Department of Internal Medicine, University of Michigan Medical School, 2800 Plymouth Road, Building 16, Room 16-371C, Ann Arbor, MI, 48109-2800, USA.
VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
Trials. 2022 Sep 30;23(1):827. doi: 10.1186/s13063-022-06770-3.
The Center for Disease Control and Prevention's National Diabetes Prevention Program (NDPP) aims to help individuals with prediabetes avoid progression to type 2 diabetes mellitus (T2DM) through weight loss. Specifically, the NDPP teaches individuals to follow a low-fat, calorie-restricted diet and to engage in regular physical activity to achieve ≥ 5% body weight loss. Most NDPP participants, however, do not achieve this weight loss goal, and glycemic control remains largely unchanged. One promising opportunity to augment the NDPP's weight loss and glycemic effectiveness may be to teach participants to follow a very low-carbohydrate diet (VLCD), which can directly reduce post-prandial glycemia and facilitate weight loss by reducing circulating insulin and enabling lipolysis. To date, there have been no high-quality, randomized controlled trials to test whether a VLCD can prevent progression to T2DM among individuals with prediabetes. The aim of this study is to test the effectiveness of a VLCD version the NDPP (VLC-NDPP) versus the standard NDPP. We hypothesize the VLC-NDPP will demonstrate greater improvements in weight loss and glycemic control.
We propose to conduct a 12-month, 1:1, randomized controlled trial that will assign 300 adults with overweight or obesity and prediabetes to either the NDPP or VLC-NDPP. The primary outcome will be glycemic control as measured by change in hemoglobin A1c (HbA1c) from baseline to 12 months. Secondary outcomes will include percent body weight change and changes in glycemic variability, inflammatory markers, lipids, and interim HbA1c. We will evaluate progression to T2DM and initiation of anti-hyperglycemic agents. We will conduct qualitative interviews among a purposive sample of participants to explore barriers to and facilitators of dietary adherence. The principal quantitative analysis will be intent-to-treat using hierarchical linear mixed effects models to assess differences over time.
The NDPP is the dominant public health strategy for T2DM prevention. Changing the program's dietary advice to include a carbohydrate-restricted eating pattern as an alternative option may enhance the program's effectiveness. If the VLC-NDPP shows promise, this trial would be a precursor to a multi-site trial with incident T2DM as the primary outcome.
NCT05235425. Registered February 11, 2022.
疾病控制与预防中心的国家糖尿病预防计划（NDPP）旨在通过减肥帮助患有前驱糖尿病的个体避免发展为 2 型糖尿病（T2DM）。具体来说，NDPP 教导个体遵循低脂肪、热量限制饮食，并定期进行身体活动，以实现≥5%的体重减轻。然而，大多数 NDPP 参与者并未达到这一体重减轻目标，且血糖控制基本保持不变。增强 NDPP 减肥和血糖效果的一个很有前途的机会可能是教导参与者遵循极低碳水化合物饮食（VLCD），这可以直接降低餐后血糖，并通过减少循环胰岛素和促进脂肪分解来促进体重减轻。迄今为止，还没有高质量的随机对照试验来测试 VLCD 是否可以预防前驱糖尿病个体进展为 T2DM。本研究旨在测试 NDPP 的 VLCD 版本（VLC-NDPP）与标准 NDPP 相比的有效性。我们假设 VLC-NDPP 将在体重减轻和血糖控制方面显示出更大的改善。
我们建议进行一项为期 12 个月、1:1 的随机对照试验，将 300 名超重或肥胖且患有前驱糖尿病的成年人分配到 NDPP 或 VLC-NDPP 组。主要结局将是通过从基线到 12 个月时糖化血红蛋白（HbA1c）的变化来衡量血糖控制。次要结局将包括体重百分比变化以及血糖变异性、炎症标志物、脂质和中期 HbA1c 的变化。我们将评估进展为 T2DM 和开始使用抗高血糖药物的情况。我们将在一个有目的的参与者样本中进行定性访谈，以探讨饮食依从性的障碍和促进因素。主要的定量分析将是意向治疗，使用分层线性混合效应模型来评估随时间的差异。
NDPP 是 T2DM 预防的主要公共卫生策略。将计划的饮食建议改为包括限制碳水化合物的饮食模式作为替代方案，可能会增强计划的效果。如果 VLC-NDPP 显示出前景，那么这将是一项以新发 T2DM 为主要结局的多地点试验的前奏。
NCT05235425。于 2022 年 2 月 11 日注册。
