Abstract P277: Effects of Physical Activity on Vascular and Cardiac Measures in Late Adolescence and Early Adulthood Vary by Intensity
Introduction: Physical activity is associated with cardiovascular health in adults, but the effects of varied intensities of physical activity on vascular and cardiac measures in late adolescence/early adulthood are unclear.
Hypothesis: Greater moderate-vigorous physical activity (MVPA), greater light physical activity (LPA) and less physical inactivity will be associated with more favorable measures of arterial stiffness, arterial thickness, cardiac strain, and cardiac stress.
Methods: In a study of the effects of obesity & diabetes on cardiovascular health, 283 subjects (mean age 22 ± 4 years, 62% female, 63% non-Caucasian) had the following measures obtained: anthropometrics, physical activity (Actical), blood pressure, blood glucose, central and peripheral measures of arterial stiffness (pulse wave velocity (PWV), brachial distensibility (BrachD), and augmentation index (AIx)), arterial thickness (cIMT), cardiac diastolic function (Ea/Aa ratio on echocardiogram), and cardiac strain (global longitudinal strain on echocardiogram). Pearson correlation coefficients were calculated and regression was performed to evaluate the relationships between PA and cardiovascular measures.
Results: Subjects accumulated a mean of 25 minutes MVPA, 203 minutes LPA, and 476 minutes (7.9 hours) inactivity per day. Greater MVPA was significantly associated with more favorable AIx (r = -0.16, p < 0.009), BrachD (r = 0.17, p < 0.008), PWV (r = -0.21, p < 0.001), cIMT (r = -0.12, p = 0.044), diastolic function (r = 0.24, p < 0.001), and cardiac strain (r = -0.13, p = 0.036). After adjustment for covariates such as age, BMI z-score, blood pressure, and glucose, MVPA was no longer significantly associated with any vascular or cardiac measures. Greater LPA was significantly associated with more favorable PWV (r = -0.13, p = 0.037) in bivariate analysis but not after adjustment for BMI z-score. Inactivity was significantly associated with cIMT (r = 0.15, p = 0.016) but no other cardiovascular measures. After adjustment for age and glucose, inactivity was significantly associated (p = 0.029) with cIMT.
Conclusions: In late adolescence and early adulthood, greater MVPA and LPA was associated with more favorable levels of several vascular and cardiac measures, although these relationships were likely mediated through other measures such as BMI. Less inactivity was associated with only one vascular measure - cIMT - but this relationship was independent of several covariates. These findings reinforce the notion that physical activity at various intensity levels, although intimately related to one another, are distinct constructs that differ in their effects on the cardiovascular system.
Author Disclosures: N.M. Edwards: None. P.R. Khoury: None. E.M. Urbina: None.
- © 2015 by American Heart Association, Inc.