Heart disease and its progression will extend into midlife
Younger individuals are experiencing a greater cumulative exposure to excess adiposity over their lifetime. However, few studies have determined the consequences of long-term obesity, according to the study’s abstract.
Dr. Jared Reis, PhD, FAHA, Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland and colleagues examined whether the duration of overall and abdominal obesity was associated with the presence and 10-year progression of coronary artery calcification (CAC), a subclinical predictor of coronary heart disease.
For this study 3,275 white and black adults aged 18 to 30 years at baseline in 1985-1986 who did not initially have overall obesity (BMI ≥30) or abdominal obesity (men: waist circumference [WC] >102 cm; women: >88 cm) in the multicenter, community-based Coronary Artery Risk Development in Young Adults (CARDIA) study.
Participants completed computed tomography scanning for the presence of CAC during the 15-, 20-, or 25-year follow-up examinations. Duration of overall and abdominal obesity was calculated using repeat measurements of BMI and WC, respectively, performed 2, 5, 7, 10, 15, 20, and 25 years after baseline.
Being obese was defined as having a BMI of at least 30 and abdominal obesity with a waist circumference of more than 40.2 inches in men and 34.6 inches in women.
During follow-up, 40.4% and 41.0% developed overall and abdominal obesity, respectively. The average duration of each type of obesity was 13 years and 12 years, respectively. The CT scans to check for hardening of the coronary artery were done at 15 years (in 2000-2001), 20 years (2005-2006), and 25 years (2010-2011).
Approximately 25.2% and 27.7% of those with more than 20 years of overall and abdominal obesity, respectively, experienced progression of CAC vs 20.2% and 19.5% of those with 0 years.
Among the participants who were not obese at the start of the study the findings revealed that those who had become obese were more likely to have coronary artery calcification (a result of calcium deposition in the coronary arteries) which can eventually lead to a heart attack.
Among those who became obese, the earlier the obesity and the longer they remained overweight the more likely the risk they would develop coronary heart disease.
In their conclusion the researchers write; “Longer duration of overall and abdominal obesity was associated with subclinical coronary heart disease and its progression through midlife independent of the degree of adiposity. Preventing or at least delaying the onset of obesity in young adulthood may lower the risk of developing atherosclerosis through middle age.
This study appears online in the Journal of the American Medical Association.
More information on obesity can be found online at the American Heart Association website.