Nephroprotective effect of vitamin E added to angiotensin receptor blocker in patients with diabetic nephropathy

Abstract

Background: Diabetes mellitus is a condition associated with increased oxidative stress as a consequence of hyperglycemia. Therefore, the use of antioxidants in people with diabetes has been advocated. Vitamin E is the most prevalent naturally occurring anti-oxidant. Aim: To evaluate the effect of the combination of angiotensin receptor blocker (ARB) and vitamin E on urine protein in patients with diabetic nephropathy. Methods: One hundred and six patients with diabetic nephropathy, who visited the Alsader medical city in Najaf governorate and Al-Furat Al-Awsat general hospital in Kufa, were investigated, 39 of them are type 1diabetics, and 67 of them are type 2 diabetics. Each patient was followed up for 3 months with valsartan (160mg/day), then for 3 months with addition of tocopherol (400mg). At the screening visits, proteinuria was determined in two 24 h urine sample, arterial blood pressure was measured twice at ten minutes rest with 2 minutes interval and serum level of potassium, sodium & creatinine were determined. Results: Proteinuria was significantly lowered when tocopherol 400mg was added to valsartan, as compared with valsartan without tocopherol. Valsartan alone caused a mean reduction of 24 h urine protein of 27% from the baseline, while the addition of tocopherol caused a mean reduction of 24 hour proteinuria of 30% from result of valsartan. That is mean the combination therapy of valsartan and tocopherol caused a reduction in proteinuria of 44% from baseline. Conclusion: The current study suggests that combination therapy of ARB and vitamin E offers an additional antiproteinuric and nephroprotective effect. Recommendation: Antioxidants, in particular vitamin E have promising nephroprotective effects. However, studies on other antioxidants like vitamin C are needed in the efforts of prevention of diabetic nephropathy