Biological 'aortic age': the effect of first-time marathon training

In large arteries, advancing age is associated with biochemical and histological changes that result in vessel stiffening. This contributes to cardiovascular (CV) risk even in healthy individuals. Cross-sectional studies have shown that lifelong athletes possess more distensible peripheral arteries, and relatively brief supervised aerobic exercise interventions benefit brachial blood pressure (BP) and peripheral artery stiffness. The dose of exercise needed to preserve or even rejuvenate the central arterial system in a real-world setting is not known, however. It remains unclear, whether age-related aortic stiffening would be reversible with real-world exercise training.

In the current study from England (1), 138 untrained healthy individuals underwent 6 months of training for the London Marathon, with an estimated training schedule of 6 to 13 miles/week. Assessment pre-training and 2 weeks post-marathon included central BP and aortic stiffness using CV magnetic resonance distensibility. Change in stiffness was assessed at the ascending and descending aorta. Biological “aortic age” was calculated from the baseline chronological age-stiffness relationship.

At baseline, chronological aging correlated with a decrease in ascending and descending aorta distensibility. Training decreased systolic and diastolic central BP by 4 mm Hg and 3 mm Hg. Descending aortic distensibility increased 9% at the pulmonary artery bifurcation and 16% at diaphragm, while remaining unchanged in the ascending aorta. These translated to a reduction in “aortic age” by 4.0 years in the descending aorta. The improvement in aortic stiffness was both functional due to BP lowering, as well as intrinsic due to structural changes in the descending aorta. Benefit was greater in older, male participants with slower running times.

Personal comment

This prospective longitudinal cohort study shows that 6 months of training and completion of a first-time marathon is sufficient to achieve reductions in central BP and aortic stiffness. The main response variable of the present study, aortic stiffness, is relevant as a key biomarker of vascular health, believed to integrate the accumulated effect of aging and exposure of the arterial system to insults and mechano-chemical stressors. Importantly, the dose of exercise in the current study was not excessive but within the recommendations of the 2018 USA Physical Activity Guidelines for healthy adults. Generalisability of the findings is, however, limited to healthy adults able to perform regular training for a marathon. In the future it would be important to address the interaction between exercise and antihypertensive agents in retarding pathological aortic stiffening.

Note: The content of this article reflects the personal opinion of the author and is not necessarily the official position of the European Society of Cardiology.