The BLSA program in pulmonary aging is currently investigating the effect of body composition on pulmonary function and the risk of developing chronic obstructive lung disease. A. We completed a study that explored the effect of body fat distribution, as measured by waist-to-hip ratio (WHR), on pulmonary function. In this study, we combined spirometric and anthropometric measurements from 1094 men and 540 women (18 - 102 yr) in the BLSA to examine the effect of WHR on forced expiratory volume in 1 second (FEV1). Cross-sectional analyses, after accounting for body mass index (BMI) and other variables, showed a strong inverse association of WHR with FEV1 in men (β= -1.338, p=0.0001) but not in women. Similar analysis of a subset of the above subjects (935 men and 439 women), showed that larger values of WHR were correlated with greater reductions of forced vital capacity (FVC) in men ( β= -1.383, p=0.0005) as compared to women (β= -0.679, p=0.02).Thus, body fat distribution has independent effects on lung function which are more prominent in men than women. Harik-Khan R, Wise RA. Fleg JL. The Effect of Gender on the Relationship between Body Fat Distribution and Lung Function Journal of Clinical Epidemiology, 54:399,2001. B. Another study examined the relationship between body mass index (BMI) and the risk of chronic obstructive lung disease in 458 BLSA men ages 40 and 73 years initially free of pulmonary disease. Over a mean follow-up of 10 years, 8.7 % of the men developed chronic obstructive lung disease. A Cox proportional hazards model showed that in men the risk of developing chronic obstructive lung disease varied inversely with baseline BMI, even after adjusting for other risk factors including cigarette smoking, age, FEV1% predicted, abdominal obesity and educational status ( Risk Ratio for lightest BMI tertile relative to heaviest BMI tertile = 2.76, 95 %confidence interval 1.15 - 6.59 ). Harik-Khan R, Fleg JL, Wise RA. Body Mass Index and the Risk of Obstructive Pulmonary Disease. Chest (in press). C. We studied the effects of socioeconomic status (SES) and race on pulmonary function. African-Americans are known to have lower lung function than Caucasians However, the relative contributions of body habitus and socioeconomic factors to this racial difference are unknown. To address this question, we analyzed data from 1242 Caucasian (806 women, 436 men) and 1084 African-American (696 women, 388 men) asymptomatic, nonsmoking adult participants of the third National Health and Nutrition Examination Survey (NHANES III). African Americans were poorer, had larger FEV1/FVC and BMI, but lower sitting height, FEV1 and FVC than Caucasians. Cross-sectional regression analyses using spirometric, anthropometric and socioeconomic data were performed separately by gender to investigate racial differences in lung function. Sitting height accounted for 35-39% of the race difference in both genders. Family income accounted for about 7.5% and 2.5% of the racial difference in women and men respectively, whereas the effect of education accounted for about 2 % in women and 4.7% in men. With further adjustment for BMI, we could account for only about half of the racial difference in FEV1 and FVC. We conclude that the racial difference in lung function is partially explained by a shorter upper body segment in African-Americans. Although low socioeconomic indicators are related to lower lung function, they explain only a small proportion of this racial difference.
