Endocrine Abstracts

Introduction and aims: Obesity is associated with increased single-nephron glomerular filtration rate, which may increase the risk of chronic kidney disease (CKD). Several biopsy studies showed the association between obesity and higher prevalence of CKD features, including segmental glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arterial sclerosis. Another approach is to study intra-renal hemodynamics by ultrasound, where renal parenchymal damage in obesity may be reflected by intra-renal resistive indices.

Methods: We examined 108 patients with different classes of obesity (90 women and 18 men, mean age: 54.62±0.4 years). All patients were divided into three groups (III classes of obesity, divided by BMI). They underwent clinical and laboratory examination, which included lipidogram, insulin, plasma homocysteine levels, microalbuminuria (MAU) in the morning urine. The result was determined directly, without any recalculation. UIA identified in excess of index higher than 20 mg/l. Study of intrarenal blood flow was performed by color Doppler with pulsed doplerometry on the device Aloka SSD-5500. We studied the main and intrarenal renal artery (segmental and interlobar) in the projection of the three segments of both kidneys. We determined the resistive characteristics of the arterial blood flow (RI and PI), calculated automatically by the standard formulas.

Results: The average level of insulin plasma and homocystein exceeded the normal laboratory data in the III class – 31.57±0.41 mE/l (P<0.001) and 18.43±0.57 mol/l (P<0.001). The level of MAU exceeded in the II class – 20.44±0.46 mg/l (P<0.05) and III class – 53.09±7.87 mg/l (P<0.001). In the study of intrarenal blood flow RI and PI in the segmental and interlobar level of the arteries in this groups of patients were above normal values. In the segmental level: I class – RI=0.64±0.01 (P<0.05) and PI=0.99±0.2 (P<0.001); II class – RI=0.71±0.01 (P<0.05) and PI=1.24±0.03 (P<0.001); III class – RI=0.70±0.01 (P<0.05) and PI=1.33±0.04 (P<0.001). In the interlobar level: I class – RI=0.63±0.01 (P<0.05) and PI=0.99±0.2 (P<0.001); II class – RI=0.70±0.01 (P<0.05) and PI=1.24±0.03 (P<0.001); III class – RI=0.68±0.01 (P<0.05) and PI=1.31±0.04 (P<0.001).

Conclusions: These results suggest that obese patients have a sign of intravascular renal resistance and an increased risk for CKD.