Cardiopulmonary exercise testing in people with minimally impaired multiple sclerosis

Background: Multiple sclerosis (MS) is a chronic demyelinating inflammatory disorder of the central nervous system that may affect respiratory system at the later stages of the disease. The aim of our study was to evaluate respiratory function and cardiopulmonary exercise testing in ambulatory without aid people with MS (pwMS), and to investigate quality of life parameters and fatigue in this population.

Methods: 25 pwMS and 16 healthy controls were included in this study. Pulmonary function tests were performed and were followed by proper cardiopulmonary exercise testing with the use of treadmill. Quality of life assessment was done with SF-36 questionnaire.

Results: The mean age of the patient group was 38.4 ± 8.2 years. Spirometric values were within normal limits, and so did lung diffusion capacity, while maximal voluntary ventilation was reduced. In cardiopulmonary exercise testing the patient group showed impairment compared to control group. The statistically significant lower parameters were V'O₂ peak, V'CO₂ peak, RER, V'O₂/kg peak, V'CO₂/kg peak, oxygen pulse peak and V'E/V'CO₂ slope. Moreover, there was a negative and statistically significant correlation between CPET values and BMI and MFIS, while there was a positive and statistically significant correlation with quality of life, evaluated by SF-36.

Conclusion: Our study showed that the main cardiopulmonary exercise testing parameters were affected in ambulatory pwMS, even without evidence of respiratory symptoms. Therefore, these people should be evaluated for pulmonary function compromise.