A gene that leads to a person having a thin constitution is linked to a higher risk of heart disease and type 2 diabetes, disorders commonly associated with overweight and obesity, said scientists.
It is known that the IRS1 gene can reduce body fat, but now the researchers of the Harvard School of Medicine, the United States, and the United Kingdom Medical Research Council, discovered that it also seems to be associated with higher levels of glucose and cholesterolIn the blood.
In the organism we have different types of adipose tissue, or fat, including the subcutaneous, which is located under the skin, and the visceral fat that is located within the compacted abdominal cavity between large organs, such as stomach, liver, kidneys andintestine.
The first, subcutaneous fat, is not linked to the typical diseases associated with obesity and even thought that it could even be protective.
But the second, visceral fat, has been related to these diseases, mainly cardiovascular, and their risks are known in the disease of the heart and type 2 diabetes.
As the researchers explain in the journal Nature Genetics, it is known that the IRS1 gene managesPeople who possess this gene.
"We discover a truly fascinating genetic history," says Professor Ruth Loos of the United Kingdom Medical Research Council.
"And when we find the effect of this gene, we are very intrigued by this unexpected finding."
"People, particularly men in a specific form of the gene are more likely to present a lower percentage of body fat, but also to develop heart disease and type 2 diabetes," he says.
"In simple terms," says the researcher, "not just overweight individuals who are predisposed for these metabolic diseases."
determining gene
The objective of the study, explains the scientist, was to look for the genes that determine how much body fat we humans have.To that end, the genomes of more than 75,000 individuals analyzed.
To do this, they gathered data from 26 genetic studies and worked together with investigators from 72 centers in 10 countries.
They found, they say, "convincing evidence" that the IRS1 gene is linked to lower levels of body fat, but also discovered that those who had the gene had higher levels of glucose and cholesterol in the blood.
When they analyzed the fat distribution patterns in individuals who have the IRS1 gene, they discovered that they had less subcutaneous fat but had not reduced their levels of visceral fat.
Researchers believe that as individuals with the IRS1 gene cannot store subcutaneous fat, they store fat in places of the organism that interfere with the normal function of the organs.
This was seen more clearly among men, researchers say.
"What we discover is that certain genetic variants keep you thin by reducing the fat under your skin," explains Dr. Loos.
"We do not know with certainty, but we can speculate that these individuals are more predisposed to store fat in other parts of the body, such as the liver and muscle."
"The effect could be more pronounced in men due to the different fat distribution between the sexes. Men store less fat than women, so they are more sensitive to changes in this distribution," he adds.
For his part, Dr. Ian Frame, research director of the Diabetes UK organization points out that "this is a robust study that offers new information about why 20% ofPeople with type 2 diabetes suffer from the disease despite having a healthy weight. "
"It is also a clear message that people with a thin constitution should not be dissenting with their health."
"Eating well and exercising are the most effective ways to reduce the risk of developing type 2 diabetes," says the expert.
