Oral Contraceptive Use and Bone Density in Young Women

描述(由申请人提供)：对于1000多万使用口服避孕药(OCS)的美国妇女来说，关于OCS对健康影响的明确证据是一个主要的公共卫生问题。最近的几项研究表明，目前的OC配方可能会抑制年轻女性的骨量峰值。然而，这种可能性还没有得到充分的评估，特别是在青少年中使用OC，这是最活跃的骨量增加的群体。这项应用的重点是彻底评估使用OC对年轻女性骨骼的影响。我们考虑了不同的骨骼部位、不同的使用时间和不同的OC雌激素含量。重要的是，据我们所知，这将是第一个记录OC停用后骨密度(BMD)变化的前瞻性研究。 我们提出了一项前瞻性的流行病学研究，研究新的和正在进行的OC使用以及在一组青春期和年轻成年女性中停用OC对骨骼的影响。该队列(n=600)将从14至30岁的HMO参与者中招募，其中300名参与者年龄在14-18岁，300名参与者年龄在19-30岁。每个年龄段将包括200名OC用户和100名对照女性。我们将评估低剂量(20微克EE)和高剂量(35微克EE)配方可能产生的不同效果。卫生组织的自动药房和会员档案将用于选择新的和正在使用OCS的女性，并随机选择没有使用激素避孕、年龄和临床频率匹配的对照女性。参与者将被纵向跟踪24-36个月。主要结果，即骨密度，将每6个月在选定的解剖部位(髋部、脊柱、全身)使用双能X射线吸收测量仪进行测量。到目前为止，我们在青少年和年轻成年女性中调查注射避孕药和骨密度之间的关系的工作中，我们用类似的方法实现了出色的参与者招募和保留，并制定了相关的测量和分析策略。 在性活跃的青少年和20多岁的女性中，OC的使用率最高。这些人也是正在积极增骨的女性。鉴于骨质疏松症对公众健康的重要性日益增加，以及OC暴露在生长的关键阶段的流行，重点评估OC使用对这些年轻女性骨骼健康的潜在不利影响--以及停止这种暴露后她们可能的改善--是至关重要的。

DESCRIPTION (provided by applicant): For the more than 10 million US women using oral contraceptives (OCs), clear evidence regarding the health effects of OCs is a major public health concern. Several recent studies suggest that current OC formulations may act to suppress peak bone mass accrual in young women. However, this possibility has not been fully evaluated, particularly with regard to OC use among adolescents, the group most actively gaining bone. This application is focused on a thorough evaluation of the impacts of OC use on bone in young women. We include consideration of different skeletal sites, varying durations of use, and differing OC estrogen content. Importantly, this would be the first prospective study to our knowledge to document changes in bone mineral density (BMD) after OC discontinuation. We propose a prospective epidemiologic study of the effects on bone of new and ongoing OC use and of OC discontinuation in a cohort of adolescent and young adult women. The cohort (n=600) will be recruited from a defined population of HMO enrollees between the ages of 14 and 30, with 300 participants aged 14-18 years and 300 aged 19-30. Each age group will include 200 OC users and 100 comparison women. We will evaluate possibly different effects from a low-dose (20 mcg EE) and a higher-dose (35 mcg EE) formulation. The HMO's automated pharmacy and membership files will be used to select women who are new and ongoing users of OCs and to randomly select comparison women who are not using hormonal contraception, frequency matching on age and clinic. Participants will be followed longitudinally for 24-36 months. The primary outcome, bone mineral density, will be measured every 6 months at selected anatomic sites (hip, spine, whole body) using dual-energy x-ray absorptiometry. In our work to date investigating the association between injectable contraception and BMD in adolescents and young adult women, we have achieved excellent participant recruitment and retention with similar methods and have developed relevant measurement and analytic strategies. OC use is highest among sexually active adolescents and women in their 20s. These are also women who are actively gaining bone. Given the increasing public health importance of osteoporosis and the prevalence of OC exposure at a crucial stage of growth, focused evaluation of the potentially adverse effects of OC use on the skeletal health of these young women--and their possible amelioration upon cessation of this exposure--is essential.