Body Fat Location is Important
Location...location...location... Obese individuals with excess visceral fat (abdominal fat that surrounds the body’s internal organs) have an increased risk for the development of type 2 diabetes, according to a new study by researchers at UT Southwestern Medical Center. By contrast, persons with excess abdominal subcutaneous fat (fat underneath the skin) were not at a higher risk for the onset of diabetes.
Diabetes type 2 is a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Type 2 diabetes makes up about 90% of cases of diabetes with the other 10% due primarily to diabetes mellitus type 1. Obesity is thought to be the primary cause of type 2 diabetes in people who are genetically predisposed to the disease.
A number of lifestyle factors are known to be important to the development of type 2 diabetes including: obesity (defined by a body mass index of greater than thirty), lack of physical activity, poor diet, stress, and urbanization. Excess body fat is associated with 30% of cases in those of Chinese and Japanese descent, 60-80% of cases in those of European and African descent, and 100% of Pima Indians and Pacific Islanders.
The new study, published in the September obesity-themed issue of the Journal of the American Medical Association, is one of the largest of its kind to assess a multiethnic population of obese people in the U.S. using extensive imaging of adipose tissue. The findings are being presented in New York at a media briefing hosted by JAMA.
"Among obese individuals, it is not necessarily how much fat a person has, but rather where the fat is located on a person that leads to diabetes," according to the paper’s senior author, Dr. James de Lemos, professor of internal medicine at UT Southwestern.
The study, which collected information from UT Southwestern’s Dallas Heart Study, sampled 732 obese adults — those with a body mass index of 30 or greater — between the ages of 30 and 65, without diabetes or cardiovascular disease.
Researchers utilized magnetic resonance imaging (MRI) and dual energy X-ray absorptiometry (DEXA) to determine where fat was stored in the body. While other studies have weighed people and used tape measures to assess their body fat, this study included the largest number of obese people to undergo extensive body-fat imaging.
"We found that individuals who developed prediabetes and diabetes had evidence of early cardiovascular disease years before the onset of diabetes," said Dr. Ian Neeland, a cardiology fellow and first author of the paper. "This finding suggests that excess visceral fat and insulin resistance may contribute to cardiovascular disease among obese individuals."
For further information see Fat Location.
Excess Fat image via Wikipedia.