Parazzini F, Bidoli E, Franceschi S, Schinella D, Tesio F, La Vecchia C, Zecchin R
Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy.
J Epidemiol Community Health. 1996 Oct;50(5):519-23. doi: 10.1136/jech.50.5.519.
To analyse the relationship between menstrual and reproductive factors and the risk of low bone mineral density (BMD).
This was a population based screening programme carried out between 1991 and 1993 among 1373 perimenopausal women in northern Italy by means of dual photon absorptiometry at the lumbar spine.
BMD was strongly related to the age at menopause. In comparison with women reporting menopause below 45 years of age, the odds ratios (OR) of being in the lowest compared with the highest BMD tertile were 0.7 (95% confidence interval (CI) 0.3,1.5) and 0.3 (95% CI 0.1,0.8), respectively, in those with menopause at age 45-49 and above 50 years: the trend in risk was significant. Likewise, the risk of being in the lowest tertile increased with years since the menopause. Compared with women who reported they had undergone the menopause less than two years before interview, the OR of being in the lowest BMD tertile were 2.1 (95% CI 1.1,4.3), 2.3 (95% CI 1.1, 5.0), and 5.7 (95% CI 2.5,12.9) respectively in women who reported menopause 2-5, 6-9, and > or = 10 years earlier. The protective effect on bone density of late age at menopause was observed in different strata of years since menopause. Likewise, the increasing risk of a low BMD with increasing years since the menopause was evident in strata of different age at menopause. No relationships were observed between BMD and the age at menarche, characteristics of menstrual cycles, and the duration of menses. Likewise, no association emerged between reproductive history, including parity and age at first pregnancy, and BMD.
In this Italian population the risk of being in the lowest BMD tertile decreased with increasing age at menopause and increased with years since menopause. No relationships emerged between BMD and other menstrual characteristics or reproductive factors.
分析月经和生殖因素与低骨矿物质密度（BMD）风险之间的关系。
这是一项基于人群的筛查项目，于1991年至1993年期间在意大利北部的1373名围绝经期妇女中开展，采用双能X线吸收法测量腰椎骨密度。
骨密度与绝经年龄密切相关。与报告绝经年龄低于45岁的女性相比，绝经年龄在45 - 49岁以及50岁以上的女性中，处于最低骨密度三分位数与最高骨密度三分位数相比的比值比（OR）分别为0.7（95%置信区间（CI）0.3,1.5）和0.3（95%CI 0.1,0.8）：风险趋势具有显著性。同样，处于最低三分位数的风险随着绝经后的年限增加而升高。与报告在访谈前不到两年绝经的女性相比，分别在2 - 5年、6 - 9年以及≥10年前绝经的女性中，处于最低骨密度三分位数的OR分别为2.1（95%CI 1.1,4.3）、2.3（95%CI 1.1,5.0）以及5.7（95%CI 2.5,12.9）。在绝经后的不同年限分层中均观察到绝经年龄较大对骨密度的保护作用。同样，在不同绝经年龄分层中，绝经后年限增加导致低骨密度风险增加的情况也很明显。未观察到骨密度与初潮年龄、月经周期特征以及月经持续时间之间的关系。同样，包括产次和首次怀孕年龄在内的生殖史与骨密度之间也未发现关联。
在这个意大利人群中，处于最低骨密度三分位数的风险随着绝经年龄的增加而降低，随着绝经后的年限增加而升高。骨密度与其他月经特征或生殖因素之间未发现关系。
