A lifetime spent being obese could be a predictor for coronary artery calcification, a major risk factor for heart disease, according to a new study.
Researchers from the National Heart, Lung, and Blood Institute found that the rate of coronary artery calcification is higher among people who have been obese for more than 20 years of their lives, compared with those who had never become obese.
The study, published in the Journal of the American Medical Association, included 3,275 white and black adults who were between ages 18 to 30 years of age at the start of the study in 1985-1986. None of them were originally obese (meaning they had a body mass index greater than or equal to 30) or abdominally obese (which researchers determined by their waist circumference: greater than 40.2 inches for men, and greater than 34.6 inches for women).
Researchers conducted scans to see how much coronary artery calcification the participants had during follow-up tests 15, 20 and 25 years after the beginning of the study. The researchers also continued taking BMI and waist circumference of the participants throughout the 25-year study time span to see who would go on to become obese, and for how long.
By the end of the study, researchers found that 40.4 percent of the study participants had become obese, and 41 percent of them had become abdominally obese. On average, people were obese for 13.3 years, and abdominally obese for 12.2 years. And 27.5 percent of all the study participants had developed coronary artery calcification.
Researchers found that the rate of coronary artery calcification went up the longer a person was obese. Specifically, for people who were obese for more than 20 years, 38.2 percent had coronary artery calcification, and for those who were abdominally obese for more than 20 years, 39.3 percent had coronary artery calcification. However, just 24.9 percent of people who didn't become obese over the study period had coronary artery calcification by the end of the study period, and 24.7 percent of people who didn't become abdominally obese over the study period had coronary artery calcification by the end of the study.
Plus, those who spent more than 20 years being obese experienced progression of coronary artery calcification, compared with those who didn't become obese.
The findings are especially important considering the high numbers of obese children and teens in the United States (though recent reports have showed some promising gains in this area). Earlier-onset obesity "will have important implications on the future burden of coronary atherosclerosis and potentially on the rates of clinical cardiovascular disease in the United States," the researchers wrote in the study.