MusculRA: The Effects of Rheumatoid Arthritis on Skeletal Muscle Biomechanics

Persons with rheumatoid arthritis (RA) suffer from increased disability and mortality, in part resulting from skeletal muscle impairments. In this study, our objective is to determine if skeletal muscle biomechanical properties are altered in RA. Up to 15 participants with early RA defined as duration of disease/symptoms of less than 6 months (where "duration" denotes the length of time the patient has had symptoms/disease, not the length of time since RA diagnosis) AND prior to starting biologic Disease-modifying anti-rheumatic drugs (bDMARD) therapy and 15 age-, sex-, and BMI-matched controls will undergo clinical assessments of skeletal muscle stiffness and elasticity as measured by the hand-held MyotonPro device. Additional study participant assessments include cardiopulmonary exercise testing, muscle strength testing, body composition measurement using BodPod, muscle oxidative capacity testing using near-infrared spectroscopy, and thigh muscle needle biopsies to compare clinical findings to an ex vivo cultured myobundle system. Primary statistical analyses will be comparisons of skeletal muscle parameters in RA compared to controls and correlations to determine relationships between variables. Thigh muscle biopsies are a low-risk procedure that may cause minor local soreness and bleeding; all other clinical assessments are non-invasive and will induce minimal discomfort to participants.