Leptin and Soluble Leptin Receptor in Serum and Urine of Children with Primary Nephrotic Syndrome Before and After Steroid Therapy

Background: Previous data revealed a urinary Ieptin loss in prepubertal and early pubertal children suffering from active nephrotic syndrome with proteinuria greater than 1 g/m-.
Objective: We evaluated leptin and soluble leptin receptor (sOB-R) in serum and urine of children with primary nephrotic syndrome before and after one month steroid therapy.
Patients & Methods: This case control prospective study included 35 primary nephrotic syndrome children and 20 age and sex matched healthy children. Leptin and sOB-R levels in serum and urine were detected at beginning of the study and after one month corticosteroid therapy.
Results: In comparison to control group, there were significantly higher urinary leptin level & serum sOB-R level and significantly lower free leptin index in nephrotic syndrome children (p < 0.01), these diftërences attenuated and became non significant with remission of proteinuria (p > 0.05) and remained significant only in corticosteroid non responsive nephrotic children (p < 0.05). Urinary leptin level and serum sOB-R showed strong positive correlations with proteinuria (p < 0.01), whereas they showed strong negative correlations with serum albumin levels (p < 0.01). Urinary leptin level and serum sOB-R level did not show significant correlation with age or lipid profile component parameters (p > 0.05).
Conclusion: Serum soluble leptin receptor level was elevated and associated with the increase of leptin loss in urine in primary nephrotic syndrome. Both of them correlated positively with proteinuria and decrease with clinical and laboratory remission of the disease.