DO ORAL CONTRACEPTIVES CAUSE WEIGHT GAIN?

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 这项资助旨在探索口服避孕药对成年期体重控制的影响。 许多妇女停止服用口服避孕药，因为她们担心会有副作用，体重增加。但是，这种未能持续服用口服避孕药导致意外怀孕率增加。令人惊讶的是，在动物（小鼠、大鼠、猫、狗、猴）中的研究表明，对卵巢切除动物施用雌激素和孕酮通常导致体重减轻，而不是体重增加。这项资助的总体目标是记录卵巢完整的灵长类动物长期口服避孕药（OC）一年后体重的变化。 我们假设，服用口服避孕药一年的猴子实际上可能经历了轻微的体重减轻;这一发现将怀疑口服避孕药导致体重增加的副作用。所有猴均完成研究方案，无不良事件。与基线相比，发现使用药丸后代谢率显著增加、体重降低和体脂%降低。 当分别分析各组（肥胖组与正常组）时，肥胖组对整个组的显著变化负责。 对于整个组和任何基于BMI的组，使用OC时的食物摄入量、活动水平或%瘦肌肉质量均未发生变化。 总的来说，OC的使用似乎增加了雌性猴子的24小时代谢率，这反过来又似乎对体重和体脂%产生不同的影响，这取决于基线体重。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This grant explores the effect of oral contraceptives on body weight control in adulthood. Many women stop taking oral contraceptives because they are concerned about a perceived side effect, weight gain. But this failure to consistently take oral contraceptives leads to increased rates of unintended pregnancy. Surprisingly, studies in animals (mice, rats, cats, dogs, monkeys) have shown that estrogen and progesterone administration to ovariectomized animals generally leads to weight loss, rather than weight gain. The overall goal of this grant is to document changes in body weight when ovary-intact primates are chronically given oral contraceptives(OC) for a one-year period of time. We hypothesized that monkeys taking oral contraceptives for a yearmay in fact experience a mild weight loss; a finding which would discredit the perceived side effect of oral contraceptives in causing weight gain. All monkeys completed the study protocol with no adverse events. A significant increase in metabolic rate, a decrease in body weight, and a decrease in % body fat with pill use was found as compared to baseline. When analyzing the groups separately (obese versus normal), the obese group was responsible for the significant changes seen for the entire group.. No changes were seen in food intake, activity level, or % lean muscle mass with OC use for the entire group and for either BMI-based group. Overall, OC use appears to increase 24 hour metabolic rate in female monkeys, which in turn appears to differentially affect weight and % body fat depending on baseline weight.