Relationship between muscle mass index and LDL cholesterol target levels: Analysis of two studies of the Korean population

Background and aims: Decreased skeletal muscle mass is an important change in body composition with aging. Maintaining the optimal low-density lipoprotein (LDL) cholesterol level is crucial for the prevention of cardiovascular diseases (CVD). We investigated whether muscle mass was associated with dyslipidemia. Methods: We analyzed the data of 17,546 adults from the 2008–2011 Korean National Health and Nutrition Examination Survey (KNHANES) and 5126 adults from the Korean Genome and Epidemiology Study (KoGES). Participants were classified into the lower skeletal muscle mass index (LSMI) group and normal group. LSMI was defined as body mass index (BMI)-adjusted appendicular skeletal muscle mass <0.789 (men) and <0.512 (women) in the KNHANES, and as sex-specific lowest quintile of the BMI-adjusted total skeletal muscle mass in the KoGES. Participants were defined as having dyslipidemia when the serum LDL cholesterol levels were higher than their LDL cholesterol management targets based on their CVD risk level. Results: The odds ratio with 95% confidence interval (CI) for dyslipidemia of the LSMI group was 1.230 (1.016–1.488, p = 0.034) after adjusting for confounding variables compared to the normal group in the 2008–2011 KNHANES. In the KoGES, the hazard ratio with 95% CI for incident dyslipidemia of the LSMI group compared to the normal group was 1.225 (1.101–1.364, p < 0.001). Regardless of abdominal obesity, LSMI was significantly associated with a higher risk of incident dyslipidemia. Conclusions: LSMI was associated with dyslipidemia regardless of abdominal obesity. Prevention of muscle mass loss may be an important strategy for LDL cholesterol management.