摘要：Objectives . This study examined the association between leisure time physical activity and cause-specific mortality among male Whitehall Study participants with chronic bronchitis. Methods . Rate ratios were calculated for 4 mortality outcomes, according to level of activity and baseline bronchitis status, in a 25-year follow-up of 6479 men. Results . After multiple adjustment for potential confounding or mediating variables, activity was inversely related to all-cause, cardiovascular, coronary heart disease, and noncardiovascular mortality among men free of chronic bronchitis. Among men with bronchitis, weak, nonsignificant positive associations were observed between activity and these outcomes, with the exception of noncardiovascular mortality. Conclusions . The suggestion of a positive activity–mortality association among individuals with chronic bronchitis—albeit weak and nonsignificant—requires further investigation. The frequently observed inverse association between leisure time physical activity and the incidence of coronary heart disease (CHD) in cohorts of healthy individuals 1, 2 has been attributed, in part, to the normalizing effect of activity on a number of CHD risk factors, including body weight and blood pressure. 3 Similar acute beneficial effects of physical activity among individuals with chronic diseases, such as type 2 diabetes 4, 5 and ischemia, 6, 7 have been revealed and may likewise partially explain the cardioprotective impact of activity observed in long-term follow-ups of these groups. 8– 17 There is also evidence suggesting that, among individuals with pulmonary diseases such as bronchitis, exercise programs have a favorable effect on cardiorespiratory fitness, quality of life, and dyspnea. 18 The trials on which these findings are based are characterized by small sample sizes, brief follow-up intervals, and multifaceted interventions, which make it difficult to isolate exerciseattributable effects. However, given this apparent short-term beneficial effect of activity, it is plausible that, in keeping with observations involving other subgroups, activity may be associated with reduced longer-term CHD risk in individuals with bronchitis. In the present study, we tested this hypothesis by following a group of British male civil servants who self-reported their chronic bronchitis status and leisure time physical activity patterns on their entry into the Whitehall Study. We compared associations between leisure time physical activity and mortality rates in men with and without bronchitis, allowing us to explore the possibility that this condition may modify the nature of these relationships. We are unaware of any other study reporting on these associations in this group.
