Serum galectin-1 at baseline predicts incident T2D at follow-up 18 years later. Galectin-1 is strongly associated with lower eGFR. MR analyses showed no causal effect of galectin-1 on CKD or T2D, but T2D patients from ANDIS belonging to SIRD subgroup showed genetically elevated galectin-1 in association with higher eGFR. This evidence concerns the gene LGALS1 and type 2 diabetes mellitus.