A Population-Based Study Examining Calcaneus Quantitative Ultrasound and Its Optimal Cut-Points to Discriminate Osteoporotic Fractures among 9352 Chinese Women and Men

Abstract

No generally accepted thresholds for quantitative ultrasound (QUS) parameters to screen individuals at high risk of osteoporotic fractures have been defined. We sought to define appropriate cutoff points for osteoporotic fractures of calcaneus ultrasound according to participants' prevalent osteoporotic fractures. This was a cross-sectional, population-based study conducted in Shanghai, China. A total of 9352 Chinese women and men aged 40 and older were studied. We measured calcaneus QUS (Achilles Express, GE Lunar) values and their relationships with osteoporotic fractures. A prevalence of 14.9 and 12.2% of osteoporotic fractures was found in the women and men (P<0.001), respectively. Subjects with osteoporotic fractures had significantly lower QUS values than those without (P<0.001). One sd decline in the stiffness index (SI)-derived T-score was associated with a high risk of nonvertebral fracture [odds ratio (OR)=1.50; 95% confidence interval (CI), 1.39-1.62; P<0.001], clinical vertebral fracture (OR=1.49; 95% CI, 1.18-1.90; P<0.01), and multi-fractures (OR=1.98; 95% CI, 1.63-2.40; P<0.001). The receiver operating characteristic analysis showed that QUS could differentiate osteoporotic fractures in postmenopausal women and men, but not in premenopausal women. The optimal cutoff points for the SI-derived T-score to detect a high risk of nonvertebral fractures, clinical vertebral fractures, and multi-fractures were -1.25, -1.55, and -1.80 in postmenopausal women, respectively, and -1.30, -1.90, and -2.00 in males, respectively. As a screening tool, the SI-derived T-score obtained from the Achilles QUS device for a postmenopausal woman or man that is less than -1.25 and -1.30, respectively, may indicate an increased risk of osteoporotic fractures and should be further evaluated by central DXA.