A new study explored associations between 6-minute walk test (6MWT) score and motor, cardiac, and respiratory performances in patients with late-onset Pompe disease (LOPD), finding that age and the use of an assistive device were clinical predictors of 6MWT score. The study, published in Muscle & Nerve, also found that cardiorespiratory adaptation during the test was another performance predictor.
“Although the 6MWT is a simple, useful, functional test, the result must be interpreted in the light of other variables: (i) age and the use of an assistive device (or the motor function measure D1 subscore), (ii) respiratory adaptation during the test, and (iii) [heart rate recovery (HRR)],” the authors wrote. “Exercise training and respiratory rehabilitation (changing the ventilatory rate) might therefore improve 6MWT performance.”
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The authors conducted a retrospective, single-center review of 15 patients with LOPD. Logistic regression was employed to assess the associations between respiratory, cardiac, and motor variables and performance on the 6MWT.
In addition to identifying the best predictors of 6MWT performance, the results also revealed that although fatigue and motivation levels modified patient performance, the results of the 6MWT were still reliable even if certain variables such as the respiratory rate or HRR changed. Thus, variations in HRR during the 6MWT might represent a screening tool for patients who need exercise rehabilitation the most, and daily physical activity levels could be compared with HRR to serve as a predictor.
The authors caution that the small sample size in the study means that the 6MWT’s determinants need better definition in larger future studies for more definitive results in terms of evaluating treatment effectiveness. However, they expect that the results obtained will aid clinicians in determining the current level of disease control in patients with LOPD.
Tard C, Bayot M, Davion JB, et al. Factors impacting performance on the six-minute walk test by people with late-onset Pompe disease. Muscle Nerve. Published online April 1, 2022. doi:10.1002/mus.27543