Joint effect of physical activity and blood lipid levels on all-cause and cardiovascular disease mortality: The Rural Chinese Cohort Study

We aimed to evaluate the joint effect of physical activity (PA) and blood lipid levels on all-cause and cardiovascular disease (CVD) mortality.We analyzed 17,236 participants from the Rural Chinese Cohort Study. Cox's proportional-hazards regression models were used to assess the hazard ratios (HRs) and 95% confidence intervals (CIs) between the joint effect of PA and blood lipid levels and risk of all-cause and CVD mortality. Restricted cubic splines were used to estimate the dose-response relationship of PA with risk of all-cause and CVD mortality. During a median follow-up of 6.01 years there were 1106 deaths (484 from CVD) among participants. For all-cause mortality, compared with the group with dyslipidemia and extremely light PA (ELPA), the HRs with dyslipidemia and light PA (LPA), moderate PA (MPA), and heavy PA (HPA) were 0.56 (95% CI 0.45-0.70), 0.59 (0.46-0.75), and 0.59 (0.45-0.78), respectively, while the HRs of groups with normal lipid levels and ELPA, LPA, MPA, and HPA were 0.88 (0.72-1.04), 0.59 (0.48-0.73), 0.53 (0.41-0.67), and 0.38 (0.29-0.50), respectively. We observed similar effects on CVD mortality. Restricted cubic splines showed a curvilinear relationship between PA and risk of all-cause and CVD mortality with normal lipid levels and with dyslipidemia.Higher PA reduces the risk of all-cause and CVD mortality. Higher levels of PA are needed in the population.