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

Transpara Deep Learning Software Matches Experienced Radiologists in Mammogram Reading
News | Computer-Aided Detection Software | January 12, 2018
Deep learning and artificial intelligence improves the efficiency and accuracy of reading mammograms, according to...
Smartphone Addiction Creates Imbalance in Brain
News | Mobile Devices | January 11, 2018
Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet,...
Fat Distribution in Women and Men Provides Clues to Heart Attack Risk
News | Women's Health | January 11, 2018
January 11, 2018 – It’s not the amount of fat in your body but where it is stored that may increase your risk for hea
Minimally Invasive Treatment Provides Relief from Back Pain

Lumbar spine MRI showing disc herniation and nerve root at baseline and one month after treatment

News | Interventional Radiology | January 11, 2018
The majority of patients were pain free after receiving a new image-guided pulsed radiofrequency treatment for low back...
Emergency Radiologists See Inner Toll of Opioid Use Disorders

Rates of Imaging Positivity for IV-SUDs Complications. Image courtesy of Efren J. Flores, M.D.

News | Clinical Study | January 11, 2018
January 11, 2018 – Emergency radiologists are seeing a high prevalence of patients with complications related to opio
CT Shows Enlarged Aortas in Former Pro Football Players

3-D rendering from a cardiac CT dataset demonstrating mild dilation of the ascending aorta.

News | Computed Tomography (CT) | January 11, 2018
Former National Football League (NFL) players are more likely to have enlarged aortas, a condition that may put them at...
Study Finds No Evidence that Gadolinium Causes Neurologic Harm

MR images through, A, C, E, basal ganglia and, B, D, F, posterior fossa at level of dentate nucleus. Images are shown for, A, B, control group patient 4, and the, C, D, first and, E, F, last examinations performed in contrast group patient 13. Regions of interest used in quantification of signal intensity are shown as dashed lines for globus pallidus (green), thalamus (blue), dentate nucleus (yellow), and pons (red).

News | Contrast Media | January 11, 2018
January 11, 2018 — There is no evidence that accumulation in the brain of the element gadolinium speeds cognitive dec

Size comparison between 3-D printed prosthesis implant and a penny.

News | 3-D Printing | January 11, 2018
January 11, 2018 — Researchers using...
RSNA 2017 technical exhibits, expo floor, showing new radiology technology advances.
Feature | RSNA 2017 | January 11, 2018
January 11, 2018 — Here is a list of some of the key clinical study presentations, articles on trends and videos from
Hip Steroid Injections Associated with Bone Changes

58-year-old woman with left hip pain. X-ray from one month prior to the steroid/anesthetic injection demonstrates moderate joint space narrowing (arrows) and bony proliferation (arrowheads).

News | Orthopedic Imaging | January 11, 2018
January 11, 2018 – Osteoarthritis patients who received a steroid injection in the hip had a significantly greater in
Overlay Init