Relationship Between Relative Grip Strength and Serum Total Cholesterol, High-Density Lipoprotein Cholesterol, Low-Density Lipoprotein Cholesterol, and Triglyceride Levels in Korean Middle-Aged or Older Adults: A Panel Regression Model

Background: This study aimed to conduct panel data analysis to investigate the effects of relative grip strength on blood lipid levels according to sex and obesity levels in adults living in South Korea Methods: A total of 1015 middle-aged or older adults (40-94 years old), who participated in a chronic screening program conducted in Yangpyeong, Gyeonggi-do from 2007 to 2015, were included in this study. Grip strength was measured using a TKK-5401 dynamometer (Takei, Japan), and relative grip strength was calculated by dividing the absolute grip strength by body mass index (BMI, kg/m(2)). Blood lipids analyzed in this study included serum triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Random effect panel regression analysis was conducted to evaluate beta values and 95% confidence intervals to investigate the independent effects of relative grip strength on blood lipid levels. Results: After adjusting for confounding variables, higher relative grip strength was associated with lower TG (beta = -34.68, P < 0.001), TC (beta = -8.47, P = 0.014), and LDL-C (beta = -8.19, P = 0.012), and higher HDL-C (beta = 6.70, P < 0.001). After additionally adjusting for BMI to evaluate the relationship between relative grip strength and blood lipid levels by obesity index, relative grip strength was only significantly associated with HDL-C (beta = 5.03, P < 0.001). However, after adjusting for waist circumference, relative grip strength was significantly correlated with all blood lipid levels (TG: beta = -33.31, P < 0.001; TC: beta = -8.04, P = 0.021; LDL-C: beta = -7.96, P = 0.015; and HDL-C: beta = 6.73, P < 0.001). Differences in changes of blood lipid levels according to an increase in relative grip strength were observed about sex and obesity level. Conclusions: We observed that relative grip strength and blood lipid levels were associated, and increased muscular strength from regular resistance exercise could help to improve blood lipid levels in middle-aged or older adults.