Depression and sarcopenia: a Mendelian randomization analysis

Area of Science:

• Genetics
• Epidemiology
• Gerontology

Background:

• Observational studies suggest a link between depression and sarcopenia.
• The causal relationship between major depressive disorder (MDD) and sarcopenia remains unclear.

Purpose of the Study:

• To investigate the potential causal effect of MDD on sarcopenia.
• To examine the potential causal effect of sarcopenia on MDD.
• Utilizing a bidirectional Mendelian randomization approach.

Main Methods:

• Employed two-sample Mendelian randomization (MR) using genetic instruments from public summary data.
• Utilized appendicular lean mass (ALM) and low hand grip strength (LHGS) for sarcopenia assessment.
• Applied inverse-variance weighted, weighted median, and MR-Egger methods for robust analysis.

Main Results:

• No significant causal effect of MDD on sarcopenia was detected (MDD on ALM: P=0.449; MDD on LHGS: P=0.506).
• No significant causal effect of sarcopenia on MDD was observed (Sarcopenia on MDD: ALM P=0.374; LHGS P=0.556).

Conclusions:

• Findings suggest no mutual causal relationship between major depressive disorder and sarcopenia.
• The study indicates that MDD and sarcopenia likely operate through independent biological pathways.