Obesity is a risk factor for many diseases, affecting several organs. The researchers identified a chain reaction.
A disease progresses, closely following the evolution of obesity in the world. This is called non-hepatic steatosis, or NASH. Also called “fatty liver” or “soda disease”, it is notably caused by an excess of sugar, and can lead to cirrhosis.
Like excess alcohol, it increases the risk of cancer or type 2 diabetes, although the mechanisms are not always well identified.
But scientists have discovered that it can also deteriorate the state of other organs, thus giving a hypothesis of explanation. In an article published in the journal Diabetology, researchers from the German Center for Diabetes Research (DZD) have shown that it could have deleterious effects on the pancreas in particular.
A circulating protein
NASH alters liver secretions. It produces more glucose, dangerous fats and some proteins. One in particular, the hepatokine fetuin-A, is released into the bloodstream, enters other organs of the body, and causes reactions there.
By exposing pancreatic cells to this protein in the laboratory, the researchers noticed an increase in inflammation. By extrapolating this reaction to a pancreas live, they believe that NASH, indirectly, could thus cause fibrosis, which leads to its more or less complete destruction. NASH could thus trigger or worsen type 2 diabetes.
The kidneys too
And it’s not the only organ affected. In another article, published this time in Scientific Reports, the scientists were able to show that the same protein was also responsible for inflammation of the kidneys.
Around these organs, excess fat is not a problem. On the contrary, it would tend to protect them and promote their regeneration. But not with a NASH. When the two are combined, the reverse happens. Instead of protecting them, the fatty envelope promotes inflammatory processes.
“The factor driving the pathological changes is fetuin-A, which is produced by a fatty liver,” explains Prof. Dorothea Siegel-Axel, diabetologist at the University of Tübingen, and one of the authors of the study.
Identification of specific mechanisms
These two studies shed light on the mechanisms linking obesity and its consequences. “The assertion that obesity itself causes disease is too imprecise,” summarizes Professor Hans-Ulrich Häring, member of the DZD board of directors. Until other parameters, such as the severity of NASH, hepatokine levels, or changes caused in other organs, have been assessed, we cannot tell if a person is at risk. increased or not. »
NASH affects at least 10% of the French population, and more than a third of Americans are affected, especially obese people. But, even for others, the risk is never zero. A British study has indeed recently shown that the “fat but fit”, big but healthy, does not exist!
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