身体测量指标与女性乳腺癌关系的前瞻性队列研究

目的研究上海女性身体测量指标与绝经前后乳腺癌之间的关系.方法采用前瞻性队列研究方法.1997-2000年在上海市区建立一个73 461人年龄40～70岁的女性队列.每2年随访一次,至2004年6月共收集乳腺癌新发病例432例.用Cox回归模型估计身体测量指标与女性乳腺癌发生的相对危险度（RR）和95%可信区间（CI）.结果调整年龄、文化程度、能量摄入、月经、生育等混杂因素后,基线调查时体重、体重指数（BMI）、腰臀围比例（WHR）和20岁后体重增加与绝经后女性乳腺癌危险性呈正相关,与绝经前女性乳腺癌发生无关.身高与乳腺癌危险的显著正相关关系仅在绝经前女性中发现,20岁时身高在161 cm以上者发生乳腺癌的危险是157.1 cm以下者的1.84倍（95%CI：1.30～2.61）.20岁时BMI处于平均水平者绝经前患乳腺癌的危险性显著高于其他两组.BMI和WHR互相调整后,WHR独立于BMI的作用接近显著性水平.调整BMI后,20岁后体重增加会显著增加绝经后乳腺癌危险（RR=1.61,95%CI：1.09～2.37）.结论对于绝经后女性,成年后体重增加和中心性肥胖都是预测乳腺癌危险的指标.因此控制成年后体重、减少腹部脂肪堆积是预防绝经后乳腺癌发生的有效措施.身高可能是影响绝经前女性乳腺癌发生的危险因素.

Anthropometry and female breast cancer: a prospective cohort study in urban Shanghai

Objective To investigate the association between anthropometry and risk of breast cancer among pre-and post-menopausal women in urban Shanghai. Methods A total of 73 461 female residents aged 40 to 70 years in urban Shanghai were recruited in a prospective cohort study (the Shanghai women's health study) during 1997 through 2000, and were actively followed up biennially. During mean follow-up period of 5.66 years, 432 incident cases of breast cancer were identified in the cohort. Cox regression model was used to estimate the adjusted relative risks (RRs) and 95% confidence intervals (C7s). Results After adjustment for some potential confounding factors, baseline weight, body mass index(BMI), waist-to-hip ratio(WHR) and weight gain since age 20 were positively associated with the increased risk of breast cancer among postmenopausal women. The positive association between height and breast cancer was found among premenopausal women. Among them, those with height taller than 161 cm at age 20 experienced 1.84 fold increased risk (95% CI: 1.30-2.61) of breast cancer compared to their counterpart with height shorter than 157.1 cm. Women who were either much heavier or lighter than average at age 20 were at reduced risk. Further analyses mutually adjusted for BMI and WHR did not substantially alter the positive association for both BMI and WHR. After further adjustment for BMI, weight gain since age 20 was significantly associated to an increased risk for postmenopausal breast cancer (RR = 1.61, 95% CI: 1.09-2.37). Conclusions Weight gain and central obesity seemed to be strong predictors for the risk of breast cancer among postmenopausal women. Controlling weight and decreasing fat around waist were effective means to prevent postmenopausal breast cancer and height might serve as a risk factor for premenopausal breast cancer.