Abstract 6204: Potentially Modifiable Risk Factors in Adolescence and High Carotid Artery Intima-Media Thickness in Young Adulthood: Population Attributable Risks from Three Prospective Cohort Studies
Background: Exposure to cardiovascular disease risk factors in adolescence are associated with the development of atherosclerosis later in life. Nevertheless, the proportion of atherosclerosis that is attributable to known risk factors in adolescence has not previously been examined.
Objective: To determine the proportion of high carotid intima-media thickness (IMT), a preclinical marker of atherosclerosis, in young adulthood that is attributable to modifiable adolescent risk factors.
Methods: Three population-based prospective cohort studies from the United States, Finland, and Australia among 1549 adults aged 29 to 39 years who were examined in adolescence at ages 12 to 18 years in 1980–1986 (baseline) and re-examined 15–20 years later, between 2001–2006 (follow-up). Adolescent risk factors (blood lipids, blood pressure, body mass index, and smoking) were classified according to established pediatric guidelines. In the absence of a clinical definition of high carotid IMT, we defined high IMT in adulthood as a maximum IMT ≥90th percentile for age, sex, race, and cohort specific values.
Results: In multivariable analyses, high LDL cholesterol (relative risk, RR=2.1; population attributable risk, PAR=17.9%), overweight or obesity (RR=1.7; PAR=7.4%), hypertension (RR=1.5; PAR=9.4%), low HDL cholesterol (RR=1.4; PAR=2.4%), and cigarette smoking (RR=1.4; PAR=5.5%) were associated with high IMT in adulthood. In analyses stratified by adolescent adiposity status, only high LDL cholesterol levels were significantly related to high IMT in adulthood for normal weight adolescents. For overweight or obese adolescents, the risk of high IMT in adulthood became stronger for each of the remaining risk factors.
Conclusions: Modifiable risk factors already present in adolescence accounts for a substantial proportion of high carotid IMT in young adults. For normal weight adolescents, primary prevention programs that target LDL cholesterol levels and maintenance of healthy weight should be the priority. For overweight or obese adolescents, risk factors other than adiposity should be measured and treated in addition to prevention programs aimed at reducing adiposity.