Resistance Training Intervention to Promote Lean Mass in Youth With IBD

Lean body mass (LBM) deficits are common in Crohn's Disease (CD) and persist beyond achievement of remission. In a recent review of 21 studies with a total of 1,479 youth with Inflammatory Bowel Disease (IBD), 93.6% of patients with CD showed deficits in LBM compared to healthy controls. LBM deficits in CD are multifactorial though largely explained by malnutrition. Even with weight restoration and remission however, youth with CD continue to show deficits in LBM compared to healthy peers. Despite proportional deficits in fat and LBM at baseline, weight restoration is explained by gains in fat without similar gains in LBM, suggesting that additional mechanisms interact to maintain deficits such as low physical activity (PA) or altered energy partitioning. Chronic LBM deficits can have deleterious effects including decreased physical function, myopenia, metabolic dysregulation, increased risk of infection, compromised peak bone mass accrual, and development of osteopenia/osteoporosis. While some factors are not readily modifiable (e.g. underlying disease mechanisms), targeting factors amenable to change may result in an increase in LBM and thus improved health outcomes. Health behaviors, including exercise, are modifiable and associated with the development of LBM. Resistance training (RT) has been associated with improved LBM in youth with and without chronic illness. To our knowledge, no evidence-based resistance training interventions have been developed to promote LBM accrual in pediatric CD. The overarching aims of this proposal are to evaluate the safety, feasibility, and effects of 12 weeks of RT on LBM in youth with CD aged 14-18. Specifically we aim to:

Aim 1: Evaluate feasibility, safety, and preliminary estimates of RT efficacy to promote LBM accrual in patients with CD aged 14-18. This will be achieved by conducting a parallel 2-arm randomized-controlled pilot trial of RT compared to usual care. At weeks 0 (pre-treatment), 6 (mid-treatment), and 12 (post- treatment), feedback regarding safety, feasibility, and acceptability will be collected from participants through surveys and interviews. Magnitude of the effect size of the intervention on LBM, muscle strength, and health-related quality of life (HRQoL) will also be estimated.

Positive findings would have broad implications for growth and long-term health outcomes including bone disease and metabolic health in these young patients. More broadly, the findings would have promising potential to be extended to patients with IBD across the developmental and disease spectrum including youth with ulcerative colitis (UC) and adults with IBD as they demonstrate similar LBM deficits. The proposed study will also provide preliminary data to inform a evaluation through a larger trial.