Krebs Erin E, Taylor Brent C, Cauley Jane A, Stone Katie L, Bowman Paula J, Ensrud Kristine E
Robert Wood Johnson Clinical Scholars Program and Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
J Am Geriatr Soc. 2006 Jan;54(1):63-9. doi: 10.1111/j.1532-5415.2005.00541.x.
To determine whether higher adiposity is associated with greater breast cancer risk in older postmenopausal women.
Prospective cohort study with mean follow-up of 11.3 years.
Four U.S. clinical centers.
Seven thousand five hundred twenty-three women (mean age 73.5) enrolled in the Study of Osteoporotic Fractures.
Weight, height, and waist and hip circumference were measured at baseline. Body composition was determined using bioelectrical impedance. Risk factor information was obtained by interview and questionnaire. Bone mineral density was measured using dual energy x-ray absorptiometry. The outcome was incident invasive breast cancer, confirmed using medical records.
After adjustment for multiple risk factors, including bone density, women in the uppermost quartiles of weight, weight gain since age 25, body mass index, waist circumference, and percentage of body fat had higher breast cancer rates than women in the first quartiles of each measure. For example, breast cancer rates were 49% higher for women in the uppermost quartile of weight (hazard ratio (HR)=1.49, 95% confidence interval (CI)=1.05-2.10), 64% higher for women in the top quartile of weight gain since age 25 (HR=1.64, 95% CI=1.15-2.34), and 58% higher for women in the top quartile of percentage of body fat (HR=1.58, 95% CI=1.11-2.23) than for women in the lowest quartile of each measure. The associations between adiposity measures and breast cancer rates were not altered when the analyses were limited to very elderly women (> or = 70).
Higher adiposity is an independent risk factor for breast cancer in elderly women.
确定在绝经后老年女性中，较高的肥胖程度是否与更高的乳腺癌风险相关。
前瞻性队列研究，平均随访11.3年。
美国四个临床中心。
7523名女性（平均年龄73.5岁）参与骨质疏松性骨折研究。
在基线时测量体重、身高、腰围和臀围。使用生物电阻抗法测定身体成分。通过访谈和问卷获取风险因素信息。使用双能X线吸收法测量骨密度。结局为确诊的浸润性乳腺癌，通过病历确认。
在对包括骨密度在内的多个风险因素进行调整后，体重、25岁以来体重增加量、体重指数、腰围和体脂百分比处于最高四分位数的女性，其乳腺癌发病率高于各测量指标处于第一四分位数的女性。例如，体重处于最高四分位数的女性乳腺癌发病率高49%（风险比（HR）=1.49，95%置信区间（CI）=1.05 - 2.10），25岁以来体重增加量处于最高四分位数的女性高64%（HR = 1.64，95% CI = 1.15 - 2.34），体脂百分比处于最高四分位数的女性高58%（HR = 1.58，95% CI = 1.11 - 2.23），与各测量指标处于最低四分位数的女性相比。当分析仅限于高龄女性（≥70岁）时，肥胖指标与乳腺癌发病率之间的关联未改变。
较高的肥胖程度是老年女性患乳腺癌的独立风险因素。
