Assessment of the causal relationship between depression and traits of sarcopenia: A bidirectional two-sample Mendelian randomization study

Abstract Background : Growing evidence reveals a significant association between depression and sarcopenia. However, the causal association between them remains elusive. We aimed to investigate the bidirectional relationship between depression and traits of sarcopenia. Methods : We used genetic variants associated with depression (n=2,113,907), grip strength (n=256,523), appendicular lean mass (n=450,243), and walking pace (n=459,915) in bidirectional two-sample Mendelian randomization. The random-effects inverse-variance weighted method was adopted as the primary method. Results : Mendelian randomization results revealed a causal relationship between depression and appendicular lean mass [β (95% confidence interval (CI)) = -0.051 (-0.086−(-0.016)), P=0.004], walking pace [OR (95% CI) = 0.973 (0.955−0.992), P=0.005]. Walking pace also revealed a causal relationship with depression [OR (95% CI) = 0.663 (0.507−0.864), P=0.002] in the reverse analysis. We observed no causal relationships between depression and grip strength. The leave-one-out sensitivity analysis verified our results. Conclusions : This Mendelian randomization analysis verified the bidirectional relationship between depression and sarcopenia. Early diagnosis and prevention of either disease may enhance the management of another.