Combined Impact and Resistance Training in Adults with Stable Crohn's Disease: The PROTECT Randomised Controlled Trial

Abstract

Background: Crohn’s disease (CD) is a predisposing factor for bone and muscle dysfunction, which could lead to osteoporotic fractures and physical disability, respectively. We tested the effect of 6 months of combined impact and resistance training on bone mineral density (BMD) and muscle function in adults with CD. Methods: This was a randomised, parallel-group, and assessor-blind trial in which participants were recruited from a large Hospital Trust in Northern England. Eligible patients were aged 16 years or older, had quiescent or mildly-active CD, and were on stable medications for at least 4 weeks. Participants were randomly assigned (1:1) to exercise or control groups using a computer-generated randomisation sequence stratified for gender and disease severity. The exercise group received usual care plus a 6-month combined impact and resistance training programme, involving three, 60-minute sessions per week and a gradual tapering of supervision to self-management. The control group received usual care only. The primary outcomes were BMD (at the femoral neck, greater trochanter and lumbar spine using dual energy X-ray absorptiometry) and muscle function (measures of upper- and lower-limb strength and endurance) at 6 months in the intention-to treat population, with analyses adjusted for baseline values, gender and disease status. Findings: Between February 20, 2018, and March 14, 2019, 47 eligible patients were randomly assigned to the exercise intervention (n=23) or control (n=24). Thirty-two (68%) participants were female and the mean age was 49·3 years (SD 13·0). At baseline, 31 (66%) had quiescent disease. Twenty-two (96%) intervention participants engaged with the exercise programme, completing a median of 50 (out of 78) sessions (IQR 36-59). Four participants (one exercise, three control) were lost to follow-up. At 6 months, BMD values were superior in the exercise group at the lumbar spine (adjusted mean difference 0·036 g/cm 2 , 95% CI 0·024 to 0·048; p<0·001) and femoral neck (0·018 g/cm 2 , 0·001 to 0·035; p=0·039), but not at the greater trochanter (0·013 g/cm 2 , -0·019 to 0·045; p=0·415). At this time-point, the exercise group also had superior values for all muscle function outcomes (e.g. grip strength 8·3 kg [6·2 to 10·5], chair stand test 4 repetitions [95% CI 3 to 6], bicep curl test 7 repetitions [95% 5 to 8]; all p<0·001), and lower fatigue severity (IBD-F score; adjusted mean difference -2, 95% CI -4 to -1; p=0·005). Three exercise-related adverse events were recorded: two instances of light-headedness and one of nausea. Interpretation: The intervention improved BMD and muscle function in adults with CD, and appears a suitable model of exercise for reducing future risk of osteoporotic fractures and disability. Trial Registration: The trial was registered with the ISRCTN registry, number ISRCTN11470370, and is complete. Funding Statement: This study was supported by the National Institute for Health Research Clinical Research Network (NIHR CRN). This study was supported by equipment grants from Northumbria University and PROcare ApS, and KJ was funded through PhD studentship at Northumbria University. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: Ethics approval was granted by the North East - Tyne & Wear South Research Ethics Committee (reference 17/NE/0308).