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.