Utility of BoneXpert in assessing bone age and bone health in Indian children and youth with type 1 diabetes mellitus

Introduction: BoneXpert (BX) performs digital radiogrammetry and reports metacarpal index (MCI) besides bone age (BA) evaluation. Its utility in subjects with type-1 diabetes (T1D) has not been reported. We conducted this study with following objectives: 1) To study the utility of BX in the assessment of BA in Indian children and youth (CY) with T1D and 2) To assess association of MCI (measured by BX) and bone health in Indian CY with T1D. Methods: The MCI and BA were assessed retrospectively in 1272 subjects with T1D using digitalised left-hand xrays. The demographic, anthropometric, clinical, dietary, biochemistry, dual x-ray absorptiometry (DXA) data and peripheral quantitative computed tomography (pQCT) data collection were performed using standard protocols and were extracted from hospital records. Results: The root mean square error of BX with respect to reference and true bone age by TW-3 method were estimated to be 0.72 years and 0.67 years respectively in Indian CY with T1D. The BX provided MCI results were in concordance with the DXA derived bone mineral density (r = 0.551) and pQCT derived cortical density (r = 0.318) measurements; MCI correlated with trabecular density at the tibia (r = 0.212). 51.5 % subjects with T1D had significantly decreased MCI. Height, tanner stage, vitamin D concentrations showed positive correlation while HbA1c and disease duration had negative correlation with MCI. Conclusion: BX may be used for accurate assessment of BA by TW-3 method and for screening for bone health in Indian CY with T1D.