Effectiveness of Inspiratory Muscle Training on Sleep in Patients With Obstructive Sleep Apnea

Universidade Federal de Pernambuco

Status: Invitation-only

Conditions: Obstructive Sleep Apnea (OSA); Sleep

Treatments: Device: Inspiratory Muscle Training

Study type: Interventional

Funder types: Other

Identifiers

NCT07149233

7.330.179

CAAE: 84723724.2.0000.5208 (Other Identifier)

Details and patient eligibility

About

The goal of this clinical trial is to evaluate the effectiveness of inspiratory Muscle Training (IMT) on both objective and subjective sleep parameters in patients with OSA.Methods: A prospective, randomized, controlled clinical trial will be conducted with patients diagnosed with OSA followed at Otavio de Freitas Hospital. Participants will be evaluated for excessive daytime sleepiness (Epworth Sleepiness Scale), sleep quality (Pittsburgh Sleep Quality Index), physical activity level (IPAQ), sleep latency, total sleep time, sleep efficiency, number of nocturnal awakenings, total time in bed, total wake time during sleep (Actigraphy), hypoxic burden during sleep (Nocturnal Oximetry), disease severity (Polysomnography), respiratory muscle strength (Manovacuometry), and respiratory muscle endurance (Powerbreathe K-series) before and after 4 weeks of training, as well as perceived change in health status after IMT (PGIC).Participants will be divided into two groups and will perform IMT for 4 weeks: the experimental group will perform IMT with a progressive weekly load (50%, 60%, 75% of MIP) adjusted using the Powerbreathe® Classic device, while the control group will use the device without load. The participants will perform IMT at home under the guidance of the principal investigator.Statistical Analysis: Data will be analyzed using SPSS version 26.0 with descriptive and analytical statistical techniques. Normality will be assessed using the Shapiro-Wilk test. For intergroup and intragroup comparisons, two-way ANOVA will be used. Tukey's post-hoc test will be applied to compare pre- and post-intervention mean variances for each group. The level of significance adopted for all analyses will be 95% (p < 0.05).Expected Results: It is expected that 4 weeks of IMT in patients with OSA will reduce excessive daytime sleepiness, sleep latency, number of awakenings, and hypoxic burden, as well as increase sleep efficiency and total sleep time, leading to improved sleep quality.

Full description

Obstructive Sleep Apnea (OSA) is a prevalent sleep-related breathing disorder characterized by repeated episodes of upper airway obstruction during sleep, leading to intermittent hypoxia, sleep fragmentation, and frequent arousals. These events disrupt sleep architecture, reduce total sleep time and sleep efficiency, and result in non-restorative sleep. As a consequence, patients often present with excessive daytime sleepiness, cognitive and functional impairments, and an increased risk of occupational errors and motor vehicle accidents.

The impact of OSA extends beyond sleep, contributing to reduced quality of life and increased cardiovascular and metabolic risks. Considering the multifactorial consequences of OSA and the barriers to continuous positive airway pressure (CPAP) adherence-including cost, discomfort, and access-there is a need for alternative or adjunctive low-cost therapies that are easy to implement and have proven efficacy.

Inspiratory Muscle Training (IMT) has emerged as a promising therapeutic strategy to improve respiratory muscle strength, reduce symptoms, and potentially enhance sleep quality. However, evidence regarding its impact on objective and subjective sleep parameters in patients with OSA remains limited.

This study aims to evaluate the efficacy of a 4-week IMT protocol, following standardized training guidelines, in adults with moderate to severe OSA who have not yet initiated CPAP therapy. Validated instruments will be used to assess sleep outcomes. The findings are expected to contribute to clinical decision-making and offer evidence for non-pharmacological, non-invasive interventions to improve sleep quality and reduce daytime symptoms in this population.

Enrollment: 30 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Male or female participants
• Age between 18 and 70 years
• Clinical diagnosis of moderate to severe Obstructive Sleep Apnea (OSA), confirmed by polysomnography
• Not currently undergoing treatment for OSA

Exclusion criteria

• Presence of neuromuscular disorders, infectious diseases, immunological conditions, tumors, or any disease that prevents inspiratory muscle training (IMT), manovacuometry, or respiratory muscle performance assessment
• Unstable angina, untreated or uncontrolled systemic arterial hypertension, left ventricular dysfunction, cerebral aneurysm, or any cardiovascular condition contraindicating IMT or respiratory muscle testing
• Upper limb deformities that prevent the use of actigraphy devices or oximetry sensors
• Other sleep disorders (e.g., insomnia, hypoventilation syndrome, or need for continuous home oxygen therapy)
• Cognitive impairment that limits the participant's ability to understand or follow study procedures
• Ongoing or planned CPAP therapy during the follow-up period
• Participation in a pulmonary rehabilitation program within 6 months prior to the study
• Moderate or high physical activity level according to the IPAQ, including regular moderate or vigorous physical activity within the past 30 days
• Use of sleep-inducing medication to treat insomnia
• Grade 2 or 3 obesity (BMI ≥ 35 kg/m²)
• Residence in a geographic area with limited or no access to telephone or internet service, preventing contact or data transmission from study devices (actigraphy and/or oximetry sensors)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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30 participants in 2 patient groups

Group 1 - Inspiratory Muscle Training (IMT)

Experimental group

Description:

Participants with moderate to severe obstructive sleep apnea (OSA) will perform inspiratory muscle training using a threshold device with progressive loading over 4 weeks. Training will begin at 50% of maximal inspiratory pressure (MIP) for the first 2 weeks, increase to 60% in week 3, and 75% in week 4. Participants will perform three sets of 30 fast, forceful inspiratory efforts, with one-minute rest intervals between sets. Training sessions will occur twice daily, seven days per week. Load adjustments will be made weekly during in-person visits. Participants will record adherence and occurrences in a training diary and will be monitored daily by the principal investigator through phone calls.

Treatment:

Device: Inspiratory Muscle Training

Group 2 - Sham Inspiratory Muscle Training

Sham Comparator group

Description:

Participants in the control group will perform sham inspiratory muscle training using the same device with the internal spring removed, providing no resistance. The training protocol will mirror that of the intervention group: three sets of 30 fast inspiratory efforts, with one-minute rest intervals, performed twice daily, seven days per week, for 4 weeks. Weekly in-person visits will be held to verify procedures, and participants will log adherence in a training diary. Daily phone follow-ups will be conducted by the principal investigator.

Treatment:

Device: Inspiratory Muscle Training