Neurohormonal & Behavioral Correlates of Obesity and Weight Loss

Completed · Not applicable

Conditions studied: Obesity

In brief

Obesity has reached epidemic levels in the United States, and is on the rise in many industrialized nations. The rate of recidivism for long-term weight loss is substantial and presents a critical problem given the importance of obesity as a modifiable risk factor for diseases like type 2 diabetes. Further, the comorbidity of depression with diseases like obesity, type 2 diabetes, and cardiovascular disease suggest that there may be an underlying shared biology for diseases of metabolic dysfunction and emotional dysregulation. The shared biology of these diseases may actually promote the precipitation and exacerbation of comorbid conditions, impacting the success of treatment. Endogenous opioid systems regulate a number of physiological and psychological processes including mood, energy management, and reward. Endogenous opioid µ-receptor-mediated reward processing is thought to be involved both in the short-term control of eating and hedonic food consumption, based on data in animal models. The present proposal will examine the function of the µ-opioid receptor (MOR) system in lean and obese human volunteers following an overnight fast and the change in µ-opioid receptor occupancy (i.e., endogenous opioid release) following the consumption of a standardized meal using PET imaging with the µ-selective radiotracer \[11C\]carfentanil. The obese individuals will be retested in the fasting and fed state following a 15% weight loss with a Very Low Calorie Diet. Further, the investigators will evaluate the function of the MOR system within the context of the individual's metabolic and psychological profile including aspects of mood and inhibitory control. This information will provide the neurobiological bases to develop novel avenues of intervention based on individual variations in central mechanisms associated with motivational systems and appetite and their potential role in weight regain. The investigators hypothesize that overeating in chronically obese individuals will be associated with a dysregulation of MOR system function, manifested by reductions in baseline MOR availability (binding potential, BP) in limbic and reward circuitry, and lower release of endogenous opioids after a standard meal, compared to lean volunteers. The latter is observed as acute reductions in the BP measure after meal ingestion.

Key facts

Study ID: NCT02063451
Run by: University of Michigan
People needed: 16
Starts: 2011-02-01
Expected to finish: 2013-01-15
Last updated by the study team: 2018-09-24

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: accepted.

You may qualify if…

Obese population defined as BMI > 30 kg/m2.
Lean population BMI < 28 but > 17 kg/m2.
Able and willing to provide written informed consent for the trial.
Right handed
age >/= 18 years

You may not qualify if…

Evidence of inherited disorders of lipid metabolism.
History of Cancer within the last 5 years except for minor skin cancers
Human immunodeficiency virus (HIV) antibody positive.
Patients with solid organ transplants.
Positive pregnancy screen in Women
Uncontrolled thyroid disease
Unstable angina or NY heart association class II failure or above
Gastrointestinal disease specifically GI motility disorders
Unstable neuropsychiatric disease including major depression/anxiety, eating disorder such as bulimia or anorexia
End stage renal or hepatic disease
Autoimmune disorders (e.g. SLE)
Body weight fluctuation of more than 5 kg in the previous 3 months
Prior bariatric surgery
A history or current alcohol/substance abuse, or opoid abuse/use and change in smoking habits or cessation in the past 6 months.
Any medical condition, which in the opinion of the investigator would make the patient unsuitable for recruitment, or could interfere with the patient participating in or completing the protocol.
Unwilling or unable to consent for the study.
> 300 lbs (gantry table limit).
having a waist diameter <53 cm (due to fMRI bore diameter)

Where it is running

University of Michigan Medical School — Ann Arbor, Michigan, United States

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.