Impact of age, sex and exercise on brachial and popliteal artery remodelling in humans

ObjectiveTo examine the impact of age, sex and exercise on wall thickness and remodelling in the popliteal and brachial arteries.MethodsWe compared wall thickness, lumen diameter and wall:lumen ratios in the brachial and popliteal arteries of 15 young (Y, 25.4 ± 0.8 yr; 7 M 8W) and 16 older sedentary (OS, 58.8 ± 1.1 yr; 8 M 8W) subjects, with 12 of the OS group also studied following 12 and 24 weeks exercise training.ResultsWall thickness and lumen diameter were higher in the popliteal than the brachial artery for both groups (P < 0.05); wall:lumen ratio was similar between arteries. Comparison of the Y and OS groups revealed no impact on wall thickness, whereas diameter values were higher in OS subjects (P < 0.05). Whilst there were no significant differences in wall thickness between men and women in the Y or OS groups, diameter was larger in men than in women for both arteries (P < 0.05). After 24 weeks of training the wall thickness of both arteries decreased (P < 0.01) and the wall:lumen ratio of the brachial (P < 0.01) and the popliteal (P < 0.05) decreased.ConclusionThe cross-sectional results suggest that ageing was associated with increased lumen diameter, although wall:lumen ratio remained unchanged. Wall:lumen ratio was higher in women than men, irrespective of subject age or the artery studied. This related primarily to differences in lumen diameter between the sexes, as wall thickness did not significantly differ between men and women. Our longitudinal data strongly suggest that exercise training is associated with beneficial effects on conduit artery wall thickness and wall:lumen ratio in both upper and lower limbs in humans.