Body mass index, physical inactivity and low level of physical fitness as determinants of all-cause and cardiovascular disease mortality - 16y follow-up of middle-aged and elderly men and women

OBJECTIVE: To investigate the independent associations and the possible int eraction of body mass index (BMI), leisure time physical activity (LTPA) an d perceived physical fitness and functional capability with the risk of mor tality. DESIGN: Prospective 16 y follow-up study. SUBJECTS: A regionally representative cohort of 35-63-y-old Finnish men (n = 1090) and women (n = 1122). MEASUREMENTS: All-cause, cardiovascular disease (CVD) and coronary heart di sease (CHD) mortality were derived from the national census data until the end of September 1996 while the initial levels of BMI, LTPA, physical fitne ss and function were determined from self-administered questionnaires. RESULTS: After adjustment for age, marital and employment status, perceived hearth status, smoking and alcohol consumption, the Cox proportional hazar ds model showed that BMI was not associated with the risk of death among th e men or the women. Compared with the most active subjects the men and wome n with no weekly vigorous activity had relative risks of 1.61 (95% confiden ce interval, CI, 0.98-2.64) and 4.68 (95% CI, 1.41-15.57), respectively, fo r CVD mortality, and for the men there was a relative risk of 1.66 (95% CI, 0.92-2.99) for CHD mortality. When compared with the men who perceived the ir fitness as better than their age-mates, the men with the 'worse' assessm ent had a relative risk of 3.29 (95% CI, 1.80-6.02) for all-cause mortality and 4.37 (95% CI, 1.80-10.6) for CVD mortality. Men with at least some dif ficulty in walking a distance of 2 km had a relative risk of 1.62 (95% CI, 1.05-2.50) for all-cause mortality when compared with those who had no func tional difficulties. In addition, in the comparison with subjects with no f unctional difficulties, the men and women who had some difficulty climbing several flights of stairs had relative risks of 1.47 (95% CI, 0.97-2.23) an d 2.39 (95% CI, 1.25-4.60) for all-cause mortality, respectively. For CVD m ortality the relative risks were 1.85 (95% Ci, 1.04-3.30) and 3.38 (1.22-9. 41), respectively. CONCLUSIONS: Although BMI did not prove to be an independent risk factor fo r mortality from CVD, CHD or from all causes combined, perceived physical f itness and functional capability did. An increase in LTPA seems to have a s imilar beneficial effect on the mortality risk of obese and nonobese men an d women, and the effect also seems to be similar for fit and unfit subjects .