Effect of endothelial nitric oxide synthase enzyme Glu 298 Asp gene polymorphism on progression of kidney disease in patients with diabetic nephropathy

Background: Interactions between hereditary and environmental variables cause diabetic nephropathy (DN) which is a complex illness. Consideration has been given to the eNOS gene as a possible susceptibility gene for DN. Objective: We aimed to determine how the eNOS Glu298Asp gene polymorphism (894G > T) contributes to DN progression. Methods: This cross-sectional study involved 100 patients with type 2 diabetes (T2DM) and having DN diagnosed with albuminuria (urinary albumin/creatinine ratio (ACR) > 30 mg/g), recruited from Tanta University hospitals inward and outpatient clinics. Both groups were divided based on the participants' estimated glomerular filtration rates (eGFR): 50 type 2 DN patients with an eGFR greater than 30 ml/min/1.73 m2 were included in group I, while 50 type 2 DN patients with an eGFR less than 30 ml/min/1.73 m2 were included in group II. A comprehensive history and physical examination were conducted on each patient. Their body mass index was measured, their lipid profiles were reviewed, their blood urea and serum creatinine levels were measured, and the patients' eGFR was calculated using the CKD-EPI equation. The patients were also genotyped for the eNOS 894G > T gene polymorphism using the PCR-RFLP technique. Results: TT genotype and T allele were found to be higher in DN group with eGFR 30 ml/min/1.73 m2 (p = 0.128, 0.120 respectively), and it could predict the risk for DN progression particularly in recessive model (aOR: 0.019, 95% C.I: 1.271-13.749). Conclusion: Because of its predictive power for DN advancement, eNOS 894G>T deserves further research as a major genetic marker for eGFR reduction and DN progression in type 2 Egyptian diabetic patients.