Endothelin-1 levels and albuminuria in patients with type 2 diabetes mellitus

Aim: To evaluate the relationship of plasma endothelin-1 (ET-1) levels, a marker of endothelial dysfunction, and urinary albumin excretion in patients with type 2 diabetes mellitus (DM). Methods: Cross-sectional study was conducted in 279 patients (132 males, mean age: 58.7 +/- 11.0 years, mean DM duration: 11.3 +/- 8.1 years). Urinary albumin excretion, ET-1, and insulin were measured. Insulin sensitivity was estimated by homeostasis model assessment (HOMA-ir) index. Results: ET-1 was associated with urinary albumin excretion after controlling for age, gender, body mass index, blood pressure, HbA1c test, and total cholesterol (R = 0.436; adjusted R-2 = 0.190, P < 0.01). Furthermore, there was a progressive increase in plasma ET-1 levels from patients with normoalbuminuria (n = 187, 0.92 +/- 0.50 pg/ml), microalbuminuria (n = 68,1.13 +/- 0.52 pg/ml) to macroalbuminuria (n = 24,1.93 +/- 1.10 pg/ml, P < 0.01). Conclusion: There is an independent association of plasma ET-1 levels with urinary albumin excretion. in addition, plasma ET-1 levels started to increase in the normal values of urinary albumin excretion suggesting that in patients with type 2 DM endothelial dysfunction is already present, in urinary albumin excretion values considered normal. (C) 2008 Elsevier Ireland Ltd. All rights reserved.