Middle-aged male athletes who play high-intensity sports have more coronary artery calcification than men who exercise less. This is according to research by Vincent Aengevaeren of Radboud university medical center, supported by the Dutch Heart Foundation. The findings are remarkable because athletes live longer than people who do not play sports.
In this study the researches investigated middle-aged and older male athletes at two timepoints with 6.3 years in between. They were on average 60 years old at follow-up. Aengevaeren and collegagues made coronary CT scans at both timepoints to study coronary atherosclerosis. Coronary atherosclerosis burden is generally estimated on CT using the ‘coronary calcification score’, which measures the calcium burden in the coronary arteries as estimate for total coronary atherosclerotic burden and is strongly associated with future cardiovascular events and mortality. However, it does not include plaque characteristics since it only measures calcification. To study plaque characteristics, they inject contrast intravenously and visualize the lumen of the coronary artery, which can give additional information on coronary atherosclerosis since atherosclerotic plaque characteristics are associated with the cardiovascular risk of the plaque.
Previously, Aengevaeren did a cross-sectional study (Measuring athletes’ risk of cardiovascular events - MARC-1) and interestingly found that lifelong exercise volume was associated with the prevalence and extent of coronary atherosclerosis. The higher the lifelong exercise volume, the higher the prevalence of coronary atherosclerosis. However, plaques appeared of a less detrimental composition. The accumulated lifelong exercise volume is the product of intensity times hours of sport and it was unclear which was the most important component.
In this follow-up study, he investigated whether this association was also present longitudinally and whether exercise intensity or volume was more important for progression of coronary atherosclerosis by separately including exercise intensity. He found that, during this follow-up period of 6.3 years, exercise volume (in MET-hours per week, a combination of intensity and hours of exercise) was not associated with progression of coronary atherosclerosis. However, those individuals performing a higher proportion of their exercise volume at very vigorous intensity exercise (i.e. 9 METs or higher, such as running) had a greater progression of coronary artery calcification and calcified plaque. Whereas individuals performing a higher proportion at vigorous intensity (6-9 METs, such as cycling) had less progression of coronary artery calcification.
This research supports the suggestion that exercise impacts coronary atherosclerosis and exercise intensity is the important factor in mediating this association. This suggests that in the future, the researchers may be able to recommend specific exercise regimens to lower progression of coronary atherosclerosis.
The important question now is: “is this association with very vigorous intensity exercise beneficial or detrimental?”. Since increased coronary calcification is generally associated with higher cardiovascular risk, it appears very vigorous intensity exercise is associated with increased risk. However, this increase in coronary artery calcification may represent plaque calcification, which could stabilize atherosclerotic plaques and may them less likely to rupture and cause a myocardial infarction. This phenomenon can also be found after patients start statin treatment, which can also increase coronary artery calcification score, but reduce plaque atheroma volume and cardiovascular risk. Aengevaeren aims to figure this out in follow-up studies.
At present, there is no reason to adjust exercise prescription based on the findings from our study as along as the clinical relevance of coronary artery calcification in unclear. Furthermore, these findings may not be applicable for women, since the association between exercise and coronary atherosclerosis may be different for women. Currently, almost all of this research has been performed in men and as such findings cannot be extrapolated to women.
About this publication
This article has been published in Circulation: Exercise Volume Versus Intensity and the Progression of Coronary Atherosclerosis in Middle-Aged and Older Athletes: Findings From the MARC-2 Study – Vincent L. Aengevaeren, Arend Mosterd, Esmée A. Bakker, Thijs L. Braber, Hendrik M. Nathoe, Sanjay Sharma, Paul D. Thompson, Birgitta K. Velthuis and Thijs M.H. Eijsvogels. Het onderzoek werd gesubsidieerd door de Hartstichting.