The relationship between lifestyles and sarcopenia-related traits: A two-sample Mendelian randomization study.

Objective: To investigate the causal association between lifestyles (smoking, drinking consumption and physical activity) and sarcopenia-related traits by Mendelian randomized analysis.

Methods: Instrumental variables from the genome-wide association study were used for analysis. The exposure factors were lifestyle factors, including smoking, alcohol consumption, moderate physical activity and vigorous physical activity, and the outcome variables were low hand grip strength and appendicular lean mass. The inverse variance weighted (IVW) method and other MR methods were used for analysis. Heterogeneity test, sensitivity analysis and pleiotropy analysis were performed.

Results: According to a primary causal effects model with MR analyses by the IVW method, smoking was a decreased risk of low hand grip strength (odds ratio (OR) = 0.899, 95% confidence interval (CI) = 0.829-0.974, P = 0.010), while alcohol consumption was a significant correlation with low hand grip strength (OR = 1.137, 95% CI = 1.020-1.267, P = 0.020). There was no significant relationship between smoking, alcohol, and appendicular lean mass. In addition, moderate or vigorous physical showed no significant correlation with low hand grip strength and appendicular lean mass.

Conclusion: This study demonstrated that smoking may be causally related to a lower risk of low hand grip strength, while alcohol may increase the risk of low hand grip strength. There was no causal relationship between physical activity and sarcopenia-related traits.