Glucocorticoid-induced osteopenia in adolescent heart transplant recipients

Background: Glucocorticoid-induced cushingoid symptoms, including osteopeni a and osteoporosis are well-documented in adult heart transplant recipients (HTR). Bone mineral density (BMD) of the axial skeleton is diminished by 1 0% to 20% within 60 days after transplantation (Tx) and most adult HTR fulf ill World Health Organization criteria for osteoporosis (BMD > 2.5 SD below norm). At present, we do not know whether glucocorticoids have similar del eterious effects in adolescent HTR. Methods: To determine the consequences of glucocorticoid immunosuppression on regional bone mineral density (BMD) and biochemical markers of bone meta bolism in adolescent HTR, we studied 19 patients (aged 16 +/- 3) at 19 mont hs (group mean) after Tx. We measured BMD (hydroxyapatite g/cm(2)) of the t otal body, lumbar spine, and pelvis using dual-energy X-ray absorptiometry (Lunar). Serum levels of bone-specific alkaline phosphatase and pyridinolin e cross-links were determined by enzyme immunoassay in serum kits. Results: The BMD of the lumbar spine (-12%), femur neck (-13%), femur troch anter (-12%), and ward's triangle (-16%) were significantly (p < 0.05) lowe r in adolescent HTR than age- and gender-matched norms. Serum levels of alk aline phosphatase (29 +/- 6 vs 22 +/- 3 U/liter) and pyridinoline cross-lin ks (5.3 +/- 1.1 vs 3.8 +/- 0.7 mmol/liter) were significantly (p < 0.05) el evated in adolescent HTR, compared with age- and gender-matched controls st udied in our laboratory. Conclusions: Our cross-sectional results demonstrate that BMD of the axial skeleton in adolescent HTR is significantly lower (-10% to 20%) than age-ma tched norms and that serum biochemical markers of bone metabolism are signi ficantly elevated, suggesting accelerated bone turnover.