4. Discussion
Our data show that respiratory muscle training with threshold preserves
and improves inspiratory muscle strength in patients with
LOPD. Some examples can be found in the literature for training rehabilitation
with Threshold. In this study we observed that MIP significantly
improved in our study population and this improvement appeared to
remain stable in the subsequent follow-up period. At the beginning of
the study some individual response are different, this can be explicate
with the adapting in training program and procedure for monitoring
pulmonary functional tests. This finding indicates that patient compliance
was reliable.
Decline in respiratory strength is the most important prognostic factor
in patients with LOPD.
Natural progression of respiratory muscle weakness in Pompe disease
in the absence of treatment has been estimated at a decrease of
3.2% in MIP per year [21]. ERT may itself stabilize respiratory function
[22,23]. However, we cannot assess the effect of the training alone
since all the patients were treated with ERT. Furthermore, evaluation
of MEP showed a positive trend even though the patients did not undergo
specific training for these muscles. Our data confirm a previous observation
of two case reports by Jones et al. [11] who demonstrated a
favorable effect of specific individual respiratory muscle training for
several weeks in two patients. However, the patients in this study
were followed up to 24 months and the observed benefits did not persist
during this period. MIP and MEP were chosen as the primary end