JCEM：绝经后女性体重变化影响性激素水平

内源性性激素是绝经后乳腺癌的危险因素，性激素改变潜在的益处是体重减轻。为了探讨绝经后女性血浆雌二醇和睾酮水平变化是否与BMI和血浆瘦素变化的有关，来自英国萨里大学癌症研究所的Michael E Jones教授及其团队进行了一项研究，该研究发现绝经后女性几年内BMI和血浆瘦素改变与雌二醇和睾酮水平的改变相关，这个结果提示个体脂肪减少导致绝经后雌二醇和睾酮水平大幅降低，为体重管理降低乳腺癌风险提供支持。该研究结果在线发表在2013年5月10日的美国《临床内分泌代谢杂志》（The journal of clinical endocrinology & metabolism）上。

该研究中是一项由超过100000例来自英国普通人群的女性志愿者组成的队列研究。受试者样本由177例45岁以上、在2004–2005年期间和2010–2011年期间提供血液样本的绝经后女性组成。主要观察指标是BMI每变化1kg/m²和血浆瘦素每变化1ng/ml，血浆雌二醇和睾酮水平变化百分比。

该研究结果表明，在BMI下降的女性中间，BMI每下降1kg/m²,雌二醇减少12.7%（95%可信区间（CI）：6.4%，19.5%；P＜0.0001），而在BMI增加的女性中间，BMI每增加1kg/m²,雌二醇增加6.4%（0.2%，12.9%；P=0.042）。睾酮对应的数据为：10.7%（3.0%，19.0%；P=0.006）和1.9%（－5.4%，9.7%；P=0.61）每kg/m² BMI变化。在有瘦素变化的女性，每ng/ml瘦素减少和增加，雌二醇分别下降3.6%（1.3%，6.0%；P=0.003）和增加1.7%（－0.3%，3.6%；P=0.094）。睾酮对应的数据为4.8%（2.0%。7.8%；P=0.009）和0.3%（－2.0%，2.6%，P=0.82）每ng/ml瘦素变化。

该研究发现，绝经后女性几年内BMI和血浆瘦素改变与雌二醇和睾酮水平的改变相关，这个结果提示个体脂肪减少导致绝经后雌二醇和睾酮水平大幅降低，为体重管理降低乳腺癌风险提供支持。

Changes in estradiol and testosterone levels in postmenopausal women after changes in body mass index.
Abstract
CONTEXT:Endogenous sex hormones are risk factors for postmenopausal breast cancer. A potential route for favourable hormonal modification is weight loss.OBJECTIVE:To measure change in plasma estradiol and testosterone levels in postmenopausal women in relation to change in BMI and plasma leptin.SETTING:Women within a cohort study of over 100,000 female volunteers from the general population, United Kingdom.PARTICIPANTS:A sample of 177 postmenopausal women aged over 45 years who provided blood samples during 2004-2005 and again during 2010-2011.MAIN OUTCOME MEASURE:Percentage change in plasma estradiol and testosterone levels per 1kg/m2 change in BMI and per 1ng/ml change in plasma leptin.RESULTS:Among women with reduction in BMI estradiol decreased 12.7% (95% confidence interval: [6.4%, 19.5%]; P<0.0001) per kg/m2 and among women with increased BMI estradiol increased 6.4% [0.2%, 12.9%] (P=0.042). The corresponding figures for testosterone were: 10.7% [3.0%, 19.0%] (P=0.006) and 1.9% [-5.4%, 9.7%] (P=0.61) per kg/m2. For women with decreases and increases in leptin, estradiol decreased by 3.6% [1.3%, 6.0%] (P=0.003) per ng/ml and increased by 1.7% [-0.3%, 3.6%] (P=0.094) respectively. The corresponding figures for testosterone were: 4.8% [2.0%, 7.8%] (P=0.009) and 0.3% [-2.0%, 2.6%] (P=0.82) per ng/ml.CONCLUSIONS:In postmenopausal women changes in BMI and plasma leptin occurring over several years are associated with changes in estradiol and testosterone levels. The results suggest that fat loss by an individual can result in substantial decreases in postmenopausal estradiol and testosterone levels and provides support for weight management to lessen breast cancer risk.