Relation between Renal Resistive Index and Serum Albumin in Nephrotic Syndrome

Abstract

BACKGROUND Renal resistive index (RRI) is a non-invasive marker of renal function, which can be measured by renal USG Doppler. High RI indicates poor prognosis, which has been associated with conditions such as proteinuria, hypertension, chronic kidney disease and renal failure. As nephrotic syndrome is characterised by significant proteinuria and hypoalbuminemia, which may progress to renal failure, it is important to see the correlation of RRI with serum albumin level. The purpose of this study was to assess the relation between renal resistive index and serum albumin in nephrotic syndrome. METHODS USG renal Doppler was done for all the children with nephrotic syndrome and RRI was calculated as [(peak - systolic velocity − end - diastolic velocity) / peak - systolic velocity]. Blood investigations were also done, from which serum albumin values were obtained. RRI was compared with mean serum albumin level. Statistical analysis of data was performed using the computer programme, Statistical Package for Social Sciences (SPSS for windows, version 21.01, Chicago, SPSS Inc.) and Microsoft excel 2010. Results on continuous measurement were presented as mean ± standard deviation and compared using Analysis of Variance (ANOVA). RESULTS The mean serum albumin in the children with nephrotic syndrome in our study was 1.82 ± 0.32 gm / dl. The mean RI value was 0.66 ± 0.14 SD, 0.64 ± 0.15 SD and 0.66 ± 0.12 SD as well as 0.63 ± 0.12 SD, 0.67 ± 0.16 SD and 0.71 ± 0.13 SD on the right and left kidney respectively for each of upper, middle, and lower pole. P value of left kidney and right kidney was 0.0057 and 0.6409 respectively. CONCLUSIONS Lower the mean serum albumin level, higher the range of RRI. KEY WORDS Serum Albumin, Renal Resistive Index, Nephrotic Syndrome, USG Renal Doppler