Obesity is associated with an impairment of coronary circulatory function

A team of University of California, Los Angeles researchers found that positron emission tomography (PET) can provide important information on the relationship between heart function and obesity. Their findings were reported at the Society of Nuclear Medicine's 52nd Annual Meeting June 18–22 in Toronto.

Since 1960, statistics show that the number of overweight and obese Americans has continued to increase. Today, reports indicate that 64.5 percent of adult Americans--about 127 million--are categorized as being overweight or obese. Every year, obesity causes at least 300,000 deaths in the United States. "The increasing prevalence of obesity in the United States is of considerable public health concern, and the mechanisms by which obesity initiates and accelerates vascular disease are still poorly understood," said Thomas H. Schindler, M.D., who works in the department of molecular and medical pharmacology at UCLA's School of Medicine. "Quantitative PET imaging--with the assessment of the functional stage of the heart vessels--may indeed provide important information to stratify (or classify) the risk of an individual for future cardiovascular events," he said. PET imaging "may be a useful tool to monitor the effects of therapeutic interventions on impaired coronary vasomotor function to improve cardiovascular outcome in the long term," added the co-author of "Obesity Is Associated With an Impairment of Coronary Circulatory Function." PET may also be able to provide information on the function of heart vessels--in the absence of hemodynamically significant obstructive coronary heart disease--and "predict the occurrence of coronary heart disease and cardiovascular events," noted Schindler.

"In overweight/obese individuals, normal cardiac single photon emission computed tomography (SPECT) imaging, which widely excludes hemodynamically obstructive coronary heart disease, and quantitative PET imaging may identify an early functional impairment of the heart vessels that may precede morphological changes in the further course of the development of coronary artery disease," said Schindler. PET imaging may identify overweight/obese individuals with normal SPECT imaging results, but at increased risk for the progression of coronary artery disease and future cardiovascular events, he explained.

"This scientific finding is one of a continuing series of studies from UCLA documenting impaired vascular reactivity in relation to hypertension, diabetes, hypercholesterolemia, smoking and obesity," said Josef Machac, M.D., director of the Clinical PET Center and Nuclear Medicine at Mount Sinai School of Medicine, New York, N.Y., and a vice chair of SNM's Scientific Program Committee (Cardiovascular Track).

The authors of "Obesity Is Associated With an Impairment of Coronary Circulatory Function" are Thomas H. Schindler, Jerson Cadenas, Michael Kreissl, Xiao-Li Zhang and Heinrich R. Schelbert, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, Calif.