Bone mineral density on long-term survivors following pediatric liver transplantation

We sought to estimate the prevalence of reduced bone mass, defined by lumbar spine bone mineral density (LS-BMD) (z-score < -2.0), and to determine the factors associated with LS-BMD after liver transplantation in children and adolescents. LS-BMD z-scores were measured in a sample of subjects who had undergone liver transplantation in childhood or adolescence using dual energy x-ray absorptiometry (EOCA). One hundred nine patients underwent DXA. The mean age at transplantation was 4.3 years (median, 1.8 years), and mean duration since transplantation was 6.2 years (median, 8 years). the mean weight z-score was -0.130 (SD, 1.26). The mean LS-BMD z-score was -0.243 (SD, 1.27). Eight patients, or 7.3% (05% confidence interval [CI], 2.4% to 12.2%), had reduced bone Mass. Compared with those without reduced bone mass, subjects with reduced bone mass were more likely to have been treated for rejection at least once (87.5% versus 51.5%; P = .07), and had greater cumulative exposure to prednisone during the year before DXA (92.3 versus 26.2 mg/kg/y; P = .001). Multiple linear regression determined that LS-BMD z-score was positively associated with time since transplantation and weight z-score and negatively associated with cumulative prednisone exposure. Serum 25-OH vitamin D was measured and reduced (< 15 ng/mL) in 5 of 87 patients, one of whom had reduced bone mass. In conclusion, the prevalence of reduced bone mass was 7.3% in our population. Only certain patients appear to be at risk for low BMD, including those with a history of rejection. Screening for reduced bone mass may bib appropriate for these patients.