Abstract P308: Physical Activity is Associated With Lower Atherosclerotic Risk and Arterial Stiffness in Youth
Introduction: The prevalence of cardiovascular (CV) risk factors in young people has increased related to the pediatric obesity epidemic. An association between physical activity (PA) and target organ damage has been firmly established in adults, and such damage confers increased CV event risk. There is an urgent need to implement prevention strategies for CV disease in youth. Promoting PA holds promise in this regard. However, in order to be a useful marker, PA needs to be quantified accurately and feasibly in the clinical setting, and its relationship to preclinical CV disease in youth needs to be understood.
Objective: We aimed to 1) examine the relationship between a subjective measure of PA and an objective measure in a young cohort, 2) determine the association of PA and other CV risk factors, and 3) test the hypothesis that PA is an independent determinant of target organ damage.
Methods: Adolescents and young adults were recruited from an ongoing study of the effects of risk factors on CV aging. At baseline adolescents with type 2 diabetes mellitus were matched by age, sex, and race to lean and obese control subjects without diabetes. These analyses were performed at 5 years follow-up on 249 subjects (mean age 22 ± 3.9 years). PA was measured with the International Physical Activity Questionnaire (IPAQ) and the Actical accelerometer. Target organ damage was assessed with echocardiography and vascular structure and function testing. Subjects were stratified into tertiles of average PA with the lean group as the standard. Differences in endpoints by PA tertile were tested by analysis of variance and χ2 tests. General linear models were constructed and used to test for independent associations.
Results: Responses to the IPAQ differed greatly from objective accelerometry. There was a weak trend toward increased CV risk factors and target organ damage in those with the lowest IPAQ scores. When subjects were stratified into tertiles of by accelerometry the less active subjects had significantly worse CV risk profiles as indicated by higher Pathobiological Determinants of Atherosclerosis in Youth (PDAY) scores, and more signs of target organ damage including stiffer arteries as indicated by greater carotid-femoral pulse wave velocities. These differences did not reach statistical significance when adjusted for metabolic variables.
Conclusion: PA is associated with CV risk factor clustering and target organ damage in young people. Measuring PA in this population is feasible, but has limitations. This study confirms the utility of PA in predicting the presence of target organ damage. Our study is the first to demonstrate a negative, cross-sectional relationship between PA and PDAY score. Future opportunities for research include examining the contribution of different levels of PA on CV aging as well as the effect of increasing PA over time.
Author Disclosures: S.G. Wittekind: None. N.M. Edwards: None. P.R. Khoury: None. C.E. McCoy: None. T.R. Kimball: None. E.M. Urbina: B. Research Grant; Significant; NIH R01 HL076269, NIH R01 HL105591, NIH UL1 TR001425.
- © 2017 by American Heart Association, Inc.