Dose-response association between physical activity and blood pressure among Chinese adults: a nationwide cross-sectional study.

Objectives: The aim of this study was to examine the dose-response associations of physical activity with blood pressure (BP) and hypertension risk among Chinese adults.

Methods: Derived from the national community-based China Hypertension Survey database during 2012--2015, a total of 203 108 residents aged at least 18 years were included. Individual-level physical activity was evaluated using a standardized questionnaire, and minutes of metabolic equivalent tasks per week (MET-min/week) were calculated, integrating domain, intensity, frequency, and duration. Multivariable linear and logistic regressions were used to estimate associations of physical activity with BP and hypertension risk, and restricted cubic spline regressions were performed for their nonlinear dose-response relationships.

Results: Overall, the median total physical activity (TPA) was 3213.0 MET-min/week and the prevalence of physical inactivity was 14.8%. TPA was negatively associated with BP. Increasing TPA levels was related to a steep decrease in systolic BP, up to approximately 2500 MET-min/week, with more modest benefits above that level of TPA. Higher levels of domain-specific and intensity-specific physical activity were found to be associated with lower BP levels and hypertension risk, except for the association between vigorous-intensity physical activity and systolic BP. We found that TPA within the range of 2000--4000 MET-min/week, a higher frequency and shorter duration were inversely associated with diastolic BP levels.

Conclusion: Total, domain-specific, and intensity-specific physical activity were inversely related to BP levels, respectively, in a dose-response fashion. Of a given amount, higher-frequency, shorter-duration, and lower-intensity physical activity produced more beneficial effects.