Elevated expression levels of serum insulin-like growth factor-1, tumor necrosis factor-α and vascular endothelial growth factor 165 might exacerbate type 2 diabetic nephropathy.

AIMS/INTRODUCTION: The present study aimed to determine the associations between expressions of insulin-like growth factor-1 (IGF-1), tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor 165 (VEGF165 ) in serum, and occurrence and development of type 2 diabetic nephropathy (DN).

MATERIALS AND METHODS: A total of 108 patients diagnosed as DN were randomly selected, including 50 patients in the microalbuminuria group, 44 patients in the macroalbuminuria group and 14 patients in the renal insufficiency group. Meanwhile, 97 healthy people were collected as a normal control group. Urinary albumin (UALB) and urine creatinine (Cr) of all participants were measured for 24 h, with their ratio (UALB/Cr) being calculated. Enzyme-linked immunosorbent assay was used to detect the serum concentrations of IGF-1, TNF-α and VEGF165 .

RESULTS: The expressions of serum IGF-1, TNF-α and VEGF165 in the type 2 DN patients were significantly higher than those in the control group (all P < 0.05). The expressions of serum IGF-1, TNF-α and VEGF165 in the type 2 DN patients were positively correlated with UALB/Cr (all P < 0.05). As type 2 DN worsened, the expressions of serum IGF-1, TNF-α and VEGF165 increased, and type 2 DN severity had positive correlations with serum IGF-1, TNF-α and VEGF165 concentrations (all P < 0.05). There was a positive association between IGF-1 and TNF-α, IGF-1 and VEGF165 , and TNF-α and VEGF165 (all P < 0.05). Logistic regression analysis showed that IGF-1 and VEGF165 were associated with the progression of DN (both P < 0.05).

CONCLUSIONS: Elevated expression levels of serum IGF-1, TNF-α and VEGF165 might exacerbate type 2 DN.