Effect of conventional risk factors for excess cardiovascular death in men: NIPPON DATA80.

BACKGROUND: The present study examined how sex differences in conventional risk factors for cardiovascular disease (CVD), especially smoking, account for excess male mortality from CVD in Japan. METHODS AND RESULTS: In a 14-year follow-up study, causes of death were ascertained among 10,546 Japanese aged 30 years or older at the baseline. The proportion of the excess male risk of CVD explained by the differences in risk factors was estimated as (HR0-HR1)/(HR0-1), where HR0 is the age-adjusted hazard ratio (men vs women) and HR1 is the age and risk factor-adjusted hazard ratio. The age-adjusted male:female ratios were 1.60 (95% confidence interval (CI), 1.32-1.94) for CVD, 1.75 (95% CI, 1.33-2.30) for stroke, and 1.55 (95% CI, 0.97-2.49) for coronary heart disease. The proportion of excess male risk of CVD explained by smoking was 46% and excess risk explained by all risk factors including smoking was 36%. In men, drinking habits decreased the excess risk of CVD. Except for the association between drinking habits and CVD, the impact of the hazard ratios of conventional risk factors had no sex difference. CONCLUSIONS: Smoking contributes substantially to excess male mortality from CVD when the smoking rates vary substantially by sex.