Over the past three decades, obesity rates for adults have doubled and rates for adolescents have tripled. Therefore, younger people are experiencing a greater cumulative exposure to excess adiposity over their lifetime, however the long-term effects of this have been poorly studied to date. In particular, abdominal obesity is known to cause the development of atherosclerosis independent of overall adiposity, however no study has to date examined whether the duration of abdominal obesity contributes to the development or progression of atherosclerosis.

The CARDIA (Coronary Artery Risk Development in Young Adults) study initially enrolled 3275 adults aged 18 to 30 between 1985 and 1986; none had overall or abdomen obesity at baseline. Patients completed CT scanning for the presence of coronary artery calcium during 15-, 20-, or 25-year follow-up examinations. The duration of overall and abdominal obesity was also calculated using regular measurements of body mass index and waist circumference that were taken over the follow-up period.

Over the follow-up period, 40.4% patients developed overall obesity, and 41.0% of patients developed abdominal obesity. Rates of CAC per 1000 person-years were higher for those who experienced either form of obesity for more than twenty years, when compared to those who were not obese. Furthermore, 25.2% of patients with more than twenty years of overall obesity experienced progression of coronary artery calcium compared to 20.2% of patients with 0 years of obesity. Similarly, 27.2% of patients with more than twenty years of abdominal obesity showed progression of coronary disease compared to 19.5% of those with 0 years. After adjustment for body mass index or waist size, and other potential confounders, the hazard ratios for coronary calcium for each additional year of overall or abdominal obesity were 1.02 and 1.03, respectively.

Conclusions:

A longer duration of both overall and abdominal obesity was associated with subclinical coronary artery disease and its progression through midlife, as measured by coronary artery calcium scoring.

• Reis JP, Loria CM, Lewis CE, et al. Association Between Duration of Overall and Abdominal Obesity Beginning in Young Adulthood and Coronary Artery Calcification in Middle Age. JAMA 2013;310:280-288.