Reference data and predictive diagnostic models for calcaneus bone mineral density measured with single-energy X-ray...

Calcaneus bone mineral density (BMD) of 7428 Chinese (4126 women, 3302 men; aged 22-94 years) was measured using single-energy X-ray absorptiometry (SXA). A reference range of calcaneus BMD values for healthy Chinese men and women was established and the usefulness of this method for screening and diagnosis in osteoporosis was evaluated. The peak BMD occurred at 20-24 years old and peak BMD in women was significantly lower than in men. BMD loss in the calcaneus started at the age of 35 years for women, and at 63 years in men. BMD loss rate was 1.2%/year for women and 0.56%/year for men after 50 years. The young normal reference for calcaneus BMD was 442.1+/-69.6 mg/cm2 for men and 388.3+/-61.7 mg/cm2 for women calculated from the mean BMD value of subjects whose age ranged from 20 to 49 years. The accumulated BMD loss in the calcaneus is similar to that of Ward's triangle. Multiple linear regression showed that both age and weight were important factors. The incidence of osteoporosis in older men and women (> or = 60 years) is 6.6% and 32.1% respectively. We conclude that calcaneus BMD measurement is useful and sensitive for the screening and diagnosis of osteoporosis. A predictive diagnostic model for osteoporosis based on the calcaneus was constructed using multiple linear regression and the WHO criteria for diagnosing osteoporosis can be applied to calcaneus BMD.