Effect of Exercise Type on Muscle Quality in Patients With OA, SARC and RA: an Explorative Study

Rationale: C4M hypothesizes that patients with low muscle strength may respond differently to different types of exercise intervention, dependent on the underlying aetiology, i.e. impaired protein synthesis versus metabolic dysfunction and that this response is predictable based on the clinical diagnosis, i.e. rheumatoid arthritis (RA), osteoarthritis (OA) and Sarcopenia alone (SARC) and a number of clinical, blood based and muscle metabolic and architectural biomarkers. Understanding the underlying biochemical response of each patient group to the different type of exercise loading could help with the development of disease-specific training, making it more effective and more predictable on outcomes. Objective: to explore effectivity, interaction and predictability of two types of exercise intervention in patients with RA, OA and SARC alone. The primary outcome of this study will be isokinetic muscle strength of the quadriceps in all three target groups. Study design: two-arm parallel-group exploratory trial including a total of 69 patients: study population 23 patients with OA, 23 patients with RA and 23 patients with SARC alone (according to the revised European Working Group on Sarcopenia in Older People consensus definition (EWGSOP-II criteria, Cruz- Jentoft 2019). Intervention: Exercise intervention for 3 times a week for 8 weeks. Main study parameters/endpoints: the main study parameter is the difference in isokinetic muscle strength pre- and post-intervention in all three patient groups. The secondary study parameters include muscle endurance; mitochondrial respiration, gene and protein expression and histology via muscle biopsies; inflammation via bloodwork and feasibility. Intervention: Exercise intervention for 3 times a week for 8 weeks. Main study parameters/endpoints: the main study parameter is the difference in isokinetic muscle strength pre- and post-intervention in all three patient groups. The secondary study parameters include muscle endurance; mitochondrial respiration, gene and protein expression and histology via muscle biopsies; inflammation via bloodwork and feasibility.