Mediation of Grip Strength on the Association Between Self-Rated Health and Estimated Cardiovascular Disease Risk

Abstract

Background: Grip strength and self-rated health (SRH) have been reciprocally related, and each has been associated with cardiovascular disease (CVD) risk. However, the pathway between SRH and grip strength in the association with CVD risk remains uncertain. This cross-sectional study evaluated whether grip strength mediates the association between SRH and estimated CVD risk. Methods: In 15,930 Koreans 40-79 years of age without CVD history from the 2014 to 2018 Korea National Health and Nutrition Examination Survey, the risk of 10-year atherosclerotic cardiovascular disease (ASCVD) was calculated using Pooled Cohort Equations. Relative grip strength (RGS) was defined as measured grip strength divided by body mass index. SRH was assessed using a single questionnaire. Results: After adjusting for the covariates, males in the non-highest RGS tertiles, the fair/poor/very poor SRH groups, or the other joined categories of RGS tertiles and SRH groups (except the highest RGS tertile and good SRH group) had higher odds for 10-year ASCVD risk ≥7.5% than the reference group. The ASCVD risk was higher in females in the lowest RGS tertile, the poor/very poor SRH group, or the combined category of lowest RGS tertile and poor SRH group than the reference group. RGS significantly mediated the relationship between better SRH and the lower ASCVD risk (indirect effect: β = -0.078, 95% CI [-0.097 to -0.060], P < 0.05) and reduced the total effect of SRH on the ASCVD risk (direct effect: β = -0.225, t = -3.203, P = 0.001). RGS mediated 26% of the association between SRH and ASCVD risk. Conclusion: Grip strength may have a mediating role in the relationship between SRH and the estimated 10-year risk of ASCVD.