Genetic Association Between Attention-Deficit/Hyperactivity Disorder and Sarcopenia: A Bidirectional Two-Sample, Two-Step Mendelian Randomized Study.

Abstract

Objective: Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders in children and adolescents, often accompanied by motor function disorders. Sarcopenia not only has skeletal muscle dysfunction but also has neurocognitive dysfunction. At present, there is no research to explore the relationship between ADHD and skeletal muscle function. The purpose of this study is to explore whether there is a causal effect between ADHD and sarcopenia.

Methods: In this study, genome-wide association study data of ADHD, appendicular lean mass (ALM), hand grip strength, and walking pace (WP) were extracted from public databases. The bidirectional two-sample Mendelian randomization (MR) method was employed to investigate the correlation between ADHD and sarcopenia-related indicators, and the inverse-variance weighted analysis as the primary analysis method.

Results: Based on the forward MR analysis, a potential causal relationship exists between ADHD and ALM (odds ratio [OR]=1.020, 95% confidence interval [CI]: 1.012-1.029, p<0.001). The reverse MR analysis indicates a link between WP and the risk of ADHD (OR=2.712, 95% CI: 1.609-4.571, p<0.001), with an accelerated WP increasing the likelihood of ADHD. Nevertheless, other MR analysis results did not show significant differences.

Conclusion: The findings of this study indicate an intricate causal relationship between ADHD and sarcopenia, suggesting the absence of a clear link. WP may be used as one of the indicators to evaluate the risk of ADHD. At the same time, we should pay more attention to the ALM of ADHD patients.