Osteoporotic fracture rate, bone mineral density, and bone metabolism in Taiwan

Taiwanese people have spinal bone mineral density (BMD) values similar to those of Caucasians, whereas their hip BMD values are 10% to 15% lower. In 1992, the prevalence of vertebral fractures, diagnosed according to the -3 SD morphometric criteria, was 18% for women and 12% for men older than 65 years in the major cities of Taiwan. Despite this high prevalence of vertebral fractures, the incidence of hip fractures in the elderly of both sexes was only 203 per 100,000 in 1996, which was lower than in Caucasians and similar to that in mainland Chinese. Hip and vertebral fractures are both associated with lower BMD values. The risk factors for low BMD in Taiwan include a lighter body weight and aging in both sexes, and menopause for women. An increased bone turnover rate is associated with a lower BMD in both men and postmenopausal women, although the rate seems to increase in women but decrease in men with aging. In Taipei City, daily calcium intake is relatively low (mean intake +/- SD; 640 +/- 240 mg), but the vitamin D stores seem to be generally adequate for middle-aged and elderly women. There was a significant association between a higher daily calcium intake and a higher BMD/lower bone turnover rate for women in this age group. Vitamin D receptor allelic polymorphism was not an important factor in low BMD and rapid bone turnover.