HEART RATE VARIABILITY AND AEROBIC FITNESS ARE INDEPENDENTLY ASSOCIATED WITH AORTIC STIFFNESS IN YOUNG ADULTS
Joseph D. Vondrasek, Nate K. McMillan, Meral N. Culver, Gregory J. Grosicki, Andrew A. Flatt. Georgia Southern University, Savannah, GA.
BACKGROUND: Aortic stiffening, indexed by carotid-femoral pulse wave velocity (cf-PWV), is associated with an increased risk of cardiovascular disease. Aerobic fitness, indexed by maximal oxygen uptake (VO2max) and cardiac-parasympathetic modulation, indexed by vagal-mediated heart rate variability (HRV), have been shown to be inversely associated with cf-PWV. However, collinearity between VO2max and HRV may be influencing the bivariate associations with PWV. PURPOSE: To determine if VO2max and HRV are independently associated with cf-PWV in healthy young adults when included in a multivariate analysis. METHODS: Twenty-one men (24±5 years; 24±17% body fat) and 20 women (21±3 years; 34±7% body fat) recorded ultra-short (i.e., 60-s), post-waking supine HRV measures for 7 days via a Bluetooth heart rate monitor and cost-free smartphone application. The week average of the natural log of the root-mean square of successive normal RR interval differences (LnRMSSD) was recorded for analysis. Participants subsequently reported to the laboratory in a fasted state during morning hours for assessment of cf-PWV via applanation tonometry and VO2max via a graded exercise test on a cycle ergometer. RESULTS: Men had greater (P <0.05) VO2max (39.5±6.4 vs. 28.1±5.9 mL·kg·min-1) and LnRMSSD (4.4 ± 0.3 vs 4.1 ± 0.5) than women, whereas cf-PWV did not reach significance (6.2±0.8 vs. 5.8±0.5, P = 0.06). VO2max, and LnRMSSD were associated (P <0.05) with cf-PWV in men (r = -0.50 and -0.62, respectively) and women (r = -0.58 and -0.53, respectively). Standard least squares regression was performed to predict cf-PWV based on VO2max, LnRMSSD, and sex. A significant model effect was observed (P = 0.002, R2 = 0.41). VO2max (β = -0.44), LnRMSSD (β = -0.35), and sex (β = 0.70) were significant predictors of cf-PWV (P <0.05). Variance inflation factors were all <3.0. CONCLUSIONS: Aerobic fitness, self-recorded ultra-short HRV, and sex were independently predictive of PWV. Lifestyle factors targeted at increasing HRV or increasing aerobic fitness may augment arterial compliance in young adults, thereby reducing long-term risk for cardiovascular disease.
Vondrasek, JD; McMillan, NK; Culver, MN; Grosicki, GJ; and Flatt, AA
"HEART RATE VARIABILITY AND AEROBIC FITNESS ARE INDEPENDENTLY ASSOCIATED WITH AORTIC STIFFNESS IN YOUNG ADULTS,"
International Journal of Exercise Science: Conference Proceedings: Vol. 16:
1, Article 141.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss1/141