Background: BoneXpert software calculates bone health index (BHI) from cortical thickness and mineralisation of three metacarpals, and bone age (BA) using 13 bones: Radius, ulna and bones in ray 1, 3, 5. Strong correlations between BoneXpert BHI and dual-energy x-ray absorptiometry (DXA) and peripheral quantitative computed CT (pQCT) measurements are reported 1. Low bone mineral density (BMD), measured by DXA, and improvement with GH is described in childhood GH deficiency (GHD) 2. The effect of GH on BHI has yet to be reported.
Objective and hypotheses: To describe BHI SDS at diagnosis of GHD and after one year of treatment.
Method: Children treated between 2005 and 2016 were identified. Children with midline defects, diagnosed before significant height loss, were included. Those with additional diagnoses or medications that may affect BHI were excluded. Change in baseline parameters was determined by paired t-test, and associations between parameters examined using Pearson correlation.
Results: 120 patients (90M), age (mean±1 S.D.) 11.5±3.5 years were studied. At diagnosis height SDS was −2.5±0.9, BA delay 1.9±1.5 years and BHI SDS −1.0±1.0. After 1 year of treatment height SDS increased by 0.7 (95th CI, 0.6, 0.8), BHI SDS by 0.8 (0.61, 1.05) and BA delay decreased by 1.1 years (−1.4, −0.8) (P<0.001 for each parameter). Change in BHI SDS related to height SDS (P=0.04) and BHI SDS at diagnosis (P<0.001).
Conclusion: These data are consistent with previous reports of the effect of GH on BMD, measured using DXA, and lend support to the use of BHI, a simple measure obtained at the time of BA estimation, for the identification and monitoring of children at risk of impaired bone health.
10 Sep 2016 - 12 Sep 2016