Impaired bone health in adolescents after liver transplantation

Long-term complications related to immunosuppressive medication are an important problem after liver transplantation (OLT). This study was carried out to evaluate the bone health and risk factors for osteoporosis and fractures in 40 pediatric liver transplant recipients. The results of 208 longitudinal bone mineral density (BMD) measurements were analyzed retrospectively. In addition, a dual-energy X-ray absorptiometry was performed to assess the bone mineral content more precisely and to detect subclinical vertebral fractures (VF). The median age of the patients was 14 years and mean postoperative follow-up 7.0 years. The results showed that over half (58%) had lumbar spine (LS) Z-score <=-1.0 and one-fifth (18%) had asymptomatic VF. LS Z-score tended to increase from the first year after OLT, but during puberty the bone mass gain was suboptimal and Z-scores decreased in some subjects. Patients with VF were older at the time of OLT (p = 0.002) and their LS Z-score was lower (p = 0.001). Children transplanted before 10 years of age had less VF (p = 0.004) and higher LS Z-score (p = 0.005) than older patients. In conclusion, adolescent liver recipients are prone to osteoporosis and prevention should be targeted especially to this age group.