Normal data for lumbar spine bone mineral content in healthy elderly Chinese: influences of sex, age, obesity and ethnicity.

Bone mineral density (BMD) at the level of the lumbar spines (L2-L4) was determined in 353 normal, elderly Chinese (248 females and 95 males, aged 40-85 years) living in Taiwan with a commercial dual-photon absorptiometer (DPA) and presented as g cm-2. The body mass index (BMI) was calculated according to the standard formula, and if the BMI was > 25 kg m-2 the patient was considered as being obese. The results show that linear correlations between the age and BMD for males or females are significant. Regular decreases of BMD values in the different age groups are found for both sexes. In addition, the BMD values of males are higher than those of females. The obese group was significantly higher than the lean one with regard to BMD for males and females including premenopausal and postmenopausal groups. In comparison with the normal data of American residents, the mean BMD of Chinese are lower than those of American residents of the same ages. Our findings indicate that the influence of sex, age, obesity and ethnicity exist in the BMD values of elderly healthy Chinese.