Quantitative ultrasound and fracture risk prediction in non-osteoporotic men and women as defined by WHO criteria

Abstract

This study sought to determine the association between calcaneal quantitative ultrasound (QUS) and fracture risk in individuals without osteoporosis according to the World Health Organization criteria (i.e., BMD T-score > -2.5). We found that calcaneal QUS is an independent predictor of fracture risk in women with non-osteoporotic bone mineral density (BMD). More than 50 % of women and 70 % of men who sustain a fragility fracture have BMD above the osteoporotic threshold (T-score > -2.5). Calcaneal QUS is associated with fracture risk. This study aimed to test the hypothesis that low calcaneal QUS is associated with increased fracture risk in individuals with non-osteoporotic BMD. We included 312 women and 390 men aged 62-90 years with BMD T-score > -2.5 at femoral neck. QUS was measured in broadband ultrasound attenuation (BUA) at the calcaneus using a CUBA sonometer. BMD was measured at the femoral neck (FNBMD) by dual energy X-ray absorptiometry using GE Lunar DPX-L densitometer. The incidences of any fragility fracture were ascertained by X-ray reports during the follow-up period from 1994 to 2011. Of the 702 participants, 26 % of women (n = 80/312) and 14 % of men (n = 53/390) experienced at least one fragility fracture during the follow-up period. In women, after adjusting for covariates, increased risk of any fracture was significantly associated with decreased BUA (HR = 1.50; 95 % CI, 1.13-1.99). Compared with that of FNBMD, the models with BUA, in women, had greater AUC (0.71, 0.85, 0.71 for any, hip and vertebral fracture, respectively), and yielded a net reclassification improvement of 16.4 % (P = 0.009) when combined with FNBMD. In men, BUA was not significantly associated with fracture risk before and after adjustment. These results suggest that calcaneal BUA is an independent predictor of fracture risk in women with non-osteoporotic BMD.