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

Abstract

Background/Aim. In the past three decades focal segmental glomerulosclerosis (FSGS) was commonly regarded as a part of obesity related glomerulopathy (ORG) a distinct entity featuring proteinuria, glomerulomegalia, progressive glomerulosclerosis and renal functional decline. The aims of the present study were to evaluate the glomerular morphometry, clinical features and two years outcome in obese and non-obese FSGS patients. Methods. The study included 35 FSGS patients (23 males, age 46.5±15.2 years); divided in two groups: obese (BMI ≥27 kg/m2- 18 patients, age 47.2±15.5 years) and non-obese (BMI <27 kg/m2- 17 patients, age 45.7±15.2 years). The serum concentrations of proteins, albumin, cholesterol, triglyceride and creatinine were determined at the time the biopsy, 6, 12, 24 months after the biopsy. Formulas Cockcroft- Gault (BMI <27 kg/m2) and Cockcroft-GaultLBW(BMI ≥27 kg/m2) were calculated. Glomerular radius (GR), glomerular volume (GV) and glomerular density (GD) were compared morphometrically between two groups. Results. At the time of kidney biopsy and 6 months later the obese had significantly lower GFR compared to non-obese. After 24 months follow-up there wasn´t any difference between groups. Obese had significantly higher GR (109.44±6,03 μm vs 98.53±14,38 μm) and GV (3.13±0.49 x106 μm3 vs 2.26±0.83 x106 μm3),only midly lower GD (1.91±0.39/mm2 vs 1.95±0.61/mm2) compared to non-obese. Significant positive association between GV and BMI (r=0.439) was found. After 12 months follow-up significantly higher percentage of non-obese patients reached complete remission (71.4% vs 37.5%) compared to obese (χ2=0.041), but after 24 months there were no significant difference. Conclusion. Obese patients at the time of kidney biopsy and 6 months later had already the significant lower kidney function compared to non-obese. However, after 12 and 24 months, this difference was still lower and without significance as well as after 24 months percentage of patients with complete remission between two groups.

Keywords

• biopsy
• glomerular filtration rate
• glomerulosclerosis, focal segmental
• kidney glomerulus
• obesity
• risk assessment
• treatment outcome