adiposity in pooled analysis of both genders. We compared body adiposity index (BAI), body mass index (BMI), and other anthropometric measures, including percent body fat (PBF), in their correlations with cardiometabolic risk factors. We also compared BAI with BMI to determine which index is a better predictor of PBF.
The cohort consisted of 698 Mexican Americans. We calculated correlations of BAI, BMI, and other anthropometric measurements (PBF measured by dual energy X-ray absorptiometry, waist and hip circumference, height, weight) with glucose homeostasis indices (including insulin sensitivity and insulin clearance from euglycemic clamp), lipid parameters, cardiovascular traits (including carotid intima-media thickness), and biomarkers (C-reactive protein, plasminogen activator inhibitor-1 and adiponectin). Correlations between each anthropometric measure and cardiometabolic trait were compared in both sex-pooled and sex-stratified groups.
BMI was associated with all but two measured traits (carotid intima-media thickness and fasting glucose in men), while BAI lacked association with several variables. BAI did not outperform BMI in its associations with any cardiometabolic trait. BAI was correlated more strongly than BMI with PBF in sex-pooled analyses (r = 0.78 versus r = 0.51), but not in sex-stratified analyses (men, r = 0.63 versus r = 0.79; women, r = 0.69 versus r = 0.77). Additionally, PBF showed fewer correlations with cardiometabolic risk factors than BMI. Weight was more strongly correlated than hip with many of the cardiometabolic risk factors examined.
BAI is inferior to the widely used BMI as a correlate of the cardiometabolic risk factors studied. Additionally, BMI’s relationship with total adiposity may not be the sole determinate of its association with cardiometabolic risk.
Total body fat and adipose tissue distribution are associated with cardiometabolic risk, yet there are conflicting data as to whether waist circumference (WC) or body mass index (BMI) is a better predictor of cardiovascular risk. To determine whether WC or BMI was more strongly associated with cardiometabolic risk, family members of patients with cardiac disease were studied (N=501; mean age, 48 years; 66% female; 36% nonwhite). Height, weight, WC, BMI, blood pressure, high-density lipoprotein cholesterol, triglycerides, glucose, high-sensitivity C-reactive protein, and lipoprotein-associated phospholipase A2 were systematically measured. Global risk was calculated using the Framingham function. Increased WC and BMI were equally strong predictors of cardiometabolic and global risk. The prevalence of cardiometabolic risk factors and their correlation with WC and BMI varied by race/ethnicity. Our data support inclusion of WC and BMI in screening guidelines for diverse populations to identify individuals at increased cardiometabolic risk.
To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.
Prospective, blinded, randomised controlled trial.
Single centre study in Odense, Denmark
43 children previously not bicycling to school were randomly allocated to control group (n=20) (ie, no change in lifestyle) or intervention group (ie, bicycling to school) (n=23).
Primary and secondary outcome measures
Change in cardiometabolic risk factor score and change in cardiorespiratory fitness.
All participants measured at baseline returned at follow-up. Based upon intention-to-treat (ITT) analyses, clustering of cardiometabolic risk factors was lowered by 0.58 SD (95% CI −1.03 to −0.14, p=0.012) in the bicycling group compared to the control group. Cardiorespiratory fitness (l O2/min) per se did not increase significantly more in the intervention than in the control group (β=0.0337, 95% CI −0.06 to 0.12, p=0.458).
Bicycling to school counteracted a clustering of cardiometabolic risk factors and should thus be recognised as potential prevention of type 2 diabetes mellitus and cardiovascular disease (CVD). The intervention did, however, not elicit a larger increase in cardiorespiratory fitness in the intervention group as compared with the control group.
Registered at http://www.clinicaltrials.gov (NCT01236222).
cardiometabolic; risk factors; bicycling; children; commuting
The impact of obesity as a systemic low-grade inflammatory process has only partially been explored. To this effect, 704 community-based school-aged children (354 obese children and 350 age-, gender-, and ethnicity-matched controls) were recruited and underwent assessment of plasma levels of fasting insulin and glucose, lipids, and a variety of proinflammatory mediators that are associated with cardiometabolic dysfunction. Obese children were at higher risk for abnormal HOMA and cholesterol levels. Furthermore, BMI z score, HOMA, and LDL/HDL ratio strongly correlated with levels of certain inflammatory mediators. Taken together, obesity in children is not only associated with insulin resistance and hyperlipidemia, but is accompanied by increased, yet variable, expression of markers of systemic inflammation. Future community-based intervention and phenotype correlational studies on childhood obesity will require inclusion of expanded panels of inflammatory biomarkers to provide a comprehensive assessment of risk on specific obesity-related morbidities.
Obesity is becoming an epidemic threat for the individual and society. The increasing prevalence of overweight children and adolescents is likely to have a great impact on the future cardiovascular health of these subjects. Obesity is a strong risk factor for cardiovascular morbidity and mortality. Cardiac abnormalities of obese children and adolescents include the echocardiographically revealed early and preclinical LV or septal hypertrophy, and left or right ventricular dysfunction. Most of these abnormalities, which are usually more pronounced in patients with morbid obesity, can be partially reversed after weight reduction.
Aim of the study
Evaluate early echocardiography changes in obese children and whether these cardiac abnormalities reverse with significant weight reduction in children and adolescents or not.
We started this study by 50 obese children and adolescents and 30 non obese controls matched for age and sex. BMI was calculated. Complete echocardiographic study was performed on each patient and control subject. Hematological and biochemical variables were determined in the obese subjects from fasting blood samples and included glucose, total cholesterol, triglycerides (TG), HDL cholesterol and LDL cholesterol. All our patients’ strict dietetic regime with exercises for 6 months. After 6 months full examination, including all measurements and echocardiography and laboratory investigations were done again.
Obese children has abnormalities of left ventricle structure and function (consisting of increased left ventricular wall dimensions and mass and alteration of diastolic function) that can be detected by echocardiography. Furthermore, (parameters of lipid metabolism) were found to be independent predictors of adverse LV remodeling and of diastolic dysfunction. As well as this study provides evidence that abnormalities of left ventricular wall dimension and mass in obese children and adolescents can improve with significant weight reduction.
This study has demonstrated that young, obese children and adolescents have early significant changes in left ventricular wall dimensions and early diastolic filling compared with non obese and this changes are reversible with weight reduction.
Obesity; Overweight; Echocardiography; Diet; Exercise; Children; Adolescent
As obesity is rapidly becoming a major medical and public health problem, the aim of our study was to determine: 1) if obesity in Caucasian adolescents at 5 different Tanner stages are associated with obesity in adulthood and its obesity-associated abnormal glucose and lipid profiles, 2) the type of fat distribution is associated with glucose and lipid profile abnormalities, and 3) the risk level and the age of appearance of these abnormalities.
For the first study, data analyses were from a case-control study of adolescents classified according to their BMI; a BMI ≥ 85th percentile for age and sex as overweight, and those with a BMI ≥ 95th percentile as obese. Subjects with a BMI < 85th percentile were classified as controls. WC:AC ratio of waist circumference to arm circumference was used as an indicator of a central pattern of adiposity. Two other indices of central adiposity were calculated from skinfolds: Central-peripheral (CPR) as subscapular skinfold + suprailliac skinfold)/ (triceps skinfold + thigh skinfold) and ratio of subscapular to triceps skinfold (STR). The sum of the four skinfolds (SUM) was calculated from triceps, subscapular, suprailliac and thigh skinfolds. SUM provides a single measure of subcutaneous adiposity. Representative adult subjects were used for comparison. Glucose and lipid profiles were also determined in these subjects. Abnormal glucose and lipid profiles were determined as being those with fasting glucose ≥ 6.1 mmol/l and lipid values ≥ 85th percentile adjusted for age and sex, respectively. Prevalence and odds ratio analysis were used to determine the impact of obesity on glucose and lipid profiles at each Tanner stages for both sexes. Correlation coefficient analyses were used to determine the association between glucose and lipid profiles and anthropometric measurements for both sexes. The second study evaluated in a retrospective-prospective longitudinal way if: 1) obesity in adolescence is associated with obesity in adulthood and 2) the nature of obesity-associated risk factors. Incidence and odds ratio analysis were used to determine the impact of obesity on glucose and lipid profiles at 7 different age groups from 9 to 38 years old in both sexes between 1974 to 2000.
Overall, glucose and lipid profiles were significantly (P < 0.01) associated with all anthropometric measurements either in male and female adolescents. WC:AC, CPR, STR and SUM are stronger predictors of both glucose and lipid profiles than BMI. Obese and overweight adolescents of Tanner stages III and higher are at increased risk of having an impaired glucose and lipid profiles than normal subjects with odds ratios of 5.9 and higher. Obesity in adolescents of 13–15 years old group is significantly (P < 0.01) associated with obesity in adulthood (with odds ratios of at least 12 for both men and women) and abnormal glucose (odds ratio of ≥ 8.6) and lipid profiles (odds ratio of ≥ 11.4).
This study confirmed that adolescents aged between 13 and 15 years old of both sexes with a BMI ≥ 85th percentile are at increased risk of becoming overweight or obese adults and presenting abnormal glucose and lipid profiles as adults. This emphasizes the importance of early detection and intervention directed at treatment of obesity to avert the long-term consequences of obesity on the development of cardiovascular diseases.
Two lower-extremity diseases (LEDs), including peripheral neuropathy and peripheral vascular disease (PVD), are leading causes of disability in the U.S. Although LEDs can be complications of diabetes, their prevelances and risk factors apart from diabetes are poorly described. This study describes the prevalence of LEDs and examines the association of obesity and cardiometabolic clustering in a population-based sample.
RESEARCH DESIGN AND METHODS
Adults aged ≥40 years (n = 2,514) were evaluated in the 2001–2004 National Health and Nutrition Examination Survey for clustering of two or more cardiometabolic characteristics, including elevated triglycerides or plasma glucose, low HDL cholesterol levels, increased waist circumference, or hypertension. Clustering was combined with BMI (dichotomized at ≥30 kg/m2) to generate three groups: obese (with or without clustering); nonobese with clustering; and nonobese without clustering. Multivariate logistic regression procedures incorporated the complex survey sampling design.
Overall, 9.0% of individuals had peripheral neuropathy alone, 8.5% had PVD alone, and 2.4% had both LEDs. The obese group was more likely to have peripheral neuropathy (odds ratio 2.20 [95% CI 1.43–3.39]), PVD (3.10 [1.84–5.22]), and both LEDs (6.91 [2.64–18.06]) compared with nonobese subjects without clustering. Within the nonobese group, clustering increased the odds of peripheral neuropathy (1.50 [1.00–2.25]) and PVD (2.48 [1.38–4.44]) compared with no clustering.
Obesity and clustering markedly increased the likelihood of LEDs in this sample and identified a group for whom preventive activities may reduce the risk of future disability.
The components of the metabolic syndrome, including prediabetes, prehypertension and dyslipidemia, represent prodromal stages of major cardiometabolic disorders. Lifestyle interventions have been shown to ameliorate or prevent the progression of individual components of the metabolic syndrome. The specific interventions utilized in randomized controlled studies often include dietary modification and physical activity. The effects of smoking cessation and the reduction of psychosocial stress on cardiometabolic risk factors need to be studied more. Because of the close concordance between the metabolic syndrome and multiple cardiometabolic diseases, the adoption of an effective lifestyle change upon initial recognition of the metabolic syndrome can be expected to delay or prevent the future development of sequelae such as diabetes, hypertension, and atherosclerotic cardiovascular and cerebrovascular diseases. Such a nonpharmacological approach to primary prevention and disease interruption carries enormous public health significance. Meeting the challenge of an implementation of effective lifestyle change at the community level requires (a) a system for the identification of at-risk populations, (b) an optimization of the knowledge base and practices of health care providers, and (c) a piloting of targeted biobehavioral intervention programs. Once identified, persons and communities at risk for cardiometabolic disorders can be empowered through increased health and nutritional literacy, the promotion of lifestyle interventions, provision of community resources, and pertinent legislative action that rewards preventive behavior. This paper reviews landmark studies that demonstrate the principles of nonpharmacological approaches to the reduction of cardiometabolic risk. We also discuss the physiological and emerging molecular genetic mechanisms that underlie the efficacy of lifestyle interventions.
Prediabetes; Diet; Exercise; Smoking cessation; Community prevention
To study associations of maternal gestational weight gain with offspring weight status in adolescence.
We surveyed 11,994 adolescents aged 9–14 enrolled in the Growing Up Today Study cohort and their mothers, members of the Nurses’ Health Study II. We used multivariable linear and logistic regression to study associations of gestational weight gain with offspring adiposity.
Mean (SD) gestational weight gain was 31.5 (11.2) pounds and offspring BMI z-score (BMI standardized for age and sex) was 0.15 (1.0) units; 6.5% of adolescents were obese (BMI greater than or equal to the 95th percentile). Gestational gain was linearly associated with adolescent adiposity: compared with 20–24 pounds, gain less than 10 pounds was associated with child BMI z-score 0.25 units lower (95% confidence interval [CI]: −0.47, −0.04), and gain greater than or equal to 45 pounds with BMI z-score 0.18 units higher (95% CI: 0.11, 0.25). Compared with women with adequate gain according to 1990 Institute of Medicine guidelines, women with excessive gain had children with higher BMI z-scores (0.14 units, 95% CI: 0.09, 0.18) and risk of obesity (odds ratio 1.42, 95% CI: 1.19, 1.70). The predicted prevalence of term low birth weight declined modestly across the range of gain (2% for gain less than 10 pounds, 1% for gain greater than or equal to 45 pounds), whereas term high birth weight increased dramatically with higher gain (10% for gain less than 10 pounds, 35% for gain of greater than or equal to 45 pounds).
Gestational weight gain is directly associated with BMI and risk of obesity in adolescence. Revised gestational weight gain guidelines should account for influences on child weight.
Body Mass Index (BMI) is widely used to assess the impact of obesity on cardiometabolic risk in children but it does not always relate to central obesity and varies with growth and maturation. Waist-to-Height Ratio (WHtR) is a relatively constant anthropometric index of abdominal obesity across different age, sex or racial groups. However, information is scant on the utility of WHtR in assessing the status of abdominal obesity and related cardiometabolic risk profile among normal weight and overweight/obese children, categorized according to the accepted BMI threshold values.
Cross-sectional cardiometabolic risk factor variables on 3091 black and white children (56% white, 50% male), 4-18 years of age were used. Based on the age-, race- and sex-specific percentiles of BMI, the children were classified as normal weight (5th - 85th percentiles) and overweight/obese (≥ 85th percentile). The risk profiles of each group based on the WHtR (<0.5, no central obesity versus ≥ 0.5, central obesity) were compared.
9.2% of the children in the normal weight group were centrally obese (WHtR ≥0.5) and 19.8% among the overweight/obese were not (WHtR < 0.5). On multivariate analysis the normal weight centrally obese children were 1.66, 2.01, 1.47 and 2.05 times more likely to have significant adverse levels of LDL cholesterol, HDL cholesterol, triglycerides and insulin, respectively. In addition to having a higher prevalence of parental history of type 2 diabetes mellitus, the normal weight central obesity group showed a significantly higher prevalence of metabolic syndrome (p < 0.0001). In the overweight/obese group, those without central obesity were 0.53 and 0.27 times less likely to have significant adverse levels of HDL cholesterol and HOMA-IR, respectively (p < 0.05), as compared to those with central obesity. These overweight/obese children without central obesity also showed significantly lower prevalence of parental history of hypertension (p = 0.002), type 2 diabetes mellitus (p = 0.03) and metabolic syndrome (p < 0.0001).
WHtR not only detects central obesity and related adverse cardiometabolic risk among normal weight children, but also identifies those without such conditions among the overweight/obese children, which has implications for pediatric primary care practice.
Abdominal fat is more related to health risk than is whole-body fat. Determining the factors related to children’s visceral fat could result in interventions to improve child health.
Given the effects of physical activity on adults’ visceral fat, it was hypothesized that, after accounting for whole-body fat, physical activity would be inversely related to children’s visceral (VAT), but not to subcutaneous (SAT), abdominal adipose tissue.
In this cross-sectional observational study conducted in forty-two 8-y-old children (21 boys, 21 girls) at risk of obesity [>75th body mass index (BMI) percentile, with at least one overweight parent], familial factors (eg, maternal BMI), historic weight-related factors (eg, birth weight), and the children’s current physical activity (self-reported and measured with accelerometry) and diet were examined as potential correlates of the children’s whole-body composition (measured with BMI and dual-energy X-ray absorptiometry) and abdominal fat distribution (measured by magnetic resonance imaging).
Accelerometer-measured physical activity was related to whole-body fat (r =−0.32, P <0.10), SAT (r =−0.29, P <0.10), and VAT (r =−0.43, P <0.05). In regression models, whole-body fat was positively associated with and the only significant correlate of SAT. Whole-body fat was positively related and accelerometer-measured physical activity was negatively and independently related to the children’s VAT.
Both SAT and VAT in 8-y-old children at risk of obesity are most closely associated with whole-body fat. However, after control for whole-body fat, greater physical activity is only associated with lower VAT, not SAT, in these children.
Visceral fat; physical activity; children; obesity; abdominal fat