Objective: To investigate the associatiojn of body mass index (BMI) at different stages of life and weight gain in adulthood with obesity-related breast cancer risk biomarkers and to provide evidence for formulating policies concerning the prevention and control of breast cancer.
Methods: A cross-sectional study was designed based on the follow-up cohort of southwest China community-based breast cancer screening of women. Using sequential sampling, eligible participants were enrolled from the cohort as the subjects of the study. Information on the basic risk factors was collected and the height, weight, and plasma biomarker levels were measured. Multiple linear regression model was applied to analyze the associations of early adulthood BMI (defined as the BMI of the participant at age 20), adulthood BMI (defined as the BMI measured at the time of enrollment), and weight gain in adulthood with the biomarkers. The concentrations of the biomarkers were incorporated in the model after log transformation.
Results: The average age of the 442 participants was 49 (45, 54) years old, the average early adulthood BMI and adulthood BMI were 21.47 (19.56, 23.11) and 24.10 (22.59, 25.97) kg/m 2, respectively, and the average weight gain in adulthood was 6.60 (2.00, 11.00) kg. Adulthood BMI was negatively associated with adiponectin level ( β=-0.026, 95% CI: -0.045--0.008, P=0.006), and positively associated with C-reactive protein level ( β=0.095, 95% CI: 0.054-0.137, P<0.001) and leptin receptor level ( β=0.090, 95% CI: 0.063-0.117, P<0.001). No association was found between adulthood BMI and resistin levels or between adulthood BMI and insulin-like growth factor-binding protein-3 levels. BMI in early adulthood was found to be negatively associated with only insulin-like growth factor-binding protein-3 levels ( β=-0.039, 95% CI: -0.068--0.010, P=0.009). Further analysis of adulthood weight gain after the age of 20 revealed that average annual weight gain in adulthood was negatively associated with adiponectin levels and positively associated with 4 other biomarkers. Furthermore, compared with those of women whose weight remained stable, the adiponectin level of women whose weight gain in adulthood exceeded 5.00 kg was much lower ( β=-0.185, 95% CI: -0.320--0.049, P=0.008), while their insulin-like growth factor-binding protein-3 ( β=0.389, 95% CI: 0.183-0.594, P<0.001) and leptin receptor ( β=0.245, 95% CI: 0.048-0.442, P=0.015) levels were higher.
Conclusion: Weight gain in adulthood is strongly associated with the changes in obesity-related breast cancer risk biomarkers. Women should maintain a stable weight throughout adulthood and it is preferred that their weight gain should not exceed 5.00 kg.
目的: 探讨中国女性不同时期体质量指数（body mass index, BMI）及成年期增重与肥胖相关乳腺癌风险标志物的关联，为乳腺癌防控策略的制定提供参考。
方法: 基于西南社区女性乳腺癌筛查随访队列，采用横断面研究设计，采用序贯抽样从中抽取符合条件的筛查对象作为研究对象，收集基本危险因素信息，测定身高、体质量及血浆标志物水平。采用多元线性回归分别分析成年早期（20岁）、成年后期BMI及成年期增重与标志物的关联。标志物浓度均进行自然对数转换后纳入模型。
结果: 442名对象的平均年龄49 (45, 54)岁，平均成年早期、后期BMI为21.47 (19.56, 23.11) kg/m2、24.10 (22.59, 25.97) kg/m2，平均成年期增重6.60 (2.00, 11.00) kg。成年后期BMI与脂联素水平呈负向相关（β=−0.026，95%CI：−0.045～−0.008，P=0.006），与C反应蛋白（β=0.095，95%CI：0.054～0.137，P <0.001）及瘦素受体水平（β=0.090，95%CI：0.063～0.117，P <0.001）呈正向相关，暂未发现与抵抗素及胰岛素样生长因子结合蛋白-3的关联。成年早期BMI仅与成年后期胰岛素样生长因子结合蛋白-3水平负向相关（β=−0.039，95%CI：−0.068～−0.010，P=0.009）。进一步分析自20岁以来的成年期增重情况发现，成年期年均增重与脂联素水平存在负向关联，与其他4种标志物水平存在正向关联。此外，成年期增重>5.00 kg组的脂联素水平较体质量稳定组更低（β=−0.185，95%CI：−0.320～−0.049，P=0.008），胰岛素样生长因子结合蛋白-3（β=0.389，95%CI：0.183～0.594，P <0.001）及瘦素受体（β=0.245，95%CI：0.048～0.442，P=0.015）水平更高。
结论: 成年期增重与肥胖相关乳腺癌风险标志物的变化密切相关，女性应在整个成年期保持体质量稳定，且最好增重不超过5.00 kg。
Keywords: Biomarker; Body mass index; Breast cancer; Weight gain in adulthood.
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