'Aged fat'—combo of age, obesity—may damage blood vessels, hasten heart failure

Researchers have identified an enzyme that may explain why age and obesity can combine to restrict blood flow through blood vessels and increase risks of heart failure.

Researchers at the Medical College of Georgia at Augusta University, publishing findings online July 10 in Arteriosclerosis, Thrombosis and Vascular Biology, discovered problems with the enzyme ADAM17 in obese and older patients.

"Older obese patients and sometimes women who suffer heart failure go to the cardiac catheterization lab, and the cardiologist finds nothing that would explain their heart failure," said Zsolt Bagi, MD, PhD, vascular biologist at the Medical College of Georgia at Augusta University. "They have normal large blood vessels in the heart [but] still the heart failure has developed."

The researchers dubbed the risk “aged fat” with evidence the two factors can have an additive effect. The walls of the coronary microvasculature can thicken without any atherosclerotic plaque, which is commonly linked to heart disease.

ADAM17 levels increase with obesity, while production of a natural inhibitor decreases with age. This exposure leads the walls of the microvasculature to become thicker, less elastic and unable to dilate properly.