Washington D.C. [USA]: Responsiveness of brain insulin can be a factor in determining where fat gets deposited in the body and to what degree a person may benefit from a lifestyle intervention.
If the person's brain responds sensitively to the hormone, a significant amount of weight can be lost, unhealthy visceral fat reduced, and the weight loss can be maintained over the long term.
However, if the person's brain responds only slightly or not at all to insulin, the person only loses some weight at the beginning of the intervention and then experiences weight regain. Over the long term, the visceral fat also increases.
Published in Nature Communications, these are the results of a long-term study by the German Center for Diabetes Research (DZD), Helmholtz Zentrum Munchen, and Tubingen University Hospital.
To which extent body fat has an unhealthy effect depends primarily on where it is stored. If fat accumulates in the abdomen, this is particularly unfavourable.
This is because the visceral fat releases numerous neurotransmitters that affect blood pressure, influence the secretion of the hormone insulin, and can cause inflammation. This increases the risk of diabetes, cardiovascular disease, and certain types of cancer.
The subcutaneous fat which accumulates on the buttocks, thighs, and hips has no adverse health effects.
It is here, the brain insulin responsiveness could play an important role.
They showed that people with high insulin sensitivity in the brain benefit significantly more from a lifestyle intervention with a diet rich in fibre and exercise than people with insulin resistance in the brain.
Not only did they lose more weight, but they also had a healthier fat distribution.
To study the distribution of body fat, the team recorded the follow-up data of 15 participants over a period of nine years, in which the insulin sensitivity in the brain was determined by magnetoencephalography before the start of 24-month lifestyle intervention.
The results, when put into conclusions state that high insulin sensitivity associated with a reduction in visceral fat and weight.
"Subjects with high insulin sensitivity in the brain benefited from lifestyle intervention with a pronounced reduction in weight and visceral fat. Even after the lifestyle intervention had ended, they only regained a small amount of fat during the nine-year follow-up," said the head of the study, Professor Martin Heni from Tubingen University Hospital. I In contrast, people with brain insulin resistance only showed a slight weight loss in the first nine months of the program.
"Afterwards, their body weight and visceral fat increased again during the following months of lifestyle intervention," said first author PD Dr. Stephanie Kullmann from the IDM.
"Our study reveals a novel key mechanism that regulates fat distribution in humans. Insulin sensitivity in the brain determines where fat is deposited, "said Heni, summarizing the results.
Since visceral fat not only plays a role in the development of type 2 diabetes but also increases the risk of cardiovascular disease and cancer, the study results may also open up new approaches for treatment options beyond metabolic diseases.