Adiponectin in children and young adults with focal segmental glomerulosclerosis

Adiponectin is an adipokine that is elevated in kidney disease. Evidence suggests that adiponectin exerts a direct effect on the podocyte and may play a role in the pathogenesis of proteinuria. The objectives of this study were to characterize serum and urine adiponectin levels over time in patients with focal segmental glomerulosclerosis (FSGS) and to evaluate the role of baseline levels of adiponectin as a predictor of clinical remission.

This was a study of 60 individuals, ages 3-38 years, with steroid-resistant FSGS enrolled in the FSGS clinical trial. Serial measurements of serum and urine adiponectin were obtained at baseline and 26 and 52 weeks.

Participants were of mean age 19.4 ± 10.2 years (50% male, 33% black). Serum adiponectin (baseline mean 14.3 ± 6.6 μg/ml) and urine adiponectin:creatinine (Uadp/cr) (baseline mean 126.8 ± 178.9 μg/ml) directly correlated with proteinuria at all time points (r = 0.37-0.81; all p < 0.05). Proteinuria, hypoalbuminemia, and hyperlipidemia were significant independent predictors of greater serum adiponectin and Uadp/cr in multivariate analysis. Lower tertiles of baseline serum adiponectin were associated with greater response to treatment at 52 weeks when adjusted for age, sex, body mass index (BMI) z score, and estimated glomerular filtration rate (eGFR) [odds ratio (OR) 0.48; 95% confidence interval (CI) 0.26-0.91, p = 0.023). For log Uadp/cr, the OR for remission was 0.43 (95% CI 0.21-0.89, p = 0.02) at 52 weeks. However, when baseline urine protein:creatinine was added to the models, the relationships were no longer significant.

Serum and urine adiponectin levels were directly associated with proteinuria and paralleled changes in proteinuria over time in children and young adults with FSGS. Although baseline adiponectin was lower in responders, response to treatment in patients with FSGS was not associated with serum and urine adiponectin levels but, rather, was related to proteinuria.