Muscles in Motion: Exercise rehabilitation for children and adolescents with Juvenile Dermatomyositis

Juvenile Dermatomyositis (JDM) is an auto-immune disease in which the
capillaries in the muscle and skin are inflamed. Patients with JDM have
significantly reduced muscle strength and exercise tolerance; even when the
disease comes into remission. There is a lack of evidence to support the role
of exercise as a therapy in children with JDM. Definitive evidence regarding
the role of exercise in the treatment of childhood myositis is needed. Evidence
from studies of adults with DM and PM and preliminary studies in juvenile
arthritis and JDM provide initial evidence to suggest that exercise may be
beneficial to the health outcome of childhood myositis and that exercise might
be safe in this population. Therefore, exercise training may be used as a
therapy to improve physical function and fitness and reduce disability in JDM.
The hypothesis of this study is that an individual tailored exercise training
program will increase the physical fitness (VO2peak), muscle strength, and will
reduce levels of fatigue of patients with JDM.

In this study, we want to investigate the effects of a 12 weeks home-based
exercise program (treadmill trained and strengthening) aimed to improve the
aerobic fitness and muscle strength of patients with JDM. Furthermore, we want
to investigate the wash-out effects of this intervention program after another
12 weeks.

The study is a Randomized Controlled Trial (RCT), with the control group also
entering the training arm directly after completing the initial protocol. The
observers, which assess the outcome variables, will be blinded to treatment
allocation.

All children (randomly) allocated to the intervention group will receive an
individual-tailored graded training program, based upon the results of the
cardiovascular exercise test at baseline (t=0). The categorization of a
training session will always start with 5-8 minutes warming-up, followed by a
session strengthening training (sets differ each 4 weeks), hereafter aerobic
training (incremental over the 12 weeks) on a treadmill, and finishing with a
cooling-down of 5-8 minutes. Patients in the control group will only receive
usual care during these first 12 weeks, hereafter the control group also will
receive an individual-tailored training program for 12 weeks.

Extent of the burden: The patients have to participate in a home-based aerobic
and strengthening training program minimally 2 times per week, 40-60 minutes
per training for 12 weeks. Furthermore, the above mentioned tests will be
performed at 3 (intervention group) or 4 (control group) time points.
Risks: From the existing literature, exercise training is safe in adult
patients with active as well as inactive stable idiopathic inflammatory
myositis. Only one study described the effects of exercise training in a child
patient with dermatomyositis [1]. In this child, no increments in disease
activity were found. Another study showed that muscle inflammation as measured
with MRI, myometry, and blood parameters did not increase immediately after and
within 60 minutes of exercise training in patients with active and inactive JDM
[2].
Benefit Evidence from studies of adults with Dermatomyositis (DM) and
Polymyositis (PM) and preliminary studies in Juvenile Arthritis and JDM provide
initial evidence to suggest that exercise may be beneficial to the health
outcome of childhood myositis. It is hypothesized that an individual tailored
exercise training program will increase the physical fitness, muscle strength,
and quality of life, and will reduce levels of fatigue of patients with JDM.