Young Adult Obesity May Affect Later Heart Disease

The longer a young adult is obese, the greater the chance of developing heart disease in middle age, a new study reports. The finding hints that preventing or even delaying the onset of obesity might help reduce heart disease in later years.

Heart disease is the leading cause of death nationwide, and obesity boosts the risk for heart disease. Past studies have linked both body mass index (BMI)—a ratio of weight to height—and waist circumference to heart disease risk. However, few studies have looked at whether the length of time a person is obese affects heart disease as well.

To learn more, a team led by NIH’s Dr. Jared Reis studied more than 3,200 young adults, ages 18 to 30, who weren’t obese at the start of the study. The subjects were followed over a 25-year period to see if and when they became obese and for how long. Heart scans looked for calcium deposits in their coronary arteries, an early warning sign of heart disease. These calcifications can arise long before symptoms are noticed—a condition called silent heart disease.

About 40% of the adults became obese during the study. Over 38% of those who were obese for more than 2 decades developed coronary artery calcification. In contrast, only about 25% of those who never became obese developed calcification. The scientists calculated that each year a young adult is obese raises that person’s risk of developing silent heart disease by 2-4%.

People in the U.S. are becoming obese at younger ages, and more than one-third of adults are obese.

“I think our findings really suggest that if we don’t measure obesity duration in addition to BMI and waist circumference, we may be underestimating the health risks of obesity,” Reis says.