Bainbridge K E, Sowers M F, Crutchfield M, Lin X, Jannausch M, Harlow S D
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA.
Am J Epidemiol. 2002 Sep 1;156(5):410-7. doi: 10.1093/aje/kwf049.
The aims of this prospective cohort study were to determine rates of premenopausal and early postmenopausal bone loss, age at onset of bone loss, and whether rates of bone loss depend on baseline bone mineral density (BMD). The cohort of 614 women aged 24-44 years at baseline from the longitudinal Michigan Bone Health Study was followed for 6 years beginning in 1992-1993. Up to five BMD measurements of the lumbar spine (L(2-4)) and the femoral neck were obtained through 1998-1999 by using dual x-ray absorptiometry and were standardized (as z scores) relative to a young adult, female BMD distribution. Regression models were used to estimate rates of BMD change and to examine BMD as a function of age. At the lumbar spine, the rate of BMD change for premenopausal women varied with time. At the femoral neck, the rate of change was -1.6% (95% confidence interval: -0.9%, -2.3%) of a z score annually (annual loss of 0.3% of baseline BMD (g/cm(2))). Evidence for age at onset of bone loss at the lumbar spine was inconclusive. Bone loss began by the midtwenties at the femoral neck. Additional annual change of -0.7% (95% confidence interval: -0.2%, -1.2%) of a z score was observed at the femoral neck for each unit increase in BMD z score at baseline.
这项前瞻性队列研究的目的是确定绝经前和绝经后早期的骨质流失率、骨质流失开始的年龄，以及骨质流失率是否取决于基线骨矿物质密度（BMD）。来自密歇根州纵向骨健康研究的614名基线年龄在24 - 44岁的女性队列，从1992 - 1993年开始随访6年。通过使用双能X线吸收法，在1998 - 1999年期间对腰椎（L(2 - 4)）和股骨颈进行了多达五次BMD测量，并相对于年轻成年女性BMD分布进行了标准化（作为z评分）。使用回归模型估计BMD变化率，并将BMD作为年龄的函数进行研究。在腰椎，绝经前女性的BMD变化率随时间变化。在股骨颈，变化率为每年z评分的 -1.6%（95%置信区间：-0.9%，-2.3%）（每年基线BMD（g/cm(2)）损失0.3%）。腰椎骨质流失开始年龄的证据尚无定论。股骨颈在二十多岁中期开始出现骨质流失。在股骨颈，基线BMD z评分每增加一个单位，每年额外观察到z评分变化 -0.7%（95%置信区间：-0.2%，-1.2%）。
