A computational study on the effect of age and sex on arterial wall biomechanics

Cardiovascular disease (CVD) is the world's leading cause of death. Long associated with ageing, CVD risk factors are increasing in young people, and in Europe, more women die from CVD than men. However, women are underrepresented in CVD research despite emerging evidence suggesting that the manifestation and presentation of CVD are sex specific. The underlying mechanism of this sex specific phenomenon remains unknown and is likely to encompass biomechanical and pathophysiological factors, including hormones, vessel morphology, hemodynamics, and vascular compliance. Previously, sex differences have been investigated for arterial mechanical properties, morphologies, and physiology. However, the synergistic effects of these sex differences on arterial biomechanics have never been considered. The aim of this study was to investigate the synergistic effects of sex specific artery biomechanics (constitutive properties), and physiology (morphology, blood pressure) on resultant mechanical behaviour. Age and sex specific artery finite element models were developed to achieve this aim. These models were used to determine the sex and age specific biomechanics of arteries under physiological loading conditions. The results from our simulations show: (i) The male model had higher values than the female model across all mechanical metrics in the young group; (ii) the male model had higher stress values and lower strain values than the female model in the old group; (iii) the mechanical metrics' values increased with age in both male and female models. However, these values increased by much larger percentages in the female models than in the male models; and (iv) these findings should be considered in future cardiovascular research.