Transforming heart health with exercise

In the UK, more than 24,000 kidney disease patients rely on haemodialysis to stay alive. But although it is life-saving treatment, it can also cause long-term damage to the heart, leaving the heart muscle unable to pump enough blood around the body. Heart disease is the most common cause of death in kidney patients receiving haemodialysis.  

We already know regular exercise is good for our heart and circulatory systems, but until now, we knew very little about the direct benefits of exercise on patients with advanced kidney disease who are on dialysis. 

Most patients receive dialysis treatment three times a week for four hours each time. In the CYCLE-HD study, patients were offered 30 minutes of moderate intensity exercise on a specially adapted bicycle during each of their dialysis sessions. Patients were then monitored for six months and their hearts assessed using MRI scans. 

Improving the heart’s ability to pump

A reliable way to measure heart health is to measure the size of the left ventricle: the heart’s main pumping chamber. In kidney patients on dialysis, the extra strain on the heart can mean the wall of this chamber thickens, which can reduce its ability to pump efficiently.  

At the end of the six-month study, the research team discovered that the left ventricles of patients who had cycled during their dialysis sessions had gone back to a more normal size again. Several other aspects of heart health had also improved – they had less scarring and the major blood vessels were less stiff. These factors all dramatically reduce someone’s risk of dying from heart disease. 

“We know that being more active can help reduce the risk of heart disease, as well as helping to control weight, reduce blood pressure and cholesterol, and improve mental health,” said Professor James Burton from the University of Leicester, who led the study. “For all those reasons – but especially because the risk of heart disease is so high – keeping active is particularly important for people on dialysis,” he continued. “By the time someone has travelled to and from the dialysis unit and spent four hours connected to the dialysis machine, there’s very little time to do anything else that day, and this happens three times a week for most patients. 

“The study shows exercise can offer significant improvements to the heart health of dialysis patients which may have a major impact on their outlook.” 

“We are delighted to have supported this fascinating study, which shows how exercising while on dialysis can have so many benefits,” said Professor Jeremy Hughes, kidney doctor and chair of trustees at Kidney Research UK. 

 “Cycling can keep patients active and help to pass the long periods of time they spend attached to their dialysis machines. 

“This study also demonstrates that this simple intervention keeps their hearts healthy and offsets the major heart risk associated with kidney failure. We hope this research will lead to other studies examining how to roll it out to other dialysis units across the country.” 

Researchers will now examine if the scheme could be rolled out to benefit patients across the UK.  

Find out more 

Watch more about this study and see the dialysis cycling in action.