Department of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Eat Weight Disord. 2012 Dec;17(4):e234-43. doi: 10.3275/8631. Epub 2012 Sep 24.
Efficacy of weight loss and maintenance therapies in obesity is difficult to quantify due to continuous weight changes over time. We assessed a single exponential model of weight changes during selected non-surgical therapies of non-diabetic obese subjects. We analyzed published mean weight data from 6 studies of ≥12 weeks duration, with comparable treatment groups, and ≥4 weight measurements during very low carbohydrate or fat diets, or treatment with Lorcaserin, Sibutramine or Orlistat. We fit data to a single exponential model to estimate maximum predicted weight loss or regain and duration of weight loss or regain for each therapy. A single exponential is the appropriate model as determined by Kolmogorov-Smirnov, constant variance, and Durbin-Watson tests. Validity of parameter estimates was indicated by coefficients of variation <25%. Sensitivity analysis showed that weight regain at the end of the weight loss phase affected parameter estimates in some instances, with variations of weight loss of 0.2-0.7% of basal. Estimated weight loss and regain were similar to observed weight changes in all studies. The model could also be used to assess dose-response relationships. Estimates from the model were used to compare concurrent obesity regimens using 95% confidence intervals, taking into account pre-determined minimal clinically important differences. This exponential model may provide accurate estimates of maximum achievable weight loss or regain and optimal duration of efficacy for a variety of non-surgical weight loss and maintenance regimens from published mean weight data and may be useful to more accurately evaluate weight loss and maintenance regimens.
由于体重随时间持续变化，肥胖症的减肥和维持治疗效果难以量化。我们评估了非糖尿病肥胖受试者接受特定非手术治疗期间体重变化的单一指数模型。我们分析了 6 项持续时间超过 12 周、治疗组可比且在极低碳水化合物或脂肪饮食或使用 Lorcaserin、Sibutramine 或 Orlistat 治疗期间进行了至少 4 次体重测量的已发表平均体重数据。我们根据单一指数模型拟合数据，以估计每种治疗方法的最大预测减肥或反弹量以及减肥或反弹的持续时间。柯尔莫哥洛夫-斯米尔诺夫、恒方差和杜宾-沃森检验表明，单一指数是合适的模型。参数估计的有效性通过变异系数 <25% 来表示。敏感性分析表明，减肥阶段结束时的体重反弹在某些情况下会影响参数估计，减肥量变化为基础体重的 0.2-0.7%。所有研究中的模型估计值都与观察到的体重变化相似。该模型还可用于评估剂量-反应关系。从模型得出的估计值用于使用 95%置信区间比较同时进行的肥胖症治疗方案，同时考虑到预先确定的最小临床重要差异。该指数模型可从已发表的平均体重数据中为各种非手术减肥和维持方案提供最大可实现减肥或反弹量和疗效持续时间的准确估计，可能有助于更准确地评估减肥和维持方案。
