Graduate Institute of Clinical Medical Sciences, Chang Gung University, and Department of Surgery, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan.
Int J Nurs Stud. 2010 Aug;47(8):994-1000. doi: 10.1016/j.ijnurstu.2010.01.002. Epub 2010 Feb 4.
Obesity is common in women with breast cancer. The risk of obesity-induced metabolic syndrome is higher in Asians than in Caucasians. Excessive body fat accumulation has been associated with a worse prognosis. However, the most popular clinical indicator of obesity is not fat itself, but body mass index (BMI).
The purposes of this study were to determine the consistency of BMI and body fat percentage (BF%) in determining obesity and to identify the best BMI cutoffs for identifying obesity in Taiwanese women with breast cancer.
Body fat and fat-free mass were measured by bioelectrical impedance 1 day before breast surgery for 200 women with breast cancer. BMI was calculated as weight (in kilograms) divided by height (in meters) squared.
BMI and BF% were highly correlated (r=0.91; p<0.001). However, BMI exhibited poor sensitivity for identifying obesity (47%). The sensitivity of BMI to detect obesity was better in women over age 60. The best BMI cutoff for obesity was 22.3 kg/m2 with a sensitivity and specificity of 89% (95% CI=83-94%) and 87% (95% CI=77-93%) respectively, and the total accuracy rate improved from 65% to 89%.
Using BMI to identify obesity in Taiwanese women with breast cancer requires careful attention to the diagnostic criterion chosen. The World Health Organization criterion tends to underestimate the prevalence of obesity, especially for younger women with breast cancer (under age 40).
肥胖在乳腺癌女性中很常见。亚洲人肥胖相关代谢综合征的风险高于白种人。过多的体脂积累与预后较差有关。然而，最常用的肥胖临床指标不是脂肪本身，而是体重指数（BMI）。
本研究旨在确定 BMI 和体脂百分比（BF%）在确定肥胖中的一致性，并确定 BMI 切点用于识别台湾乳腺癌女性肥胖的最佳值。
在乳腺癌手术前一天，通过生物电阻抗法对 200 名乳腺癌女性进行体脂和去脂体重的测量。BMI 计算为体重（千克）除以身高（米）的平方。
BMI 和 BF% 高度相关（r=0.91；p<0.001）。然而，BMI 对肥胖的敏感性较差（47%）。BMI 对肥胖的检测敏感性在 60 岁以上的女性中更好。肥胖的最佳 BMI 切点为 22.3 kg/m2，其敏感性和特异性分别为 89%（95% CI=83-94%）和 87%（95% CI=77-93%），总准确率从 65%提高到 89%。
在台湾乳腺癌女性中使用 BMI 来识别肥胖需要仔细注意所选择的诊断标准。世界卫生组织的标准往往低估了肥胖的流行率，尤其是对年轻的乳腺癌女性（<40 岁）。
