While it may not make you love your love handles, a recent study suggests abdominal fat may not deserve the bad rap it has developed.
Abdominal fat has long been suspected of causing metabolic syndrome — a collection of conditions, ranging from diabetes to high blood pressure, known to increase one’s risk of heart attack. But researchers from Yale University School of Medicine in Chevy Chase, Maryland, report insulin resistance in skeletal muscle is to blame for the development of metabolic syndrome — not belly fat.
Insulin resistance in skeletal muscle inhibits the muscle’s ability to make glycogen — the stored form of energy from carbohydrates. Researchers compared a group of young, healthy, insulin sensitive subjects to a group of young, healthy, insulin resistant subjects. They discovered instead of storing the energy away as glycogen in the liver and muscle — as insulin sensitive individuals do — the insulin resistant subjects divert the energy to fatty acid production. This increases the level of lipids or fats in the bloodstream, thus worsening the metabolic syndrome.
“We measured abdominal fat in these two groups of individuals, and there is absolutely no difference in the volume of abdominal fat,” Yale professor Gerald I. Shulman, M.D., Ph.D., told Ivanhoe.
“Many studies, many people, many investigators believe abdominal fat is the root of the metabolic syndrome and we’re saying it’s not abdominal fat — it’s insulin resistance. In fact, the abdominal fat is something that may come later in the course of the disease, but it’s not a primary, underlying factor,” said Dr. Shulman, the study’s lead author.
According to the study, the metabolic syndrome is a very common metabolic abnormality. More than 50 million Americans live with the condition — and roughly half of all Americans are predisposed to it. Because of the wide range of associated health complications and the growing prevalence of the condition, it is considered one of the nation’s more serious health issues.
SOURCE: Ivanhoe interview with Gerald I. Shulman, M.D., Ph.D.; Proceedings of the National Academy of Sciences, published online July 16, 2007