Purpose: To determine whether intrarenal arterial resistance index (RI) value is related to increased urinary albumin excretion and whether RI value is an independent good indicator to evaluate early renal damage in nonhypertensive, nondiabetic obese subjects.
Methods: Sixty-four nonhypertensive, nondiabetic obese patients (OB) and 35 age- and sex-matched normal healthy subjects were involved in this study. Clinical characteristics and blood biochemistry of all the subjects were measured. Urinary albumin/creatinine ratio (ACR) and sonographic evaluation of renal blood flow were determined.
Results: ACR and interlobar arterial RI were significantly higher in obese patients than those of normal healthy subjects. Interlobar arterial RI value was higher in patients with microalbuminuria than those with normoalbuminuria. Correlation analysis showed interlobar artery RI value had a positive correlation with ACR (r = 0.615, p < 0.01) and plasma free fatty acids (FFAs, r = 0.407, p < 0.01). ACR had a positive correlation with BMI (r = 0.380, p < 0.01), waist circumference (r = 0.414, p < 0.01), plasma FFAs (r = 0.537, p < 0.01). Multivariate regression analyses showed that ACR was best predicted by interlobar artery RI value even when body mass index, waist circumference, FFAs, and high-sensitive C reaction protein were added in the statistical analysis.
Conclusions: Interlobar arterial RI may be an independent predictor of microalbuminuria in nonhypertensive, nondiabetic obese patients, and interlobar arterial RI could be a useful tool for assessment early renal damage in obese patients.