Randomized Explanatory Trial of a Mediterranean Dietary Pattern Weight Loss Intervention for Primary Care Practices

摘要 美国的肥胖流行病几乎有增无减，越来越令人担忧的统计数据显示， 其他慢性疾病的平行上升以及由此导致的医疗保健费用的增加。美国 预防服务工作组（USPSTF）建议对初级保健患者进行肥胖筛查 体重指数（BMI）≥30 kg/m2的受试者接受了强化的多成分行为干预， 减肥干预。然而，在初级保健中实施的减肥干预措施的有效性 最近的一项荟萃分析显示，2年后体重仅轻微减轻（1.2 kg）。 此外，之前在美国研究的减肥干预措施在很大程度上未能改善 心血管疾病（CVD）事件发生率或总死亡率。 越来越多的证据表明地中海饮食对健康有益， 观察和临床试验数据支持这种饮食模式的健康益处， 高质量的脂肪和碳水化合物的消费。积极的健康结果包括减少CVD事件 最近的数据表明，它对癌症预防、认知健康和全因死亡率都有好处。许多人 提出了一个问题，即地中海式饮食是否可以在美国遵循（美国人的口味可以接受）， 特别是在低收入和少数民族人群中，他们的心血管疾病发病率非常高。 我们的研究团队已经根据东南部的文化偏好（“Med-South 这种饮食模式在低收入人群中，主要是少数民族， 人口数量。在一项评估Med-South饮食干预的大型前后研究中， 糖尿病患者的体重减轻（2年时为初始体重的3.6%）。缺少的是一种解释 （疗效）随机试验测试是否以初级保健为基础的减肥干预，强调 健康的饮食模式（Med-South）可以产生长期的体重减轻和改善CVD风险状况。 因此，我们提出了一项随机试验，以评估一种基于临床的减肥干预措施， 风格的饮食模式。将在5个初级保健中心（n=350名参与者）进行，代表不同的 患者和环境的范围。BMI ≥ 30 kg/m2的患者将入组并随机分配至 干预或加强常规护理。为确保充分的亚组代表性，将≥ 40%的样本 糖尿病患者中，≥ 40%为男性，≥ 40%为非裔美国人。干预措施将在3 研究人员在24个月内分阶段进行：第一阶段（4个月）侧重于采用地中海式饮食模式; 第二阶段（8个月）体重减轻;第三阶段（12个月）体重减轻维持。成果将 在4、12和24个月时进行评估。主要结局是24个月时的体重减轻。次要结局 包括生理、行为和心理社会测量变化。我们还将评估执行情况 成本和增量成本效益的干预相对于增强的日常护理组。

ABSTRACT The obesity epidemic in the US continues nearly unabated, with increasingly alarming statistics regarding the parallel rise in other chronic diseases and the resulting increase in healthcare costs. The United States Preventive Services Task Force (USPSTF) recommends that primary care patients be screened for obesity and that those with a body mass index (BMI) ≥30 kg/m2 receive an intensive, multicomponent behavioral weight loss intervention. However, the effectiveness of weight loss interventions implemented in primary care settings has been limited, with a recent meta-analysis showing only modest weight loss (1.2 kg) after 2 years. In addition, previously studied weight loss interventions in the US have largely failed to improve cardiovascular disease (CVD) event rates or total mortality. A growing body of evidence points to the health benefits of the Mediterranean (Med) diet, with strong observational and clinical trial data supporting the health benefits of this dietary pattern that includes generous consumption of high-quality fats and carbohydrates. Positive health outcomes include reduced CVD events and recent data suggests benefits for cancer prevention, cognitive health, and all-cause mortality. Many have raised the question whether a Med-style diet can be followed in the US (be acceptable to the American palate), particularly among low-income and minority populations who experience disproportionally high rates of CVD. Our research team has adapted a Med-style diet to the cultural preferences of the Southeast (“Med-South diet”) and this dietary pattern has achieved high levels of acceptability in low-income, primarily minority populations. In a large pre-post study evaluating the Med-South dietary intervention, we saw significant weight loss (3.6% of initial weight at 2 years) among participants with diabetes. What is missing is an explanatory (efficacy) randomized trial testing whether a primary care-based weight loss intervention emphasizing a healthful eating pattern (Med-South) can yield long-term weight loss and improved CVD risk profiles. Thus, we propose a randomized trial to assess a clinic-based, weight loss intervention promoting a Med- style dietary pattern. It will be conducted at 5 primary care sites (n=350 participants) representing a diverse spectrum of patients and settings. Patients with a BMI ≥ 30 kg/m2 will be enrolled and randomized to intervention or augmented usual care. To assure adequate subgroup representation, ≥ 40% of the sample will have diabetes, ≥ 40% will be male, and ≥ 40% will be African American. The intervention will be delivered in 3 phases over 24 months by research staff: Phase I (4 months) focuses on adopting a Med-style dietary pattern; Phase II (8 months) on weight loss; and Phase III (12 months) on weight loss maintenance. Outcomes will be assessed at 4, 12, and 24 months. The primary outcome is weight loss at 24 months. Secondary outcomes include change in physiologic, behavioral, and psychosocial measures. We will also assess implementation cost and the incremental cost-effectiveness of the intervention relative to the augmented usual care group.