Too much clot
Obesity and diabetes threaten tidal wave of heart disease
Editor’s Note: This story, first published in 2007, has been updated.
Whatever the cause or causes, the delicate inner lining of an artery is injured—scratched, if you will—revealing the underlying collagen infrastructure. Platelets rush to site to repair the injury and prevent bleeding. They attach themselves to the exposed collagen, and recruit other platelets to join them.
Along comes thrombin to further sound the alarm and “set” the clot. Thrombin, an enzyme, chops up a protein called fibrinogen into short, sturdy strands of fibrin that trap platelets and other blood cells like fish in a net.
Just enough clot can save a life. Too much clot, however, can take it, by blocking an artery and triggering a heart attack or stroke.
This may be what’s behind the high rates of heart disease among people with type 2 diabetes and obesity.
Currently about 66 million Americans—nearly a third of the adult population—are obese. Most will develop heart disease. “There is no greater threat to American’s cardiovascular health,” warns Douglas Vaughan, M.D., former chief of Cardiovascular Medicine at Vanderbilt University Medical Center.
The prevalence of type 2 diabetes also is burgeoning, and is expected to double—to nearly 40 million people—within a decade. At least 85 percent of these people will die from blood clots that stop their hearts or their brains. Women seem to be more vulnerable than men.
“Unless the underlying mechanisms responsible for these events can be identified, there will be an unprecedented number of diabetic patients suffering thrombotic episodes in the next 10 years,” predicts Stephen Davis, M.D., Ph.D., chief of the Vanderbilt Division of Diabetes, Endocrinology and Metabolism. (See “How to tell if you’re at risk”).
In 2006, Davis and Vaughan joined forces with their colleagues at Vanderbilt to tackle one of the most urgent mysteries of modern medicine—why exactly do obesity and diabetes increase the risk of life-threatening blood clots?
Vaughan has since left Vanderbilt to chair the Department of Medicine at Northwestern University Feinberg School of Medicine. But his former colleagues are continuing their inquiry through a Specialized Center of Clinically Oriented Research (SCCOR) supported by the National Heart, Lung, and Blood Institute. Their goal: to investigate bleeding and clotting disorders, and to rapidly translate their discoveries into clinical practice