The NPY

Apr 17, 2008 07:38 GMT  ·  By

Bad news. Having a big belly seems to mean that you'll have an even bigger one. A new research published in the FASEB Journal and carried out by a team led by Dr. Kaiping Yang at the Lawson Health Research Institute affiliated with the University of Western Ontario shows that abdominal fat tissue synthesizes a hormone that stimulates fat cell production and hunger: Neuropeptide Y (NPY), previously believed to be synthesized only in the brain.

One of the main reasons why overweight people have a larger appetite than healthy weighed people is because their brains produce extra amounts of NPY, which is the most powerful appetite boosting hormone known so far, making the individual experience a constant hunger.

The new research proved that, in the case of obese rats, NPY is also synthesized locally by abdominal fat. A fat cell cannot multiply, but NPY spurs the number of fat cells by boosting the number of fat cell precursor cells, which transform into fat cells.

"This may lead to a vicious cycle where NPY produced in the brain causes you to eat more and therefore gain more fat around your middle, and then that fat produces more NPY hormone which leads to even more fat cells," said Yang.

Being overweight is clearly not healthy, but abdominal fat, because of its location and byproducts, is the most harmful for the health, increasing the risk for heart disease, Type 2 diabetes, hypertension and some cancers. The team wants to see whether fat-produced NPY is released into the body's blood stream. In this case, it reaches the brain, boosting the hunger sensation. A simple blood test can assess the levels of NPY.

"If you can detect NPY early and identify those at risk for abdominal obesity we can then target therapy to turn off NPY. It would be much easier to use drugs to prevent obesity than to treat the diseases caused by obesity," said Yang.