Study of Effects From Gastric Bypass Weight Loss on Brain Tissue

2014-08-27 03:43:17 | BioPortfolio


This study will evaluate how large, intentional weight reduction affects the human brain and possible ways to reverse the changes associated with excess body weight. Subtle changes in some brain regions occur in people who are overweight. Such changes may involve the regulation of eating behavior, though it is not clear whether the changes were present before weight gain or are a consequence. Magnetic resonance imaging (MRI) will be used to study local structures of the brain.

Patients ages 18 to 45 who are undergoing gastric bypass surgery and who are not pregnant or breastfeeding may be eligible for this study. A study group of lean participants will serve as controls. Patients will visit the Phoenix Indian Medical Center for about 3 days at a time for tests. They will have a medical examination, electrocardiogram, and tests of blood and urine. Questionnaires they will complete involve patients' moods and possible influence on eating behaviors, as well as food preferences. A taste test, smell test, and assessment of decision-making processes will be conducted. An oral glucose tolerance test involves a needle placed intravenously (IV) in the arm, for drawing blood after patients drink a sugar solution. The test takes about 3-1/2 hours, with six blood samples taken (about 2 tablespoons total). A meal test also includes use of an IV line. After patients consume a liquid meal, blood will be collected to analyze levels of blood sugar and hormones. For the DEXA scan, which measures body composition, patients will lie still while low-dose X-rays are used for 5 to 10 minutes. Urine will be collected for 1 whole day, to measure cortisol, a hormone. The MRI scan uses a strong magnetic field to obtain images of body organs and tissues. Patients having any metal in the body that may interfere with the scanning machine should not have this test. For the MRI procedure, patients will lie on a table that slides into the enclosed tunnel of the scanner and be asked to lie still. Patients will be able to communicate with the MRI staff at all times during the scan, and they may ask to be removed from the machine at any time.


BACKGROUND: We have identified subtle changes in some brain regions of obese subjects by using a new computerized technique (voxel-based morphometry, VBM) which allows for studying the local structure of the brain by taking very detailed pictures of the brain through magnetic resonance imaging (MRI) and then processing these images with sophisticated statistical software. Some of these regions may interfere with an obese person's ability to predict future consequences of his or her eating behaviors. These changes may explain why people have difficulty losing weight. However, it is not clear whether these changes in the brain are present before or are a consequence of weight gain.

OBJECTIVES: The main aim of this study will be to evaluate the effects of a large and intentional weight reduction on the brains of obese individuals for assessing the possible reversal of the changes associated with excess body weight. Additional objectives will be a) to determine the possible behavioral correlates of the changes in brain tissue composition associated with a large and intentional weight reduction and b) to confirm the results of our previous exploratory analysis showing that human obesity is associated with changes in brain structure in areas related to the regulation of eating behavior.

DESIGN: This is a longitudinal protocol mainly focused on obese patients undergoing roux-en-Y gastric bypass (RYGBP), which represents the most effective approach currently available to achieving substantial weight loss, thus maximizing our chances of detecting significant changes in brain tissue composition. Therefore, we propose to study brain morphology and the metabolic and behavioral characteristics of 40 obese patients undergoing RYGBP prior to and 3, 6, 12, 24, and 48 months after the surgery. Forty lean subjects (at 0, 12, 24, and 48 months) will also be studied for comparison.

OUTCOME MEASURES: The volumes of the different components of the brain by VBM of MRI pictures; metabolic parameters relevant to the relationship between obesity and the brain by measuring fasting concentrations and postprandial responses of some metabolites; the ability to regulate reward and behavior by specific tasks and questionnaires; the ability to detect and discriminate smells by olfaction tests.

Study Design



Weight Loss


NIDDK, Phoenix
United States




National Institutes of Health Clinical Center (CC)

Results (where available)

View Results


Published on BioPortfolio: 2014-08-27T03:43:17-0400

Clinical Trials [1579 Associated Clinical Trials listed on BioPortfolio]

BestFIT: a Personalized Weight Loss Program

The purpose of this study is to learn how to personalize weight loss programs. In this research we will study: 1. Whether a weight loss counselor should decide if the traditional weight...

A Trial of the Ideal Protein System Versus Low Fat Diet for Weight Loss

This study will examine whether, compared to a standard, low-fat, calorie-restricted diet intervention, the clinic-supported Ideal Protein weight loss method will result in greater weight ...

Keep It Off: A Weight Loss Maintenance Study

The goal of this project is to test whether a phone and mail-based program designed to help people who have recently lost weight helps them keep the weight off over a 2 year period.

Sleep During Weight Loss and Weight Loss Maintenance

The purpose of the study is to examine the changes of sleep during weight loss and weight loss management. The research staff will also obtain data on sleep disturbances, insomnia symptoms...

Applying Social Comparison Theory to Behavioral Weight Loss: Does Modifying Group Membership Improve Outcome?

The purpose of this study is to determine whether a modified behavioral treatment for weight loss that includes one-on-one treatment for individuals struggling to lose weight is associated...

PubMed Articles [8380 Associated PubMed Articles listed on BioPortfolio]

The role of group cohesion in a group-based behavioral weight loss intervention.

Behavioral weight loss interventions are often delivered in groups. Group cohesion may enhance program attendance and, thereby, weight loss. In this secondary analysis, our goals were to: (1a) assess ...

No consistent evidence of a disproportionately low resting energy expenditure in long-term successful weight-loss maintainers.

Evidence in humans is equivocal in regards to whether resting energy expenditure (REE) decreases to a greater extent than predicted for the loss of body mass with weight loss, and whether this disprop...

Weight loss thresholds to detect early hypernatremia in newborns.

The literature indicates a single universal cut-off point for weight loss after birth for the risk of hypernatremia, without considering other factors. The aim of this study was to construct and inter...

Cognitive and behavioural strategies for weight management in overweight adults: Results from the Oxford Food and Activity Behaviours (OxFAB) cohort study.

Though many overweight and obese adults attempt to lose weight without formal support, little is known about the strategies used in self-directed weight loss attempts. We set out to assess cognitive a...

Weight loss in achalasia is determined by its phenotype.

Patients with achalasia present with dysphagia, regurgitation, and varying degrees of weight loss. However, despite it being a disorder of the lower esophageal sphincter with functional obstruction in...

Medical and Biotech [MESH] Definitions

Decrease in existing BODY WEIGHT.

An eating disorder that is characterized by the lack or loss of APPETITE, known as ANOREXIA. Other features include excess fear of becoming OVERWEIGHT; BODY IMAGE disturbance; significant WEIGHT LOSS; refusal to maintain minimal normal weight; and AMENORRHEA. This disorder occurs most frequently in adolescent females. (APA, Thesaurus of Psychological Index Terms, 1994)

A condition of involuntary weight loss of greater then 10% of baseline body weight. It is characterized by atrophy of muscles and depletion of lean body mass. Wasting is a sign of MALNUTRITION as a result of inadequate dietary intake, malabsorption, or hypermetabolism.

Inflammation of the PERICARDIUM that is characterized by the fibrous scarring and adhesion of both serous layers, the VISCERAL PERICARDIUM and the PARIETAL PERICARDIUM leading to the loss of pericardial cavity. The thickened pericardium severely restricts cardiac filling. Clinical signs include FATIGUE, muscle wasting, and WEIGHT LOSS.

General ill health, malnutrition, and weight loss, usually associated with chronic disease.

More From BioPortfolio on "Study of Effects From Gastric Bypass Weight Loss on Brain Tissue"

Quick Search


Relevant Topics

Alzheimer's Disease
Of all the types of Dementia, Alzheimer's disease is the most common, affecting around 465,000 people in the UK. Neurons in the brain die, becuase  'plaques' and 'tangles' (mis-folded proteins) form in the brain. People with Al...

Obesity is the condition in which excess fat has accumulated in the body (mostly in subcutaneous tissues). clinical obesity is considered to be present when a person has a BMI of over 30 (Oxford Dictionary of Medicine). It is becoming increasing common i...

Searches Linking to this Trial