Radiofrequency echographic multispectrometry assessment of osteoporosis in severe motor and intellectual...

Conventional bone mineral density (BMD) assessment using dual-energy X-ray absorptiometry is challenging in individuals with severe motor and intellectual disability (SMID) because of scoliosis, hip dislocation, joint contractures, and involuntary movements. Radiofrequency echographic multispectrometry (REMS) is a feasible, radiation-free alternative to bedside BMD assessment. In this cross-sectional study, we aimed to characterize REMS-based BMD profiles of lumbar spine (L1-L4) and femoral neck in individuals with SMID residing at a care facility and identify clinical factors associated with reduced BMD. Demographic variables, feeding status, and physical activity levels were obtained, and subgroup and multivariate regression analyses were performed. REMS measurements were successfully obtained at both sites in 84.3% of 121 participants. Femoral neck demonstrated significantly lower BMD, compared with lumbar spine (p = 0.038). T-scores at both sites were strongly correlated (r = 0.65, p < 0.001). Subgroup comparisons revealed no significant differences based on feeding route or physical activity. Multivariable analyses identified age and body weight as independent determinants of femoral neck T-scores. Physical activity was not independently associated with BMD after adjustment. These findings indicate that REMS enables bedside assessment, with body weight and age as primary determinants of BMD. Although physical activity may contribute to bone health, its independent effect appears limited. These results highlight the potential role of REMS in clinical evaluation, longitudinal monitoring, and osteoporosis prevention strategies in individuals with SMID. Given the high osteoporosis risk in this population, REMS-derived BMD should be interpreted cautiously to avoid underestimation of disease severity.