Exercise and Vascular Function in Haemodialysis Patients

Life expectancies in haemodialysis patients are significantly shorter than the general population due to higher cardiovascular disease risk. This is mediated by higher prevalence of cardiovascular risk factors associated with chronic kidney disease and the haemodialysis procedure. Consequently ageing of the arterial system is accelerated in this condition leading to higher prevalence of arterial plaques and increased arterial stiffness. Higher physical activity and fitness are associated with lower cardiovascular disease and all-cause mortality in haemodialysis patients and the general population. Moreover, physical inactivity is associated with increased arterial stiffness and plaques which narrow heart arteries. Worryingly the haemodialysis population is on average highly inactive with low fitness. Current research demonstrates that exercise which improves fitness improves arterial health. Increased bloodflow during exercise stimulates the release of nitric oxide causing arteries to dilate. Regular exercise is believed to lead to beneficial remodelling of arteries and lower arterial stiffness. Exercise is reported to improve arterial function across a range of conditions. However published research regarding the possible benefits of long term aerobic exercise on arterial health in this population is conflicting. Limitations in study design, moderately high participant dropout rates and low statistical power hamper a definitive conclusion. Importantly a gold standard measure of arterial function has not been used in previously published studies. There is ample evidence that exercise programmes in people on dialysis improve fitness, physical function, and quality of life. It is also clear that a state of higher physical activity and fitness is associated with better arterial function in the general population. It would be advantageous for reasons of health counselling to determine whether the process of improving physical fitness and activity levels may also improve arterial health in haemodialysis patients.