Renal ultrasonography is useful for evaluating diabetic renal failure

AIM: It has been reported that the course of renal function is heterogeneous in patients with diabetic nephropathy. This study was undertaken to examine the clinical usefulness of renal ultrasonography in evaluating diabetic chronic renal failure (CRF) patients. METHODS: The renal sizes of type 2 diabetic patients with various degrees of renal injury, non-diabetic subjects without renal diseases and patients with non-diabetic CRF were measured by ultrasonography. The renal area index (RAI) was calculated from renal measurements and body surface area. The rate of renal function decline (delta l/cre) was analyzed by calculating the slope of the regression line for the reciprocal of serum creatinine concentrations over time. The correlations between delta l/cre and various clinical and laboratory parameters, including RAI, were analyzed. RESULTS: The RAI values of type 2 diabetic patients with nephropathy increased on the whole. It was also found that the RAI value of diabetic CRF patients was heterogeneous. There was a significant correlation between RAI and log delta l/cre (r = 0.492, p < 0.01). In addition to RAI, urinary protein excretion, serum albumin concentration and mean blood pressure significantly correlated with log delta l/cre. The correlation between RAI and log delta l/cre remained significant after adjustment for age, gender and serum albumin concentration. However, it was no longer significant after inclusion of mean blood pressure in the multivariate analysis. CONCLUSION: Although RAI is not a completely independent predictor of the risk of progression of diabetic renal failure, RAI could be a useful marker for the evaluation of diabetic renal failure. Renal involvement in diabetic patients is heterogeneous, and since renal ultrasonography is non-invasive and safe to perform, it is useful in evaluating diabetic CRF patients.