The effects of threshold inspiratory muscle training in patients with obstructive sleep apnea: a randomized experimental study

Respiratory muscle training for obstructive sleep apnea: Systematic review and meta-analysis

Obstructive sleep apnea is the most common sleep disorder. This review aims to evaluate the effectiveness and safety of respiratory muscle training in the treatment of patients with obstructive sleep apnea. The study protocol was registered in Prospero Platform (CRD42018096980). We performed searches in the main databases: Medical Literature Analysis and Retrieval System Online (MEDLINE) via Pubmed; Excerpta Medica dataBASE (Embase) via Elsevier; Cochrane Central Register of Controlled Trials (CENTRAL) via Cochrane Library; Latin American and Caribbean Literature on Health Sciences (LILACS) through the Portal of the Virtual Health Library and Physiotherapy Evidence Database (PEDro) for all randomised-controlled trials published before July 2022. The randomised-controlled trials were assessed for risk of bias and certainty of evidence. Thirteen randomised-controlled trials were included. All studies had an overall high risk of bias. Inspiratory muscle training probably improves systolic blood pressure and sleepiness when compared with sham. However, inspiratory muscle training probably does not improve diastolic blood pressure and maximum expiratory pressure, and may not be superior to sham for apnea-hypopnea index, forced expiratory volume in 1 s, forced vital capacity, sleep quality and quality of life. In addition, it is uncertain whether there is any effect of inspiratory muscle training on maximum inspiratory pressure and physical capacity. Inspiratory muscle training may also improve maximum inspiratory pressure and maximum expiratory pressure compared with oropharyngeal exercises. However, it may not be superior for apnea-hypopnea index, sleep quality, sleepiness, quality of life and functional capacity. When associated with physical exercise, inspiratory muscle training may not be superior to physical exercise alone for maximum inspiratory pressure, maximum expiratory pressure, systolic and diastolic blood pressure, and functional capacity. At the same time, when associated with cardiac rehabilitation exercises, inspiratory muscle training may reduce apnea-hypopnea index, improve inspiratory muscle strength, sleepiness and sleep quality compared with cardiac rehabilitation alone. However, it may not be superior for improving quality of life. Regarding expiratory muscle training, it may improve expiratory muscle strength and sleep quality, but not sleepiness when compared with sham. The evidence on the effects of expiratory muscle training in apnea-hypopnea index is very uncertain.

Effects of inspiratory muscle training on the severity of obstructive sleep apnea in individuals after stroke: a protocol for a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing in cerebrovascular diseases, requiring a multidisciplinary approach. There are few studies evaluating the effects of inspiratory muscle training (IMT) in individuals with OSA and the findings regarding the possible effect on apnea hypopnea index (AHI) reduction are controversial.

OBJECTIVE

This protocol for a randomized clinical trial will assess the effects of IMT on the severity of obstructive sleep apnea, sleep quality, and daytime sleepiness in individuals after stroke participating in a rehabilitation program.

METHODS

This study will be a randomized controlled trial with blinded assessors. Forty individuals after stroke will randomized to two groups. For 5 weeks, both groups will participate in the rehabilitation program activities, including aerobic exercise, resistance training, and educational class when they will receive guidance on the behavioral management of OSA. The experimental group will also perform high-intensity IMT 5 times a week, for 5 weeks, consisting initially of five sets of five repetitions achieving 75% of the maximal inspiratory pressure, increasing one set each week, totaling nine sets at the end of training. The primary outcome will be the severity of OSA measured as AHI at 5 weeks. Secondary outcomes will include sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI) and daytime sleepiness measured by Epworth Sleepiness Scale (ESS). Outcomes will be collected by a researcher blinded to group allocation at baseline (week 0), after intervention (week 5), and 1 month beyond intervention (week 9).

TRIAL REGISTRATION

Clinical Trials Register: NCT05135494.

Effects of inspiratory muscle training on blood pressure- and sleep-related outcomes in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

PURPOSE

Obstructive sleep apnea (OSA) is frequently accompanied by hypertension, resulting in cardiovascular comorbidities. Continuous positive airway pressure is a standard therapy for OSA but has poor adherence. Inspiratory muscle training (IMT) may reduce airway collapsibility and sympathetic output, which may decrease OSA severity and blood pressure. In this meta-analysis of randomized controlled trials (RCTs), we evaluated the efficacy of IMT in patients with OSA.

METHODS

We searched PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov databases for relevant RCTs published before November 2022.

RESULTS

Seven RCTs with a total of 160 patients with OSA were included. Compared with the control group, the IMT group exhibited significantly lower systolic and diastolic blood pressure (mean difference [MD]: - 10.77 and - 4.58 mmHg, respectively), plasma catecholamine levels (MD: - 128.64 pg/mL), Pittsburgh Sleep Quality Index (MD: - 3.06), and Epworth Sleepiness Scale score (MD: - 4.37). No significant between-group differences were observed in the apnea-hypopnea index, forced vital capacity (FVC), ratio of forced expiratory volume in 1 s to FVC, or adverse effects. The data indicate comprehensive evidence regarding the efficacy of IMT for OSA. However, the level of certainty (LOC) remains low.

CONCLUSION

IMT improved blood pressure- and sleep-related outcomes without causing adverse effects and may thus be a reasonable option for lowering blood pressure in patients with OSA. However, additional studies with larger sample sizes and rigorous study designs are warranted to increase the LOC.

Pulmonary Function Test and Obstructive Sleep Apnea Hypopnea Syndrome in Obese Adults: A Retrospective Study

Objective

We explore risk factors related to severe obstructive sleep apnea (OSA) in obese patients, including pulmonary ventilation function, diffusion function, and impulse oscillometry (IOS) data.

Methods

The medical records of 207 obese patients who were prepared to undergo bariatric surgery in a hospital from May 2020 to September 2021 were retrospectively reviewed. Polysomnography (PSG), pulmonary ventilation function, diffusion function, and IOS parameters were collected according to the ethical standards of the institutional research committee (registration number: KYLL-202008-144). Logistic regression analysis was used to analyze the related independent risk factors.

Results

There were significantly statistical difference in a number of pulmonary ventilation and diffusion function parameters among the non-OSAHS group, the mild-to-moderate OSA group, and the severe OSA group. However, only airway resistance parameters R5%, R10%, R15%, R20%, R25%, and R35% increased with increasing OSA severity and were positively correlated with apnea hypopnea index (AHI). Age (P = 0.012, 1.104 (1.022, 1.192)), body mass index (P< 0.0001, 1.12 (1.057, 1.187)), gender (P = 0.003, 4.129 (1.625, 10.49)), and R25% (P = 0.007, 1.018 (1.005, 1.031)) were independent risk factors for severe OSA. In patients aged 35 to 60, RV/TLC (P = 0.029, 1.272 (1.025, 1.577)) is an independent risk factor for severe OSA.

Conclusion

R25% was an independent risk factor for severe OSA in obese individuals, while RV/TLC was also an independent risk factor in those aged 35 to 60. Pulmonary function tests (PFTs), particularly IOS levels, are recommended to assess severe OSA in obese patients.

Effects of respiratory training on obstructive sleep apnea: systematic review and meta-analysis

PURPOSE

This systematic review sought to answer the following focused question: "What are the effects of respiratory training devices on obstructive sleep apnea (OSA) outcomes in adults?" METHODS : The acronym "PICOS" was used to determine eligibility criteria, which consists of (P population) = adults with mild to moderate OSA, (I intervention) = spirometry devices or breathing exercises, (C comparison) = compared to no breathing exercises in adults (> 18 years) with mild to moderate OSA, (O outcomes) = improved sleep quality (sleep quality indexes) and improved apnea-hypopnea indexes (AHI), (S study types) = randomized, pseudo-randomized, and non-randomized clinical trials. The search was performed in the following databases: PubMed/Medline, LILACS, Scopus, Web of Science, Scopus, and Cochrane Library, in addition to gray literature through Google Scholar, Proquest, and Open Grey. The risk of bias was assessed using the Cochrane Collaboration tool. The certainty of the evidence was assessed using the GRADE tool. Meta-analyses of random effects were performed for the outcomes of interest.

RESULTS

A total of 1171 references were found. Applying the eligibility criteria, six studies were included in qualitative synthesis. Expiratory exercises showed a decrease in the apnea-hypopnea index (AHI) when compared to baseline (MD =  - 8.4; 95% CI =  - 12.4 to - 4.4; I2 = 19%). There was a decrease in values compared to baseline (MD =  - 4.4; 95% CI =  - 8.2 to - 0.6; I2 = 0%) for the Epworth Sleepiness Scale (ESS), when considering the inspiratory exercises. Both groups of breathing exercises showed a significant decrease in the mean index assessed by the Pittsburgh Sleep Quality Index (PSQI).

CONCLUSION

Results of this meta-analysis suggests that breathing exercises lead to a measurable improvement in AHI for patients with mild to moderate OSA, as well as an improvement in sleep quality and daytime sleepiness.

SYSTEMATIC REVIEW REGISTRATION

CRD42020148513 (PROSPERO).

Inspiratory muscle training as adjuvant therapy in obstructive sleep apnea: a randomized controlled trial

The aim of this randomized controlled trial was to analyze the effects of an inspiratory muscle training (IMT) program on apnea and hypopnea index (AHI), inspiratory muscle strength, sleep quality, and daytime sleepiness in individuals with obstructive sleep apnea (OSA), whether or not they used continuous positive airway pressure (CPAP (+/−) therapy. The intervention group underwent IMT with a progressive resistive load of 40-70% of the maximum inspiratory pressure (PImax) for 30 breaths once a day for 12 weeks. The control group was submitted to a similar protocol, but with at a minimum load of 10 cmH₂O. Changes in the AHI were the primary outcome. PImax was measured with a digital vacuometer, daytime somnolence was measured by the Epworth sleepiness scale (ESS), and the quality of sleep by the Pittsburgh Sleep Quality Index (PSQI). CPAP use was treated as a confounder and controlled by stratification resulting in 4 subgroups: IMT−/CPAP−, IMT−/CPAP+, IMT+/CPAP−, and IMT+/CPAP+. Sixty-five individuals were included in the final analysis. Significant variations were found in the 4 parameters measured throughout the study after the intervention in both CPAP− and CPAP+ participants: PImax was increased and AHI was reduced, whereas improvements were seen in both ESS and PSQI. The twelve-week IMT program increased inspiratory muscle strength, substantially reduced AHI, and had a positive impact on sleep quality and daytime sleepiness, whether or not participants were using CPAP. Our findings reinforce the role of an IMT program as an adjunct resource in OSA treatment.

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.

Respiratory Muscle Training in Patients with Obstructive Sleep Apnoea: A Systematic Review and Meta-Analysis

Background: Effective treatments for obstructive sleep apnoea (OSA) include positive pressure, weight loss, oral appliances, surgery, and exercise. Although the involvement of the respiratory muscles in OSA is evident, the effect of training them to improve clinical outcomes is not clear. We aimed to determine the effects of respiratory muscle training in patients with OSA. Methods: A systematic review was conducted in seven databases. Studies that applied respiratory muscle training in OSA patients were reviewed. Two independent reviewers analysed the studies, extracted the data and assessed the quality of evidence. Results: Of the 405 reports returned by the initial search, eight articles reporting on 210 patients were included in the data synthesis. Seven included inspiratory muscle training (IMT), and one included expiratory muscle training (EMT). Regarding IMT, we found significant improvement in Epworth sleepiness scale in −4.45 points (95%CI −7.64 to −1.27 points, p = 0.006), in Pittsburgh sleep quality index of −2.79 points (95%CI −4.19 to −1.39 points, p < 0.0001), and maximum inspiratory pressure of −29.56 cmH2O (95%CI −53.14 to −5.98 cmH2O, p = 0.01). However, the apnoea/hypopnea index and physical capacity did not show changes. We did not perform a meta-analysis of EMT due to insufficient studies. Conclusion: IMT improves sleepiness, sleep quality and inspiratory strength in patients with OSA.

The effectiveness of oropharyngeal exercises compared to inspiratory muscle training in obstructive sleep apnea: A randomized controlled trial

BACKGROUND

Inspiratory muscle training (IMT) and oropharyngeal exercises (OE) have different advantages and disadvantages and a comparison of these modalities has been recommended. The aim of this study was to compare the effects of IMT and OE on important outcomes for patients with OSAS.

METHODS

This was a randomized controlled clinical trial. Forty-one clinically stable OSAS patients not receiving CPAP therapy were randomly divided into three groups. Patients in the IMT group (n = 15) trained with a threshold loading device 7 days/week for 12 weeks. Patients in the OE group (n = 14) practiced exercises 5 days/week for 12 weeks. Twelve patients served as control group. Apnea-hypopnea index (AHI), respiratory muscle strength, snoring severity and frequency (Berlin Questionnaire), daytime sleepiness (Epworth Sleepiness Scale; ESS), sleep quality (Pittsburg Sleep Quality Index; PSQI), impact of sleepiness on daily life (Functional Outcomes of Sleep Questionnaire; FOSQ), and fatigue severity (Fatigue Severity Scale; FSS) were evaluated before and after the interventions.

RESULTS

AHI and sleep efficiency did not change significantly in any of the groups. Significant decreases in snoring severity and frequency, FSS and PSQI total scores were found in the IMT and OE groups after the treatments (p < 0.05). There was a significant reduction in neck and waist circumference and significant improvement in respiratory muscle strength (MIP and MEP) in IMT group compared to control group (p < 0.05). The%MEPpred value and FOSQ total score significantly increased and ESS score reduced after the treatment in OE group compared to control group (p < 0.05).

CONCLUSIONS

Our results indicate that both OE and IMT rehabilitation interventions are applicable in rehabilitation programs for OSAS patients who do not accept CPAP therapy. Our findings could lead to increase these methods' use among rehabilitation professionals and decrease in cost of CPAP treatment in OSAS.

Effectiveness of respiratory muscle training for patients with obstructive sleep apnea: A protocol of systematic review and meta-analysis

BACKGROUND

This study will evaluate the effectiveness and safety of respiratory muscle training (RMT) for patients with obstructive sleep apnea (OSA).

METHODS

Randomized controlled trials will be retrieved through electronic database searches from MEDLINE, EMBASE, Cochrane Library, CINAHL, Scopus, CBM, and CNKI from the beginning to the present. All electronic databases will be searched without any language limitation. Two researchers will independently select studies, collect data, and assess study quality, respectively. RevMan 5.3 software will be used for statistical analysis.

RESULTS

The primary outcome is severity of OSA, as measured by polysomnography or any relevant tools. The secondary outcomes are hypopnea index, apnea index, respiratory event index, respiratory disturbance index, sleep-related quality of life, and any expected or unexpected adverse events.

CONCLUSION

The results of this study will summarize current evidence of RMT for the treatment of patients with OSA.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040051.

Inspiratory Muscle Training in the Severity of Obstructive Sleep Apnea, Sleep Quality and Excessive Daytime Sleepiness: A Placebo-Controlled, Randomized Trial

PURPOSE

Exercise programs have been considered as an adjuvant treatment in obstructive sleep apnea (OSA). However, few studies have focused on the effects of the inspiratory muscle training (IMT) in reducing the severity and the symptoms of OSA.

PATIENTS AND METHODS

A randomized controlled trial was conducted and approved by the local Ethics Committee. All subjects signed the informed consent form and were randomized into 2 groups: a) IMT group (n = 8), 8 weeks of IMT with 75% of maximal inspiratory pressure (MIP) and b) placebo group (n = 8): subjects performed IMT without load.

RESULTS

IMT group showed reduction in the apnea-hypopnea index (AHI) (p = 0.01), in the Berlin questionnaire score (p = 0.001) and an increase in inspiratory muscle strength (p = 0.018). IMT group demonstrated a reduction in the AHI (31.7 ± 15.9 events/h vs 29.9 ± 15.8 events/h; p <0.001), in the Berlin questionnaire scores (2.6 ± 0.5 vs 1.2 ± 0.5; p = 0.016), Pittsburgh Sleep Quality Index (PSQI) score (7.2 ± 3.6 vs 3.7 ± 1.3; p = 0.008), in the Epworth Sleepiness Scale (ESS) (12.5 ± 4.0 vs 7.7 ± 3.0; p = 0.008) and increase in MIP (83.6 ± 26.5 cmH₂O and 127.9 ± 32.5 cmH₂O; p = 0.010).

CONCLUSION

The IMT promotes discrete changes in the AHI and improves sleep quality and excessive daytime sleepiness in OSA. Moreover, IMT is a cheap, useful and simple home-based training program and can be considered as an adjunct therapy for OSA patients.