Morphometric analysis of glomeruli, clinical features and outcome in obese and non-obese patients with focal segmental glomerulosclerosis patients

Abstract

Background/Aim. In the past three decades, focal seg-mental glomerulosclerosis (FSGS) was commonly regarded as a part of obesity-related glomerulopathy (ORG), a dis-tinct entity featuring proteinuria, glomerulomegaly, progres-sive glomerulosclerosis, and a decline of renal function. The present study aimed to evaluate the glomerular morphome-try, clinical features, and a two-year outcome in the obese and non-obese FSGS patients. Methods. The study includ-ed 35 FSGS patients (23 males, aged 46.5 ± 15.2 years) di-vided into two groups: Obese [body mass index (BMI) ≥ 27 kg/m2 (18 patients, aged 47.2 ± 15.5 years)] and non-obese [BMI < 27 kg/m2 (17 patients, aged 45.7 ± 15.2 years)]. The serum concentrations of proteins, albumin, cholesterol, tri-glyceride, and creatinine were determined at the time of the biopsy, and 6, 12, and 24 months after the biopsy. Cock-croft-Gault (BMI < 27 kg/m2) and Cockcroft-GaultLBW (BMI ≥ 27 kg/m2) formulas were calculated. Glomerular radius (GR), glomerular volume (GV), and glomerular den-sity (GD) were compared morphometrically between the two groups. Results. At the time of the kidney biopsy and 6 months later, the obese had significantly lower glomerular filtration rate (GFR) compared to the non-obese. After 24 months of follow-up, there were not any differences be-tween the groups. The obese had a significantly higher GR (109.44 ± 6.03 μm vs. 98.53 ± 14.38 μm) and GV (3.13 ± 0.49 × 106 μm3 vs. 2.26 ± 0.83 × 106 μm3), and only slightly lower GD (1.91 ± 0.39/mm2 vs. 1.95 ± 0.61/mm2) compared to the non-obese. A significant positive associa-tion between GV and BMI (r = 0.439) was found. After 12 months of follow-up, a significantly higher percentage of the non-obese patients reached complete remission com-pared to the obese (71.4% vs. 37.5%, respectively; p = 0.041), but after 24 months there were no significant differences. Conclusion. Obese patients, at the time of the kidney biopsy and 6 months later, had already a significantly lower kidney function compared to the non-obese ones. However, 12 and 24 months after, this difference was not statistically significant. Also, 24 months after, there was no significant difference between the two groups in the per-centage of patients with complete remission of the nephrot-ic syndrome.