The causal relationships between limb fat distribution and mental disorders: A Mendelian randomization study

This study employs a two-sample Mendelian randomization (MR) analysis to investigate the causal relationship between limb fat distribution and 4 major mental disorders. This study utilized summary data from genome-wide association studies (GWAS) on limb fat mass and major mental disorders in a European population. Two-sample MR analysis was used to assess the causal relationship between limb fat mass and major mental disorders. Inverse variance weighting estimates were reported as primary results. Additional sensitivity analyses included the MR-Egger, weighted median, simple mode, and weighted mode methods to confirm the robustness of the findings. There is considerable evidence supporting a causal relationship between attention-deficit deficit hyperactivity disorder (ADHD) and limb fat mass. The study indicated a significant negative correlation between right arm fat mass and left leg fat mass (P < .05) and ADHD, and a significant positive correlation between left arm fat mass and right leg fat mass (P < .05) and ADHD. Furthermore, a similar causal relationship was found between body fat mass and major depressive disorder (MDD) (P < .05). However, no significant causal relationship was found in schizophrenia and bipolar disorder. The results indicated that right arm fat mass and left leg fat mass were negatively correlated with ADHD and MDD, whereas left arm fat mass and right leg fat mass were positively correlated with ADHD and MDD.