ABSTRACT
BACKGROUND: Bone mineral content(BMC) can be determined by many methods, which are different in detecting position, clinical significance and differentiation between normal group and people with osteoporosis.OBJECTIVE: To establish a normal BMC standard by observing lumbar BMC with quantitative computerized tomography(QCT) measurement in Shenzhen women, so as to provide basis for clinical prevention and treatment of osteoporosis in the region.DESIGN: Randomized controlled, observational and comparative study taking normal women as subjects.SETTING: Medical imaging department of a hospital at district level.PARTICIPANTS: A total of 120 women aged 30 to 69 years, who received physical examination in the Central Hospital of Longgang district in Shenzhen from September 2000 to March 2002, were enrolled in this study. They were divided into four groups: 30 - 39 age group, 40 - 49 age group, 50 - 59 age group and 60 - 69 age group with 30 in each.METHODS: Trabecular and cortical BMC of lumber bodies(L1-3) were measured with QCT software so as to establish a standard of normal BMC in Shenzhen women and compare it with that of other regions.MAIN OUTCOME MEASURES: The mean BMC in Shenzhen women, and comparison with that of other regions at home and abroad.RESULTS: The results of QCT showed linear correlation between BMC and bone ash weight, which could be expressed by the following linear regression equation: ash weight =0. 92432 × BMC + 39. 0633. Lumbar BMC loss increased with age in Shenzhen perimenopausal women. The annual loss of spongy bone and compact bones was 1.38% and 0. 84%, respectively. BMC of women aged 50 to 59 years was[ (135.31 ± 18.36) mg/cm3], obviously higher than that of women in Changchun city, Beijing city and the United States [(120.21 ±37.40), (116.7 ±26.6), and(119.5 ±27.1) mg/cm3]( t = 2. 002, 3. 383, 3. 636, P ＜ 0.05 - 0. 01 ) . Moreover, BMC of women aged 30 to 39 years was also obviously higher than that of corresponding American women( t = 3.119, P ＜ 0.01 ). No significant difference was found in BMC among women of the other age groups in these regions( P ＞ 0. 05).CONCLUSION: This is the first time in our country to establish a standard of normal BMC in perimenopausal women with QCT measurement, which provides basis for early prevention and treatment of osteoporosis as well as evaluation of prognosis and fracture risk.