Benefits of supervised community physical activity in obstructive sleep apnoea

Validation of the Revised Illness Perception Questionnaire of Obstructive Sleep Apnea among Elderly Chinese in the General Population

PURPOSE

The prevalence of under-diagnosis among individuals with obstructive sleep apnea (OSA) is alarming, and may be associated with perceptions regarding OSA. To facilitate future studies on OSA, this study validated the revised version of the Illness Perception Questionnaire (IPQ-R) for OSA in a general population.

METHODS

A random anonymous population-based telephone survey interviewed 580 adults aged ≥ 50 years in Hong Kong, who self-reported not having been told by doctors as having OSA, from February 5 to March 19, 2021.

RESULTS

The confirmatory factor analysis identified a modified 7-factor model (i.e., timeline chronic, consequence, personal control, treatment control, illness coherence, timeline cyclical, and emotional representation) that showed satisfactory model fit index and internal consistency. Nine items were removed from the original version because of low factor loadings. No floor and ceiling effects were observed. Convergent validity was supported by the positive associations between the consequence subscale with perceived negative outcomes of OSA and between the illness coherence subscale and perceived understanding of OSA symptoms. The participants tended to endorse the items of timeline chronic, treatment control, and illness coherence but not with those of emotional representations. The mean scores of the IPQ-R subscales differed by age and education level.

CONCLUSION

The modified IPQ-R of OSA showed acceptable psychometric properties. It is applicable to assessing illness perceptions of OSA in the Chinese general population aged ≥ 50 years not having received OSA diagnosis. The validated tool would support future studies and health practices related to OSA.

Exercise capacity remains supernormal, though mildly reduced in middle-aged military personnel with Moderate to Severe Obstructive Sleep Apnea

INTRODUCTION

The relationship between moderate to severe OSA and exercise capacity remains unclear. Prior studies showing a reduction in VO₂ max in this population have mostly involved middle-aged, overweight patients. We aimed to study this relationship in a similarly aged population of military personnel with previously undiagnosed moderate to severe OSA.

METHODS

We studied late-career male military personnel who underwent CPET and polysomnography (PSG). Patients were categorized either into an OSA group (apnea-hypopnea index (AHI) ≥ 15 events/h) or a control group (AHI < 15 events/h). VO₂ max was compared between groups.

RESULTS

170 male military personnel met criteria for the study. Mean AHI was 29.0/h in the OSA group (n = 58) versus 7.4/h in the controls (n = 112) while SpO₂ nadir was slightly lower (86.0% vs. 89.0%). Patients were of similar age (53.1 vs. 53.7 years), and BMI was slightly higher in the OSA group (27.5 kg/m² vs. 26.3 kg/m²). Percent-predicted VO₂ max was supernormal in both groups, though it was comparatively lower in the OSA group (117% vs. 125%; p < 0.001).

CONCLUSIONS

Military personnel with moderate to severe OSA were able to achieve supernormal VO₂ max values, yet had an 8% decrement in exercise capacity compared to controls. These findings suggest that OSA without significant hypoxemia may not significantly influence exercise capacity. It remains likely that the effects of untreated OSA on exercise capacity are complex and are affected by several variables including BMI, degree of associated hypoxemia, and regularity of exercise. Statistically lower VO₂ max noted in this study may suggest that untreated OSA in less fit populations may lead to significant decrements in exercise capacity.

IFN- Is Protective in Cytokine Release Syndrome-associated Extrapulmonary Acute Lung Injury

The mechanisms by which excessive systemic activation of adaptive T lymphocytes, as in cytokine release syndrome (CRS), leads to innate immune cell-mediated acute lung injury (ALI) or acute respiratory distress syndrome, often in the absence of any infection, remains unknown. Here, we investigated the roles of IFN-γ and IL-17A, key T-cell cytokines significantly elevated in patients with CRS, in the immunopathogenesis of CRS-induced extrapulmonary ALI. CRS was induced in wild-type (WT), IL-17A- and IFN-γ knockout (KO) human leukocyte antigen-DR3 transgenic mice with 10 μg of the superantigen, staphylococcal enterotoxin B, given intraperitoneally. Several ALI parameters, including gene expression profiling in the lungs, were studied 4, 24, or 48 hours later. Systemic T-cell activation with staphylococcal enterotoxin B resulted in robust upregulation of several chemokines, S100A8/A9, matrix metalloproteases, and other molecules implicated in tissue damage, granulocyte as well as agranulocyte adhesion, and diapedesis in the lungs as early as 4 hours, which was accompanied by subsequent neutrophil/eosinophil lung infiltration and severe ALI in IFN-γ KO mice. These pathways were significantly underexpressed in IL-17A KO mice, which manifested mildest ALI and intermediate in WT mice. Neutralization of IFN-γ worsened ALI in WT and IL-17A KO mice, whereas neutralizing IL-17A did not mitigate lung injury in IFN-γ KO mice, suggesting a dominant protective role for IFN-γ in ALI and that IL-17A is dispensable. Ruxolitinib, a Janus kinase inhibitor, increased ALI severity in WT mice. Thus, our study identified novel mechanisms of ALI in CRS and its differential modulation by IFN-γ and IL-17A.

Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke

Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.

Resistance Training of Inspiratory Muscles After Coronary Artery Disease May Improve Obstructive Sleep Apnea in Outpatient Cardiac Rehabilitation: RICAOS Study

Background

Obstructive sleep apnea (OSA) affects 5% of the adult population and its prevalence is up to 13 times higher in coronary artery disease (CAD) patients. However, OSA in this population is less symptomatic, leading to lower adherence to positive airway pressure (CPAP). While oropharyngeal exercise showed a significant decrease in apnea-hypopnea index (AHI) in patients with moderate OSA, there have been no studies testing the impact of specific inspiratory muscle training (IMT) for these patients. The aim of our study was to assess the effectiveness of IMT on AHI reduction in CAD patients with moderate OSA.

Methods

We included patients with CAD involved in a cardiac rehabilitation program and presenting an AHI between 15 and 30. Patients were randomized in a 1:1 allocation to a control group (CTL – classic training) or an IMT group (classic training + IMT). IMT consisted in 60 deep inspirations a day, 6 days a week, into a resistive load device set at 70% of the maximum inspiratory pressure (MIP). After 6 weeks, we compared AHI, neck circumference, Epworth Sleepiness Scale, Pittsburgh Sleep Quality index, and quality of life with the 12-item Short Form Survey before and after rehabilitation.

Results

We studied 45 patient (60 ± 9 y, BMI = 27 ± 6 kg.m⁻²). The IMT group (n = 22) significantly improved MIP ( p < 0.05) and had a significant decrease in AHI by 25% (−6.5 ± 9.5, p = 0.02). In the CTL group (n = 23), AHI decreased only by 3.5% (−0.7 ± 13.1; p = 0.29). Between groups, we found a significant improvement in MIP ( p = 0.003) and neck circumference ( p = 0.01) in favor of the IMT group. However, we did not find any significant improvement of AHI in the IMT group compared to CTL ( p = 0.09).

Conclusion

A specific IMT during cardiac rehabilitation contributes to reduce significantly AHI in CAD patients with moderate OSA. Magnitude of the decrease in OSA severity could be enhanced according to implementation of specific IMT in this population.

Effect of exercise training on body composition in patients with obstructive sleep apnea: a systematic review and meta-analysis

Reduction in adiposity is considered a cornerstone in the treatment of obstructive sleep apnea (OSA). Exercise training is one of the interventions used in the treatment of OSA. However, it remains unclear whether exercise training alleviates OSA by improving body composition. This study aimed to verify the effect of exercise training on body composition and the apnea-hypopnea index (AHI) in patients with OSA. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in PROSPERO. PubMed/Medline, Scopus, and Cochrane databases were used for systematic review. Analyses were performed using Review Manager software (version 5.3; R Foundation for Statistical Computing, Vienna, Austria). Exercise training significantly reduced body mass index (mean difference = -0.55 kg/m²; 95% CI = -0.95 to -0.15), body fat percentage (mean difference = -1.19%; 95% CI = -2.03 to -0.35), neck circumference (mean difference = -0.55 cm; 95% CI = -1.08 to -0.02), total body weight (mean difference = -2.13 kg; 95% CI = -4.30 to 0.04), and AHI -8.06 events/hour; 95% CI = -10.47 to -5.66). Although body composition was improved by exercise, this improvement was clinically small. Moreover, improvement in AHI by exercise may not be entirely due to improvements in adiposity. PROSPERO #: CRD42020210509.

Longer-term effects of supervised physical activity on obstructive sleep apnea and subsequent health consequences

Although recent trials have shown promising benefits of exercise on obstructive sleep apnea (OSA) severity, the long-term effect of these interventions remains unknown. The aim of this study was to assess the effect of a 9-month community physical activity program on OSA severity one year later in free-living conditions. OSA patients, previously included in a 9-month randomized controlled trial (EXESAS study) evaluating the effects of supervised community physical activity on OSA severity, were invited to participate in an extra one-year observational study. Twenty-eight patients completed the study. Although OSA severity did not significantly worsen over the real-life period (9 to 21 months of follow-up), reductions in apnea-hypopnea index (AHI) and oxygen desaturation index were no longer significant after 21 months of follow-up compared to baseline (baseline AHI: 22.2 ± 6.3 /h; 9 months: 16.3 ± 6.4 /h; 21 months: 18.7 ± 8.9 /h). Benefits observed at 9 months on daytime sleepiness and mental health were preserved at 21 months, whereas cardiorespiratory fitness slightly decreased. Per-protocol analysis revealed that patients who stopped exercise at 9 months had worsened OSA severity compared to those who continued exercise during the real-life period (AHI: +9.0 ± 8.8 vs. -1.3 ± 5.3 /h; p < .01). In conclusion, our study suggested that improvements in OSA severity remain transient and is dependent on long-term adherence to regular physical activity practice.

Effects of exercise training on autonomic modulation and mood symptoms in patients with obstructive sleep apnea

We evaluated the effects of exercise training (ET) on the profile of mood states (POMS), heart rate variability, spontaneous baroreflex sensitivity (BRS), and sleep disturbance severity in patients with obstructive sleep apnea (OSA). Forty-four patients were randomized into 2 groups, 18 patients completed the untrained period and 16 patients completed the exercise training (ET). Beat-to-beat heart rate and blood pressure were simultaneously collected for 5 min at rest. Heart rate variability (RR interval) was assessed in time domain and frequency domain (FFT spectral analysis). BRS was analyzed with the sequence method, and POMS was analyzed across the 6 categories (tension, depression, hostility, vigor, fatigue, and confusion). ET consisted of 3 weekly sessions of aerobic exercise, local strengthening, and stretching exercises (72 sessions, achieved in 40±3.9 weeks). Baseline parameters were similar between groups. The comparisons between groups showed that the changes in apnea-hypopnea index, arousal index, and O₂ desaturation in the exercise group were significantly greater than in the untrained group (P<0.05). The heart rate variability and BRS were significantly higher in the exercise group compared with the untrained group (P<0.05). ET increased peak oxygen uptake (P<0.05) and reduced POMS fatigue (P<0.05). A positive correlation (r=0.60, P<0.02) occurred between changes in the fatigue item and OSA severity. ET improved heart rate variability, BRS, fatigue, and sleep parameters in patients with OSA. These effects were associated with improved sleep parameters, fatigue, and cardiac autonomic modulation, with ET being a possible protective factor against the deleterious effects of hypoxia on these components in patients with OSA.

Effect of a Graduated Walking Program on the Severity of Obstructive Sleep Apnea Syndrome. A Randomized Clinical Trial

Background: Obstructive sleep apnea syndrome (OSAS) is a common disease. The objective of this research was to determine the effectiveness of a graduated walking program in reducing the apnea–hypopnea index number in patients with obstructive sleep apnea syndrome (OSAS). Methods: A randomized controlled clinical trial with a two-arm parallel in three tertiary hospitals was carried out with seventy sedentary patients with moderate to severe OSAS. Twenty-nine subjects in each arm were analyzed by protocol. The control group received usual care, while usual care and an exercise program based on progressive walks without direct supervision for 6 months were offered to the intervention group. Results: The apnea–hypopnea index decreased by six points in the intervention group, and improvements in oxygen desaturation index, total cholesterol, and Low-Density Lipoprotein of Cholesterol (LDL-c) were observed. A higher decrease in sleep apnea–hypopnea index (45 ± 20.6 vs. 34 ± 26.3/h; p = 0.002) was found in patients with severe vs. moderate OSAS, as well as in oxygen desaturation index from baseline values (43.3 vs. 34.3/h; p = 0.046). Besides, High-Density Lipoprotein of Cholesterol (HDL-c) values showed a higher increase in the intervention group (45.3 vs. 49.5 mg/dL; p = 0.009) and also, a higher decrease in LDL-c was found in this group (141.2 vs. 127.5 mg/dL; p = 0.038). Conclusion: A home physical exercise program is a useful and viable therapeutic measure for the management of OSAS.

Adipose tissue as a key player in obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a major health concern worldwide and adversely affects multiple organs and systems. OSA is associated with obesity in >60% of cases and is independently linked with the development of numerous comorbidities including hypertension, arrhythmia, stroke, coronary heart disease and metabolic dysfunction. The complex interaction between these conditions has a significant impact on patient care and mortality. The pathophysiology of cardiometabolic complications in OSA is still incompletely understood; however, the particular form of intermittent hypoxia (IH) observed in OSA, with repetitive short cycles of desaturation and re-oxygenation, probably plays a pivotal role. There is fast growing evidence that IH mediates some of its detrimental effects through adipose tissue inflammation and dysfunction. This article aims to summarise the effects of IH on adipose tissue in experimental models in a comprehensive way. Data from well-designed controlled trials are also reported with the final goal of proposing new avenues for improving phenotyping and personalised care in OSA.

Fast growing evidence strongly suggests that cardiovascular and metabolic alterations induced by intermittent hypoxia in OSA are mediated through adipose tissue inflammation and dysfunction.bit.ly/2W929Pe

Effect of exercise training on heart rate variability in patients with obstructive sleep apnea: A randomized controlled trial

While obstructive sleep apnea (OSA) increases chemoreflex, leading to an autonomic dysfunction in the long term, no studies have yet assessed the potential benefit of exercise on cardiac autonomic activity in these patients. The aim of this study was to evaluate potential improvement in cardiac autonomic function (CAF) measured through heart rate variability (HRV) after a 9-month physical activity program in patients with OSA. Seventy-four patients with moderate OSA, aged 40-80 years, were randomly assigned to an exercise group (n = 36, 3 × 1 h/wk) or a control group (n = 38) during 9 months. Linear and nonlinear HRV parameters were measured during night using a Holter ECG. After 9 months, mean R-R intervals increased in the exercise group without any changes in HRV parameters, while controls decreased global (standard deviation of normal-to-normal intervals, total power) and parasympathetic (root mean square successive difference of N-Ns, very low frequency, high frequency, and standard deviation of the instantaneous beat-to-beat variability) indices of HRV (P < 0.05 for all). Significant correlations with moderate effect size were found between changes in apnea severity and changes in R-R intervals (P < 0.05). Improvement in moderate-to-vigorous physical activity was also correlated to improvement in nocturnal oxygen parameters (P < 0.05). In conclusion, supervised community physical activity may prevent a decline in nighttime CAF observed in nontreated community-dwelling patients with moderate OSA over a 9-month period. Thus, beyond apnea-hypopnea index improvement, exercise may be cardioprotective in OSA patients through bradycardia, CAF preservation, and VO_2peak increase.

Does obstructive sleep apnea affect exercise capacity and the hemodynamic response to exercise? An individual patient data and aggregate meta-analysis

Obstructive sleep apnea (OSA) has been linked to altered cardiovascular response to exercise. A systematic review and individual patient data (IPD) meta-analysis were conducted to assess whether OSA patients present reduced exercise capacity. PubMed, Embase and Web of Science were searched until September 2018. Studies which performed sleep recording in both OSA patients and controls and measured maximal oxygen consumption (VO_2peak) via a maximal exercise test were included. IPD were provided for five trials upon the 18 eligible (N = 289) and a two-stage IPD meta-analysis model was used, allowing to standardize the apnea cutoff and adjust for confounders. IPD meta-analysis demonstrated that moderate to severe OSA patients had similar VO_2peak (mean difference: -1.03 mL·kg^-1 min^-1; 95% CI: -3.82 to 1.76; p = 0.47) and cardiovascular response to exercise compared to mild or non-OSA patients. By contrast, aggregate data (AD) meta-analysis including the 13 trials for which IPD were unavailable (N = 605) revealed that VO_2peak was reduced in OSA patients compared to controls (mean difference: -2.30 mL·kg^-1 min^-1; 95% CI: -3.96 to -0.63; p < 0.001) with high heterogeneity. In conclusion, IPD meta-analysis suggests that VO_2peak and the cardiovascular response to exercise are preserved in moderate to severe OSA patients while AD meta-analysis suggests lower VO_2peak in severe OSA.