While sports often garner attention in cases of sudden cardiac arrest in younger people, the reality may be different, a Cedars-Sinai study has found.

"Obesity and other common risk factors may play a greater role than previously thought,” says Dr. Sumeet Chugh, associate director of the Smidt Heart Institute and lead researcher for the study.

Sports were cited only in a small percentage of cardiac arrests in those aged 5 to 34. By contrast, combinations of obesity, hypertension, high cholesterol, diabetes, and smoking—standard cardiovascular risk factors—were found in nearly 60% of cases.

The study, published in Circulation, a journal of the American Heart Association, shed light on a public health problem among the young that has remained largely unsolved. The findings underscore the importance of early screening.

Dr. Chugh suggests extending prevention efforts to routine visits for children and young adults. "The added benefit of such screenings is that early efforts to reduce cardiovascular risk are known to translate into reduction of adult cardiovascular disease," he says.

The findings came out of a larger research enterprise called the Oregon Sudden Unexpected Death Study, an ongoing, comprehensive assessment of all sudden cardiac arrests in the Portland, Oregon metropolitan area, home to 1 million people. The study, founded and led by Dr. Chugh, has been underway for more than 15 years.

Data collected in the study provided Dr. Chugh and his team with information to mine for answers to what causes sudden cardiac arrest, which can result in instantaneous death.

Although "sudden cardiac arrest" and "heart attack" often are used interchangeably, the terms are not synonymous. Sudden cardiac arrest is the result of defective electrical activity in the heart. Patients may have little or no warning.

A heart attack—myocardial infarction—typically is caused by clogged coronary arteries that reduce blood flow to the heart muscle.

The study was funded in part by grant R01 HL126938 from the National Institutes of Health, National Heart Lung and Blood Institute.