Para- and perirenal fat thickness is an independent predictor of chronic kidney disease, increased renal resistance index and hyperuricaemia in type-2 diabetic patients.

BACKGROUND: Many interfering factors may reduce the reliability of waist circumference (WC) measurement in estimating the risk for chronic kidney disease (CKD) associated with obesity. Therefore, we determined the independent associations of para- and perirenal ultrasonographic fat thickness with the main markers of kidney function. METHODS: A cross-sectional study was performed in 151 type-2 diabetic subjects. Para- and perirenal fat thickness was measured from the inner side of the abdominal musculature to the surface of the kidneys. CKD was defined as eGFR < 60 mL min(-1)1.73 m(-2). RESULTS: Using both univariate and multivariate regression analyses, eGFR, renal resistance index and uricaemia were best predicted by para- and perirenal fat thickness even when BMI and waist circumference were further added in the statistical model (r(2): 0.366, P = 0.001; r(2): 0.529, P = 0.005; r(2): 0.310, P = 0.026, respectively), whereas waist circumference and BMI did not contribute independently of para- and perirenal fat thickness. Albuminuria was predicted by waist circumference but not by para- and perirenal fat thickness. In subjects with waist circumference above the diagnostic values of metabolic syndrome (48M/59F), eGFR significantly and progressively declined across tertiles of para- and perirenal fat thickness (87.0 ± 27.9 vs 83.5 ± 26.0 vs 62.3 ± 30.6 mL min(-1) 1.73 m(-2), adjusted P < 0.0001) despite comparable waist circumference, and an increasing frequency of CKD was observed across tertiles of subjects with waist circumference both below and above the metabolic syndrome diagnostic values (P < 0.05). CONCLUSIONS: Para- and perirenal fat thickness is an independent predictor of kidney dysfunction in type-2 diabetes explaining an important proportion of the variance of eGFR, renal resistance index and uricaemia.

Waist circumference is strongly associated with renal resistive index in normoalbuminuric patients with type 2 diabetes.

OBJECTIVE: Anthropometric parameters may play a role in modulating the risk of kidney dysfunction. The aim of this study was to evaluate whether anthropometric indices and the metabolic syndrome are associated with alterations of the renal resistive index (RI) in normoalbuminuric type 2 diabetic (T2DM) patients. METHODS: A sample of 99 consecutively recruited patients with T2DM (76 male and 23 female) was examined. The RI was assessed by duplex Doppler sonography. RESULTS: In univariate analysis, a significant association between the RI values and age (r = 0.507, p < 0.0001), gender (being higher in women, p = 0.002), systolic blood pressure (r = 0.285, p = 0.011), smoking habit (being lower in current smokers, p = 0.047), estimated glomerular filtration rate (r = -0.435, p < 0.0001), and intima-media thickness of the carotid arteries (r = 0.271, p = 0.020) was observed. As far as anthropometric parameters are concerned, a strong correlation between waist circumference (WC; r = 0.401, p < 0.0001), BMI (r = 0.337, p = 0.003) and RI values was found but only WC maintained a significant correlation after adjusting for several confounders (p = 0.001). CONCLUSIONS: In normoalbuminuric T2DM patients, the intrarenal hemodynamic abnormalities seem primarily associated with WC.