MO164: Is there a Place for the Resistivity and Pulsatility Index in Diabetic Nephropathy?

Abstract

Abstract BACKGROUND AND AIMS Resistivity index (RI) and pulsatility index (PI) are important Doppler ultrasound (US) parameters for the evaluation of intrarenal haemodynamics. One of the pathogenetic mechanism in diabetic nephropathy (DKD) is the arteriolar hyalinosis and the interlobar arteries were proved as hallmarks for distal vasoconstriction or dilatation. Therefore, Doppler parameters are commonly used in the early detection of intrarenal vasoconstriction. We compared the results of colour Doppler parameters RI and PI in type 2 diabetic nephropathy (DKD) with hypertensive (HT) patients with proteinuria and tried to assess the risk for the disease progression. METHOD A total of 141 patients with DKD and 146 hypertensive patients were examined using an Esaote MyLab X8 eXP Ultrasound device following a precise protocol by a single examiner. All patients had proteinuria values 300–500 mg/24 h. RI and PI were measured in the interlobar arteries on three levels for each kidney, and a mean was calculated. All patients were age and sex matched and had eGFR over 45 mL/min/1.73 m2. GraphPad Prism program was used, and correlation indices were calculated. RESULTS Mean RI values were 0.71 for ND group (SD = 0.06; 95% CI), 0.66 for HT group (SD 0.06; 95% CI); t-test was highly significant (P < .05). Mean PI values were 1.27 for ND group (SD = 0.33; 95% CI), 1.04 for HT group (SD = 0.24), t-test was also highly significant between the two groups with P values under.05. Cut-off values for RI in DKD were above 0.72. PI values were higher with age in diabetic patients. PI and RI were highly significant in case of patients with more than 5 years from the onset of diabetes. CONCLUSION RI can be considered a suggestive parameter for the presence of DN. PI alongside RI correlated with the duration of diabetes, age and incipient DN. We recommend the use of RI in the early evaluation of DKD. Although Doppler US examination is time-consuming, it can be easily performed in non-obese and compliant patients.