The relationship between renal renal resistive index and hypertensive end-organ damage

Abstract

Background/Aim: The prevalence of hypertension increases with age and one out of every three adults over the age of 40 has hypertension. Hypertensive end-organ damage is an important predictive factor for patient morbidity and mortality. This study aimed to investigate the role of the renal resistive index (RI) in predicting retinopathy and nephropathy in hypertensive patients. Methods: This study was cross-sectional in design. Sixty hypertensive patients who were followed in Samsun Research and Training Hospital Internal Medicine outpatient clinic were included in the study. In all patients, a routine ophthalmological examination, including visual acuity, anterior segment examination, and dilated ocular fundus examination, was performed. Urinary albumin to creatinine ratio (mg/g) was measured in spot urine samples, and a level ≥30 mg/g was accepted as the presence of proteinuria. Renal Doppler ultrasonography was performed using Esaote mylab x 9 model sonography device vovex probe (C1-8) 3.5 MHz. RI values were measured using Xflow Doppler at the level of interlobular or arcuate arteries of both kidneys. First, the patients were divided into two groups (with or without retinopathy). The patients who had retinopathy were then divided into two groups according to their retinopathy degree. Hypertensive retinopathy was graded according to the Scheie classification. The patients were also divided into two groups according to their proteinuria status (with or without proteinuria). Results: The mean of renal RI was 0.59 (0.04) in patients without retinopathy (n=15), 0.63 (0.05) in patients with grade 1 hypertensive retinopathy (n=29), and 0.66 (0.04) in patients with grade 2 hypertensive retinopathy (n=15). The difference between groups was statistically significant (overall P=0.001). It has been shown that proteinuria develops more frequently in cases in which the renal value is above 0.7, and these results were statistically significant (P=0.034).  Conclusion: This study indicates that renal RI increase is a valuable tool for estimating retinopathy and proteinuria in hypertensive patients.