Chronic kidney disease associated with atypically low levels of physical activity

A study led by researchers at the National Institute for Health Research (NIHR) Leicester Biomedical Research Centre (BRC) – a partnership between Leicester’s Hospitals, the University of Leicester and Loughborough University – has highlighted chronic levels of physical inactivity in people with kidney disease.

The research, which examined data from 5,258 people from 17 sites across England and covered all stages of chronic kidney disease, found that only six per cent of patients with the most severe kidney disease (those on dialysis) were sufficiently physically active. By comparison, 35 per cent of all UK adults are sufficiently physically active. The results are published in Nephrology Dialysis Transplantation. 

Chronic kidney disease is graded according to its severity, with stage 1 being mild and stage 5 being severe. Beyond that, patients require dialysis or a kidney transplant.

In the largest study of its kind to date, physical activity levels were measured using the General Practice Physical Activity Questionnaire, as well as self-reported measures of cardiorespiratory fitness and whether participants felt confident to be active. The results showed that patients who were male, younger and did not have multiple health conditions had the highest levels of physical activity.

Dr Thomas Wilkinson, lead author of the study and a research associate in the Leicester Kidney Lifestyle Team at the University of Leicester, said: “Our research reveals the high numbers of patients with kidney disease who are physically inactive. These results show that people with kidney disease are even less active than patients with cancer, who were studied in similar research. It’s important to explore why that is as being physically active can reduce the risk of death, as well as prevent high blood pressure, heart disease and type 2 diabetes – health conditions that patients with chronic kidney disease are more susceptible to. Being physically active is also associated with better health-related quality of life and an improved ability to complete daily activities.”

Using the questionnaires, the team sought to understand why some people in the study were more active than others. According to the data, the biggest factor in being physically inactive was a lack of confidence in being able to exercise. The researchers also found those with poor physical function and fitness levels were less likely to be active. The data showed there was an uplift in physical activity for patients following a kidney transplant. Previous studies have shown how, post-transplant, often patients feel better and are able to begin to return to their previous levels of activity. 

Professor Alice Smith, leader of the Leicester Kidney Lifestyle Team and Professor of Lifestyle Medicine in our Department of Health Sciences, added: “While the majority of patients across all stages of renal disease are physically inactive, our results show that initiatives aimed at promoting confidence to be active may be the key to increasing physical activity. Examples of how this could work in practice include goal setting, social and group activities, and education programmes.”

The research was published in Nephrology Dialysis Transplantation. The group is now developing new educational resources to inform kidney patients about the important role physical activity has on their health, as well as investigating how best to encourage people with kidney disease to exercise at home.

• 'Prevalence and correlates of physical activity across kidney disease stages: an observational multicentre study’ doi:10.1093/ndt/gfz235