Effect of renin–angiotensin–aldosterone system (RAAS) blockade on visfatin levels in diabetic nephropathy

Abstract

Plasma visfatin levels are elevated in diabetic nephropathy in parallel to the severity of proteinuria and glomerular filtration rate. The aim of this study was to find out whether the renin-angiotensin-aldosterone system (RAAS) blockage has any effect on the plasma visfatin levels. Thirty-two patients with diabetic proteinuria (>500 mg/day) with a normal glomerular filtration rate (GFR) and 33 healthy subjects were enrolled. Patients were treated with ramipril 5 mg daily for 2 months. Proteinuria, GFR, high-sensitivity C-reactive protein (hsCRP), visfatin, flow-mediated dilatation (FMD) and homeostasis model assessment of insulin resistance (HOMA-IR) index measurements were performed both before and after the treatment. The plasma visfatin, and hsCRP levels of the patients were significantly higher and the FMD was significantly lower (P < 0.001 for all). The visfatin levels were significantly correlated to FMD, systolic and diastolic blood pressures, proteinuria, eGFR, HOMA-IR and hsCRP. Ramipril treatment resulted in a significant decrease in plasma visfatin, proteinuria, hsCRP, HOMA-IR and increase in FMD (P < 0.001) in patients (P < 0.001 for all). The present study suggests that plasma visfatin levels are related to the endothelial functions, inflammation and the severity of proteinuria in diabetic nephropathy. Treatment with ramipril causes a significant decrease in visfatin levels along with the improvement of proteinuria, endothelial dysfunction and inflammatory state in diabetic nephropathy.