P.04Resistance exercises with blood flow restriction in patients with sporadic inclusion body myositis

Sporadic inclusion body myositis (sIBM) is the most common muscle disease affecting older adults with no disease-modifying treatment. Resistance exercises increase muscle hypertrophy, but weakness prevents exercising with higher resistance. In healthy subjects, augmentation of light-load training with blood flow restriction improved muscle strength; and similar exercises were safe in the elderly. We therefore investigate whether resistance exercises with blood flow restriction is safe and helpful in sIBM patients. We explored methods for exercising weak leg muscles, and options for better outcome measures. A matched-control pilot study, with 12-week treatment and 4-week follow-up periods, where participants concentrated on lower limbs resistance exercises with 50% blood flow restriction 3 times per week, at 20%-30% of their repetition maximum. Patients are reviewed 4-weekly for muscle strength, blood biomarkers, 2-minute walk test (2MWT), timed up-and-go (TUG) test, minimal chair height standing ability test (MCHSAT), thigh girths, and quality of life scales. 4 patients with varying abilities were on the exercise arm, and 3 acted as controls. Muscle groups with MRC score ≥2 were able to be exercised. We found strength testing by hand-held dynamometer was unreliable, whereas the 2MWT, TUG test and MCHSAT showed less variability. All patients could perform their exercises at significantly increased repetitions or weights by week 4, without concerning adverse events, with trend towards continued improvement over the 4-month period. Resistance exercises with blood flow restriction appear safe, and may be helpful in sIBM patients, even in weakened muscles, enabling improvement in muscle strength and endurance.