Aims: Low muscle mass is associated with advanced atherosclerosis. However, only very few studies on the elderly have investigated a dose-response relationship between muscle mass and atherosclerosis. Furthermore, whether the relationship between muscle mass and atherosclerosis is stronger than that between body mass index (BMI) and atherosclerosis among the elderly population remains to be determined.
Methods: A community-based sample of apparently healthy elderlies (≥ 65 years) was cross-sectionally examined for the association between appendicular skeletal muscle mass (ASM) and brachial-ankle pulse wave velocity (baPWV), a measure of atherosclerosis. We categorized the participants according to sex-specific quintiles of the ASM index (ASM/height2) or BMI. Using multivariable linear regression, we compared the slope of one standard deviation higher ASM index for baPWV with the corresponding slope of BMI, separately (single-index model) and jointly (simltaneously-adjusted model).
Results: The ASM index and BMI of a total of 995 participants (60.0% women, mean age 73 years) were significantly inversely associated with baPWV in a dose-response manner across the quintiles in both sexes. The slope for the ASM index tended to be greater than that for BMI in the single-index and simultaneously-adjusted models in both sexes after adjusting for confounders.
Conclusions: Among a community-dwelling elderly population, the association between ASM and baPWV was stronger than, and independent of that between BMI and baPWV. These findings suggest that ASM provides more important information on atherosclerosis in the elderly than BMI does.
Keywords: Appendicular muscle mass; Atherosclerosis; Body mass index; Brachial-ankle pulse wave velocity; Elderly.