Guinan Emer M, Connolly Elizabeth M, Kennedy M John, Hussey Juliette
Nutr J. 2013 Jul 15;12:99. doi: 10.1186/1475-2891-12-99.
Breast cancer prognosis can be adversely influenced by obesity, physical inactivity and metabolic dysfunction. Interventions aimed at improving surrogate markers of breast cancer risk such as insulin resistance may result in improved breast cancer outcomes. The design of such interventions may be improved through increased understanding of metabolic presentation in this cohort. This cross-sectional study aimed to characterise the metabolic profile of breast cancer survivors relative to abdominal obesity and insulin resistance. A secondary aim was to compare measures of energy output across these groups.
Sixty-nine women (mean (SD) age 53.43 (9.39) years) who had completed adjuvant chemotherapy and radiotherapy for breast cancer were recruited. All measures were completed during one assessment conducted 3.1 (1.0) years post diagnosis. Body composition was measured by bioimpedance analysis and waist circumference (WC). Fasting (12 hour) blood samples were drawn to measure lipid profile, glucose, insulin, glycosylated haemoglobin A1c (HBA1c) and C-reactive protein (CRP). Insulin resistance was estimated by the homeostatic model assessment index (HOMA-IR)). Energy output was evaluated by resting metabolic rate (RMR) measured by indirect calorimetry and physical activity measured by accelerometry. Characteristics were compared across four groups (1. WC <80 cm, not insulin resistant; 2. WC 80-87.9 cm, not insulin resistant; 3. WC >88 cm, not insulin resistant; 4. WC >80 cm, insulin resistant) using ANOVA (p < 0.05).
Group 4 was characterised by significant disturbances in measures of glucose metabolism (glucose, insulin, HOMA-IR and HBA1c) and raised CRP compared to other groups. Group 4 also displayed evidence of dyslipidemia and higher body composition values compared to Groups 1 and 2. Both absolute and adjusted RMR were significantly higher in the Group 4 versus all other groups. Physical activity levels were similar for all groups.
The results from this study suggest that participants who were both centrally obese and insulin resistant showed evidence of dyslipidemia, low-grade inflammation and glucose dysregulation. Metabolic profiles of participants who were centrally obese only were not significantly different from lean participants. Consideration of baseline metabolic presentation may be useful when considering the therapeutic targets for future interventions in this cohort.
肥胖、缺乏身体活动和代谢功能障碍可能对乳腺癌预后产生不利影响。旨在改善乳腺癌风险替代指标（如胰岛素抵抗）的干预措施可能会改善乳腺癌的预后。通过增加对该队列代谢表现的了解，可改进此类干预措施的设计。这项横断面研究旨在描述乳腺癌幸存者相对于腹部肥胖和胰岛素抵抗的代谢特征。次要目的是比较这些组之间的能量输出指标。
招募了69名完成乳腺癌辅助化疗和放疗的女性（平均（标准差）年龄53.43（9.39）岁）。所有测量均在诊断后3.1（1.0）年进行的一次评估中完成。通过生物电阻抗分析和腰围（WC）测量身体成分。抽取空腹（12小时）血样以测量血脂谱、葡萄糖、胰岛素、糖化血红蛋白A1c（HBA1c）和C反应蛋白（CRP）。通过稳态模型评估指数（HOMA-IR）估算胰岛素抵抗。通过间接测热法测量的静息代谢率（RMR）和通过加速度计测量的身体活动来评估能量输出。使用方差分析（p < 0.05）比较四组（1. WC < 80 cm，非胰岛素抵抗；2. WC 80 - 87.9 cm，非胰岛素抵抗；3. WC > 88 cm，非胰岛素抵抗；4. WC > 80 cm，胰岛素抵抗）的特征。
与其他组相比，第4组的葡萄糖代谢指标（葡萄糖、胰岛素、HOMA-IR和HBA1c）存在明显紊乱，且CRP升高。与第1组和第2组相比，第4组还表现出血脂异常和更高的身体成分值。第4组的绝对和校正RMR均显著高于所有其他组。所有组的身体活动水平相似。
本研究结果表明，中心性肥胖且胰岛素抵抗的参与者表现出血脂异常、低度炎症和葡萄糖调节异常的迹象。仅中心性肥胖参与者的代谢特征与瘦参与者无显著差异。在考虑该队列未来干预的治疗靶点时，考虑基线代谢表现可能会有所帮助。
