Exercise and Disease Progression in Amyotrophic Lateral Sclerosis Patients

This work aimed to evaluate the effects of a moderate aerobic exercise with controlled intensity determined by Cardiopulmonary Exercise Testing (CPET) and its role on the functional status in ALS patients versus standard care. Additionally, the investigators explored the performance of CPET variables - oxygen uptake (VO2) expressed in L/min, in percentage of predicted or in metabolic equivalents (METs) at peak effort, at anaerobic threshold (AT), the respiratory compensation point (RCP) when achieved, Dioxide Carbon output in L/min (VCO2) and the minute ventilation in L/min (VE) throughout the study.

Assessments:(diagnostic visit - T0), at study entry (T1) and 6 months after (T2) using:

Functional status by Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R), Respiratory function tests (RFT): Forced Vital Capacity predicted (%FVC) and Oxygen saturation provided by pulse oximetry.

CPET was performed in both groups at study entry and 6 months later (T1 and T2), using a treadmill (WOODWAY®) coupled with a gas exchange analyzer (METALYZER® 3B) with ergo-spirometry system using a breath-by-breath technology developed by CORTEX® systems.

Intervention:

G1(Interventional group) performed moderate exercise protocol two times/week in a treadmill in the lower range of the training zone determined by CPET + standard care (range of motion exercise, gait and balance training under continuous pulse oximetry observation).

G2 (control group) performed a standard care exercise program at home or at other rehabilitation units without pulse oximetry observation.

Inclusion criteria

• Consecutive patients diagnosed with definite, probable, or probable laboratory supported ALS
• Disease duration from first symptoms between 6-24 months to exclude slow and fast progression
• ALSFRS-R ≥ 30
• FVC (%predicted) ≥ 70%

Exclusion criteria

• Other medical conditions, like cardiac insufficiency and lung disorders or others conditions limiting exercise training;
• Heavy smoking habits with laboratorial evidence of significant bronchial constriction;
• Signs of associated dementia or psychiatric disorders.

Note: None of the patients were on tube feeding, invasive or non-invasive mechanical ventilation at admission of study protocol (T1).