Physicians Committee for Responsible Medicine, A Randomized, Crossover Trial of the Effect of a Dietary Intervention on Intracellular Lipid, Insulin Sensitivity, and Glycemic Control in Type 2 Diabetes
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Intramyocellular lipid content
研究概览
简要总结
The purpose of this study is to compare the effects of a low-fat, plant-based dietary intervention and a portion-controlled dietary intervention (compliant with current American Diabetes Association (ADA) guidelines) on changes in intramyocellular and hepatocellular lipid content in adults with type 2 diabetes. Changes in insulin sensitivity and glycemic control will also be assessed in this study. The study duration is 44 weeks.
详细描述
Type 2 diabetes is a disease characterized by discordance between the amount of insulin produced by pancreatic β-cells and the amount of insulin required to overcome insulin resistance in the liver and peripheral tissues. The development of insulin resistance has been strongly associated with the prolonged accumulation of lipids (fats) in the liver cells ("hepatocellular lipid") and muscle cells ("intramyocellular lipid"). Conventional pharmacologic therapeutics for type 2 diabetes, like metformin, are designed to reduce the accumulation of hepatocellular and intramyocellular lipids and, thereby, augment insulin sensitivity. Research has shown that a low-fat, plant-based diet, in which the consumption of lipids is limited, is a similarly effective therapeutic intervention for the reduction of hepatocellular and intramyocellular lipid content and the improvement of insulin sensitivity in type 2 diabetes.
The purpose of this study is to compare the effects of low-fat, plant-based dietary intervention and a portion-controlled dietary intervention (compliant with current American Diabetes Association (ADA) guidelines) on hepatocellular and intramyocellular lipid content in adults with type 2 diabetes. Using a cross-over design, participants with type 2 diabetes will be randomly assigned to start with a plant-based or a portion-controlled diet for 22 weeks. The two groups will then switch to the opposite diet regimen for an additional 22 weeks. Before and after each intervention period, the investigators will measure intramuscular and liver fat content. The investigators will also assess the relationship between these variables, insulin sensitivity, and glycemic control.
The investigators hypothesize that both dietary interventions will result in reductions in intramuscular and liver fat content, and that these changes will be associated with improvements in insulin sensitivity and glycemic control in individuals with type 2 diabetes. The investigators further hypothesize that the low-fat, plant-based dietary intervention will elicit greater changes in intracellular lipid concentration, compared with the portion-controlled dietary intervention.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •are as follows:
- •Men and women with type 2 diabetes treated by diet and/or oral hypoglycemic agents other that sulfonylureas
- •Age ≥18 years
- •Body mass index 26-40 kg/m2
- •Medications (antidiabetic, antihypertensive, and lipid-lowering) have been stable for the past 3 months
- •HbA1c between 6-10.5% (42-88 mmol/mol)
排除标准
- •are as follows:
- •Diabetes mellitus, type 1 and/or treatment with insulin or sulfonylureas
- •Metal implants, such as a cardiac pacemaker or an aneurysm clip
- •History of any endocrine condition that would affect body weight, such as thyroid disease, pituitary abnormality, or Cushing's syndrome
- •Smoking during the past six months
- •Alcohol consumption of more than 2 drinks per day or the equivalent, episodic increased drinking (e.g., more than 2 drinks per day on weekends), or a history of alcohol abuse or dependency followed by any current use
- •Use of recreational drugs in the past 6 months
- •Use within the preceding six months of medications that affect appetite or body weight, such as estrogens or other hormones, thyroid medications, systemic steroids, antidepressants (tricyclics, MAOIs, SSRIs), antipsychotics, lithium, anticonvulsants, appetite suppressants or other weight-loss drugs, herbs for weight loss or mood, St. John's wort, ephedra, beta blockers
- •Pregnancy or intention to become pregnant during the study period
- •Unstable medical or psychiatric illness
- •Evidence of an eating disorder
- •Likely to be disruptive in group sessions
- •Already following a low-fat, vegan diet
- •Lack of English fluency
- •Inability to maintain current medication regimen
- •Inability or unwillingness to participate in all components of the study
- •Intention to follow another weight-loss method during the trial
- •Participants will also review and complete the Yale MRI Safety Questionnaire to determine eligibility for the study.
研究组 & 干预措施
Low-fat, vegan diet
For a 22-week period, participants will be asked to follow a low-fat vegan diet which consists of whole grains, vegetables, legumes, and fruits, with no restriction on energy intake. Animal products and added oils will be excluded. In choosing grain products and starchy vegetables (e.g., bread, potatoes), participants will be encouraged to select those retaining their natural fiber and having a glycemic index <70, using tables standardized to a value of 100 for glucose.
干预措施: Dietary intervention (Behavioral)
Portion-controlled diet
For a 22-week period, participants will be asked to follow a portion-controlled diet which will include individualized diet plans that reduce daily energy intake by 500 kcal for overweight participants, and keep carbohydrate intake reasonably stable over time. It will derive 50% of total energy from carbohydrates, 20% from protein, and less than 30% from fat (≤7% saturated fat), with less than 200 mg/day of cholesterol/day.
干预措施: Dietary intervention (Behavioral)
结局指标
主要结局
Intramyocellular lipid content
时间窗: 1.) Change from week 0 to week 22; 2.) Change from week 22 to week 44
Proton magnetic resonance (MR) spectroscopy at 4T (Bruker) will be implemented to quantify intramyocellular lipid concentrations.
Hepatocellular lipid content
时间窗: 1.) Change from week 0 to week 22; 2.) Change from week 22 to week 44
Proton magnetic resonance (MR) spectroscopy at 4T (Bruker) will be implemented to quantify intramyocellular lipid concentrations.
Insulin sensitivity
时间窗: Change from baseline to 22 weeks and change from 22 weeks to 44 weeks
Insulin resistance will be assessed by the Homeostatic Model Assessment (HOMA) PREDIM indexes
Concentration of glucose
时间窗: 1.) Change from week 0 to week 22; 2.) Change from week 22 to week 44
Concentration of glucose will be assessed during a standard meal test (Boost Plus, Nestle, Vevey, Switzerland; 720 kcal, 34% of energy from fat, 16% protein, 50% carbohydrate). Plasma concentrations of glucose will be measured at 0, 30, 60, 120, and 180 min.
Concentration of C-peptide
时间窗: 1.) Change from week 0 to week 22; 2.) Change from week 22 to week 44
Concentration of C-peptide be assessed during a standard meal test (Boost Plus, Nestle, Vevey, Switzerland; 720 kcal, 34% of energy from fat, 16% protein, 50% carbohydrate). Concentration of C-peptide will be measured at 0, 30, 60, 120, and 180 min.
Rate of glycemic control
时间窗: 1.) Change from week 0 to week 22; 2.) Change from week 22 to week 44
Rate of glycemic control will be assessed through HbA1C.
次要结局
- Resting energy expenditure(Change from baseline to 22 weeks and change from 22 weeks to 44 weeks)
- Concentration of plasma lipids(Change from baseline to 22 weeks and change from 22 weeks to 44 weeks)
- Body weight(Change from baseline to 22 weeks and change from 22 weeks to 44 weeks)
- Gut microbiome composition(Change from baseline to 22 weeks and change from 22 weeks to 44 weeks)
- Postprandial metabolism(Change from Baseline to 22 weeks and change from 22 weeks to 44 weeks)
- Body Composition(Change from baseline to 22 weeks and change from 22 weeks to 44 weeks)