Forearm bone mass and biochemical markers of bone remodelling in normal Chinese women

Abstract

We studied bone mineral content and density (BMC/BMD) and bone turnover markers in normal Chinese women from the age of 20 to 80 years and compared the data with those for normal women from the Western part of the world (Denmark). In all subjects (5 at each age;n=305) BMC and BMD were determined at three sites of the nondominant forearm with single X-ray absorptiometry (SXA). In addition, 10 women had five repeated measurements to determine the reproducibility of the equipment, demonstrating coefficients of variation of 1%–2% depending on the measurement site. The Chinese premenopausal women were on the average heavier (1 kg) than the postmenopausal women, but they were also taller (6 cm). The postmenopausal women had highly significantly less bone mass than the premenopausal women; 15% at the 1/4-distal site, 25% at the 8-mm-distal site, and 35% at the ultradistal site. At age 50, bone mass in Chinese women was very similar to that of a comparable group of Danish women. After age 50, bone loss accelerated and the rate of loss seemed more rapid in the Chinese than in the Danish women. Within the first 5 postmenopausal years, the most cortical part decreased by approximately 3.9%, the mixed cortical and trabecular site by 9.5%, and the mainly trabecular site by 16.2%. In the following 5 years the decreases were 6.3%, 5.5%, and 6.6%, respectively, and 5.6%, 11.3%, and 8.9% for year 11–15 after menopause. The bone decrement continued throughout the 25th year of menopause, and except for the ultradistal site, the rate of loss did not change very much. The postmenopausal women had highly significantly higher levels of all bone turnover markers than premenopausal women. The markers stayed high at all ages. We conclude that the present study gives the normal values of Chinese women's bone mass at three sites of the distal forearm. The data were collected in a way which allows them to be used as reference for normal Chinese women. The data demonstrate that women from the East and West are relatively similar in terms of bone mass.