A recent study investigated the association between arterial health in teenagers and cardiorespiratory fitness measured by the peak oxygen uptake and ventilatory threshold.
Arterial health, determined by the ability of the arteries to carry oxygenated blood from the heart to other parts of the body, is an important determinant of overall good health. The arteries are muscular tubes with high elasticity. The elasticity of the artery gives it the ability to stretch in response to each pulse and helps maintain a relatively constant pressure of blood flow in the artery.
The loss of arterial elasticity
The loss of elasticity of arterial walls is a result of thickening and hardening of the tissue lining the arterial wall, known as arteriosclerosis. Arteriosclerosis can be caused by a poor diet, an unhealthy lifestyle, or genetic factors. Several degenerative changes associated with ageing also contribute to stiffening of arteries. However, arterial stiffness can begin in childhood and adolescence due to many cellular and molecular factors.
Poor arterial health gradually restricts the flow of blood to organs and tissues leading to severe health problems such as coronary artery disease and stroke. In addition, studies show that arterial stiffness is also associated with the circulatory and respiratory system’s ability to supply oxygen to skeletal muscles during sustained physical activity. In other words, arterial health is associated with cardiorespiratory fitness. Many studies show that youth with low cardiorespiratory fitness have a higher risk of developing cardiovascular disease later in life.
Assessing arterial health
When the heart contracts, it generates a pulse or energy wave. The stiffness of the arteries affects the speed of travel of this wave through the artery. The pulse wave velocity (PWV) is the measurement of the speed of travel of the wave and indicates the degree of arterial stiffness.
Assessing cardiorespiratory fitness
Peak oxygen uptake or maximal rate of oxygen consumption during incremental exercise is a measure of the cardiorespiratory fitness of an individual. On the other hand, ventilatory threshold refers to the point when ventilation starts to increase at a rate faster than the peak oxygen consumption. Ventilatory threshold is reached when breathing surpasses the normal ventilation rate of an individual. Both peak oxygen uptake and ventilatory threshold are established parameters of cardiorespiratory fitness.
What is the association between arterial health and cardiorespiratory fitness?
A recent study investigated the association between cardiorespiratory fitness and arterial stiffness in adolescents. The study conducted in the University of Jyvaskyla, Finland, was published in the European Journal of Applied Physiology. The participants included 16-19-year-old boys and girls who performed a ramp exercise test until voluntary exhaustion. The researchers assessed the body composition, arterial stiffness, and cardiorespiratory fitness of the participants. Peak oxygen uptake and ventilatory threshold were measured to assess cardiorespiratory fitness while arterial stiffness was assessed using pulse wave velocity.
Higher cardiorespiratory fitness associated with lower arterial stiffness
The results showed an inverse relationship between arterial stiffness in adolescents and their cardiorespiratory fitness. Adolescents with a higher peak oxygen uptake had lower arterial stiffness. In addition, the researchers observed that a higher ventilatory threshold is associated with a better arterial health.
First study to show an association between arterial health and ventilatory threshold
The authors claim that this is the first study that shows the relationship between ventilatory threshold and arterial stiffness. The results show that adolescents with a higher oxygen uptake at ventilatory threshold also had lower arterial stiffness compared with other adolescents. The study also concludes that higher peak oxygen uptake in adolescents is related to lower arterial stiffness. The study results, however, may not be generalizable because of a small size and homogenous nature of the study sample.
Arterial health can be improved
These study results show that in teenagers, arterial stiffness is related to both peak oxygen uptake and ventilatory threshold that contribute to the cardiorespiratory fitness. Various environmental, lifestyle and genetic factors play a role in developing arterial stiffness at a young age. Of these, some factors can be controlled. Exercise training, increased physical activity and an improved lifestyle can contribute to a better arterial health and therefore a reduced risk of cardiovascular disease.
Written by Preeti Paul, MS Biochemistry
Reference: Eoro A. Haapla et al., Peak oxygen uptake, ventilatory threshold, and arterial stiffness in adolescents. European Journal of Applied Physiology. https://doi.org/10.1007/s00421-018-3963-3