Cardiovascular Disease Risk In Middle-Aged Ultra-Endurance Athletes

Abstract

It is widely accepted that aerobic exercise reduces cardiovascular disease (CVD) risk. However, recent studies suggest that volumes of exercise that greatly exceed physical activity guidelines may be damaging to the heart. Currently, it is unclear if individuals who train for ultra-endurance races have an elevated risk of developing CVD compared to those that perform lower amounts of physical activity. Additionally, little work has been done to examine vascular function in these athletes. PURPOSE: To evaluate cardiovascular function and calculate CVD risk to determine if individuals that train for ultra-endurance races have a greater risk compared to individuals that engage in moderate physical activity. METHODS: We examined cardiovascular function in athletes (ATH, 14M/11F, 50±1 y) that had been training for ultra-endurance events for 10+ years and controls (CON, 9M/9F, 49±2 y) that were meeting current ACSM physical activity guidelines. We used cardiac computed tomography (CT) to calculate coronary artery calcium scores (CACS) and contrast-enhanced magnetic resonance imaging (MRI) to identify myocardial fibrosis (MF). Carotid-femoral pulse wave velocity (cfPWV) was used to evaluate aortic stiffness and ultrasound assessment of carotid intima-media thickness (CIMT) was used to determine vascular structure of the carotid artery. Additionally, we used Doppler ultrasound to assess vascular endothelial function by measuring flow-mediated dilation (FMD) of the brachial artery. Finally, we used a risk score calculator to determine 10-year CVD risk. RESULTS: CACS > 0 was observed in 8 ATH and 2 CON; however, the presence of CAC was not significantly different between groups (P>0.05). Additionally, no participant in ATH or CON had MF. ATH had lower cfPWV compared to CON (6.2±0.2 vs 6.9±0.2 m/s, P<0.05), while no difference in CIMT (ATH; 0.64±0.02 vs CON; 0.62±0.03 mm, P>0.05) or FMD (ATH; 3.6±0.8 vs CON; 5.6±1.2 %, P>0.05) was observed. Furthermore, there was no group difference in calculated CVD risk (ATH; 2.4 ± 0.6 vs CON; 1.6 ± 0.3 %, P>0.05). CONCLUSION: Middle-aged ATH with 10+ years of training for ultra-endurance races are not at a greater risk of developing CVD than individuals that are meeting current physical activity guidelines.