Association between serum fibroblast growth factor 21 and diabetic nephropathy

Fibroblast growth factor 21 (FGF-21) is a new metabolic regulator with beneficial effects on lipid and glucose metabolism in animal models of diabetes mellitus. The aim of this study was to explore the relationship between FGF-21 and diabetic nephropathy in humans. Serum FGF-21 levels were determined in groups of control (n = 50) and type 2 diabetes mellitus (T2DM) patients with normoalbuminuria (n = 158), microalbuminuria (n = 68), and macroalbuminuria (n = 38) using enzyme-linked immunosorbent assay. Multiple linear regression models were used to analyze the associations between FGF-21 or other biomedical indices and urinary albumin excretion (UAE). Median serum FGF-21 levels were increased in T2DM patients compared with nondiabetic controls and were significantly higher in patients of higher UAE group. In groups of control and T2DM patients with normoalbuminuria, microalbuminuria, and macroalbuminuria, median serum (interquartile range) FGF-21 levels were 467.89 (294.59-519.56), 492.30 (354.59-640.42), 595.01 (480.49-792.31), and 665.20 (448.68-829.75) ng/L (P < .001), respectively. After adjustment for the confounders, FGF-21, fasting plasma glucose, and high-density lipoprotein cholesterol levels were found to be independently associated with UAE in diabetic patients. Serum FGF-21 level is independently correlated with UAE in T2DM patients, indicating that circulating FGF-21 may be involved in diabetic nephropathy.