News | June 19, 2013

High Sugar Intake Linked To Low Dopamine Release in Insulin Resistant Patients

PET study indicates that overeating and weight gain contributing to onset of diabetes could be related to a deficit in reward circuits in the brain

 High Sugar Intake  Low Dopamine Release Insulin Resistant Patients SNMMI 2013

June 19, 2013 — Using positron emission tomography (PET) imaging of the brain, researchers have identified a sweet spot that operates in a disorderly way when simple sugars are introduced to people with insulin resistance, a precursor to type 2 diabetes. For those who have the metabolic syndrome, a sugar drink resulted in a lower-than-normal release of the chemical dopamine in a major pleasure center of the brain. This chemical response may be indicative of a deficient reward system, which could potentially be setting the stage for insulin resistance. This research could revolutionize the medical community’s understanding of how food-reward signaling contributes to obesity, according to a clinical study being presented at the Society of Nuclear Medicine and Molecular Imaging’s 2013 Annual Meeting.

“Insulin resistance is a significant contributor to obesity and diabetes,” said Gene-Jack Wang, M.D., lead author of the study and professor of radiology at Stony Brook University and researcher at the U.S. Department of Energy’s Brookhaven National Laboratory in Upton, N.Y. “A better understanding of the cerebral mechanisms underlying abnormal eating behaviors with insulin resistance would help in the development of interventions to counteract the deterioration caused by overeating and subsequent obesity. We suggest that insulin resistance and its association with less dopamine release in a central brain reward region might promote overeating to compensate for this deficit.”

An estimated one-third of Americans are obese, according to the U.S. Centers for Disease Control and Prevention. The American Diabetes Association estimates that about 26 million Americans are living with diabetes and another 79 million are thought to be prediabetic, including those with insulin resistance.

The tendency to overeat may be caused by a complex biochemical relationship, as evidenced by preliminary research with rodents. Wang’s research marks the first clinical study of its kind with human subjects.

“Animal studies indicated that increased insulin resistance precedes the lack of control associated with pathological overeating,” said Wang. “They also showed that sugar ingestion releases dopamine in brain regions associated with reward. However, the central mechanism that contributes to insulin resistance, pathological eating and weight gain is unknown.”

He continued, “In this study we were able to confirm an abnormal dopamine response to glucose ingestion in the nucleus accumbens, where much of the brain’s reward circuitry is located. This may be the link we have been looking for between insulin resistance and obesity. To test this, we gave a glucose drink to an insulin-sensitive control group and an insulin-resistant group of individuals and we compared the release of dopamine in the brain reward center using PET.” 

In this study, a total of 19 participants — including 11 healthy controls and eight insulin-resistant subjects—consumed a glucose drink and, on a separate day, an artificially sweetened drink containing sucralose. After each drink, PET imaging with C-11 raclopride — which binds to dopamine receptors — was performed. Researchers mapped lit-up areas of the brain and then gauged striatal dopamine receptor availability (which is inversely related to the amount of natural dopamine present in the brain). These results were matched with an evaluation in which patients were asked to document their eating behavior to assess any abnormal patterns in their day-to-day lives. Results showed agreement in receptor availability between insulin-resistant and healthy controls after ingestion of sucralose. However, after patients drank the sugary glucose, those who were insulin-resistant and had signs of disorderly eating were found to have remarkably lower natural dopamine release in response to glucose ingestion when compared with the insulin-sensitive control subjects.

“This study could help develop interventions, i.e., medication and lifestyle modification, for early-stage insulin-resistant subjects to counteract the deterioration that leads to obesity and/or diabetes,” said Wang. “The findings set a path for future clinical studies using molecular imaging methods to assess the link of peripheral hormones with brain neurotransmitter systems and their association with eating behaviors.”

For more information: www.snmmi.org.

 

 

Related Content

PET/CT Changes Care for 59 Percent of Suspected Recurrent Prostate Cancer Cases
News | Prostate Cancer | June 13, 2018
A recently presented investigational clinical trial evaluated the impact of 18F fluciclovine positron emission...
Accuray TomoTherapy System Beneficial in Two Total Body Irradiation Studies
News | Radiation Therapy | June 13, 2018
Recently published data from two new studies demonstrate the benefits of Accuray’s TomoTherapy System in the delivery...
Women More Likely to Use Other Preventive Health Services Following Mammography
News | Mammography | June 13, 2018
Medicare beneficiaries who undergo breast cancer screening with mammography are more likely than unscreened women to...
Reduced hippocampal volume on MRI

This figure shows reduced hippocampal volume over the course of 6 years as seen on progressive volumetric analysis and also coronal MRI evaluations (arrows).Progressive volume loss in the mesial temporal lobe on MRI is a characteristic imaging feature of AD. This patient was a case of Alzheimer’s Dementia.

 

News | Neuro Imaging | June 12, 2018
According to a UCLA Medical Center study, a new technology shows the potential to help doctors better determine when...
High Prevalence of Atherosclerosis Found in Lower Risk Patients
News | Magnetic Resonance Imaging (MRI) | June 08, 2018
Whole-body magnetic resonance angiography (MRA) found a surprisingly high prevalence of atherosclerosis in people...
Nuclear imaging scan showing very good tissue delineation. Scan performed on a Biograph Vision positron emission tomography/computed tomography (PET-CT) system from Siemens Healthineers.

Nuclear imaging scan showing very good tissue delineation. It offers crisp overall image quality and sharply delineates the muscle and fat planes, vertebral margins and end plates, billiary radicals, renal calyces, aortic wall and papillary muscles of the heart. Scan performed on a Biograph Vision positron emission tomography/computed tomography (PET-CT) system from Siemens Healthineers.

Technology | PET-CT | June 05, 2018
June 5, 2018 — The U.S.
Lung Decision Precision
News | Lung Cancer | June 04, 2018
For smokers and former smokers, the threat of lung cancer always lurks in the shadows.
New Ultrasound Guidelines Reliably Identify Children Who Should be Biopsied for Thyroid Cancer

Image courtesy of Loyola Medicine

News | Pediatric Imaging | May 29, 2018
A Loyola Medicine study has found that new ultrasound guidelines can reliably identify pediatric patients who should be...
News | Digital Radiography (DR) | May 25, 2018
Konica Minolta Healthcare Americas Inc. announced that two clinical studies utilizing the company’s Dynamic Digital...
Breast Cancer Survivors Not Getting Recommended Number of Mammograms Post-Surgery
News | Mammography | May 24, 2018
Breast cancer survivors are not getting the recommended level of screening post-surgery, according to a newly-published...
Overlay Init