Associations Among Skeletal Muscle Mass, Bone Mineral Density, and Cardiometabolic Risk Factors in Young and Middle-Aged Adults

PURPOSE: Although skeletal muscle mass (SMM) is closely associated with bone mineral density (BMD) and cardiometabolic risk factors, most studies have focused primarily on older adults or individuals with specific diseases (e.g., osteoporosis and cardiometabolic disease). Identifying the relationships among SMM, BMD, and cardiometabolic risk factors at a young age could be valuable in establishing a proactive prevention strategy to reduce the incidence of chronic diseases later in life. This study aimed to explore the relationships between these factors in young and middle-aged adults.METHODS: A total of 117 participants were included in the final analysis, after excluding 26 who did not meet the inclusion criteria. The study sample comprised 25 young men, 22 middle-aged men, 36 young women, and 34 middle-aged women. SMM was assessed using lean mass and relative skeletal muscle mass index (RSMI). BMD indices were measured for the lumbar spine, femoral neck, total hip, and whole body. Additionally, arterial stiffness was evaluated using brachial-ankle pulse wave velocity (baPWV). Blood samples were collected to measure high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, triglycerides, fasting glucose, and glycated hemoglobin levels.RESULTS: Analysis according to sex and age revealed a positive correlation between SMM and BMD indices in both men and women. Additionally, SMM was positively correlated with HDL-C levels across sexes. In young men, SMM (lean mass and lean arm mass) was negatively correlated with baPWV. Furthermore, HDL-C levels positively correlated with BMD in both men and women. Moreover, the RSMI had an indirect effect on the association between BMD indices and HDL-C levels.CONCLUSIONS: The findings of this study suggest that maintaining or increasing SMM before aging may positively influence BMD, lipid profiles, and arterial stiffness.