Effects of Processed Meat on Brain Regions Related to Reward and Craving in Patients With Type 2 Diabetes, Obese Subjects and Healthy Controls
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Functional brain imaging of reward circuitry
研究概览
简要总结
The purpose of this study is to
- Compare effects of two isocaloric meals (processed meat hamburger vs. vegetarian sandwich) in response to the postprandial period by using functional brain imaging of reward circuitry implicated in food motivation and energy balance in patients with type 2 diabetes (T2D), obese subjects and healthy controls.
- Characterize some of the pathophysiological mechanisms of action of different meals in obese and T2D subjects vs. in healthy controls (serum concentrations of glucose, FFA, IRI, C-peptide, gastrointestinal hormones, oxidative stress markers)
详细描述
The mesolimbic dopaminergic system of the brain, which converges on the nucleus accumbens (part of the striatum), plays a central role in reward and craving, and this system appears to mediate hedonic food responses. In rodent studies, extracellular concentrations of dopamine and its metabolites in the nucleus accumbens increased more after the consumption of highly palatable food than standard rodent feed pellets. Furthermore, microinjections of opiate into the nucleus accumbens increased food intake and the reward value of food. Clinical studies that used functional brain imaging have reported greater activation in the nucleus accumbens or other regions of the striatum in obese than lean individuals after they viewed or consumed palatable, high-calorie food. Of particular interest, striatal dopamine D2 receptor availability was significantly lower in obese individuals than in nonobese matched controls, which raised the possibility that overeating may compensate for low dopaminergic activity. The recurrent activation of the striatum may down-regulate dopamine availability and further heighten the drive to overeat. However, the information on the exact effect of different foods and nutrients on the mesolimbic dopaminergic system is missing.
Preliminary findings that lead to the project
A positive association between high consumption of total and red meat, especially processed meat, and incidence of T2D has been demonstrated. Previous studies support the concept that increased oxidative stress may play an important role in T2D manifestation. Dietary fat quality has been proposed to be a critical factor. Several studies have suggested that a high intake of saturated fatty acids naturally present in meat contributes to the risk of glucose intolerance. In an intervention study, humans suffering from metabolic syndrome who were consuming a diet rich in saturated fats displayed higher oxidative stress markers postprandially. It is not clear if saturated fatty acids per se or via increased oxidative stress markers may activate the mesolimbic dopaminergic system.
In contrast, some intervention trials (including ours) demonstrated a greater improvement in insulin sensitivity, glycemic control and a reduction in oxidative stress markers in T2D patients consuming a vegetarian diet compared to a conventional diabetic diet. The effect of a vegetarian diet on the mesolimbic dopaminergic system has not been studied yet.
Aims and priorities of the project
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 30 Years 至 70 Years（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Inclusion criteria for T2D:
- •Type 2 diabetes mellitus for at least one year
- •Treatment of T2D: diet or oral antidiabetic agents (stable drug therapy at least 3 month before the trial
- •The presence of metabolic syndrome - any three of the following symptoms:
- •Abdominal obesity - waist circumf. in men> 102 cm, in women > 88 cm
- •Diagnosis and treatment of type 2 diabetes or raised fasting plasma glucose level (FPG>5,6 mmol/l)
- •Raised blood pressure (BP): systolic BP > 130 mm Hg or diastolic BP >85 mm Hg, or treatment of previously diagnosed hypertension
- •Reduced HDL cholesterol in men < 1 mmol/l, in women < 1,3 mmol/l (or treatment)
- •Raised triglycerides > 1,7 mmol/l (or treatment)
- •HbA1c (according to IFCC) ≥4.2 a ≤10.5%
- •Men and women aged 30-70 years
- •Body Mass Index (kg/m2) in the range of 25- 45
- •The signed informed consent
排除标准
- •Exclusion criteria for T2D:
- •Type 1 diabetes mellitus
- •Unstable drug therapy at least 3 month before the trial
- •Treatment with Byetta or Victosa
- •Pregnancy (positive β-HCG test), breast feeding or trying to become pregnant
- •Presence of pacemaker or other metal implant in the body (MR)
- •Alcoholism or drug use
- •Significant weight loss (more than 5% of body weight) in previous 3 months before the screening
- •Presence of other medical condition, which occurs during physical examination, laboratory tests, ECG, including pulmonary, neurological or inflammatory disease, which would be considered by the examiner to distort the consistency of data
- •Metal in the body (fMRI)
研究组 & 干预措施
Type 2 diabetics
Patients with type 2 diabetes Interventions: processed meat hamburger and vegan sandwich
干预措施: Processed meat hamburger (Other)
Type 2 diabetics
Patients with type 2 diabetes Interventions: processed meat hamburger and vegan sandwich
干预措施: Vegan sandwich (Other)
Obese subjects
Obese subjects without diabetes Interventions: processed meat hamburger and vegan sandwich
干预措施: Processed meat hamburger (Other)
Obese subjects
Obese subjects without diabetes Interventions: processed meat hamburger and vegan sandwich
干预措施: Vegan sandwich (Other)
Healthy lean controls
Healthy lean controls Interventions: processed meat hamburger and vegan sandwich
干预措施: Processed meat hamburger (Other)
Healthy lean controls
Healthy lean controls Interventions: processed meat hamburger and vegan sandwich
干预措施: Vegan sandwich (Other)
结局指标
主要结局
Functional brain imaging of reward circuitry
时间窗: 24 months
fMRI (functional magnetic resonance imaging) of the brain pre- and postprandially simultaneously with both meal tests with the use of the modern method of arterial spin labeling (ASL) which allows quantification of the blood perfusion of the brain regions involved in craving and reward.
次要结局
- Serum concentrations of oxidative stress markers(24 months)
- Serum concentrations of gastrointestinal hormones(24 months)
研究者
Hana Kahleova
MD, PhD
Institute for Clinical and Experimental Medicine