Effect of hormonal contraception on bone mineral density

最近的研究表明，使用长效醋酸甲羟孕酮（DMPA）可能对骨密度（BMD）产生不良影响。 相比之下，据报道使用口服避孕药有有益效果或没有效果。 在一项初步研究中，我们观察到DMPA使用者的BMD下降了3.0%，而30-35 mug药丸使用者的BMD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仅含20 μ g雌二醇的药丸的效果的数据。 考虑到美国每年有超过1100万女性使用激素避孕，因此获得这些药物对骨骼健康影响的准确信息似乎势在必行。 为了解决这一重要问题，我们建议进行一项前瞻性临床试验，比较使用DMPA或含有20 μ g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2年内BMD的变化。 每个队列将由229名年龄为16 - 33岁的白色、黑人或西班牙裔人种/种族的女性组成。 将分析主要结局（即BMD和骨代谢生物标志物），以评估每个避孕组在6、12、18和24个月时较基线的变化，并与对照组中观察到的变化进行比较。 此外，我们将能够评估激素避孕对那些停止其方法的人的BMD的潜在不良影响的可逆性，通过在停止时和从这一点开始的6个月间隔进行骨扫描和测量生物标志物。 本研究将是第一个研究种族/民族和年龄在避孕相关BMD变化中的作用，同时以多变量方式解释行为相关性（例如，既往避孕药使用、营养摄入、运动习惯、饮酒、吸烟）的研究。 最终，这项研究将确定哪些女性（如果有的话）由于在生育年龄使用这些激素避孕药而导致骨质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.