College of Medicine and Public Health, Flinders University, Adelaide, Australia.
Flinders Centre for Innovation in Cancer, Flinders University , Adelaide, Australia.
BMC Public Health. 2018 Apr 6;18(1):460. doi: 10.1186/s12889-018-5357-1.
Breast cancer (BC) incidence in Australian women aged 45 to 64 years ('middle-aged') has tripled in the past 50 years, along with increasing alcohol consumption and obesity in middle-age women. Alcohol and obesity have been individually associated with BC but little is known about how these factors might interact. Chronic psychological stress has been associated with, but not causally linked to, BC. Here, alcohol could represent the 'missing link' - reflecting self-medication. Using an exploratory cross-sectional design, we investigated inter-correlations of alcohol intake and overweight/obesity and their association with BC incidence in middle-aged women. We also explored the role of stress and various lifestyle factors in these relationships.
We analysed population data on BC incidence, alcohol consumption, overweight/obesity, and psychological stress. A case control study was conducted using an online survey. Cases (n = 80) were diagnosed with BC and controls (n = 235) were women in the same age range with no BC history. Participants reported lifestyle data (including alcohol consumption, weight history) over consecutive 10-year life periods. Data were analysed using a range of bivariate and multivariate techniques including correlation matrices, multivariate binomial regressions and multilevel logistic regression.
Ecological inter-correlations were found between BC and alcohol consumption and between BC and obesity but not between other variables in the matrix. Strong pairwise correlations were found between stress and alcohol and between stress and obesity. BMI tended to be higher in cases relative to controls across reported life history. Alcohol consumption was not associated with case-control status. Few correlations were found between lifestyle factors and stress, although smoking and alcohol consumption were correlated in some periods. Obesity occurring during the ages of 31 to 40 years emerged as an independent predictor of BC (OR 3.5 95% CI: 1.3-9.4).
This study provides ecological evidence correlating obesity and alcohol consumption with BC incidence. Case-control findings suggest lifetime BMI may be important with particular risk associated with obesity prior to 40 years of age. Stress was ecologically linked to alcohol and obesity but not to BC incidence and was differentially correlated with alcohol and smoking among cases and controls. Our findings support prevention efforts targeting weight in women below 40 years of age and, potentially, lifelong alcohol consumption to reduce BC risk in middle-aged women.
在过去的 50 年里，澳大利亚 45 至 64 岁的中年女性乳腺癌（BC）的发病率增加了两倍，同时中年女性的酒精摄入量和肥胖率也在上升。酒精和肥胖已被单独与乳腺癌相关联，但尚不清楚这些因素如何相互作用。慢性心理压力与乳腺癌有关，但与乳腺癌没有因果关系。在这里，酒精可能代表着“缺失的一环”-反映了自我治疗。我们采用探索性横断面设计，研究了中年女性饮酒量和超重/肥胖的相互关系及其与乳腺癌发病率的关系。我们还探讨了压力和各种生活方式因素在这些关系中的作用。
我们分析了乳腺癌发病率、酒精消费、超重/肥胖和心理压力的人群数据。使用在线调查进行了病例对照研究。病例组（n=80）被诊断为乳腺癌，对照组（n=235）为同年龄段且无乳腺癌病史的女性。参与者报告了连续 10 年生活期间的生活方式数据（包括酒精消费、体重史）。使用相关矩阵、多元二项式回归和多层次逻辑回归等多种技术分析了数据。
在乳腺癌与酒精消费和乳腺癌与肥胖之间发现了生态相互关联，但矩阵中的其他变量之间没有关联。在压力和酒精以及压力和肥胖之间发现了强烈的两两相关性。在报告的整个生命历史中，病例组的 BMI 往往高于对照组。酒精消费与病例对照状态无关。尽管在某些时期吸烟和饮酒之间存在相关性，但在生活方式因素与压力之间发现的相关性很少。在 31 至 40 岁之间发生的肥胖症成为乳腺癌的独立预测因素（OR 3.5，95%CI：1.3-9.4）。
这项研究提供了生态学证据，将肥胖症和酒精消费与乳腺癌发病率相关联。病例对照研究结果表明，终生 BMI 可能很重要，尤其是在 40 岁之前肥胖的风险更高。压力在生态上与酒精和肥胖相关联，但与乳腺癌发病率无关，并且在病例和对照组中与酒精和吸烟的相关性不同。我们的研究结果支持针对 40 岁以下女性体重的预防措施，以及可能的终生酒精消费，以降低中年女性的乳腺癌风险。
