Slow Metabolism to Blame for Weight Gain

Many people blame their high weight on a slow metabolism.  In this article, Researchers at Beth Israel Deaconess Medical Center (BIDMC) claim they have discovered a genetic "switch" that can speed up an individual's basal metabolic rate.  This would lead to a reduction in the risk for obesity and diabetes.  Their research, which was published in Nature, involves a process in which a gene that encodes a protein called nicotinamide N- methyltransferase (NNMT) is turned off  This gene is found in the fat cells and the liver.  NNMT is known to process vitamin B3 and was previously linked with certain cancers.  Lead researcher Dr. Barbara Kahn said she and her team began researching NNMT in relation to metabolism after studying GLUT4, a major sugar transporter in the fat cells of genetically engineered mice.  Their research lead to findings that mice that produced large amounts of GLUT4 were insulin sensitive and protected against diabetes, while mice with no GLUT4 were insulin resistant and at risk for diabetes.  This lead to them doing a DNA microarray analysis.  “We extracted the DNA from the fat tissue and analyzed levels of 16,000 genes at the same time ….And we found that the NNMT gene [and the GLUT4 transporter] were the most highly reciprocally regulated,” Kahn said.  This means that the mice without the GLUT4 transporter had higher levels of NNMT.  When the researchers turned off the NNMT gene in mice on high-fat diets, the mice did not gain as much weight compared to when the NNMT gene was functioning normally.  In addition, the mice did not change their eating or exercise habits, showing that the NNMT only affected the mice’s basal metabolic rates and nothing else.  According to Kahn, NNMT affects a biochemical mechanism known as a futile cycle, which plays a role in metabolic regulation.  “If we have an efficient metabolism, we don’t need many calories; the cells can get all the energy we need from a small number of calories,” Kahn said.  “If we have an inefficient metabolism, more calories get burned and we can eat more without gaining weight….But when we knock down this NNMT gene, we affect this [futile cycle].  We speed it up, and it will burn up more calories.”

This new technique could help treat obesity and prevent diabetes.  Obesity and diabetes affects more than 1/3 of adults in the US.  25.8 million people in the world have diabetes, 8.3% of those being Americans.  If we could find techniques to help people control their eating habits, we could save millions of lives and millions of dollars in health care.









Original article: http://www.foxnews.com/health/2014/04/09/new-genetic-switch-technique-may-lead-to-accelerate-metabolism/
To learn more about obesity and diabetes, visit: http://www.medschool.lsuhsc.edu/genetics_center/louisiana/article_obesitydiabetes.htm