The Effects of Blocking Angiotensin Receptors on Early Stages of Diabetic Nephropathy

This study aimed to investigate the beneficial effects of angiotensin receptor blockers (ARBs) on markers of endothelial function in patients with early stage of diabetic nephropathy (DN). This cross-sectional study was conducted on 32 participants with IDDM from January 2010 until May 2011 in Isfahan, Iran. The participants were candidate for receiving ARBs or angiotensin‑converting enzyme inhibitors (ACEIs) to decrease microalbuminuria. The inclusion criteria were as follows: the age of onset of insulin‑dependent diabetes mellitus (IDDM)less than 15 years; normal glomerular filtration rate (GFR); normal blood pressure; normal cardiovascular examination; negative urine culture, receiving no medications except insulin. Microalbuminuria was measured in two fasting urine samples with a sampling interval of at least 1–2 months by ELISA method. Patients with two abnormal results were included. Microalbumin to creatinin ratio equal to or more than 30 mg/gm was considered abnormal. The fasting blood samples to determine serum nitric oxide (NO) and vascular cell adhesion molecule (VCAM) were obtained at the time 0 (before starting the study), and after 2 months of receiving ARBmedication. Valsartan tablet (Diovan, Novartis Company) with a dose of 1 mg/kg/day up to 80 mg/day in a single dose was administered. Urine microalbumin to creatinin ratio after valsartan consumption was lower than microalbumin level before the medication, P < 0.05. After valsartan consumption, serum VCAM‑1 level reduced and NO level increased significantly, P < 0.05. Angiotensin receptor blockers may reduce VCAM‑1 and microalbuminuria and may increase NO levels in early stages of DN. Thus administration of ARBs might be considered even in early stages of DN.