Mastication training in adult patients with mitochondrial diseases: a pilot study.

Patients with mitochondrial diseases often complain about fatigue, muscle pain,
loss of muscle strength and diminished endurance in physical activities. Easily
fatigued muscles during mastication is a frequently reported clinical symptom
in patients with mitochondrial disease
Current usual care of these complaints during mastication is the adaption of
food.
Although current usual care is based on compensatory strategies, aerobic
training (cycling, during 8 weeks)) was found to have meaningful effects in
skeletal muscle endurance in patients with a mitochondrial disease (mutation
3243 A * G), with no adverse effects of the training. Furthermore, a study on
efficacy of low intensity mastication training using chewing gum was performed
in patients with Duchenne muscular dystrophy, which showed improvement of the
masticatory performance after a 4 week training (30 minutes, 3 times a day, 5
days a week).

The aim of this pilot study is to assess the effect of low intensity
mastication training in patients with a mitochondrial disease on masticatory
performance, efficacy, endurance, bite force and the feasibility of this
training .

Ten participants with mitochondrial disease will be asked to participate in the
low intensity mastication training during 8 weeks.
A comparison group of ten adult participants with mitochondrial diseases (age
and sex matched to the adults in the intervention group) will serve as control
group.

The intervention will consist of an 8 weeks low intensity mastication training
using sugar free chewing gum. The instructions for training are 1 piece of
sugar free chewing gum per exercise, 3 exercises a day of each 20 minutes, 5
days a week. Participants are free to choose the time of training, with an
interval of at least 4 hours between the two exercises.
Participants are asked to keep a diary (f2) to check for compliance and
potential complications.
Participants in the control group will be asked to do nothing additional to
their daily routine. They are supposed to continue using the compensatory
strategies (if applicable) they have already learned.

- Time investment: two times 20-30 minutes, at the start and end of the study;
- When assigned to the intervention group: 20 minutes, 3 times a day, 5 days a
week, during 8 weeks chewing on a sugar free chewing gum. This burden is in
proportion because it is a low intensity training and the participant is free
to choose the time of training, thereby fitting in his daily routine. Besides a
two days rest period per week is included to increase compliance;
- It is possible to experience more fatigued muscles during mastication.
- It is possible to experience lack of energy caused by the intervention.
During training, there is an increased energy demand, which theoretically could
increase the oxidative stress. However, this was not found in studies with
endurance training in patients with a mitochondrial disease.

In conclusion the mastication training used in this study has an acceptable,
low overall risk.