以往的研究已经证实了体重指数与乳腺癌之间的关联，但是脂肪质量比体重指数更直接地测量人体脂肪组织的量。该研究调查了绝经后妇女的体脂肪量、无脂肪质量和其他人体测量指标对乳腺癌的关联，根据是否使用激素替代治疗（HRT）进行了分组。研究对象来自1993-1997年之间建立起来的丹麦饮食、癌症和健康队列，包括了进行基础测量的24,219名绝经后的妇女。通过全国性的登记获得了乳腺癌发病情况（结果）、其他癌症诊断情况和存活状况（截尾变量）的信息，截至2016年。采用Cox回归模型估计风险比（HR）和95%置信区间（CI），同时根据HRT使用和年龄进行分层和调整已知的乳腺癌危险因素。在总共431,104人年的观察期内，1919名妇女发生了乳腺癌。在从未使用HRT的人群中，在65岁或更大年龄组中，每1 kg/m2增加的体脂肪质量指数（BFMI）的HR为1.06（95% CI，1.03-1.08），每10%增加的体脂肪百分比的HR为1.30（95% CI，1.14-1.47）。在65岁以下的年龄组中，与乳腺癌的HR接近于1。对于脂肪无质量指数，每1 kg/m2增加的HR分别为1.11（95% CI，1.02-1.21）和1.17（95% CI，1.10-1.23），分别用于65岁以下和65岁以上的乳腺癌。互相调整会减弱BFMI和体脂肪百分比的HR，而脂肪无质量指数的HR则几乎不受影响。在曾经使用HRT的人群中，任何身体成分测量值与两个年龄组的乳腺癌发病率之间均没有统计学显著的关联。在从未使用HRT的绝经后妇女中，BFMI与65岁或以上年龄组的乳腺癌有关联。无论年龄，与BFMI相比，无脂肪质量指数更强烈地与绝经后乳腺癌发生率相关。 版权所有©2023 Elsevier Inc.。保留所有权利。

Previous studies have established associations between body mass index and breast cancer, but fat mass is a more direct measure of the amount of fat tissue in the body than body mass index. This study examined the association between body fat mass, fat-free mass, and other anthropometric measures and breast cancer in postmenopausal women according to use of hormone replacement therapy (HRT).From the Danish Diet, Cancer and Health cohort established during 1993-1997, 24,219 postmenopausal women were included who had anthropometric and bioimpedance measurements performed by a laboratory technician at baseline. Information on breast cancer incidence (outcome), other cancer diagnoses, and vital status (censoring variables) through 2016 was obtained from nationwide registers. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CIs) while adjusting for known breast cancer risk factors and stratifying by HRT use and running age.During a total of 431,104 person-years, 1919 women developed breast cancer. Among never-users of HRT, the HR for breast cancer at or after age 65 years was 1.06 (95% CI, 1.03-1.08) per 1 kg/m2 higher body fat mass index (BFMI), and 1.30 (95% CI, 1.14-1.47) per 10% higher body fat percentage. The corresponding HRs for breast cancer before age 65 years were close to unity. The HRs were 1.11 (95% CI, 1.02-1.21) and 1.17 (95% CI, 1.10-1.23) for each 1 kg/m2 increase in fat-free mass index, respectively, for breast cancer below and above age 65 years. Mutual adjustment attenuated the HRs for BFMI and body fat percentage, whereas the HRs for fat-free mass index were largely unaffected. Among ever-users of HRT, there was no statistical significant association between any of the body composition measures and breast cancer incidence in the two age groups.Among postmenopausal women who never used HRT, BFMI was associated with breast cancer in women aged 65 years or older. Fat-free mass index was found to be more strongly associated with postmenopausal breast cancer incidence than BFMI independently of age in never-users of HRT.Copyright © 2023 Elsevier Inc. All rights reserved.