Effect of hormonal contraception on bone mineral density

最近的研究表明，使用醋酸甲羟孕酮(DMPA)可能会对骨密度(BMD)产生不利影响。相比之下，口服避孕药的使用据报道有有益的效果或没有效果。在一项初步研究中，我们观察到服用DMPA的人骨密度下降了3.0%，而服用30-35片口服药的人骨密度增加了0.1%-2.9%。然而，关于BMD和DMPA之间的具体关系的问题尚未得到充分解决。此外，几乎没有关于最近上市的只含有20杯雌二醇的药片的效果的数据。考虑到美国每年有1100多万女性使用激素避孕药，获得有关这些药物对骨骼健康影响的准确信息似乎是当务之急。为了解决这个重要的问题，我们建议进行一项前瞻性临床试验，比较服用DMPA或含有20毫克雌二醇的口服避孕药的妇女与不使用激素避孕药的妇女在两年时间间隔内骨密度的变化。每个队列将由229名年龄在16岁至33岁之间的白人、黑人或西班牙裔种族/民族的女性组成。将分析主要结果(即骨密度和骨代谢的生物标志物)，以评估与对照组相比，每组避孕组在6、12、18和24个月时的基线变化。此外，我们将能够评估激素避孕对那些停止使用该方法的人的潜在不利影响的可逆性，方法是在停止使用该方法时进行骨扫描并测量生物标记物，从此时起每隔6个月进行一次。这项研究将首先调查种族/民族和年龄在避孕相关骨密度变化中的作用，同时以多元方式考虑行为相关因素(例如，以前是否使用避孕药、营养摄入量、锻炼习惯、饮酒和吸烟)。最终，这项研究将确定哪些妇女(如果有的话)因在生育年龄使用这些激素避孕药而面临骨量减少或骨质疏松症的风险增加。

Recent studies have suggested that use of depot medroxyprogesterone acetate (DMPA) may have an adverse effect on bone mineral density (BMD). In contrast, use of oral contraceptives has been reported to have a beneficial effect or no effect. In a preliminary study, we observed a decrease of 3.0 percent in BMD among users of DMPA as compared with an increase of 0.1 percent-2.9 percent among users of 30-35 mug pills. Questions regarding the specific relationship between BMD and DMPA, however, have not been fully addressed. Furthermore, almost no data are available on the effects of the recently marketed pills containing only 20 mug of estradiol. Considering that over 11 million women in the US use hormonal contraception each year, it seems imperative to obtain accurate information on the effects of these medications on skeletal health. To address this important question, we propose to conduct a prospective clinical trial comparing changes in BMD over a 2-year interval experienced by women using DMPA or oral contraceptives containing 20 mug estradiol as compared with women not using hormonal contraception. Each cohort will be comprised of 229 women aged 16 to 33 years of white, black, or Hispanic race/ethnicity. The primary outcomes (ie, BMD and biomarkers of bone metabolism) will be analyzed to assess changes from baseline within each contraceptive group at 6, 12, 18, and 24 months as compared to changes observed among controls. Furthermore, we will be able to assess the reversibility of potential adverse effects of hormonal contraception on BMD among those who discontinue their method by conducting a bone scan and measuring biomarkers at the point of discontinuation and at 6-month intervals from this point. This study will be among the first to investigate the role of race/ethnicity and age in contraceptive-related BMD changes while accounting for behavioral correlates (eg, prior contraceptive use, nutritional intake, exercise habits, alcohol use, smoking) in a multivariate fashion. Ultimately, this study will determine which women, if any, are placed at increased risk of osteopenia or osteoporosis as a result of using these hormonal contraceptives during their reproductive years.