The findings also are likely to apply to people of normal weight, Hong said, although the genes involved have yet to be identified. For now, the researchers hope the results will lead others to use direct measurements of abdominal visceral fat in future studies. The study also suggests that people who are overweight should periodically be checked for diabetes.
What's next?
As part of the Heritage Family Study, colleagues of the Washington University
researchers have begun hunting for the disease-related genes in the 98 families.
They are using genetic tags that help indicate the position of disease-related
genes along the length of human chromosomes the way street names help locate
someone's house.
Once genes linked to the traits are identified, tests could be developed to indicate a person's risk for becoming diabetic and gaining abdominal fat. Designing such tests would be easiest if a few -- or even one -- genes were responsible for the link.
Finding disease-related genes also may help clarify whether genes underlie the appearance of four traits in some families. High blood pressure, obesity, insulin resistance and high levels of fats in the blood called triglycerides all occur in some families, a condition that has been labeled syndrome x or metabolic syndrome. Insulin resistance and obesity are considered cornerstones of the syndrome.
The researchers note that people shouldn't ignore the important influence of diet and exercise on health, however. Non-genetic factors appear to account for more than 50 percent of the likelihood of developing insulin resistance or abdominal visceral fat, for example. In the diabetes study, the influence of lifestyle was factored in by evaluating families whose parents had lived together an average of 20 years and had older children.
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Contact: Barbra Rodriguez
rodrigub@medicine.wustl.edu
314-286-0122
Washington University in St. Louis
24-Feb-1999