Gene For Insulin Resistance Syndrome Linked To Heart Disease, Women Particularly Affected.(Dunnigan-type familial partial lipodystrophy)

2001 JUN 7 - (NewsRx Network) -- The discovery that a rare genetic condition speeds the development of heart disease may open the door to new understanding of the link between heart disease and insulin resistance, a problem of blood sugar metabolism.

The condition - Dunnigan-type familial partial lipodystrophy (FPLD) - bears striking similarities with a more common metabolic problem called "insulin resistance syndrome" or "metabolic syndrome X." The gene mutation responsible for FPLD causes weight gain in the abdomen, chest, and face. Affected individuals also have high insulin levels, high blood pressure, high triglycerides, and low levels of high-density lipoprotein (HDL).

Likewise, syndrome X is characterized by central obesity, high levels of insulin circulating in the blood, high triglycerides, low HDL, and high blood pressure. Syndrome X is known to speed the development of heart disease.

Although researchers have suspected the FPLD trait might speed the development of heart disease, this study confirms that suspicion by studying people with the trait.

A study in the May 8, 2001, issue of the journal Circulation included data on 23 FPLD carriers and 17 controls (family members who did not have the FPLD trait). All the carriers had insulin resistance as well as significantly more type 2 diabetes, hypertension, and lipid abnormalities than those in the control group. FPLD carriers had six times the risk of coronary heart disease as their non-carrier relatives in the control group: 34.8% vs. 5.9% at any age, and 26.1% vs. 0% before age 55. The average age of developing heart disease was 46.5 years in individuals with FPLD.

"FPLD appears to be an appropriate human single-gene model for insulin resistance syndrome," says author Robert A. Hegele, MD, a scientist at the Robarts Research Institute and professor of medicine and biochemistry at the University of Western Ontario in London, Ontario, Canada. "Studying these people might provide some insight for insulin resistance syndrome. Sometimes studying the rare genetic forms of a condition can lead to a better understanding of the common forms."

This approach has worked before. For example, studies of a rare form of high cholesterol led to the creation of the statin class of cholesterol-lowering drugs, now one of the world's most-prescribed drug groups.