Circulating leptin levels and bone mineral density in children with biliary atresia

Aim: To investigate circulating leptin levels in biliary atresia (BA) patients and the association of leptin with bone mineral density (BMD) and the severity of BA. Methods: We have examined 50 patients with BA and 15 matched healthy controls. Serum leptin, osteocalcin and C-terminal telopeptide of type I collagen (CTX) levels were measured by sandwich enzyme-linked immunosorbent assay (ELISA). BMD of the lumbar spine was measured by dual energy X-ray absorptiometry. Results: Serum leptin levels of BA patients were lower than those of healthy controls (2.7 +/- 0.3 vs. 7.1 +/- 1.7 ng/mL, p = 0.0001). Among the BA patients, serum leptin levels were significantly lower in patients with jaundice than patients without jaundice (1.7 +/- 0.2 vs. 3.4 +/- 0.4 ng/mL, p = 0.001 BMD of BA patients was correlated (p < 0.001) with leptin levels, age and BMI (r = 0.55, r = 0.75 and r = 0.58, respectively). The serum CTX levels were significantly higher in jaundice patients compared with jaundice-free patients and the healthy controls (0.6 +/- 0.2 vs. 0.2 +/- 10.1 ng/mL, p 0.01), whereas the serum osteocalcin levels in BA patients were not different from those in the controls. Conclusion: Circulating leptin levels are correlated with BMD and the presence of jaundice in BA, suggesting that the leptin may play a physiological role in maintaining bone mass of BA patients with jaundice.