Factors Associated With Variations in Pulmonary Function Among Elderly Japanese-American Men

Abstract

To identify lifestyle, anthropometric, biochemical, and clinical characteristics associated with pulmonary function in elderly men. Cross-sectional population-based study. Japanese-American men (n=3,111) aged 71 to 93 years, who completed spirometry at the fourth examination of the Honolulu Heart Program (1991 to 1993). Pulmonary function measurements (FEV1 and FVC) were obtained using American Thoracic Society guidelines. Potential factors associated with pulmonary function were examined using Pearson correlation coefficients and general linear models. Age- and height-adjusted mean levels of FEV1 and FVC were compared across quintiles of continuous variables and by status of prevalent disease and medication or vitamin use. Stepwise multiple linear regression was used to identify factors independently associated with pulmonary function overall and among never smokers. A number of correlates of pulmonary function were initially identified. In multivariate analyses, age, current smoking, pack-years of smoking, emphysema, asthma, wheezing without colds, subscapular skinfold thickness, ECG abnormality, heart rate, WBC count, and eosinophil count were all negatively and independently associated with FEV1, while height, grip strength, physical activity, and mean corpuscular hemoglobin concentration were positively associated. With a few exceptions, similar relations were observed with FVC and among never-smokers. Cigarette smoking, respiratory symptoms and disease, and several cardiovascular risk factors were independently associated with pulmonary function in elderly Japanese-American men. In most cases, inadequate control for smoking does not appear to account for these associations. Results suggest that a number of factors that are correlates of FEV1 and FVC in younger age groups are also associated with pulmonary function beyond the age of 70 years.