Adiponectin in children with chronic kidney disease: role of adiposity and kidney dysfunction.

Low serum adiponectin is a known cardiovascular risk in adult chronic kidney disease (CKD). However, adiponectin concentrations and their relation with other cardiovascular risks have not been studied in children with preterminal CKD. Forty-four children and adolescents who were aged 6 to 21 yr and had stages 2 to 4 CKD had serum adipocytes, lipoproteins, markers of inflammation, homocysteine, and insulin levels determined cross-sectionally. There were 29 lean (body mass index [BMI] <85th percentile) and 15 nonlean (BMI > or =85th percentile) patients. Mean serum adiponectin level was 30.6 +/- 14.1 microg/ml (range 7.1 to 67.8 microg/ml). A total of 83% of patients had elevated adiponectin level. Despite similar kidney function, lean patients had significantly higher adiponectin levels than nonlean patients (34.1 +/- 13.4 microg/ml versus 23.6 +/- 13.3 microg/ml; P = 0.02). In univariate analysis, serum adiponectin negatively correlated with age (r = -0.34, P = 0.02), BMI (r = -0.47, P = 0.001), leptin (r = -0.41, P = 0.006), GFR (r = -0.39, P = 0.02), and insulin (r = -0.36, P = 0.01) and positively correlated with ApoA2 (r = 0.30, P = 0.04); no significant associations were found with markers of inflammation or homocysteine. Multivariate stepwise analysis showed that GFR (beta = -0.008, P = 0.001), BMI (beta = -0.16, P = 0.015), and age (beta = -0.04, P = 0.018) independently predicted serum adiponectin levels. Separate analysis of lean patients showed no significant relations with age or BMI; only GFR independently predicted serum adiponectin level (beta = -0.01, P = 0.0008). It is concluded that serum adiponectin is elevated in children and adolescents with stages 2 to 4 CKD and that decreased kidney function is a major determinant of elevated adiponectin concentrations. Despite overall elevated adiponectin, overweight patients display lower serum adiponectin levels and might be at risk for future cardiovascular complications.