Association of interleukin-6 -174 G>C promoter polymorphism with increased risk of type 2 diabetes mellitus patients with diabetic nephropathy in Turkey.

Objective: Diabetic nephropathy (DN) is a serious complication of diabetes mellitus. We aimed to evaluate the interleukin (IL)-6 gene polymorphisms in type 2 DN and control subjects.

Materials And Methods: The patients selected from the Department of Endocrinology and Metabolism Diseases included 43 type 2 diabetes mellitus patients without DN and 43 type 2 diabetes mellitus patients with DN and 340 healthy normal controls. All subjects underwent venous blood drawing for complete hormonal assays, lipid profile, glucose, and insulin and Il-6 gene polymorphism genetic analysis.

Results: IL-6 -174 G>C genotype distribution was different between the control group and the type 2 diabetes mellitus patients (p=0.004). The higher frequency of the polymorphic G allele was also similar for the group with type 2 diabetes mellitus as for the control group. The frequency of the polymorphic G allele was 83.9% in diabetic patients with nephropathy versus 70.9% in those without nephropathy (p=0.039).

Conclusion: We suggest that the -174 G>C polymorphism of the IL-6 gene is an independent risk factor for DN in Turkish type 2 diabetes mellitus patients.