遗传因素、生活方式和环境因素与多囊卵巢综合征(PCOS)的发生相关.身体质量指数(BMI)的增加会加剧生殖及代谢障碍,降低PCOS女性的生育能力.本文对在中国大陆21个研究中心开展的一项大样本、多中心、随机对照试验进行二次分析.共有1000名PCOS女性参加本试验.其中, 998名PCOS女性被纳入分析.BMI增加与月经失调加剧、高睾酮水平、高代谢综合征患病率以及生活质量降低相关.BMI正常组、超重组和肥胖组的女性人均排卵率分别为83.0%、78.2%和63.6% (P ＜ 0.001),活产率分别为23.6%、18.1%和15.3%(P = 0.030).与中国南方的PCOS患者相比,北方的PCOS患者生殖结局较差,血糖和血脂代谢不良,运动量少,以及总排卵率更低(81.2% vs 74.8%,绝对差:6.4%,95%置信区间:1.2%～11.5%).结果显示,中国南北方的汉族PCOS女性具有典型的表型特征.与生活在中国南方的女性相比,在同样的干预措施下,中国北方的女性BMI更高,糖脂代谢障碍更严重,临床结局更差.表型特征及排卵的差异可以通过BMI差异加以解释.“,”Genetic, lifestyle, and environmental factors contribute to the etiology of polycystic ovary syndrome (PCOS). Increased body mass index (BMI) exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS. This is a secondary analysis of a large-sample, multicenter, randomized controlled trial conducted at 21 sites in Chinese mainland. A total of 1000 women diagnosed with PCOS were enrolled in this trial. Of these, 998 women with PCOS were included in the analysis. Increased BMI was associated with more severe menstrual irregularities, elevated testosterone level, higher prevalence of metabolic syndrome, and poorer quality of life. The rates of ovulation per woman for the normal, overweight, and obese BMI groups were 83.0%, 78.2%, and 63.6%, respectively (P＜0.001), and the rates of live birth were 23.6%, 18.1%, and 15.3% (P=0.030). Northern PCOS patients showed more severe reproductive, glucose, and lipid profiles; less exercise; and lower total ovulation rates compared with PCOS patients from Southern China (74.8% vs 81.2%, absolute difference 6.4%, 95% confidence interval 1.2%-11.5%). The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China. The women living in Northern China showed a higher BMI, more severe glycolipid metabolism profiles, and subsequently worse clinical outcomes by the same interven-tions than those living in Southern China. The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.