Reduced cardiovascular mortality risk in male smokers who are physically active. Results from a 25-year follow-up of the prospective population study men born in 1914

Abstract

Objective: To assess to what extent physical activity during leisure time may modify the mortality risk associated with smoking.

Methods: Population-based cohort study in the city of Malmö, Sweden. The 642 men included in this study were all born in 1914 and were all free of cardiovascular disease at the baseline examination in 1968 and 1969. Smoking habits and physical activity during leisure time were assessed by a structured questionnaire. Main outcome measures were total and cardiovascular mortality rates during 25 years of follow-up.

Results: The total and cardiovascular mortality rates in smokers were 33.2 per 1000 person-years and 15.9 per 1000 person-years, respectively. Corresponding figures in nonsmokers were 17.8 per 1000 person-years and 7.5 per 1000 person-years. Mortality rates in smokers were strongly related to daily tobacco consumption. Physically active men had lower overall (adjusted relative risk [RR], 0.7; 95% confidence interval [CI], 0.5-0.9) and cardiovascular (adjusted RR, 0.6; 95% CI, 0.3-0.9) mortality rates than sedentary men. Physically active men who never smoked (used as the control category) had the lowest death rate, and physically inactive smokers the highest (adjusted RR, 3.6; 95% CI, 2.1-6.3). The cardiovascular death rates in these 2 groups were 4.3 per 1000 person-years and 16.6 per 1000 person-years, respectively (adjusted RR, 5.5; 95% CI, 2.2-13.6). Vigorous physical activity in smokers was associated with an almost 40% lower cardiovascular mortality rate (RR, 0.6; 95% CI, 0.3-1.2; P = .11).

Conclusions: Regular physical activity was associated with lower total and cardiovascular mortality rates. Similar effects were observed in both nonsmokers and smokers.