Bone density and fragility fractures in patients with developmental disabilities

Abstract

We investigated prior fractures, osteoporosis risk factors, and bone mineral density (BMD) in 107 institutionalized adults with developmental disabilities. We found a very high prevalence of BMD in the osteoporotic range and a significant correlation between lower BMD and prior fragility fractures. The purpose of this study was to investigate factors contributing to osteoporosis and fragility fractures among developmentally disabled adults. Adults from a residential center participated in a prospective study in which bone mineral density (BMD) at the forearm and heel were measured with a portable X-ray densitometer. Prior fragility fractures were identified from chart review. Among 107 participants, 84 (78.5%) had a measurement within the osteoporotic range. The heel was more severely abnormal (mean T-score -3.1 +/- 1.5) than the forearm (-1.6 +/- 1.3, p < .0.0001). Radiographically confirmed prior fragility fractures (17 [16.3%]) were associated with lower heel (p = 0.0155) and forearm (p = 0.0172) T-scores. In multiple regression analysis, there were independent associations between forearm BMD and prior fragility fractures (p = 0.0126) and between heel BMD and prior fragility fractures (p = 0.0291). The odds ratio for prior fracture increased by 2.02 (95% CI 1.12-3.64) for each standard deviation (SD) decrease in heel T-score and by 2.39 (95% CI 1.08-5.32) for each SD decrease in forearm T-score. We found a very high prevalence of osteoporotic BMD measurements in institutionalized adults with developmental disabilities. Lower heel and forearm BMD measurements were significantly and independently associated with prior fragility fractures in this population.