Association between Sarcopenia and the Risk of Depression: the mediating effects of Obesity

Abstract Background The increased incidence of depression in people with sarcopenia may further increase the disease burden in middle-aged and older adults. We aimed to explore whether obesity factors mediate the associations of sarcopenia with the risk of depression.Methods We included 5341 participants aged ≥ 45 years old in 2011–2012 and followed up until 2018. Sarcopenia consists of three factors as proxies, including muscle strength, appendicular skeletal muscle mass (ASM), and physical performance. The degree of obesity was reflected by BMI and WC. Cox proportional hazards regression models were used to examine the associations between sarcopenia, obesity and the risk of depression. The mediation effects of obesity indicators on the association between sarcopenia and depression were analyzed.Results Compared with no-sarcopenic group, the sarcopenic group had a higher risk of depression (HR, 1.238; 95%CI, 1.091–1.403). Only the interaction between gender and sarcopenia on depression was found in all subgroups. The results showed a significant association between sarcopenia and the risk of depression in the male population (HR, 1.224; 95%CI, 1.007–1.488). The association between sarcopenia and depression was partially mediated by BMI (mediated proportion = 31.81%) and WC (proportional mediation = 20.28%) in the Chinese middle-aged and elderly male population.Conclusion The Chinese middle-aged and elderly male population with sarcopenia had a higher risk of depression, and obesity partially mediated this association. Therefore, we suggested that appropriate weight gain in middle-aged and elderly male population might serve as an intervention to reduce future incidence of depression.