Published online Nov 19, 2023. doi: 10.5498/wjp.v13.i11.929
Peer-review started: August 19, 2023
First decision: September 19, 2023
Revised: October 6, 2023
Accepted: October 23, 2023
Article in press: October 23, 2023
Published online: November 19, 2023
Sarcopenia is a complex geriatric disorder marked by a gradual and progressive reduction of skeletal muscle mass, decrease in skeletal muscle strength, and deterioration in physical performance. Depression is also common among the elderly. Observational studies have suggested that depression is associated with sarcopenia.
The causal relationship between depression and sarcopenia remains unclear.
To investigate the causal relationship between depression and sarcopenia.
We performed a Mendelian randomization (MR) analysis to identify the bidirectional relationship between depression and sarcopenia-related traits. Summary-level data and independent variants were used as instrumental variables that came from large genome-wide association studies of depression (414055 cases and892299 controls), of appendicular lean mass (ALM, 450243 participants), and of hand grip strength (exposures: 360000 participants; outcomes: 334925 participants).
We identified a negative association of depression with lower ALM. In the reverse MR analysis, we also observed an inverse association of hand grip strength with depression. Similar results were obtained in the sensitivity analyses.
Depression was causally related to decreased muscle mass. Declined muscle strength might lead to a higher risk of depression.
Our findings highlighted a potential bidirectional relationship between depression and sarcopenia with implications for both mental and physical health.