Individual and Synergistic Relationships of Low Muscle Mass and Low Muscle Function with Depressive Symptoms in Korean Older Adults

This study examined the relationship of low appendicular skeletal muscle mass and low muscle function with depressive symptoms in Korean older adults. Community-dwelling Korean older adults aged 65 years and older (n = 521) participated in this study. Appendicular muscle mass (ASM) and muscle function (MF) scores were assessed using dual-energy X-ray absorptiometry (DXA) scanning and sit-to-stand mean power based on a 30 s chair stand test, respectively. Depressive symptoms were evaluated using the Korean form of the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of depressive symptoms according to ASM- and MF-based subgroups; normal ASM/normal MF, low ASM/normal MF, normal ASM/low MF, and low ASM/low MF. The prevalence of depressive symptoms was 21.3% in all patients: 20.7% in women and 21.5% in men. Compared to the normal ASM/normal MF participants (OR = 1), the risk of depressive symptoms rose incrementally in subjects with low ASM/normal MF (OR = 2.963, p = 0.019), normal AMS/low MF (OR = 3.843, p = 0.002), and low ASM/low MF (OR = 7.907, p < 0.001), respectively. The current findings suggest that the coexistence of low ASM and low MF is significantly and independently associated with an increased risk for depressive symptoms, with dynapenia having a stronger relationship.