Exercise and physical activity reduce the risk of cardiovascular disease (CVD). It has been observed that an active person has between 30% and 40% lower risk of CVD. However, previous cross-sectional studies have failed to determine whether exercise has a significant impact on accelerating coronary atherosclerosis and plaque morphology. a recent Circulation The journal article has focused on investigating the relationship between exercise volume and intensity and the progression of coronary atherosclerosis in middle-aged and older male athletes.
Study: Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes: Findings from the MARC-2 Study. Image Credit: sciencepics / Shutterstock
Coronary artery calcification (CAC) is a biomarker of coronary atherosclerotic plaque burden and future risk of CVD events. This biomarker can be measured using the computed tomography (CT) imaging technique. In addition, a more detailed study of coronary plaque morphology can be performed using coronary CT angiography (CCTA).
Athletes typically have CAC scores ≥100 Agatston units, linked to lifetime exercise volume and intensity of physical training. In active athletes, atherosclerotic plaque morphology has been found to be more or partially calcified. Recent studies have indicated that amateur athletes have greater coronary atherosclerosis compared with less active healthy controls.
About the study
The current study used the CAC and CCTA score to assess the relationship between exercise training characteristics and coronary atherosclerosis in middle-aged and older male athletes. This study hypothesized that higher exercise volume and intensity are associated with a higher incidence of coronary atherosclerosis.
This study is known as MARC-2 (Measuring Athletes’ Risk of Cardiovascular Events 2), a continuation of the MARC-1 (Measuring Athletes’ Risk of Cardiovascular Events 1) study.
The MARC-2 study recruited asymptomatic middle-aged and older men older than 45 years and showed no abnormalities in their sport medical evaluation between May 2019 and February 2020. People who underwent coronary intervention were excluded percutaneous during follow-up.
Relevant information on the exercise characteristics of the participants was obtained through a validated questionnaire. This questionnaire focused on collecting information on the type of sport, frequency, duration of each sport (in years), duration of an exercise session, and performance level, i.e., recreational versus competitive, from the cohort of study.
A metabolic equivalent of the task (MET) was assigned for all sports reported based on the Compendium of Physical Activities. The current study used exercise volume, expressed in MET hours/week, during the study period.
The current study included a total of 291 men. Based on the eligibility criteria, 287 men were ultimately included in the MARC-2 CAC analyzes and 284 in the plaque analyses. The mean follow-up between CT scans was observed to be 6.3 years. In addition, blood pressure levels and the use of antihypertensives and statins increased substantially in the follow-up period. However, the participants’ cholesterol level remained the same throughout the follow-up period. Six participants had quit smoking.
Exercise intensity, but not volume, was correlated with progression of coronary atherosclerosis. The impact of vigorous exercise was found to be less effective in the progression of CAC; however, very vigorous exercise was associated with a more significant progression of CAC and (calcified) plaque. This finding is in line with the MARC-1 cross-sectional observation that revealed that specific exercise intensities rapidly ameliorate calcified plaque development.
Exercise at a very high intensity level has been associated with calcified plaque formation, suggesting that certain mechanisms may be involved to facilitate coronary atherosclerosis in athletes. For example, higher intensity exercise produces higher levels of catecholamines, which can increase a person’s heart rate and blood pressure. According to previous studies, increased heart rate accelerates atherosclerosis, possibly due to the increased frequency of turbulent blood flow.
No correlation was found between the exercise volume and the progression of coronary atherosclerosis during follow-up. The finding of this study is in line with a previous study that revealed that 74% of recreational athletes had no significant difference in exercise volume between individuals with and without CAC progression after 4.1 years of follow-up. It is possible that exercise volume is associated with the onset of coronary atherosclerosis but not with its progression. More research is required to determine differences in atherosclerosis according to exercise intensity, that is, within separate groups (running and cycling).
The longitudinal study design and the evaluation of the CAC and CCTA score in a sizeable athletic population are key strengths of this study. The prevalence and severity of atherosclerosis was found to increase with lifetime exercise volume in athletes.
Higher intensity running promotes further calcification of atherosclerotic plaque, but is that good or bad? Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes: Findings from the MARC-2 Study
—Matthew Lancaster (@LancasterM) January 5, 2023