Obstructive Sleep Apnea Syndrome, Objectively Measured Physical Activity and Exercise Training Interventions: A Systematic Review and Meta-Analysis

Abstract

A systematic review of English and French articles using Pubmed/Medline and Embase included studies assessing objective physical activity levels of obstructive sleep apnea (OSA) patients and exploring the effects of exercise training on OSA severity, body mass index (BMI), sleepiness, and cardiorespiratory fitness [peak oxygen consumption (VO2peak)]. Two independent reviewers analyzed the studies, extracted the data, and assessed the quality of evidence. For objective physical activity levels, eight studies were included. The mean number of steps per day across studies was 5,388 (95% CI: 3,831-6,945; p < 0.001), which was by far lower than the recommended threshold of 10,000 steps per day. For exercise training, six randomized trials were included. There was a significant decrease in apnea-hypopnea-index following exercise training (mean decrease of 8.9 events/h; 95% CI: -13.4 to -4.3; p < 0.01), which was accompanied by a reduction in subjective sleepiness, an increase in VO2peak and no change in BMI. OSA patients present low levels of physical activity and exercise training is associated with improved outcomes. Future interventions (including exercise training) focusing on increasing physical activity levels may have important clinical impacts on both OSA severity and the burden of associated co-morbidities. Objective measurement of physical activity in routine OSA management and well-designed clinical trials are recommended. Registration # CRD42017057319 (Prospero).

Keywords: exercise training; meta-analysis; obstructive sleep apnea; physical activity; randomized controlled trials; systematic review.

Figure 1

Prisma flow chart of articles identified and evaluated during the study selection process for (A) physical activity and (B) exercise training.

Figure 1

Prisma flow chart of articles identified and evaluated during the study selection process for (A) physical activity and (B) exercise training.

Figure 2

Forest plot for mean physical activity levels in obstructive sleep apnea patients. Ref (, –22).

Figure 3

Forest plot presenting steps per day before and after interventions [continuous positive airway pressure (CPAP) and exercise]. Ref (–, –22).

Figure 4

Forest plot for the mean change in apnea–hypopnea index (AHI) (events/h) following exercise training. The diamond reflects the 95% confidence interval of the pooled estimate of mean difference. Ref (, , –33).

Figure 5

Forest plot for the mean change in Epworth sleepiness scale following exercise training. The diamond reflects the 95% confidence interval of the pooled estimate of mean difference. Ref (16, 22, 30, 33).

Figure 6

Forest plot for the mean change in peak oxygen consumption (VO2peak) following exercise training. The diamond reflects the 95% confidence interval of the pooled estimate of mean difference. VO2peak measured in milliliter per kilogram per minute. Ref (16, 22, 30, 31, 33).

Figure 7

Forest plot for the mean change in body mass index (BMI) (kilogram per square meter) following exercise training. The diamond reflects the 95% confidence interval of the pooled estimate of mean difference. Ref (22, 30, 33).

Figure 8

Hypothetical relationship between exercise training/physical activity and obstructive sleep apnea (OSA). The rostral fluid shift contributes to the pathogenesis of OSA and its attenuation via physical activity (47) and exercise training has been shown to alleviate OSA. The strength and fatigability of the upper airway dilators have been shown to be altered in patients with OSA. Specific exercise training modalities may improve upper airway function in OSA patients and thus contribute to decrease OSA severity. An elevated body mass index (BMI) is a key risk factor for the development of OSA while sleep disturbances can influence body composition. Exercise training has been shown to favorably modify body composition (increase lean mass, decrease fat mass) and can reduce BMI, therefore potentially alleviating the severity OSA. OSA is often accompanied by cardiovascular and metabolic co-morbidities, which can impair exercise tolerance. Exercise training has been shown to be beneficial for the improvement of a number of these co-morbidities (hypertension, dyslipidemia, type 2 diabetes, etc.).