Resistive index of intrarenal artery in evaluation of diabetic nephropathy

Abstract

Diabetes mellitus is one of the systemic diseases affecting the kidneys. Diabetic nephropathy is a serious microvascular complication of diabetes mellitus. It is the most important cause of death in type I diabetic patients, of whom 30%-40% eventually develop end-stage renal failure and 40% of type II diabetics are at risk of developing diabetic nephropathy. So, diagnosis of diabetic nephropathy is paramount for the survivability of the diabetic patients not only because of the consequences of renal progression but also because of the strong association with the risk of developing cardiovascular disease. A total number of 53 subjects were enrolled in this present cross sectional study in the department of Radiology and Imaging, Bangabandhu Sheikh Mujib Medical University (BSMMU) in collaboration of Nephrology and Medicine of the same institution during two years (2011-13) aim to evaluate the diagnostic usefulness of renal resistive index (RI) by duplex Doppler ultrasonography for detection of renal dysfunction in diabetic patients. Clinically diagnosed diabetic patients having diabetic nephropathy referred to the department of Radiology and Imaging in BSMMU for ultrasonography of Kidneys, Ureters and Bladder (KUB) region or whole abdomen were selected as sample. Biochemical reports (Serum creatinine and Urinary albumin) and the RI value of intrarenal artery were correlated and analyzed. Only those patients biochemically were diagnosed as having diabetic nephropathy was included. Those with incomplete data, hydro nephrosis and renal calculus were excluded. Both the kidneys were visualized by commercially available real time scanner (GE Voluson) equipped with a curvilinear transducer operating at 3.5 MHz First Gray scale ultrasonography was done followed by Color Doppler of intra renal artery and then RI was measured. Majority (45.3%) patients were in 6th decade with the mean age was of 52.66±7.4 years and ranging from 38 to 65 years in patients. Male was found to be 54.7% of diabetic patients with male to female ratio 1.2: 1. Resistive index of (≥ 0.7) was found in 73.6% patients with diabetes with the mean resistive index of 0.71±0.04. Positive correction between resistive index with serum creatinine (r=0.581, p<0.01) and albuminuria (r=0.725, p<0.01) were observed. It can be concluded that Resistive Index measured by duplex Doppler ultrasonography is useful diagnostic modality for detection of renal dysfunction in diabetic nephropathy patients. Resistive Index has value in identifying diabetic patients who are developing nephropathy and can be used as an additional diagnostic tool. Also it is well correlated with Serum Creatinine and Albuminuria which are the biochemical parameters to diagnose diabetic nephropathy.