Associations between ultra-distal forearm bone mineral density and incident fracture in women

Abstract

Summary Bone mineral density measured at the ultra-distal forearm site was associated with any fracture, as well as distal radius fracture in women from a longitudinal cohort study. Purpose Femoral neck (BMD hip ) and lumbar spine (BMD spine ) bone mineral density (BMD) are routinely used to assess fracture risk. More data are needed to understand how ultra-distal forearm BMD (BMD UDforearm ) may assist fracture prediction. Methods Using a Lunar DPX-L, Geelong Osteoporosis Study women ( n = 1026), aged 40–90 years, had BMD measured. Incident low-trauma fractures were radiologically verified. Using Cox proportional hazard models, hazard ratios (HR) were calculated for BMD UDforearm as a continuous variable (expressed as a one-unit decrease in T-score) and a categorical variable (normal/osteopenia/osteoporosis). Areas under receiver operating characteristics (AUROC) curves were calculated. Analyses were conducted for any fracture and distal radius fractures. Results During 14,270 person-years of follow-up, there were 318 fractures (85 distal radius). In adjusted models, continuous BMD UDforearm was associated with any (HR 1.26;95%CI 1.15–1.39) and distal radius fractures (HR 1.59;95%CI 1.38–1.83). AUROCs for continuous BMD UDforearm , 33% forearm(BMD 33%forearm ), BMD hip , BMD spine , and FRAX without BMD were similar for any fracture ( p > 0.05). For distal radius fracture, the AUROC for BMD UDforearm was higher than other sites and FRAX ( p < 0.05). In adjusted models, those with osteoporosis had a higher likelihood of any fracture (HR 2.12; 95%CI 1.50–2.98). For distal radius fractures, both osteopenia and osteoporosis had a higher risk (HR 4.31; 95%CI 2.59–7.15 and 4.81; 95%CI 2.70–8.58). AUROCs for any fracture were similar for categorical BMD at all sites but lower for FRAX ( p < 0.05). For distal radius fractures, the AUROC for BMD UDforearm , was higher than other sites and FRAX ( p < 0.05). Conclusion Ultra-distal forearm BMD may aid risk assessments for any distal radius fractures. Supplementary Information The online version contains supplementary material available at 10.1007/s00198-024-07041-4.