Causal relationship between IgA nephropathy and common neuropsychiatric disorders: A two-sample Mendelian...

Utilizing two-sample Mendelian randomization (TSMR), this study seeks to determine the causal relationship between IgA nephropathy and five prevalent neuropsychiatric disorders. By exploring the genetic associations between IgA nephropathy and neuropsychiatric disorders, this research aims to contribute to the prevention of neuropsychiatric disorders in patients with IgA nephropathy.

Public genome-wide association study databases were searched, with IgA nephropathy as the exposure factor, including 15,587 patients with IgA nephropathy and 462,197 healthy controls. The outcome factors were five common neuropsychiatric disorders (bipolar disorder, depressive disorder, schizophrenia, anorexia nervosa, and Alzheimer's disease), with outcome data drawn from five datasets in the PGC and GWAScatalog databases. Inverse-variance weighting served as the primary method for causal effect estimation, supplemented by MR-Egger, weighted median, weighted mode, and simple mode methods. Heterogeneity was tested using Cochran's Q test, and sensitivity analysis was conducted using MR-Egger and MR-presso.

MR analysis indicated a positive causal relationship between IgA nephropathy and depressive disorder (OR = 1.010, 95%CI: 1.003-1.017, P = 3.27 × 10^-3), and a potential positive causal relationship between IgA nephropathy and anorexia nervosa (OR = 1.165, 95%CI: 1.030-1.319, P = 0.015).

There is a positive causal relationship between IgA nephropathy and depressive disorder, and a potential positive causal relationship with anorexia nervosa. No causal relationship was found with schizophrenia, bipolar disorder, or Alzheimer's disease.