KL and diabetic kidney disease: DeFronzo et al. [15] believed that metformin, as a first-line oral hypoglycemic drug, not only acts as a hypoglycemic agent but also acts as an AMPK activator, intervening in the pathological development process of the abovementioned diabetic nephropathy by activating the AMPK signaling pathway, thereby exerting a renal protective effect and delaying the diabetic nephropathy development; Klotho is an antiaging gene, and its expressed klotho protein is produced in the distal convoluted tubules of the kidney.