#apaperaday: Exercise Training in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis

In today’s #apaperaday, Prof. Aartsma-Rus reads and comments on the paper titled: Exercise Training in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis.

Today’s pick is from Journal of Rehabilitation Medicine by Hammer et al on exercise training in Duchenne patients. From work with the totoros lined up for exercising. Doi 10.2340/jrm.v53.985.

Duchenne is characterized by loss of muscle tissue and function. Due to the absence of dystrophin muscle fibers are sensitive to damage during contraction. So exercise can be damaging. However, no exercising is also damaging as this will cause loss of muscle as well.

Training is a controversial topic for Duchenne. The general consensus appears to be that the right type of exercise (submaximal and not eccentric) is good to maintain muscle tissue and function but also to keep active and improve quality of life. However, this is little studied.

Authors performed a systematic review on Duchenne exercise training. They found 12 studies, all in Western world, conducted in 1966-2018. Comment: for 1966 study not all participants may have been Duchenne patients as genetic confirmation was not possible (gene discovery 1986)

The studies contained 282 patients, 108 wheelchair dependent, 86 ambulant and 88 unknown ambulatory status. Studies lasted 36 days – 12 months. Not all participants completed the study, due to illness, lack of motivation or death due to respiratory failure.

The challenge for analyzing was the limited number of participants for most of the studies, the fact that different outcomes were tested for in different studies and that often it was not indicated how missing data was handled. A meta analysis was not feasible.

For 2 studies looking at strength, the training either improved strength or maintained it. Studies looking at endurance showed an increase in endurance for exercise training. Only 1 study looked at quality of life and saw now effect.

The question is which quality of life scale was used – general scales often do not capture effects that may be seen as impactful by Duchenne patients (or other rare disease patients), while they would seem trivial to healthy individuals.

Safety was good for all of the studies. The training was supervised and guidelines were given to avoid damaging exercise. While the systemic analysis suggests positive effects of training on strength and endurance, the certainty of the data is limited due to limited group sizes.

Furthermore, these conclusions were based on only a few studies. Authors stress that results have to be interpreted with caution. They also stress that more research is needed in this area (agreed!), suggesting trials that are appealing and easy to participate in.

E.g. ‘fun’ activities that can be done also at home and also using activity monitoring at home to reduce the burden of the ‘exercise trial’. On the other hand, I think group training & exercise (wheelchair hockey, martial arts) should also be considered for the social aspects.