INTRARENAL RESISTANCE INDEXES ARE INDEPENDENTLY ASSOCIATED WITH GLYCATED HEMOGLOBIN LEVELS IN NON-DIABETIC ESSENTIAL HYPERTENSIVE PATIENTS WITH NORMAL RENAL FUNCTION

Abstract

Objective: Intrarenal resistance indexes (IRI) are markers of an early renal microvascular damage. The identification of factors that can influence the IRI could be useful in the prevention of renal damage in essential hypertensive (EH) patients. The aim of the study was to evaluate whether mild changes of glucose metabolism are associated with increased IRI in non-diabetic EH patients. Design and method: In 271 EH patients (age 50 ± 13 years, 141 males, 102 never treated) with normal renal function we measured the glomerular filtration rate, plasma lipids levels, fasting plasma glucose (PG), insulin (I), and glycated hemoglobin (GH), the HOMA-index, the area under the curve of PG (GAUC) and I (IAUC) after an oral glucose tolerance test (OGTT), the PG level at 120 minutes of OGTT (G120), and we measured IRI by Doppler ultrasound of intrarenal vessels. Results: Patients were divided according to quartiles of IRI. PG, GAUC, G120 and GH increased progressively with increasing levels of IRI. No differences were found in I levels and HOMA across IRI quartiles. IRI was significantly and directly correlated with age, diastolic blood pressure, PG, I, HOMA, GAUC, G120, and GH. At logistic regression analysis, the highest IRI quartile (average value: 0.68 ± 0.04) was independently associated with HG>5.9% (OR = 4.09, P = 0.027) and G129 (OR = 1.01, P = 0.009). Conclusions: In non-diabetic EH patients with normal renal function, subtle changes in glucose homeostasis are associated with increased intrarenal vascular resistance and might contribute to development of overt renal damage.