THE BONE-MINERAL DENSITY CHANGE WITH AGING OF JAPANESE WOMEN MEASUREDBY SINGLE-ENERGY X-RAY ABSORPTIOMETRY AND DUAL-ENERGY X-RAY ABSORPTIOMETRY

The calcaneus bone mineral density of 473 Japanese women was measured by single energy X-ray absorptiometry (SXA) and the verterae bone mine ral density of 198 Japanese women was measured by dual energy X-ray ab sorptiometry (DEXA). The calcaneus bone mineral density of Japanese wo men starts decreasing from age 30, and the rate of decrease accelerate s from the age of 50. The vertebrae bone mineral density starts decrea sing from the age of 35, and a conspicuous decrease can be seen from t he age of 50 as well. Because bone deterioration of Japanese women is thought to start earlier than Caucasian, the necessity of osteoporosis screening before menopause was suggested. A high positive correlation (r = 0.804) between calcaneus bone mineral density and vertebrae bone mineral density was found, and a high degree of precision of SXA was shown.