Bone mineral density differences at the femoral neck and Ward's triangle: a comparison study on the reference data between Chinese and Caucasian women.

The incidence of hip fracture is lower in Chinese women compared with those from western countries, though they usually have lower bone mineral density (BMD). In this study, reference data (from Caucasian women) supplied by the manufacturer of Hologic Inc. was compared with data obtained from healthy women in Changsha, Hunan province, P.R.C. A total of 1488 Chinese women aged 15-95 years were randomly chosen for the study. Measurements of BMD were taken at the hip by dual energy X-ray absorptiometry (DXA) (QDR 4500A, Hologic Inc., USA). The BMD and the BMD decrease rate were somewhat lower than reference curves at all age groups and all sites except for the femoral neck and Ward's triangle. Chinese women reached their peak BMD 5-10 years later than their counterparts, and had a lower BMD decrease rate for about 35 years after peak BMD was attained. The fact that Chinese women take longer time to reach peak BMD and have a lower BMD decrease rate at the neck and Ward's triangle after peak BMD is attained protects them against hip fractures, and is a phenomenon that needs to be studied in the future.