Stress hormones are the main factor in diabetes linked to obesity, according to a new study.
- Researchers have noticed that overeating in mice increases their stress hormone.
- Additional experiments have shown that this increase in stress hormones may be responsible for the increased risk of diabetes in obese people.
- This discovery – if confirmed – could lead to new therapeutic approaches to combat insulin resistance and diabetes.
According to thePasteur Institute of Lilleobesity is the leading risk factor for diabetes and 80% of obese people are diabetic. To explain this association, many doctors suggest that being too overweight causes an alteration in the way insulin sends signals in the liver and fat cells.
Researchers at Rutgers University’s Robert Wood Johnson School of Medicine have made a discovery that challenges this hypothesis. They claim that it is stress hormones – and not impaired cellular insulin signaling – that are the main factor in obesity-related diabetes.
Their discovery was presented in the journal Cell Metabolism, on October 21, 2024.
Diabetes: stress from overeating may play a role
To understand the mechanisms behind diabetes in people with obesity, researchers studied mice that ate more than necessary. They noticed that this overeating led to an increase in one of the stress hormones, norepinephrine, within a few days, “indicating the rapidity with which excess food stimulates the sympathetic nervous system.”
To determine the effect of these organic compounds on metabolic health, the team brought together rodents genetically engineered to not produce catecholamines (the term for all stress hormones) outside of their brains and central nervous systems. She fed them food high in obesity-promoting fat and sugar. At the end of the experiment, although the animals had eaten as many calories and become just as obese as their “normal” counterparts, they did not develop diabetes.
“We were pleased to find that our mice ate so much, because this indicates that the differences in insulin sensitivity and lack of metabolic disease are not due to reduced food intake or reduced l obesity, but with a considerable reduction in stress hormones. These mice may not have an increase in stress hormones that counteract insulin. Therefore, insulin resistance does not develop during development. obesity“, indicates Dr. Christoph Buettner, lead author of the study, in a press release. For him, his work could help explain why some obese people develop diabetes while others do not, or why stress can worsen diabetes even with little weight gain.
Diabetes and stress: towards new treatments?
For the researcher, the increase in catecholamine levels would thus be “the fundamental mechanism underlying insulin resistance in obesity”. “Stress and obesity, in essence, work through the same basic mechanism to cause diabetes, through the action of stress hormones”he specifies.
The study also notes that given the results obtained, drugs that reduce catecholamines should help prevent or treat diabetes. However, current data collected on these treatments – prescribed for example to treat high blood pressure – do not show major beneficial effects on diabetes. “This may be because current drugs do not block the relevant receptors or they affect the brain and body in complex ways”believes Dr. Buettner. However, he believes his discovery could help develop therapeutic approaches to diabetes that focus on reducing stress hormones rather than targeting insulin signaling.
But for now, the scientist plans to conduct further studies on humans to confirm his findings. “We would also like to study whether short-term overeating, as some of us experience during the holidays by gaining 2 to 4 kilos, increases insulin resistance with increased activation of the sympathetic nervous system.”he adds.
