Lung function predicts mortality, whether it is associated with functional status in the general population remains unclear. This study examined the association of lung function with multiple measures of functioning in early old age. Data are drawn from the Whitehall II study; data on lung function (forced expiratory volume in one second, height FEV1), walking speed (over 2.44 m), cognitive function (memory and reasoning), and self-reported physical and mental functioning (SF-36) were available on 4443 individuals, aged 50–74 years. In models adjusted for age, one standard deviation (SD) higher height-adjusted FEV1 was associated with greater walking speed (beta=0.16, 95% CI: 0.13, 0.19), memory (beta=0.09, 95% CI: 0.06, 0.12), reasoning (beta=0.16, 95% CI: 0.13, 0.19), and self-reported physical functioning (beta=0.13, 95% CI: 0.10, 0.16). Socio-demographic measures, health behaviours (smoking, alcohol, physical activity, fruit/vegetable consumption), BMI and chronic conditions explained two-thirds of the association with walking speed and self-assessed physical functioning and over 80% of the association with cognitive function. Our results suggest that lung function is a good “summary” measure of overall functioning in early old age.
Aged; Aging; physiology; psychology; Cognition; physiology; Female; Health Status; Humans; Lung; physiology; Male; Middle Aged; Spirometry; Walking; physiology; ageing; lung function; cognitive function; physical function
The authors examined the extent to which socioeconomic position, behavior-related factors, cardiovascular risk factors, inflammatory markers, and chronic diseases explain the association between poor lung function and mortality in 4,817 participants (68.9% men) from the Whitehall II Study aged 60.8 years (standard deviation, 5.9), on average. Forced expiratory volume in 1 second (FEV1) was used to measure lung function in 2002–2004. A total of 139 participants died during a mean follow-up period of 6.4 years (standard deviation, 0.8). In a model adjusted for age and sex, being in the lowest tertile of FEV1/height2 was associated with a 1.92-fold (95% confidence interval: 1.35, 2.73) increased risk of mortality compared with being in the top 2 tertiles. Once age, sex, and smoking history were taken into account, the most important explanatory factors for this association were inflammatory markers (21.3% reduction in the FEV1/height2-mortality association), coronary heart disease, stroke, and diabetes (11.7% reduction), and alcohol consumption, diet, physical activity, and body mass index (9.8% reduction). The contribution of socioeconomic position and cardiovascular risk factors was small (≤3.5% reduction). Taken together, these factors explained 32.5% of the association. Multiple pathways link lung function to mortality; these results show inflammatory markers to be particularly important.
forced expiratory volume; inflammation; middle aged; mortality; respiratory function tests
Cognitive performance has been associated with mental and physical health, but it is unknown whether the strength of these associations changes with ageing and with age-related social transitions, such as retirement. We examined whether cognitive performance predicted mental and physical health from midlife to early old age.
Participants were 5414 men and 2278 women from the Whitehall II cohort study followed for 15 years between 1991 and 2006. The age range included over the follow-up was from 40 to 75 years. Mental health and physical functioning were measured six times using SF-36 subscales. Cognitive performance was assessed three times using five cognitive tests assessing verbal and numerical reasoning, verbal memory, and phonemic and semantic fluency. Socioeconomic status and retirement were included as covariates.
High cognitive performance was associated with better mental health and physical functioning. Mental health differences associated with cognitive performance widened with age from 39 to 76 years of age, while physical functioning differences widened only between 39 and 60 years but not after 60 years of age. Socioeconomic status explained part of the widening differences in mental health and physical functioning before the age of 60. Cognitive performance was more strongly associated with mental health in retired than non-retired participants, which contributed to the widening differences after 60 years of age.
The strength of cognitive performance in predicting mental and physical health may increase from midlife to early old age, and these changes may be related to socioeconomic status and age-related transitions, such as retirement.
To investigate whether separate physical tests of the lower extremities, that assess movement speed and postural control, were associated with cognitive impairment in older community-dwelling subjects.
Subjects and methods
In this population-based, cross-sectional, cohort study, the following items were assessed: walking speed, walking 2 × 15 m, Timed Up and Go (TUG) at self-selected and fast speeds, one-leg standing, and performance in step- and five chair-stand tests. The study comprised 2115 subjects, aged 60–93 years, with values adjusted for demographics, health-related factors, and comorbidity. Global cognitive function was assessed using the Mini-Mental State Examination (MMSE), and cognitive impairment was defined by the three-word delayed recall task of the MMSE. Subjects who scored 0/3 on the three-word delayed recall task were defined as cases (n = 328), those who scored 1/3 were defined as intermediates (n = 457), and the others as controls (n = 1330).
Physical tests performed rapidly were significantly associated with cognitive impairment; this was the case in increased time of five chair stands (P = 0.009, odds ratio [OR] = 1.03), TUG (P < 0.001, OR = 1.11) and walking 2 × 15 m (P < 0.001, OR = 1.05). Inability to stand on one leg for 10 seconds was associated with increased risk of being a case (P < 0.001, OR = 1.78), compared to those able to stand for 30 seconds or longer. More steps during the step test (P < 0.001, OR = 0.95) and higher fast walking speed (P < 0.001, OR = 0.51) were associated with lower risk of being a case.
Slower movements and reduced postural control were related to an increased risk of being cognitively impaired. All tests that were performed rapidly were able to separate cases from controls. These findings suggest that physical tests that are related to lower extremity and postural control, emphasizing velocity, might be useful in investigating relationships between physical and cognitive function; furthermore, they can be used to complement cognitive impairment diagnoses.
cognition; movement speed; TUG; walking
BACKGROUND: No standard exists for the adjustment of lung function for height and age in children. Multiple regression should not be used on untransformed data because, for example, forced expiratory volume (FEV1), though normally distributed for height, age, and sex, has increasing standard deviation. A solution to the conflict is proposed. METHODS: Spirometry on representative samples of children aged 6.5 to 11.99 years in primary schools in England. After exclusion of children who did not provide two repeatable blows 910 white English boys and 722 girls had data on FEV1 and height. Means and standard deviations of FEV1 divided by height were plotted to determine whether logarithmic transformation of FEV1 was appropriate. Multiple regression was used to give predicted FEV1 for height and age on the transformed scale; back transformation gave predicted values in litres. Other lung function measures were analysed, and data on inner city children, children from ethnic minority groups, and Scottish children were described. RESULTS: After logarithmic (ln) transformation of FEV1 standard deviation was constant. The ratios of actual and predicted values of FEV1 were normally distributed in boys and girls. From the means and standard deviations of these distributions, and the predicted values, centiles and standard deviation scores can be calculated. CONCLUSION: The method described is valid because the assumption of stable variance for multiple regression was satisfied on the log scale and the variation of ratios of actual to predicted values on the original scale was well described by a normal distribution. The adoption of the method will lead to uniformity and greater ease of comparison of research findings.
Impaired lung function is associated with systemic inflammation and is a risk factor for cardiovascular disease in older adults. It is unknown when these associations emerge and to what extent they are mediated by smoking, chronic airways disease, and/or established atherosclerosis. We explored the association between the forced expiratory volume in one second (FEV1) and the systemic inflammatory marker C‐reactive protein (CRP) in young adults.
Associations between spirometric lung function and blood CRP were assessed in a population based birth cohort of approximately 1000 New Zealanders at ages 26 and 32 years. Analyses adjusted for height and sex to account for differences in predicted lung function and excluded pregnant women.
There were significant inverse associations between FEV1 and CRP at both ages. Similar results were found for the forced vital capacity. These associations were similar in men and women and were independent of smoking, asthma, and body mass index.
Reduced lung function is associated with systemic inflammation in young adults. This association is not related to smoking, asthma, or obesity. The reasons for the association are unexplained, but the findings indicate that the association between lower lung function and increased inflammation predates the development of either chronic lung disease or clinically significant atherosclerosis. The association between poor lung function and cardiovascular disease may be mediated by an inflammatory mechanism.
inflammation; C‐reactive protein; spirometry; cohort studies
prospective cohort study of 2512 Welshmen aged 45-59 living in
Caerphilly in 1979-1983 was used to investigate associations between
diet and lung function.
(phase I) and at five year follow up (phase II), forced expiratory
volume in one second (FEV1) was measured using a McDermott
spirometer and dietary data were obtained using a semi-quantitative
food frequency questionnaire.
function, indicated by high maximum FEV1 given age and
height, was associated with high intakes of vitamin C, vitamin E,
β-carotene, citrus fruit, apples, and the frequent consumption of
fruit juices/squashes. Lung function was inversely associated with
magnesium intake but there was no evidence of an association with fatty
fish. Following adjustment for confounders including body mass index,
smoking history, social class, exercise, and total energy intake, only
the associations with vitamin E and apples persisted, with lung
function estimated to be 39 ml (95% confidence interval (CI) 9 to 69)
higher for vitamin E intakes one standard deviation (SD) apart and
138 ml higher (95% CI 58to 218) for those eating five or more apples
per week compared with non-consumers. Decline in lung function between
phases was not significantly associated with the changing intakes of
apples or vitamin E. An association between high average apple
consumption and slow decline in lung function lost significance after
adjustment for confounders.
positive association is seen between lung function and the number of
apples eaten per week cross sectionally, consistent with a protective
effect of hard fruit rather than soft/citrus fruit. The recent
suggestion that such effects are reversible was not supported by our
Background: Taller people and those with better lung function are at reduced risk of coronary heart disease (CHD). Biological mechanisms for these associations are not well understood, but both measures may be markers for early life exposures. Some studies have shown that leg length, an indicator of pre-pubertal nutritional status, is the component of height most strongly associated with CHD risk. Other studies show that height-CHD associations are greatly attenuated when lung function is controlled for. This study examines (1) the association of height and the components of height (leg length and trunk length) with CHD risk factors and (2) the relative strength of the association of height and forced expiratory volume in one second (FEV1) with risk factors for CHD.
Subjects and methods: Cross sectional analysis of data collected at detailed cardiovascular screening examinations of 1040 men and 1298 women aged 30–59 whose parents were screened in 1972–76. Subjects come from 1477 families and are members of the Midspan Family Study.
Setting: The towns of Renfrew and Paisley in the West of Scotland.
Results: Taller subjects and those with better lung function had more favourable cardiovascular risk factor profiles, associations were strongest in relation to FEV1. Higher FEV1 was associated with lower blood pressure, cholesterol, glucose, fibrinogen, white blood cell count, and body mass index. Similar, but generally weaker, associations were seen with height. These associations were not attenuated in models controlling for parental height. Longer leg length, but not trunk length, was associated with lower systolic and diastolic blood pressure. Longer leg length was also associated with more favourable levels of cholesterol and body mass index than trunk length.
Conclusions: These findings provide indirect evidence that measures of lung development and pre-pubertal growth act as biomarkers for childhood exposures that may modify an individual's risk of developing CHD. Genetic influences do not seem to underlie height-CHD associations.
HTLV-I infection has been linked to lung pathology and HTLV-II has been associated with an increased incidence of pneumonia and acute bronchitis. However it is unknown whether HTLV-I or -II infection alters pulmonary function.
We performed pulmonary function testing on HTLV-I, HTLV-II and HTLV seronegative subjects from the HTLV outcomes study (HOST), including vital capacity (VC), forced expiratory volume in one second (FEV1), and diffusing lung capacity for carbon monoxide (DLCO) corrected for hemoglobin and lung volume. Multivariable analysis adjusted for differences in age, gender, race/ethnicity, height and smoking history.
Mean (standard deviation) pulmonary function values among the 257 subjects were as follows: FVC = 3.74 (0.89) L, FEV1 = 2.93 (0.67) L, DLCOcorr = 23.82 (5.89) ml/min/mmHg, alveolar ventilation (VA) = 5.25 (1.20) L and DLCOcorr/VA = 4.54 (0.87) ml/min/mmHg/L. There were no differences in FVC, FEV1 and DLCOcorr/VA by HTLV status. For DLCOcorr, HTLV-I and HTLV-II subjects had slightly lower values than seronegatives, but neither difference was statistically significant after adjustment for confounding.
There was no difference in measured pulmonary function and diffusing capacity in generally healthy HTLV-I and HTLV-II subjects compared to seronegatives. These results suggest that previously described HTLV-associated abnormalities in bronchoalveolar cells and fluid may not affect pulmonary function.
There is mounting evidence that estimates of intakes of a range of dietary nutrients are related to both lung function level and rate of decline, but far less evidence on the relation between lung function and objective measures of serum levels of individual nutrients. The aim of this study was to conduct a comprehensive examination of the independent associations of a wide range of serum markers of nutritional status with lung function, measured as the one-second forced expiratory volume (FEV1).
Using data from the Third National Health and Nutrition Examination Survey, a US population-based cross-sectional study, we investigated the relation between 21 serum markers of potentially relevant nutrients and FEV1, with adjustment for potential confounding factors. Systematic approaches were used to guide the analysis.
In a mutually adjusted model, higher serum levels of antioxidant vitamins (vitamin A, beta-cryptoxanthin, vitamin C, vitamin E), selenium, normalized calcium, chloride, and iron were independently associated with higher levels of FEV1. Higher concentrations of potassium and sodium were associated with lower FEV1.
Maintaining higher serum concentrations of dietary antioxidant vitamins and selenium is potentially beneficial to lung health. In addition other novel associations found in this study merit further investigation.
Data collected during seven population health surveys over 18 years in Busselton, Western Australia, were examined to determine the effect of smoking on lung function and to investigate the development of chronic airflow limitation. Lung function was measured and details of respiratory illness and smoking histories were collected from subjects attending surveys at three year intervals from 1966 to 1984. Data from ex-smokers and asthmatic patients (diagnosis based on answer to questionnaire) were excluded. Regression of height adjusted forced expiratory volume in one second (FEV1) on age was calculated individually for 759 non-smokers and 225 regular smokers with four or more observations. Decline in height adjusted FEV1 was similar for men and women. In smokers the rate of decline in FEV1 was greater than in non-smokers and was related to the amount smoked, to the extent that a smoker could expect a 20-30% greater rate of decline than a non-smoker of the same age. Chronic airflow limitation (defined as FEV1/FEV less than 65% or FEV1 less than 65% predicted on at least two occasions) was common, occurring in 24% of men and 18% of women who were regular smokers and in 5% of male and 8% of female non-smokers. These figures are higher than those reported in other populations, especially for women and for non-smokers. Not all chronic airflow limitation was associated with respiratory symptoms, confirming that the condition may be unrecognised until it is advanced.
The best method for expressing lung function impairment is undecided. We tested in a population of patients with chronic obstructive pulmonary disease (COPD) whether forced expiratory volume in 1 second (FEV1) or FEV1 divided by height squared (FEV1/ht2) was better than FEV1 percent predicted (FEV1PP) for predicting survival.
FEV1, FEV1PP, and FEV1/ht2 recorded post bronchodilator were compared as predictors of survival in 1095 COPD patients followed for 15 years. A staging system for severity of COPD was defined from FEV1/ht2 and compared with the Global Initiative for Obstructive Lung Disease (GOLD) staging system.
FEV1/ht2 was a better univariate predictor of survival in COPD than FEV1 and both were better than FEV1PP. The best multivariate model for predicting survival included FEV1/ht2, age and sex. Comparing the GOLD stages with the FEV1/ht2 groups found that survival was more coherent within each FEV1/ht group than it was within each GOLD stage. FEV1/ht2 had 60% more people in its most severe group than the severest GOLD stage with these extra subjects having equivalently poor survival and had 155% more in the least severe group with equivalent survival. GOLD staging misclassified 51% of subjects with regard to survival.
We conclude that GOLD criteria using FEV1PP do not optimally stage COPD with regard to survival. An alternative strategy using FEV1/ht2 improves the staging of this disease. Studies which stratify COPD patients to determine the effect of interventions such as drug trials, rehabilitation, or management guidelines should consider alternatives to the GOLD classification.
chronic obstructive pulmonary disease; spirometry; respiratory function tests
Cognitive and physical functions are closely linked in old age but less is known about this association in midlife. We assessed whether cognitive function predicts physical function and whether physical function predicts cognitive function in middle-aged men and women.
Data were from Whitehall II; an ongoing large-scale, prospective occupational cohort study of employees from 20 London-based white-collar Civil Service departments. The participants, 3446 men and 1274 women aged 45–68 years at baseline (1995–1997), had complete data on cognitive performance and physical function both at baseline and follow-up (2002–2004). A composite cognitive score was compiled from the following tests: verbal memory, inductive reasoning (Alice Heim 4-I), verbal meaning (Mill Hill), phonemic and semantic fluency. Physical function was measured using the physical composite score of the short form (SF-36) scale. Average follow-up was 5.4 years.
Poor baseline cognitive performance predicted poor physical function at follow-up (β=0.08, p<0.001) while baseline physical function did not predict cognitive performance (β=0.01, p=0.67). After full adjustment for socio-demographic, behavioral and biological risk factors, baseline cognitive performance (β=0.04 p=0.009) remained predictive of physical function.
Despite previous work indicating that the association between physical and cognitive performance may be bidirectional, our findings suggest that in middle age, the direction of the association is predominantly from poor cognition to poor physical function.
Physical functioning, cognitive function, memory, psychosocial factors, longitudinal, SF-36
The protective effects of breastfeeding on early life respiratory infections are established, but there have been conflicting reports on protection from asthma in late childhood. The association of breastfeeding duration and lung function was assessed in 10-year-old children.
In the Isle of Wight birth cohort (n = 1456), breastfeeding practices and duration were prospectively assessed at birth and at subsequent follow-up visits (1 and 2 years). Breastfeeding duration was categorised as “not breastfed” (n = 196); “<2 months” (n = 243); “2 to <4 months” (n = 142) and “≥4 months” (n = 374). Lung function was measured at age 10 years (n = 1033): forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio and peak expiratory flow (PEF). Maternal history of asthma and allergy was assessed at birth. The effect of breastfeeding on lung function was analysed using general linear models, adjusting for birth weight, sex, current height and weight, family social status cluster and maternal education.
Compared with those who were not breastfed, FVC was increased by 54.0 (SE 21.1) ml (p = 0.001), FEV1 by 39.5 (20.1) ml(p = 0.05) and PEF by 180.8 (66.1) ml/s (p = 0.006) in children who were breastfed for at least 4 months. In models for FEV1 and PEF that adjusted for FVC, the effect of breastfeeding was retained only for PEF (p = 0.04).
Breastfeeding for at least 4 months enhances lung volume in children. The effect on airflow appears to be mediated by lung volume changes. Future studies need to elucidate the mechanisms that drive this phenomenon.
Deterioration of executive functions in the elderly has been associated with impairments in walking performance. This may be caused by limited cognitive flexibility and working memory, but could also be caused by altered prioritization of simultaneously performed tasks. To disentangle these options we investigated the associations between Trail Making Test performance—which specifically measures cognitive flexibility and working memory—and dual task costs, a measure of prioritization.
Methodology and Principal Findings
Out of the TREND study (Tuebinger evaluation of Risk factors for Early detection of Neurodegenerative Disorders), 686 neurodegeneratively healthy, non-demented elderly aged 50 to 80 years were classified according to their Trail Making Test performance (delta TMT; TMT-B minus TMT-A). The subjects performed 20 m walks with habitual and maximum speed. Dual tasking performance was tested with walking at maximum speed, in combination with checking boxes on a clipboard, and subtracting serial 7 s at maximum speeds. As expected, the poor TMT group performed worse when subtracting serial 7 s under single and dual task conditions, and they walked more slowly when simultaneously subtracting serial 7 s, compared to the good TMT performers. In the walking when subtracting serial 7 s condition but not in the other 3 conditions, dual task costs were higher in the poor TMT performers (median 20%; range −6 to 58%) compared to the good performers (17%; −16 to 43%; p<0.001). To the contrary, the proportion of the poor TMT performance group that made calculation errors under the dual tasking situation was lower than under the single task situation, but higher in the good TMT performance group (poor performers, −1.6%; good performers, +3%; p = 0.035).
Under most challenging conditions, the elderly with poor TMT performance prioritize the cognitive task at the expense of walking velocity. This indicates that poor cognitive flexibility and working memory are directly associated with altered prioritization.
Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcohol may be an important source of oxidants; however, wine contains several antioxidants. In this study we analyzed the relation of beverage specific alcohol intake with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in a random sample of 1555 residents of Western New York, USA.
We expressed pulmonary function as percent of predicted normal FEV1 (FEV1%) and FVC (FVC%) after adjustment for height, age, gender and race. To obtain information on alcohol intake we used a questionnaire that reliably queries total alcohol and beverage specific recent (past 30 days) and lifetime alcohol consumption. Results: Using multiple linear regression analysis after adjustment for covariates (pack-years of smoking, weight, smoking status, education, nutritional factors and for FEV1%, in addition, eosinophil count), we observed no significant correlation between total alcohol intake and lung function. However, we found positive associations of recent and lifetime wine intake with FEV1% and FVC%. When we analyzed white and red wine intake separately, the association of lung function with red wine was weaker than for white wine.
While total alcohol intake was not related to lung function, wine intake showed a positive association with lung function. Although we cannot exclude residual confounding by healthier lifestyle in wine drinkers, differential effects of alcoholic beverages on lung health may exist.
OBJECTIVE: To examine the role of exposure to the 1984 Bhopal gas leak in the development of persistent obstructive airways disease. DESIGN: Cross sectional survey. SETTING: Bhopal, India. SUBJECTS: Random sample of 454 adults stratified by distance of residence from the Union Carbide plant. MAIN OUTCOME MEASURES: Self reported respiratory symptoms; indices of lung function measured by simple spirometry and adjusted for age, sex, and height according to Indian derived regression equations. RESULTS: Respiratory symptoms were significantly more common and lung function (percentage predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and FEV1/FVC ratio) was reduced among those reporting exposure to the gas leak. The frequency of symptoms fell as exposure decreased (as estimated by distance lived from the plant), and lung function measurements displayed similar trends. These findings were not wholly accounted for by confounding by smoking or literacy, a measure of socioeconomic status. Lung function measurements were consistently lower in those reporting symptoms. CONCLUSION: Our results suggest that persistent small airways obstruction among survivors of the 1984 disaster may be attributed to gas exposure.
OBJECTIVES: To determine if the rate of change in forced expiratory volume in one second (FEV1) in subjects with high exposure to Latrobe Valley brown coal dust was significantly greater than the rate of change among subjects with low exposure. METHODS: A retrospective dynamic cohort design with variable time windows. This study was conducted over a period of 14 years from 1980 to 1994 and used data collected by the State Electricity Commission (SEC) Lung Function Unit for an asbestos surveillance programme. The subjects were exposed to low, medium, or high levels of coal dust. Basic spirometry with wedge bellows spirometers was used to assess lung function. A general linear model (GLM) was used to assess the effects of smoking and exposure to coal dust upon the change in forced expiratory volume in one second (FEV1) while adjusting for age and height. RESULTS: The mean (95% confidence interval (95% CI) rate of decline in FEV1 was 40 (36 to 44) ml/year. Age was a significant predictor of change. A significant effect was found for smoking (P = 0.02) and for exposure to coal dust (P = 0.008). The only significant difference with exposure to coal dust was between the high and mixed exposure categories. CONCLUSION: There is no convincing evidence of excessive decline in FEV1 with exposure to coal dust > 0.75 mg/m3. The absence of a dose response relation provides some evidence against a causal relation. On the basis of this study, reduction of the exposure standards currently applied to brown coal dust in the Victorian electricity industry is not warranted to prevent respiratory disease.
While some studies suggest that poor fetal growth rate, as indicated by lower birth weight, is associated with poor respiratory function in childhood, findings among adults remain inconsistent. A study was undertaken to determine the association between early growth and adult respiratory function.
A longitudinal birth cohort study was performed of 5390 men and women born full term and prospectively followed from the fetal period to adulthood. Weight at birth and infancy were recorded, and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were assessed by standard spirometry at age 31 years.
Adult FEV1 and FVC increased linearly with higher birth weight in both men and women with no apparent threshold. After adjustment for sex, adult height and other potential confounders operating through the life course, every 500 g higher birth weight was associated with a higher FEV1 of 53.1 ml (95% CI 38.4 to 67.7) and higher FVC of 52.5 ml (95% CI 35.5 to 69.4). These positive associations persisted across categories of smoking, physical activity and body mass index, with the lowest respiratory function noted among those with lower birth weight who were smokers, led a sedentary lifestyle or were overweight. Weight gain in infancy was also positively associated with adult lung function.
Birth weight is continuously and independently associated with adult respiratory function. It is plausible that poor growth in early life may restrict normal lung growth and development, which could have long‐term consequences on lung function later in life.
Rationale: The relative contribution of body proportion and social exposures to ethnic differences in lung function has not previously been reported in the United Kingdom.
Objectives: To examine ethnic differences in lung function in relation to anthropometry and social and psychosocial factors in early adolescence.
Methods: The subjects of this study were 3,924 pupils aged 11 to 13 years, of whom 80% were ethnic minorities with satisfactory lung function measures. Data were collected on economic disadvantage, psychological well-being, tobacco exposure, height, FEV1, and FVC.
Measurements and Main Results: The lowest FEV1 was observed for Black Caribbean/African children after adjusting for standing height (SH) (white boys: 2.475 L; 95% confidence interval [CI], 2.442–2.509; white girls: 2.449 L; 95% CI, 2.464–2.535]; Black Caribbean boys: −14% [95% CI, −16 to −12]; Black Caribbean girls: −13% [95% CI, −16 to −11]; Black African boys: −15% [95% CI, −17 to −13]; Black African girls: −17% [95% CI, −19 to −14]; Indian boys: −13% [95% CI, −16 to −11]; Indian girls: −11% [95% CI, −14 to −8]; Pakistani/Bangladeshi boys: −7% [95% CI, −9 to −5]; Pakistani/Bangladeshi girls: −9% [95% CI, −11 to −6]). Adjustment for upper body segment instead of SH achieved a further reduction in ethnic differences of 41 to 51% for children of Black African origin and 26 to 39% for the other groups. Overcrowding (boys) and poor psychological well-being (boys and girls) were independent correlates of FEV1, explaining up to a further 10% of ethnic differences. Similar patterns were observed for FVC. Social exposures were also related to height components.
Conclusions: Differences in upper body segment explained more of the ethnic differences in lung function than SH, particularly among Black Caribbeans/African subjects. Social correlates had a smaller but significant impact. Future research needs to consider how differential development of lung capacity is compromised by the social patterning of growth trajectories.
anthropometry; spirometry; ethnicity; socioeconomic factors; adolescence
Fifteen year chronic bronchitis mortality was investigated among 17,717 male civil servants aged 40-64 years participating in the Whitehall Study. Associations were assessed between mortality and Medical Research Council standardised questions about chronic phlegm production and breathlessness, and a measure of lung function. Low FEV1 was the most powerful single predictor of mortality; controlling for age, smoking habits and employment grade, the relative hazards ratio (RHR) was 20. Using mortality rates standardised for age and smoking, the proportion of mortality in the total population statistically attributable to low FEV1 (population excess fraction) was 57%. Breathlessness while walking on the level was the best predictor among the questions and combinations of questions; the relative hazards ratio was 12 and the population excess fraction, 39%. A Medical Research Council definition of chronic bronchitis including chronic phlegm production and breathlessness was also strongly associated with chronic bronchitis mortality (RHR = 13); however, the population excess fraction was only 20%. This definition identified only 30% of the 64 deaths, and added almost nothing to prediction by FEV1 alone. The results suggest that although the combination of chronic phlegm production and chronic airflow limitation is strongly associated with mortality from chronic bronchitis, the presence of chronic phlegm production alone is not associated with mortality.
Methods: In 2001 the cohort was assessed for current lung function, smoking status, and respiratory symptoms. Birth details obtained from the Aberdeen Maternity and Neonatal Databank recorded birth weight, gestation, parity, and mother's age and height.
Results: 381 subjects aged 45–50 years were traced and tested for lung function; 323 (85%) had birth details available. A significant linear trend (p<0.01) was observed between birth weight and current forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) values (adjusted for height, age, sex, weight, deprivation category (Depcat), childhood group, and smoking status). This trend remained significant after adjusting birth weight for gestation, parity, sex, mother's height and weight (p = 0.01). The relationship between birth weight and FEV1 and FVC remained significant when adjusted for smoking history. There was no association between birth weight and current wheezing symptoms.
Conclusion: There is a positive linear trend between birth weight, adjusted for maternal factors, and lung function in adulthood. The strength of this association supports the "fetal origins hypothesis" that impairment of fetal growth is a significant influence on adult lung function.
Common carotid artery intima media thickness (IMT) is a measure of generalized atherosclerosis and has been shown to be associated with cognitive function. We examine two questions: does socioeconomic status (SES) moderate this association and is IMT more strongly associated with specific aspects of cognitive function?
Data are drawn from the Phase 7 (2003–2004) of the Whitehall II study (N=3896). In cross-sectional analyses the association between IMT and six measures of cognition (short term verbal memory, inductive reasoning, vocabulary, semantic and phonemic fluency and a measure of global cognitive status) was examined in analyses adjusted for previous history of coronary heart disease, health behaviours and other vascular risk measures such as blood pressure, cholesterol and body mass index.
The overall association between IMT and the 6 measures of cognition was restricted to the low SES group (p=0.02). Within this group, IMT was significantly associated with inductive reasoning (p=0.001), vocabulary (p=0.002), phonemic (p=0.006) and semantic fluency (p=0.02). The covariates examined explained about a quarter of the association between IMT and cognition in the low SES group. The associations with the measure of inductive reasoning (p=0.02), vocabulary (p=0.02) and phonemic fluency (p=0.04) remained after adjustment for all covariates.
SES is an important modifier of the association between IMT and cognition, an inverse association between the two was observed only in the low SES group. It is possible that high cognitive reserve among the high SES individuals prevents the functional manifestations of atherosclerosis. Verbal memory was not one of the cognitive domains associated with IMT.
cerebrovascular diseases; cognitive aging; carotid intima-media thickness
Methods: The associations of self-reported indicators of childhood socioeconomic position with adult lung function (forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and forced expiratory flow rate during mid expiration (FEF25–75), all measured using standard procedures) were assessed in a cross sectional study of 3641 British women aged 60–79 years.
Results: In confounder adjusted analyses, each individual indicator of childhood circumstances was inversely associated with each measure of lung function. In the fully adjusted models (including mutual adjustment for each of the other indicators of childhood socioeconomic circumstances), only childhood occupational social class and access to a car were associated with lung function in adulthood. However, there were strong linear trends of worsening lung function with greater numbers of indicators of childhood poverty (all p values <0.001).
Conclusions: Childhood poverty is associated with poorer lung function in women aged 60–79 years. Adverse childhood circumstances that affect both lung growth and development and cardiovascular disease in later life may explain some of the well known associations between poor lung function and cardiovascular disease, or lung function may be an important mediating factor in this association.
BACKGROUND: Fresh fruit consumption and vitamin C intake have been associated with improved lung function in adults. Whether this is due to enhancement of lung growth, to a reduction in lung function decline, or to protection against bronchospasm is unclear. METHODS: In a cross- sectional school based survey of 2650 children aged 8-11 from 10 towns in England and Wales the main outcome measure was forced expiratory volume in one second (FEV1) standardised for body size and sex. Exposure was assessed by a food frequency questionnaire to parents and by measurement of plasma levels of vitamin C in a subsample of 278 children. RESULTS: FEV1 was positively associated with frequency of fresh fruit consumption. After adjustment for possible confounding variables including social class and passive smoking, those who never ate any fresh fruit had an estimated FEV1 some 79 ml (4.3%) lower than those who ate these items more than once a day (95% CI 22 to 136 ml). The association between FEV1 and fruit consumption was stronger in subjects with wheeze than in non-wheezers (p = 0.020 for difference in trend), though wheeze itself was not related to fresh fruit consumption. Frequency of consumption of salads and of green vegetables were both associated with FEV1 but the relationships were weaker than for fresh fruit. Plasma vitamin C levels were unrelated to FEV1 (r = - 0.01, p = 0.92) or to wheeze and were only weakly related to fresh fruit consumption (r = 0.13, p = 0.055). CONCLUSIONS: Fresh fruit consumption appears to have a beneficial effect on lung function in children. Further work is needed to confirm whether the effect is restricted to subjects who wheeze and to identify the specific nutrient involved.