Ghrelin

compiled by Linda Thornton)

Recently a lot of information has been circulating about a hormone called "ghrelin" which has been found to interfere with the ability to lose weight. The sensation of hunger is extremely powerful. We all experience it and we believe those with PWS experience it even more strongly and constantly. Feeling hungry can result in irritability, anxiety, stress in the best of us. The nature of that powerful stimulus has, until now, never been clearly identified.

Of course, it has stimulated great interest in PW circles with some research already being done. Ghrelin has been found to be "3-fold higher in seven adult individuals with PWS than in healthy controls".(High Circulating Ghrelin: A Potential Cause for Hyperphagia and Obesity in Prader-Willi Syndrome. Angelo DelParigi, Matthias Tschop, et al Journal of Clinical Endocrinology and Metabolism, December 2002)

"Two years ago, scientists found that when they gave a hormone called ghrelin to rodents, it stimulated feeding. Last year, tests done in Washington University, Seattle, showed that "the concentration of ghrelin in a person's blood rises significantly before meals and plummets afterwards. And in one of the latest studies, investigators observed that people receiving premeal infusions of the hormone increased their food intake by an average of 30 percent."

Not only is the hormone Ghrelin a strong hunger stimulant, it increases food intake, body weight and growth-hormone (GH) secretion.

Because ghrelin affects appetite as well as GH secretion, and both are abnormal in PWS, it has been hypothesized that this condition might involve ghrelin dysregulation. Tests have done have shown that after overnight fasting, ghrelin levels were 4.5-fold higher in PWS subjects than in other equally obese subjects , and 2.5-fold higher than in lean controls.

While it is made in the stomach, ghrelin works on the brain. Intervention studies using blockers of ghrelin action or secretion would be needed to test this hypothesis. Since obesity is such a major problem in the general population, you can be sure there will be a rush to discover this "blocker" and maybe - just maybe, scientists are coming closer to discovering just what it is that causes obesity , and not just in PWS, but in the general population.

We look forward to finding out more about ghrelin ("ghre," means growth in Hindi and related languages. The name's initial letters also reference ghrelin's role as a growth hormone releasing factor) and what it can do for PWS."