Exercise as it relates to Disease/How Exercise Impacts Those Suffering with Chronic Kidney Disease

This page is a critique of: Mustata S, Groeneveld S, Davidson W, Ford G, Kiland K, Manns B. Effects of exercise training on physical impairment, arterial stiffness and health-related quality of life in patients with chronic kidney disease: a pilot study. International Urology and Nephrology. 2010;43(4):1133-1141.

Kidney. Author: Henry Gray (1918) Anatomy of the Human Body

Distribution of bloodvessels in cortex of kidney. Author: Henry Gray (1918) Anatomy of the Human Body

Background

Chronic kidney disease (CKD): conditions that relate to kidney damage or reduced kidney function lasting for three or more months. It is far-reaching as 8-16% of people worldwide suffer from some form of CKD. There are five stages, categorised by glomerular blood filtration rate. CKD can be impacted by obesity, diabetes and hypertension, which can play a role in the development of CKD but are preventable, which may help in prevention/reversal of CKD.

Implications:

• Muscle wasting → weakness and decreased ability to exercise
• Physical activity (PA) level decreases
• Excessive fatigue
• Decreased PA → increased cardiovascular (CV) health related morbidity and mortality
• Decreased health related quality of life (HRQOL)
• Higher risk of kidney disease progressing into end-stage-renal-disease (ESRD)
• Higher risk of acute kidney injury
• Cognitive decline
• Anaemia
• Impacts on bodily minerals → affect bone structure and density causing fractures

Exercise is a suitable intervention for obesity, diabetes, and hypertension. By improving many of the factors relating to CKD - bone density, muscle strength and PA levels, it may help decrease risk of further development but more research is needed on the topic.

Article Critique

Where is this research from?

The research was conducted in Calgary, Canada

• Department of Nephrology, Dept. Medicine University of Calgary
• Department of Respirology, Dept. Medicine, University of Calgary
• University of Calgary
• Alberta Health Services
• Rockyview General Hospital

There do not seem to be any linked affiliations that would bias the research; all those involved are from health professions, suggesting they are doing the research for a valid and legitimate outcome, not to portray specific results.

What kind of research was this?

This is a pilot study, a small-scale trial to assess the feasibility of completing research on a larger scale, for example as a randomized control trial (RCT). Pilot studies assess the approach, provide insight into improvements that could be made, and gain baseline data for future research . Pilot studies do not test hypothesis, evaluate safety, efficacy, or effectiveness, they do not help estimate size for future research, and the small sample size may give imprecise data.

The type of evidence gained differs from other research such as a RCT or meta-analysis. As pilot studies do not have pre-existing data available to guide research or test a hypothesis. Meta-analysis are also very different because they collect data from a variety of sources and collate results to gain better understanding in a specific area.

What did the research involve?

Participants all suffer from stage 3 and 4 CKD with no extreme risk factors associated with exercise, comparisons were made to assess physical impairments, arterial stiffness, and HRQOL. Supervised baseline exercise testing was completed before they were randomly put into two test groups:

1. Standard care
2. Combination of standard care and additional exercise

Medication was not adjusted through the period and the professionals testing them were not made aware of the study aims. Those exercising were part of two supervised exercise sessions in clinic and also completed at home exercise – walking, which increased to three times a week through out the course of the twelve-month trial. Heart rate monitors and Borg’s Rate of Perceived Exertion scale were used to assess intensity.

RPE

6	No exertion at all
7	Extremely light
8
9	Very Light
10
11	Light
12
13	Somewhat hard
14
15	Hard
16
17	Very Hard
18
19	Extremely hard
20	Maximum exertion

Randomizing the test groups is helpful in gaining valid research, as it is more difficult to bias results in randomised groups. Improvements could be made to measuring arterial stiffness – using gold standard, by giving other home exercise options or increasing delivered exercise to increase adherence to the task.

Limitations to the study include

• No information about previous health before CKD was developed or before study
• Mix of supervised and self recording data could cause over estimating exercise
• Lower age of exercising group may alter results
• Gold standard measure for arterial stiffness not used

Basic results

The study shows a statistical significance between baseline and post tests scores for both groups concerning exercise capacity and arterial stiffness, with all positive changes in the exercise group. This is not evident in HRQOL but there is an evident clinical significance gained through the questionnaires used.

Researchers found early intervention to be important to reduce risk factors associated with both CKD and cardiovascular disease (CVD), as evidence showed significant improvement in both physical impairment and arterial stiffness in pre-dialysis patients over the twelve-months, even with low adherence to activity, at a median of 43.3 minutes a week. This may help reduce risk factors for CVD morbidity and mortality. Improvements are less compared to that of healthy sedentary populations implying CKD may be a barrier to improvement.

Conclusions

Exercise is shown to have positive benefits on factors and symptoms of CKD and other chronic diseases. A larger scale study would be beneficial to help gain a greater understanding of the effects of exercise in pre-dialysis CKD patients, and which forms of exercise are best, especially due to the limited sources available.

Studies in more recent years have also found that more research is needed into exercise relating to CKD. To gain understanding of the physiological changes behind the benefits , whether or not resistance training has more effect that just benefiting muscle and bone, and to determine guidelines specific to CKD patients. Another study has also presented findings that show delivery of exercise to patients helps improve adherence to exercise.

Advice and Resources

All participants went through supervised testing with medical professionals and it is strongly advised that people with any chronic diseases complete a pre-exercise questionnaire and visit a medical health professional to ensure safety while exercising. Begin with small amounts of physical activity and gradually increase intensity as the body adapts. This may be in the form of walking more frequently instead of using other transport. Below are links to increase CKD knowledge and start safe exercise.

Australian Department of Health - CKD: http://www.health.gov.au/internet/main/publishing.nsf/Content/chronic-kidney

Chronic Kidney Disease Management Handbook: e-copy of the handbook: http://kidney.org.au/cms_uploads/docs/ckd-management-in-gp-handbook-3rd-edition.pdf

ESSA exercise pre-screening questionnaire: https://www.essa.org.au/wp-content/uploads/2011/09/Screen-tool-version-v1.1.pdf

International Physical Activity Questionnaire - Short: http://www.sdp.univ.fvg.it/sites/default/files/IPAQ_English_self-admin_short.pdf

International Physical Activity Questionnaire - Long: http://www.sdp.univ.fvg.it/sites/default/files/IPAQ_English_self-admin_long.pdf