July 5, 2007 (Insidermedicine) A revolutionary weight loss strategy is being developed to treat obese people with metabolic syndrome using simple, non-toxic chemical injections, according to a report published in Nature Medicine.

It is estimated that approximately 60 million Americans are affected by metabolic syndrome, a group of risk factors that combined increase a person’s chance of getting heart disease, diabetes, and stroke. One main risk factor for this syndrome appears to be abdominal obesity. For years scientists have suspected a link between stress and obesity, but until now, the relationship was not well understood.

To investigate the association, researchers manipulated neurotransmitters, which are chemicals used by neurons to transit signals to each other. They used the neuropeptide NPY and the receptor it activates, YR2. NPY and YR2 work in two types of cells in fat tissue – the endothelial cells that line blood vessels and the fat cells themselves.

Researchers fed mice either a normal or a high fat and sugar diet and subjected them to stressors similar to those they would encounter in the wild. They found that stressed mice on normal diet did not gain weight, but those on a high-fat diet gained more weight than expected, particularly around the abdominal area. The mice also began to demonstrate the metabolic and cardiovascular results of being obese.

Researchers believe that stress leads to the release of NPY from the sympathetic nerves, which is taken up by Y2R causing the release of even more NPY. This process leads to the growth of abdominal fat and development of metabolic syndrome. Interestingly, scientists were able to prevent abdominal weight gain and metabolic syndrome in the stressed mice by injecting a Y2R blocker in the abdominal fat. This suggests that NPY works on fat tissue and not the brain, and that stressed animals process their food differently than non-stressed animals.

The injections may provide a safe, effective, non-surgical way of eliminating undesirable body fat, and help people reduce the risks associated with metabolic syndrome. At this time however, their effectiveness and safety in humans remains to be established.

Reporting for Insidermedicine, I’m Dr. Susan Sharma.