Calcaneal ultrasound predicts early postmenopausal fractures as well as axial BMD. A prospective study of 422 women.

Low calcaneal ultrasound measurement (quantitative ultrasound, QUS) has been shown to predict fractures in elderly women. However, only a few studies have examined its ability to predict perimenopausal and early postmenopausal fractures. We conducted a prospective population-based cohort study to assess the capability of QUS as compared to axial BMD measurement to predict early postmenopausal fractures at that age. Four hundred and twenty-two women (mean age 59.6, range 53.7-65.3) from the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) were randomly chosen to undergo a calcaneal ultrasound measurement. In all, 9.4% of these women were premenopausal at the time of measurement. Thirty-two follow-up fractures were reported during the mean follow-up of 2.6 years (SD 0.7). These were validated with patient record perusal. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were significantly lower among women with than without fracture ( P-values 0.028, 0.001 and 0.001, respectively). Mean T-score adapted from SI was -1.5 (95% CI -1.7 to -1.2) for fracture group and -1.0 (95% CI -1.1 to -0.9) for the non-fracture group. All QUS measurements predicted fractures even after adjusting for age, weight, height, previous fracture history, femoral neck BMD and use of hormone replacement therapy according to Cox regression. The adjusted hazard ratios (HR, 95% confidence interval) of a follow-up fracture for a 1 SD decrease were 1.80 (1.27-2.56), 1.72 (1.21-2.45) and 1.43 (1.01-2.03) for SOS, SI and BUA, respectively. Similarly, the adjusted HR for a 1 SD decrease of spinal BMD was 1.27 (0.85-1.94) and for that of femoral neck BMD 1.14 (0.78-1.70). In receiver operator analyses, the area under the curve (AUC) was greatest for QUS measurements: SOS (AUC=0.68), stiffness (AUC=0.67), BUA (AUC=0.62) and least for lumbar BMD (AUC=0.56), while and femoral neck BMD (AUC=0.59). The difference between AUCs was statistically significant between SI and lumbar BMD ( P=0.02, Duncan's P=0.07). We conclude that low calcaneal QUS predicts early postmenopausal fractures as well as or even better than axial BMD.