Exercise as it relates to Disease/Do pedometers increase physical activity in youth with chronic kidney disease

This is an analysis of the journal article: Akber A, Portale A, Johansen K. Use of pedometers to increase physical activity among children and adolescents with chronic kidney disease. Pediatric Nephrology. 2014;29(8):1395-1402. Completed by a University of Canberra Student.

Background
The current international guidelines defining Chronic Kidney Disease (CKD) is decreased kidney function shown by glomerular filtration rate (GFR) of less than 60mLmin per 1.73m2 or makers of kidney damage or both for a period of at least 3 months. 1 in 10 Australians are affected by the disease and it contributes to 1 in 9 deaths. People living in low socioeconomic areas, Indigenous Australians and the elderly more likely to be affected.

This study was completed after an earlier study in 2012, using pedometers, discovered that patients with CKD are less active than the recommended amounts of 15 000 steps for boys and 12 000 steps for girls. Therefore, ways of increasing physical activity in patients with CKD is important.

Authors
Aalia Akber from the department of paediatrics, division of nephrology at Kaiser Oakland medical centre.

Anthony A. Portale from the department of paediatrics, division of nephrology at the university of California, San Francisco.

Kirsten L. Johansen from the department of medicine, division of nephrology at UCSF and nephrology section, San Francisco VA medical centre.

All authors have previously completed a very similar study that only went for 7 days and they have all completed numerous other studies in children with chronic diseases. There is no known bias of the authors, the supporters were disclosed however do not appear to create any bias as neither have products that would benefit from this study. The research supporters included Genzyme Corp a biotechnology company that specialised in treatments of rare genetic disorders, multiple sclerosis, oncology and immunology and Abbot Laboratories a healthcare company that creates products in diagnostics, medical devices, nutrition and branded generic pharmaceuticals.

Approved by Committee on Human Research at UCSF and registered on clinicaltrials.gov.

Patients were recruited from UCSF paediatric nephrology outpatient clinic and children's outpatient haemodialysis centre.

What kind of research was this?
This study is a clinical trial as it is studying an intervention on a particular group without a control group. The level of evidence in this study is less than that of a systemic review or meta-analysis as it does not have multiple sources to confirm findings and findings could differ from similar studies conducted.

What did the research involve?
The researched involved recording data at the baseline and at the end of the 12-week intervention. These include height, weight, BMI and a review of medical records. Physical performance was assessed using the 6-minute walk test and physical functioning was done through self-reporting using the PedsQL 4.0, only using the physical functioning domain of the 4 domains measured. Throughout the intervention steps were recorded by a pedometer worn. At the end of each day the number of steps taken that day was recorded into a log book. Weekly the youth were contacted either by phone or email to discuss the daily step count recorded and the mean steps taken over 7 days was calculated. Also, during the contact feedback was provided, barriers to reaching the goal were discussed and new goals were set for the following week.

Limitations exist in the absence of a control group, it is unclear whether changes in test results are due to practice or increase in physical activity. It is also unclear whether the changes in physical activity were due to the intervention due to the lack of a control group.

Basic Results
Results for the 6-minute walk test increased overall by 16m. Transplant recipients improved by 31m whereas patients undergoing dialysis decreased by 28m. There was no significant change seen in the self-reported physical function.

Researchers interpretation
The researchers concluded that the use of a pedometer and counselling on increasing physical activity did not lead to an increase in average number of steps walked per day. There was a correlation between increased or decreased physical activity and changes in physical performance.

The results are also not easy to interpret as many of the follow up results are not presented in the same way in which they were presented for the baseline tests. The baseline tests were presented as a cohort whereas the follow up results are broken into individual categories such as dialysis and transplant recipients therefore, the follow up results cannot be compared to the baseline results.

Conclusion to be taken
It is unclear whether using pedometers and education on increasing daily step count had an effect on the youth in this particular study. The patients that increased their step count had positive changes in their physical functioning and performance. However, due to the lack of a control group it also cannot be determined whether the improved physical functioning and performance was due to the increase in physical activity or due to practice effect. Therefore, this study is inconclusive as it cannot be said that it had an effect or did not have an effect as there is nothing to compare it to. There was no data presented on BMI, GFR or haemoglobin concentration from the follow up so these aspects cannot be compared either. This would be useful to compare whether an increase in physical activity has a positive effect on these aspects. This study can provide a basis for further studies to be completed such as including a control group to determine whether the intervention is effective.

There are no further studies available to determine whether this intervention is effective however, other factors effecting physical activity in youth with CKD have been completed such as the effect of screen time.

Practical advice
This study provides no practical advice as is cannot be said that using pedometers and education works to improve physical activity in youth with CKD or does not. Further studies should be done in this area prior to advice given about ways to increase physical activity in children and adolescents with CKD.