Inflammatory bowel disease and diabetic nephropathy risk: a two-sample Mendelian randomization analysis

Background: Previous studies have reported the link between inflammatory bowel disease (IBD) including Crohn’s disease (CD) and ulcerative colitis (UC) and Diabetic nephropathy (DN). However, due to the inherent limitations of retrospective studies, the association between the two forms is still unclear. The purpose of this study was to evaluate the etiology of IBD on DN using the Mendelian Randomization (MR) analysis. Methods: : We downloaded summary statistics of IBD, UC, CD and DN from the Open Genome-Wide Association Study (GWAS) with a bidirectional Mendelian randomization (MR). Five different MR methods were performed to prove causality. Inverse variance weighted (IVW) method is the main method, supplemented by MR-Egger regression, weighted median, weighted model, simple model. Results: : Genetically determined IBD (OR=1.016, 95% CI=0.944-1.094, P=0.668), UC (OR = 0.955, 95% CI 0.860-1.060, P = 0.393) and CD (OR = 1.039, 95% CI 0.967-1.117, P = 0.299) all showed that there was no causal relationship on DN. The result of supplementary method was consistent with that of IVW method. Conclusions: : There have been many reports of kidney disease in patients with IBD, particularly DN. However, our study did not observe a strong genetic association between IBD and DN. This work supplemented the results of previous retrospective studies.