Doctors at Eastern Virginia Medical School's Strelitz Diabetes Center have been studying weight-loss surgery patients to determine if certain types of fat are more likely to result in the development of negative health factors such as Type 2 diabetes and cardiovascular disease. Their findings were presented at the American Diabetes Association meeting in Orlando, Fla., June 27.

The study is being conducted in conjunction with Stephen G. Wohlgemuth, MD, medical director of bariatric surgery at Sentara Norfolk General Hospital's Metabolic & Weight Loss Surgery Center and assistant professor of clinical surgery at EVMS.

"The primary goal of the study is to identify important new factors in visceral fat that might explain the link between obesity, diabetes and heart disease," explains Jerry Nadler, MD, director of the EVMS Strelitz Diabetes Center and chair of internal medicine.

Initial data indicate that people with diabetes have increased levels of an inflammatory enzyme called lipoxygenase in their visceral fat - that is fat surrounding their internal organs. According to Dr. Wohlgemuth, people with large amounts of visceral fat are more likely to have metabolic syndrome (high blood pressure, high cholesterol, insulin resistance) relative to people with primarily subcutaneous fat - fat lying directly under the skin layers - such as cellulite. People with large amounts of visceral fat generally have large bellies and are an apple shape; individuals with larger amounts of subcutaneous fat are typically a pear shape with a bigger bottom and thighs.

The doctors believe that inflammation is a key factor in the development of diabetes, and the presence of these proteins may explain why visceral fat is linked to Type 2 diabetes and cardiovascular disease.

"For a long time, people thought that fat cells just stored excess calories for energy, but they're actually very productive cells," says David Lieb, MD, assistant professor at the Diabetes Center and a co-author of the abstract. "They [fat cells] may make good and bad things. We think that they likely make bad things (inflammation) when people gain excess weight - people get sick because their fat cells are stressed."

"Individuals with Type 2 diabetes are at increased risk for developing cardiovascular disease, and have two to four times the risk for developing heart disease compared to people without diabetes. We know that increased visceral fat increases the risk for cardiovascular disease and diabetes. Currently it is unclear why this occurs, our goal is to find out," Dr. Lieb says.

To accomplish this, the researchers are working to identify the different hormones and inflammatory proteins (lipoxygenases) found in obese individuals, with and without diabetes, before and after their surgical procedure.

"We found lipoxygenase in both the blood vessels and immune cells of visceral fat," says Anca D. Dobrian, PhD, assistant professor of physiological sciences and lead author of the study. "We are currently following up with additional research to investigate both the mechanisms that contribute to visceral fat inflammation and cardiovascular complications." Dobrian and the research team anticipate that these studies will translate well into treatments for patients with diabetes and cardiovascular disease.

"It is very exciting that our team has identified damaging forms of lipoxygenases selectively in the visceral fat only in these obese patients," Dr. Nadler says. "This indicates the potential to develop new medications to target particular forms of lipoxygenases and reduce inflammation in the fat to help prevent the diabetes and heart-related complications of obesity."

Ultimately, these findings could lead to a better understanding of the link between central obesity and major diseases afflicting the U.S. population, identifying why bariatric surgery leads to improvement in blood sugar and also may allow scientists to develop new drugs to target the particular lipoxygenase pathway as a means to treat diabetes.