Glucagon-like peptide-1 receptor agonists, inflammation, and kidney diseases: evidence from Mendelian randomization

It has been proved that glucagon-like peptide-1 receptor (GLP1R) agonists have positive effects on renal outcomes in diabetic patients. However, it remains unknown whether GLP1R agonists could provide similar protection against other kidney diseases. We performed two-sample Mendelian randomization (MR) analyses to determine the causal effects of GLP1R agonists on multiple kidney diseases. Exposure to GLP1R agonist was proxied by the available cis-eQTLs for GLP1R. Primary outcomes included the risk assessment for diabetic nephropathy, IgA nephropathy, membranous nephropathy, nephrotic syndrome, chronic kidney disease, acute glomerulonephritis, chronic glomerulonephritis and calculus of kidney/ureter. Type 2 diabetes and body mass index were used as positive control. Two-stage network MR analyses were conducted to assess the mediation effect of inflammatory proteins on the relationships between GLP1R agonists and kidney diseases. After meta-analyses of both discovery and validation cohorts, genetically proxied GLP1R agonist was found to significantly associated with a decreased risk of diabetic nephropathy (OR = 0.72, 95%CI = 0.54-0.97, p = 0.031) and IgA nephropathy (OR = 0.58, 95%CI = 0.36-0.94, p = 0.027). Two-stage network MR revealed that there was an indirect effect of GLP1R agonist on IgA nephropathy through signaling lymphocytic activation molecule family member 1 (SLAMF1), with a mediated proportion of 34.27% (95% CI, 1.47-67.03%, p = 0.041) of the total effect. The findings of current study presented genetic proof for the potential protective effects of GLP1R agonists in the development of diabetic nephropathy and IgA nephropathy, offering a novel sight for future mechanistic and clinical applications.