Physical activity should play a key role in the multi-component intervention of patients with sleep apnea as it has a positive influence on the Apnea-Hypopnea Index (AHI) and risk factors for diseases such as diabetes.1
Continuous positive airway pressure (CPAP) is the current gold standard in the treatment of sleep apnea. It reduces daytime sleepiness and improves the quality of life, but has a limited impact on cardiovascular risk. Research has therefore focused on the development of combined modality strategies for therapy. Physical activity and exercise are considered to be particularly important components, as they have the potential to have a positive effect on the sympathetic nervous system, oxidative stress, systemic inflammation, and endothelial function, and to improve the metabolic profile that sleep apnoea often combines with intermittent hypoxia, obesity, and cardiovascular disease.
The EPISONO cohort study found that physical activity is not only able to reduce the risk of sleep apnea but is also a protective factor against the risk of type-2 diabetes in these patients. A meta-analysis to evaluate observational studies in which physical activity was objectively measured revealed a rather low average activity level of 5,388 instead of the recommended 10,000 steps per day in patients with sleep apnea. "There is, therefore, a great need for strategies to help these patients improve their physical activity levels," says Prof. Monique Mendelson (Université Grenoble Alpes, France).
Through structured exercise training, the AHI has been reduced by 32%, corresponding to -8.9 events per hour. In untreated sleep apnea patients, exercise training led to an improvement in sleepiness and physical performance, but not to a change in body weight. "Studies have consistently shown that AHI improves in the absence of BMI, suggesting that loss of body fat, particularly in the neck area, is probably not the main mechanism that explains the improvement in sleep apnea through exercise," said Prof. Mendelson.
Therefore, the concept of a fluid shift was proposed as the underlying pathophysiology of sleep apnea. In this concept, the fluid that accumulates in the legs during the day moves up the chest and neck during the night and exerts pressure on the upper airways, leading to apnoea and hypopnoea. In a randomized controlled trial, this fluid shift was measured by segmental bioelectrical impedance analysis, and the change in AHI in sleep apnoea patients who walked for 30 minutes 5 days a week for 4 weeks was compared with a control group. As a result, the AHI in the exercise group was significantly reduced by about 30% in addition to a significant improvement in the nocturnal change in leg fluid.
Given all these results, Prof. Mendelson concluded that physical activity should be part of a multi-component and individualized management program for sleep apnea.
Mendelson M. Physical activity and exercise training as therapeutic interventions for sleep apnoea. ERS International Virtual Congress 2020, 7-9 September, 2020.