Adiponectin levels and arteriosclerotic risk factors in pediatric renal transplant recipients

ADPN, a recently discovered adipocytokine, has attracted great attention because of its anti-atherogenic properties. It was suggested as a protective factor for the cardiovascular system because of its close correlation with several risk factors. Our aim was to investigate serum ADPN levels in pediatric RTR and to document possible relationships between ADPN and arteriosclerotic risk factors. Twenty-one RTR, aged 16.3 +/- 4.0 yr, and 23 healthy age and sex-matched control subjects were enrolled in this study. Serum lipid/lipoprotein fractions, homocysteine and ADPN levels as well as intima-media thickness of the cIMT were determined in both groups. Significantly higher serum ADPN (p < 0.001) and homocysteine (p < 0.05) levels as well as higher cIMT (p < 0.001) were found in RTR compared with the control subjects, whereas apolipoprotein B and lipoprotein (a) levels were not significantly different. HDL cholesterol was positively correlated with log ADPN (r = 0.585, p < 0.01). There were inverse correlations between log time post-transplantation and log ADPN as well as HDL cholesterol (r = -0.438, p < 0.05 and r = -0.578, p < 0.05, respectively). There were no correlation between log ADPN, log homocysteine, log apolipoprotein B, lipoprotein (a), creatinine clearance and cumulative steroid dose. Despite reasonable lipid profiles and remarkably elevated ADPN levels, our pediatric RTR with stable graft function displayed a risk for arteriosclerosis because of increased cIMT and mild hyperhomocysteinemia. Regarding the close positive correlation between ADPN and HDL cholesterol, it could be speculated that ADPN is a novel negative surrogate marker of arteriosclerosis. To our knowledge, this is the only report investigating levels and diverse correlates of ADPN in a pediatric RTR group. Further studies in larger groups of recipients are needed to clarify the interaction between arteriosclerotic risk factors and ADPN.