Nitric Oxide Bioavailability and Its Potential Relevance to the Variation in Susceptibility to the Renal and Vascular Complications in Patients With Type 2 Diabetes

Abstract

OBJECTIVE—We compared the renal and systemic vascular (renovascular) response to a reduction of bioavailable nitric oxide (NO) in type 2 diabetic patients without nephropathy and of African and Caucasian heritage.RESEARCH DESIGN AND METHODS—Under euglycemic conditions, renal blood flow was determined by a constant infusion of paraminohippurate and changes in blood pressure and renal vascular resistance estimated before and after an infusion of l-Ng-monomethyl-l-arginine.RESULTS—In the African-heritage group, there was a significant fall in renal blood flow (Δ−46.0 ml/min per 1.73 m2; P < 0.05) and rise in systolic blood pressure (Δ10.0 mmHg [95% CI 2.3–17.9]; P = 0.017), which correlated with an increase in renal vascular resistance (r2 = 0.77; P = 0.004).CONCLUSIONS—The renal vasoconstrictive response associated with NO synthase inhibition in this study may be of relevance to the observed vulnerability to renal injury in patients of African heritage.