Correlates of leptin in children with chronic kidney disease.

To investigate the relative associations of renal function, obesity, and inflammation with serum leptin levels in children with chronic kidney disease (CKD). This was a cross-sectional analysis of 317 children from the Chronic Kidney Disease in Children study, a large cohort of pediatric patients with stage II-IV CKD. Linear regression modeling was used to evaluate the association of serum leptin level with glomerular filtration rate calculated using the plasma iohexol disappearance curve, demographics, body mass index (BMI), and cardiovascular risk factors, including inflammatory cytokines, insulin resistance, and serum lipid levels. In univariate analyses, elevated serum leptin level was significantly associated with increased BMI, older age, and female sex (Pxa0<xa0.001 for all). Leptin level also correlated positively with serum triglycerides and insulin resistance (Pxa0<xa0.001) and negatively with serum high-density lipoprotein cholesterol (Pxa0=xa0.002). Leptin level was not associated with glomerular filtration rate calculated using the plasma iohexol disappearance curve or inflammatory cytokines. In multivariate analysis, BMI, age, female sex, and serum triglyceride levels were significantly associated with serum leptin level. Increased leptin production was associated with female sex, older age, and adiposity in children with mild to moderate CKD. Renal function was not associated with serum leptin level, indicating that decreased clearance does not contribute to elevated leptin levels.