Exercise as it relates to Disease/Effect of a low-impact exercise program on bone mineral density in Crohn’s Disease

What is the background to this research?
Crohn’s Disease is a chronic autoimmune disease that falls under the Inflammatory Bowel Disease category. The cause is unknown but genetics, environmental factors, and immunobiological elements are suggested triggers. Among those with Inflammatory Bowel Disease, osteoporosis is a common resultant due to steroidal treatment that causes malabsorption. Individuals living with Crohn’s Disease can be significantly restricted physically, socially, educationally, professionally, and emotionally. With the possible addition of osteoporosis, quality of life can deteriorate. This study conducted on people with Crohn’s Disease aimed to determine the effects of a 12-month low-impact exercise program on bone mineral density. This research is crucial as malabsorption of calcium and vitamin D in these individuals would contribute to osteoporosis more than people without malabsorption issues. This research is important because Crohn’s is a debilitating disease that requires lifelong maintenance as it has no cure. Crohn’s and Colitis affects 1 in 250 Australian’s aged 5-40 with almost 75,000 Australian’s currently living with these forms of Inflammatory Bowel Disease. This number is set to surpass 100,000 by 2022. With these people already experiencing a lower quality of life due to their limitations and constant management requirements, finding a way to increase bone mineral density in a low-impact and achievable way would largely improve quality of life.

Where is the research from?
This study was based in Leicester, England and was published in 1998. Seven researchers conducted the study;


 * 1) Richard Robinson and John Mayberry from the Gastrointestinal Research Unit in Leicester General Hospital.
 * 2) *Richard’s main research focus is on bone formation and bone mineral density in Crohn’s and Colitis sufferers and he has 7 publications.
 * 3) *John’s main research focus is Inflammatory Bowel Disease, Coeliac Disease and Achalasia research and he has 469 publications.
 * 4) Tara Krzywicki and Len Almond from the Department of Physical Education and Sports Science at Loughborough University.
 * 5) *Tara’s main research focus is Crohn’s Disease and she has two publications.
 * 6) *Len’s main research focus is physical education and exercise science and he has 43 publications.
 * 7) Keith Abrams from the Department of Epidemiology and Public health at the University of Leicester.
 * 8) *Keith’s main research focus is on meta-analyses and systemic reviews of disease and medicinal treatments and he has 146 publications.
 * 9) Farook Al-Azzawi from the Menopause Research Unit of the Department of Obstetrics and Gynaecology at the Leicester Royal Infirmary.
 * 10) *Farook’s main research focus is on gynaecology and endocrinology and he has 156 publications.
 * 11) S J Iqbal from the Department of Biochemistry at the Leicester Royal Infirmary.
 * 12) *Iqbal’s main research focus is on Crohn’s Disease and he has eight publications.

What kind of research was this?
This study was a 12-month randomised control trial (RCT). An RCT design is the only study design that can assess cause-effect relationships between the intervention and the outcome. It also reduces bias as participants are randomised to balance individual characteristics. This allows for outcomes of the study to be ascribed to the intervention rather than individual participant differences. Participants in this study were randomised by stratified block randomisation into an exercise or control group. This is effective as a block randomisation balances the number of participants therefore increases comparability between groups, and a stratified approach balances prognostic factors of participants. The study was approved by the Leicestershire Ethical Committee once all participants had given written consent.

What did the research involve?
400 mailed study invitations were sent to Crohn’s sufferers in the Leicester area. This is a more expensive measure but produces a higher response rate than an email invitation. Some participants were excluded and the researchers were left with 117 eligible participants. Exemplary intra-tester reliability was shown through all data being collected by the same researcher. Intra-tester produces less data variability than inter-tester therefore produces more externally valid results. Bone mineral density was measured using a DEXA scan which is the gold standard for measuring this variable. Exercise sessions consisted of a 5-minute warm up, 12 all-body floor-based low-impact exercises and a 5-minute cool down. The exercise group had to complete a minimum of 120 sessions over the 12-months for full adherence. This was feasible as low-intensity exercise does not amplify gastrointestinal symptoms or lead to flare-ups in this population. Compliance was monitored by a self-reported exercise diary which was only assessed by researchers twice. Motivation and support were only provided to the exercise group three times over the 12 months. The control group was advised to maintain current physical activity and dietary habits.

What were the basic results?
Bone mineral density increased at all measured sites (femoral neck, lumbar spine, greater trochanter and Ward’s triangle) in the exercise group compared to the control group but the difference was not significant. Those in the exercise group who were fully compliant (completed more than the minimum 120 sessions over the 12 months) had an increase in bone mineral density at all measured sites but there was a significant increase in greater trochanter bone mineral density compared to the control group. It was also found that an increase in bone mineral density at the hip and spine was positively correlated to the number of exercise sessions and repetitions of individual exercises that were completed. These findings support the claim that low-impact exercise can improve bone mineral density in those with Crohn’s Disease but do not over-emphasize the relationship.

What conclusions can we take from this research?
This research shows that bone mineral density can be improved in individuals with Crohn’s Disease through a low-impact exercise program only when adhered to and progressive overload is applied. A positive correlation exists between amount of exercise and amount of bone mineral density gained. These findings are consistent with a study by Leonard et al. that found low-magnitude mechanical stimuli is associated with increased bone mineral density in Crohn’s sufferers.

Practical advice
A limitation of this study was finding significant results given the small sample size. A larger sample gives a smaller confidence interval meaning more precise results. This could be an issue in a clinical population as Crohn’s sufferers experience indiscriminate symptoms and therefore have a higher chance of dropping out or adhering less due to periodic discomfort. Some practical advice for similar studies would be to monitor participants more closely to improve adherence. Gauging adherence via a self-reported journal twice in a 12-month study is unsatisfactory especially given a clinical population that requires extra caution to be taken. Although low impact exercise is effective if adhered to, there is evidence that suggests resistance and plyometric training increase bone formation. However greater caution is required in a clinical population when completing high risk exercise.

Further information/resources
This article – Effect of Low-Impact Exercise Program on Bone Mineral Density in Crohn’s Disease: A Randomized Controlled Trial (1998)

https://www.gastrojournal.org/article/S0016-5085(98)70362-2/pdf

Research paper - Bone Loss in Crohn’s Disease: Exercise as a Potential Countermeasure (2005)

https://academic.oup.com/ibdjournal/article/11/12/1108/4685985?login=true

Advice for patients and caregivers, resources, news, events and research - Crohn’s and Colitis Foundation

https://www.crohnscolitisfoundation.org/

Inflammatory Bowel Disease support Australia

https://www.ibdsupport.org.au/

Research paper – Low-Intensity Exercise Improves Quality of Life in Patients with Crohn’s Disease (2007)

https://crohnsandcolitishub.com.au/wp-content/uploads/2018/02/Low-intensity-exercise-research.pdf