Value of Plasma Level of Endothelin-1 and Nitric Oxide in Diabetic Nephropathy

Endothelial dysfunction is the central pathophysiologic denominator for all microvascular complications of diabetes, including nephropathy. Abnormalities of endothelin-1 and nitric oxide (NO) modulate renal structure and function in diabetes. We study the role of endothelin-1 and NO in the diabetic kidney. This study includes a total of 60 type-2 diabetic patients and 20 healthy subjects as a control group (group 1). Diabetics were classified into three groups. Group 2 included 20 patients without microalbuminuria, group 3 included 20 patients with microalbuminuria, and group 4 included 20 patients with macroalbuminuria. All individuals were subjected to history taking, physical examination, urine analysis, HbA1C test, kidney function tests, abdominal ultrasonography, and evaluation of urinary albumin concentration, nitric oxide levels, and plasma endothelin-1 (ET-1) levels. Our results showed an elevated plasma level of endothelin-1 of 4.09 ± 0.32, 5.04 ± 0.20, and 5.74 ± 0.11 pg/ml for group 2, 3, and 4, respectively, an elevated plasma level of nitric oxide in type-2 diabetic patients with early stages of diabetic nephropathy, and a decreased level in late stages of diabetic nephropathy of 40.08 ± 1.66, 46.11 ± 1.75, and 31.17 ± 2.16 μmol/l for group 2, 3, and 4, respectively. There was a statistically significant difference between all groups and the control group regarding NO and ET-1 (p < 0.001 and p < 0.001, respectively). The enhanced NO production may contribute to hyperfiltration in early diabetic nephropathy. ET-1 may have a role in microvascular damage in diabetics. Targeting the ET-1 system might be potentially beneficial in preventing and/or treating kidney disease in diabetics.