Ghrelin hormone increases appetite, favours build up of abdominal fat

Washington, May 21 (ANI): In a new study, scientists the University Hospital of Navarra have found that the ghrelin hormone not only increases appetite, but also favours the accumulation of lipids in visceral fatty tissue, located in the abdominal zone and considered to be the most harmful.

Ghrelin is a hormone produced in the stomach and its function is to tell the brain that the body has to be fed. Thus, the level of this secretion increases before eating and decreases after.

However, Amaia Rodríguez Murueta-Goyena, doctor in biology and main researcher of the study, and colleagues discovered that, besides stimulating the hypothalamus to generate appetite, ghrelin also acts on the tabula rasa cortex.

They observed how this hormone favoured the accumulation of lipids in visceral fatty tissue. In concrete, it causes the over-expression of the fatty genes that take part in the retention of lipids, Rodríguez said.

It is precisely this accumulated fat in the region of the abdomen that is deemed to be most harmful, as it is accompanied by comorbilities, visceral obesity being related to higher blood pressure or type 2 diabetes.

Moreover, being located in the abdominal zone and in direct contact with the liver, this type of fatty tissue favours the formation of liver fat and increases the risk of developing resistance to insulin.

The researcher pointed out that normally, on being associated with hypertension, high levels of triglycerides, resistance to insulin and hypercholesterolemia, visceral fat favours the metabolic syndrome.

Rodriguez said that ghrelin can show itself in acylated or deacylated form, the difference being in the octanoic acid present in the composition of the former.

Previously it was thought that only the acylated form was active in the process of weight increase, but many studies point to both hormones being biologically functional.

Researchers pointed out that this discovery of the twin action of ghrelin on the organism opens the door to future treatment for obesity and which, for the time being, is limited to in vitro studies in cell and animal models.

The study was published recently in the International Journal of Obesity. (ANI)