[Mediating effect of physical activity on association between sedentary leisure-time and obesity indexes among hypertensive individuals]

Abstract

Objective: To explore the mediating effect of physical activity on association between sedentary leisure-time and obesity indexes among hypertensive individuals. Methods: After excluding of those with a prior history of heart disease, stroke and cancer, a total of 20 178 hypertensive participants in the China Kadooire Biobank (CKB) study from Wuzhong district of Suzhou city were included. Mediating effect analysis was used to analyze the mediating effect of physical activity (PA) on correlation between sedentary leisure-time and body fat percentage (BFP), waist circumference (WC) and body mass index (BMI). Results: After adjusted for age, gender, smoking status, alcohol consumption, education levels, intake frequencies of meat and intake frequencies of fresh fruit, sedentary leisure-time (SLT) was negatively correlated with PA (β=-0.246, P<0.001), but positively associated with BFP (β=0.061, P<0.001), WC (β=0.087, P<0.001) and BMI (β=0.071, P<0.001). After including the mediator variable PA, the direct effect of SLT on obesity index was still significant. PA was negatively correlated with BFP, WC and BMI (β=-0.052, -0.083 and -0.028, respectively, P<0.001). Analysis of mediating effect indicated that the association of SLT with BFP, WC and BMI were partly mediated by PA, the proportion of mediating effect was 20.820%, 23.421% and 9.915%. Stratified by gender, PA had mediating effect on SLT and all obesity indexes in women, while only on SLT and BFP and WC in men. Conclusions: There is a significant mediating effect of PA on correlation between SLT and obesity indexes among hypertensive individuals. Hypertensive patients should increase the level of physical activity and reduce sedentary behavior to achieve a profounder healthy effect.