Epidemiology Research Program, American Cancer Society, 250 Williams Street NW, Atlanta, GA 30303, USA.
Am J Epidemiol. 2012 Apr 15;175(8):785-92. doi: 10.1093/aje/kwr378. Epub 2012 Jan 27.
Weight cycling has been associated with an increased risk of death in some studies, but few studies differentiated weight cycling initiated by intentional weight loss from that initiated by illness. The association of weight cycling with death was examined among 55,983 men and 66,655 women in the Cancer Prevention Study II Nutrition Cohort from 1992 to 2008. A weight cycle was defined as an intentional loss of 10 or more pounds (≥4.5 kg) followed by regain of that weight, and the lifetime number of weight cycles was reported on a questionnaire administered at enrollment in 1992. A total of 15,138 men and 10,087 women died during follow-up, which ended in 2008. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards regression models. When the models were adjusted for age only, weight cycling was positively associated with mortality (P for trend < 0.0001). However, after adjustment for body mass index and other risk factors, low numbers of weight cycles (1-4 cycles) were associated with slightly lower mortality rates (hazard ratio (HR) = 0.93, 95% confidence interval (CI): 0.89, 0.97 in men and HR = 0.93, 95% CI: 0.89, 0.98 in women), whereas high numbers of weight cycles (≥20 cycles) were not associated with mortality (HR = 1.03, 95% CI: 0.89, 1.19 in men and HR = 0.99, 95% CI: 0.88, 1.12 in women). These results do not support an increased risk of mortality associated with weight cycling.
体重循环在一些研究中与死亡风险增加有关，但很少有研究将由有意减肥引起的体重循环与由疾病引起的体重循环区分开来。这项研究在 1992 年至 2008 年间，对癌症预防研究 II 营养队列中的 55983 名男性和 66655 名女性进行了研究。体重循环被定义为有意减去 10 磅或更多（≥4.5 公斤），然后体重又恢复，在 1992 年入组时进行的问卷中报告了一生中体重循环的次数。在随访期间，共有 15138 名男性和 10087 名女性死亡，随访于 2008 年结束。使用 Cox 比例风险回归模型估计危险比和 95%置信区间。当仅根据年龄调整模型时，体重循环与死亡率呈正相关（趋势 P < 0.0001）。然而，在调整体重指数和其他危险因素后，低次数的体重循环（1-4 次）与死亡率略低相关（男性 HR = 0.93，95%CI：0.89，0.97；女性 HR = 0.93，95%CI：0.89，0.98），而高次数的体重循环（≥20 次）与死亡率无关（男性 HR = 1.03，95%CI：0.89，1.19；女性 HR = 0.99，95%CI：0.88，1.12）。这些结果不支持体重循环与死亡率增加有关。
