Exercise intensity differently affects coronary atherosclerosis progression

Vigorous intensity exercise helps slow the progression of coronary atherosclerosis, whereas very vigorous intensity exercise seems to be associated with greater progression, according to a study that involved male athletes.

The study included 289 middle-aged and older men (median age 54 years) from the Measuring Athlete’s Risk of Cardiovascular Events (MARC)-1 study who were invited for follow-up in MARC-2 study. All participants underwent coronary computed tomography angiography to determine the prevalence and severity of coronary artery calcification (CAC) and plaques.

The mean follow-up duration was 6.3 years. The volume of exercise training at follow-up was 41 metabolic equivalent of task (MET) hours/week. Exercise intensity was at very vigorous intensity (≥9 MET hours/week) for 34 percent of the participants, vigorous intensity (6–9 MET hours/week) for 44 percent, and moderate intensity (3–6 MET hours/week) for 0 percent.

The prevalence of CAC increased from 52 percent at baseline to 71 percent at follow-up, while the median CAC score increased from 1 to 31.

Regression analyses showed no association between exercise volume during follow-up and changes in CAC or plaque. Meanwhile, each 10-percent increase in vigorous intensity exercise correlated with a smaller increase in CAC score (β, −0.05; p=0.02). In contrast, each 10-percent increase in very vigorous intensity exercise was associated with a greater increase in CAC score (β, 0.05; p=0.01).

Additionally, men who performed very vigorous exercise had greater odds of plaque progression (per 10 percent: adjusted odds ratio [aOR], 1.09; p=0.04; third vs first intensity tertile: aOR, 2.04; p=0.06). This progression was driven by an increase in calcified plaques (per 10 percent: aOR, 1.07; p=0.053; third vs first intensity tertile: aOR, 2.09; p=0.03).

The findings suggest that the acceleration in coronary atherosclerosis progression may reflect increased plaque calcification. More studies are needed to assess the cardiovascular risk associated with coronary atherosclerosis in athletes to establish the clinical implications of the present data.