Activation of Brain Centers Responsible for Decreasing Appetite and Improvement of the Cardiometabolic Profile by Short-term Walnut Consumption in Obesity: A Pilot Study
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 10
- 试验地点
- 2
- 主要终点
- brain centers activation related to food intake assessed using functional magnetic resonance imaging (fMRI)
研究概览
简要总结
The purposes of the study are:
- Study Aim 1. To assess the mechanisms underlying the biological effects of short-term walnut consumption on appetite with functional magnetic resonance imaging (fMRI) and assessing neurocognitive function/memory
- Study Aim 2. To investigate the effects of walnut consumption (48g per day over 5 days) on appetite and satiety by analyzing molecules which regulate energy homeostasis such as adipokines, as well as resting metabolic rate which measures energy expenditure.
- Study Aim 3. To investigate the effects of walnuts (48g per day over 5 days) on insulin resistance, lipids, and inflammatory markers in obesity as well as the effect of walnuts when consumed as part of a mixed meal, on glucose excursions, insulin secretion and the excretion of gut peptides and free fatty acids.
详细描述
Study Overview:
The study is a short-term, pilot, double-blinded, randomized, cross-over inpatient study testing the effects of either 48 g of walnuts per day vs. an ad libitum diet without walnuts on appetite and satiety, insulin resistance, basal metabolic rate, lipids, adipokines, heart rate, vascular reactivity, and markers of inflammation. The investigators propose that subjects stay in the controlled environment of our Clinical Research Center (CRC) for the entire duration of each arm of the study (5 days), which will be separated from the other arm by a one month long wash out period. Walnuts/placebo administration will be in the form of a milkshake with identical macronutrient content. Each study subject will be fed an identical diet during both admissions to minimize variability.
Study Design:
Screening: Potential subjects will be initially screened through telephone to determine that they are eligible for inclusion in the study according to the inclusion/exclusion criteria. If they pass the phone screening then they will be asked to come at CRC for a screening visit. They will have a detailed medical history, physical exam, fasting lab tests such as fructosamine, international normalized ratio (INR), prothrombin time (PT), complete blood count (CBC), metabolic panel including glucose and lipid profile, electrocardiogram (EKG), vitals, anthropometry and pregnancy test for women and if eligible for participation they will sign the informed consent of the study.
Subjects meeting eligibility criteria will be randomized to start with either the active intervention or placebo. Subjects will complete a 3-day food diary prior to visit 1 to document baseline diet. They will also meet the dietitian who will advise them on following a prudent diet and maintaining a stable exercise pattern for 2 weeks before the first visit and between both visits. Subjects will also be advised to avoid walnuts during this period. Subjects will also be required to maintain their weight +/- 3kg between screening and between study visits.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •10 otherwise healthy men or women, 18-65 years old, with a Body Mass Index (BMI) >30kg/m2 or a BMI >27kg/m2 with comorbidities that would require treatment for obesity (assessed through the screening questionnaire and the medical history and physical exam examination during the screening visit).
排除标准
- •Diagnosis of diabetes, defined per American Diabetes Association (ADA) criteria as hemoglobin a1c (Hba1c) > 7.0% and/or fasting glucose > 125 mg/dL and/or random glucose > 200 mg/dL
- •Subjects with any medical condition or on any treatment which would interfere with the study outcomes or would make participation potentially harmful such as pregnancy or breastfeeding, anemia, unstable heart disease, stroke, malabsorption syndromes according to a detailed medical history.
- •Present alcoholism or drug abuse or use of any medications the dose of which would be changing or plan to initiate any new medications during the study period. These conditions will be screened for by a detailed history and systems review.
- •Individuals with nut allergies or allergies to the ingredients of the milkshake (walnuts, mangos, strawberries, bananas, berry medley, pineapple juice, safflower oil, walnut flavoring) are excluded.
- •Subjects with any type of bioimplant activated by mechanical, electronic, or magnetic means (e.g. cochlear implants, pacemakers, neuron or biostimulators, electronic infusion pumps, etc.)
- •Subjects with any type of metallic implant that could potentially be displaced or damaged during MRI, such as aneurysm clips, metallic skull plates, surgical implants etc. or metal containing tattoos.
- •Anxiety of small spaces and/or claustrophobia
- •Subjects with neurological or psychiatric problems which may interfere with or complicate testing (e.g. presence of titubation)
- •Body weight above the limitation of the MRI scanning table (330lbs/150 Kg) or body dimensions that could difficult the performance of the scan.
- •Subjects who cannot adhere to the experimental protocol for any reason
- •Uncontrolled infectious diseases (e.g. human immunodeficiency virus (HIV), hepatitis, chronic infections etc)
- •Any uncontrolled endocrine condition, e.g. Cushing's, Acromegaly, etc
- •Any cancers or lymphoma
- •Eating disorders like anorexia, bulimia
- •Weight loss surgery or gastrectomy
结局指标
主要结局
brain centers activation related to food intake assessed using functional magnetic resonance imaging (fMRI)
时间窗: fasting Day 5
The investigators will use functional magnetic resonance imaging (fMRI) to identify brain centers activation related to food intake after the consumption of the walnut shake compared to the placebo shake.
次要结局
未报告次要终点
研究者
Christos Mantzoros
MD DSc h.c. PhD mult
Beth Israel Deaconess Medical Center