Cardiovascular disease mortality in relation to physical activity during adolescence and adulthood in Japan: Does school-based sport club participation matter?

We examined potential associations of sport club participation during adolescence and sports-related physical activity during adulthood with mortality from cardiovascular diseases (CVD) in a Japanese population. Between 1988 and 1990, 29,526 men and 41,043 women aged 40-79 years responded to a questionnaire including questions about the frequency of sports participation at baseline and sport club participation during junior/senior high school. Subjects were followed-up until the end of 2009, and 4230 cardiovascular deaths (870 CHD, 1859 stroke) were identified. Cox proportional-hazard regression models were used to estimate hazard ratios (HR). During the first-two thirds of the follow-up - where the proportional hazards assumption was met - the multivariate-adjusted HR (95% confidence interval) for total CVD mortality was 0.77 (0.61-0.98) among men and 0.82 (0.61-1.10) among women who were physically active at baseline (≥5 h/week versus 1-2 h/week). The corresponding HRs for coronary heart disease (CHD) mortality were 0.65 (0.39-1.07) and 0.40 (0.17-0.91), respectively. The combined associations of sports participation during adulthood and adolescence were also examined. Among men who participated in sports for ≥5 h/week at baseline, the multivariate-adjusted HR for those who also engaged in sport club activities during adolescence was 0.89 (0.61-1.30) for total CVD mortality and 0.24 (0.08-0.71) for CHD mortality when compared to non-participants. Among women, no statistically significant differences were found between sport club participants and non-participants. In conclusion, participating in sport clubs during adolescence might lead to a more pronounced risk-reduction for CHD mortality among men who also participate in sport activities during adulthood.