Association between low muscle mass and depression in South Korean adults

Although the association between sarcopenia and depression is well-established, studies exploring the link between low muscle mass and depression in the general population are limited. This study aimed to investigate whether participants’ muscle mass proportion was associated with the prevalence of depression. Additionally, we examined whether individuals with lower muscle mass exhibited greater symptom burden, using both categorical and continuous analytic approaches. Data from the 2022 Korea National Health and Nutrition Examination Survey were used for this study. Altogether, 4185 participants who completed the Patient Health Questionnaire-9 were included. Muscle mass was measured using the bioelectrical impedance analysis method, and the participants were divided into low, medium, and high groups based on the proportion of appendicular muscle mass relative to body weight. The association between low muscle mass and depression was analyzed using multiple logistic regression. Men in the low muscle mass group exhibited 1.99 times higher odds of depression, (odds ratio = 1.99, 95% confidence interval = 1.03–3.85) and 1.61 times higher in women (OR = 1.61, 95% CI = [1.00-2.58]) using the medium muscle mass proportion group as a reference. Furthermore, in continuous analyses, higher muscle mass proportion was inversely associated with PHQ-9 scores in both men and women, suggesting a negative relationship between muscle mass proportion and depressive symptom burden. This study identified an association between reduced muscle mass and depression. Future prospective studies should explore whether this relationship is causal and determine whether interventions to increase muscle mass can help reduce the prevalence of depression. Such investigations could offer valuable insights into population-level strategies for mitigating depression.