Circadian Rhythm, Exercise Snacks, Obstructive Sleep Apnea (OSA), Physical Activity, Sleep
Conditions
Keywords
Obstructive Sleep Apnea, exercise training, circadian rhythm, exercise snacks
Brief summary
Obstructive Sleep Apnea Syndrome (OSA) is a condition characterized by repeated pauses or reductions in breathing during sleep, which can negatively affect sleep quality, daytime functioning, and physical capacity. Although regular exercise is known to have beneficial effects in OSA, the effects of different exercise approaches on circadian rhythm and functional capacity have not been sufficiently investigated.The primary aim of this study is to compare the effects of exercise snacking and aerobic exercise on circadian rhythm and functional capacity in individuals with OSA, in comparison with a control group. The secondary aim is to evaluate the effects of these exercise interventions on peripheral muscle strength, fatigue level, body composition, quality of life, and physical activity level.Participants will be randomly assigned to three groups: an aerobic exercise group, an exercise snacking group, and a control group. While the exercise groups will follow their respective intervention programs, the control group will continue their routine treatment.This study aims to answer whether exercise snacking, which consists of short bouts of exercise distributed throughout the day, may be an alternative or complementary approach to traditional aerobic exercise in individuals with OSA. In addition, this study aims to be the first randomized controlled trial evaluating the effects of exercise snacking on circadian rhythm and functional capacity in individuals with OSA.
Detailed description
Obstructive Sleep Apnea Syndrome (OSA) is a common sleep-related breathing disorder characterized by repeated episodes of partial or complete upper airway obstruction during sleep. It is associated with intermittent hypoxia, sleep fragmentation, and increased risk of cardiovascular and metabolic comorbidities. Emerging evidence also suggests a bidirectional relationship between OSA and circadian rhythm disruption, where each condition may negatively influence the other. Therefore, improving circadian regulation may be an important therapeutic target in OSA management.Exercise is a widely accepted non-pharmacological intervention in OSA due to its potential benefits on sleep-related outcomes and overall health. However, adherence to conventional structured exercise programs may be limited due to time constraints and sustainability issues. Recently, exercise snacking-short bouts of exercise performed throughout the day-has been proposed as a time-efficient and more feasible alternative to traditional exercise approaches. This strategy may improve long-term adherence by integrating physical activity into daily routines without requiring supervised sessions.Despite its potential advantages, evidence regarding the effects of exercise snacking in individuals with OSA is currently limited. In addition, there is a lack of randomized controlled trials comparing exercise snacking with aerobic exercise while also evaluating circadian rhythm-related outcomes in this population.This study is designed as a prospective, single-blind, randomized controlled trial. A total of 39 individuals diagnosed with moderate to severe OSA will be randomly assigned to three groups: aerobic exercise group, exercise snacking group, and control group. The intervention period will last 8 weeks. The aerobic exercise group will perform supervised aerobic and resistance-based training, while the exercise snacking group will perform short, home-based exercise bouts distributed across the day. The control group will continue usual medical care and receive a single session of sleep hygiene education.The study will evaluate the effects of the interventions on circadian rhythm and functional capacity as primary outcomes, and on secondary outcomes including fatigue, muscle strength, body composition, physical activity level, insomnia severity, and quality of life. Assessments will be performed at baseline and after the 8-week intervention period.
Interventions
BEHAVIORALAerobic Exercise Training
Participants in the aerobic exercise group will undergo an 8-week supervised aerobic exercise program on a cycle ergometer, performed twice per week. Each session will last approximately 30-45 minutes and will include a 5-minute low-intensity warm-up and a 5-minute cool-down period. Exercise intensity will be set at a moderate level according to the Karvonen method. The main exercise duration will be progressively increased throughout the intervention period: 20 minutes during weeks 1-2, 25 minutes during weeks 3-4, 30 minutes during weeks 5-6, and 35 minutes during weeks 7-8. Participants' heart rate will be monitored during exercise sessions, and perceived exertion will be assessed using the Borg Rating of Perceived Exertion Scale.In addition, all participants will be instructed to perform resistance exercises once per week. The exercises will target the upper extremity, lower extremity, and core muscles and will consist of three different exercises.
BEHAVIORALExercise Snacking
The exercises will be performed by participants at home and supervised by the researcher. Since progression of each exercise will be implemented every two weeks, participants will be scheduled to attend the clinic every two weeks, where the exercises will be demonstrated. Each session will consist of six different exercises (squat, heel raises, marching in place, jumping jacks, upright row, and chest press). Each exercise will be performed for 1 minute, followed by a 1-minute seated rest interval. Thus, each session will last approximately 12 minutes. Exercise progression will be applied every two weeks for each exercise. During the sessions, participants will monitor their heart rate and oxygen saturation. An oxygen saturation level below 90% will be defined as the exercise termination criterion. Participants will be provided with a daily logbook to record completion of exercise snacking sessions.
Sponsors
Istanbul University - Cerrahpasa
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Individuals diagnosed with OSAHS (AHI ≥ 15) confirmed by polysomnography, with moderate or severe disease, who have been receiving CPAP therapy for at least 3 months. * Adults aged 30-65 years. * No participation in any regular exercise program within the last 6 months.
Exclusion criteria
* Individuals with OSAHS and a body mass index (BMI) \> 35 kg/m² * Severe chronic pulmonary disease * Neurological or musculoskeletal disorders that prevent exercise * Unstable cardiovascular conditions * Unstable metabolic conditions * Severe psychiatric disorders such as bipolar disorder or schizophrenia * Pregnancy or breastfeeding * Individuals working night shifts or with schedules that may cause jet lag * Use of steroid or hormone therapy * Use of melatonin or sleep-regulating medications within the last 3 months * Presence of acute infection or inflammation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pittsburgh Sleep Quality Index (PSQI) Total Score | From baseline to the end of the intervention at 8 weeks | Sleep quality assessed using the Pittsburgh Sleep Quality Index. Total scores range from 0 to 21, with higher scores indicating poorer sleep quality. |
| Epworth Sleepiness Scale (ESS) Total Score | From baseline to the end of the intervention at 8 weeks | Daytime sleepiness will be assessed using the Epworth Sleepiness Scal (ESS).Scores ≥10 indicate excessive daytime sleepiness. |
| Morningness-Eveningness Questionnaire (MEQ) Total Score | From baseline to the end of the intervention at 8 weeks | Circadian rhythm preference will be assessed using the Morningness-Eveningness Questionnaire (MEQ).The questionnaire consists of 19 items evaluating sleep-wake preferences and chronotype.Higher scores indicate morningness, whereas lower scores indicate eveningness. |
| Serum Cortisol Level | From baseline to the end of the intervention at 8 weeks | Fasting morning serum cortisol concentration measured by chemiluminescent immunoassay. |
| Serum Thyroid-Stimulating Hormone (TSH) Level | From baseline to the end of the intervention at 8 weeks | Fasting morning serum TSH concentration measured by chemiluminescent immunoassay. |
| Functional Capacity | From baseline to the end of the intervention at 8 weeks | Functional capacity will be assessed using the 6-Minute Walk Test (6MWT) according to American Thoracic Society criteria. Walking distance covered within 6 minutes will be recorded in meters. Higher values indicate better functional capacity. |
| Total Sleep Time (Sleep Diary) | From baseline to the end of the intervention at 8 weeks | Total sleep time will be assessed subjectively using a sleep diary based on the Consensus Sleep Diary (CSD). Participants will complete the diary for 7 consecutive days at baseline and at week 8. Total sleep time will be recorded in minutes. |
| Total Sleep Time (Wearable Device) | From baseline to the end of the intervention at 8 weeks | Total sleep time will be objectively assessed using a Polar Unite wearable activity tracker with Sleep Plus Stages™ algorithm. Measurements will be collected over 3 consecutive nights at baseline and at week 8. Total sleep time will be expressed in minutes. |
| Sleep Efficiency (Wearable Device) | From baseline to the end of the intervention at 8 weeks | Sleep efficiency will be assessed using a Polar Unite wearable activity tracker with Sleep Plus Stages™ algorithm. Measurements will be collected over 3 consecutive nights at baseline and at week 8. Sleep efficiency will be expressed as percentage (%). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Insomnia Severity | From baseline to the end of the intervention at 8 weeks | Insomnia severity will be assessed using the Insomnia Severity Index (ISI). The ISI consists of 7 items scored from 0 to 4, with a total score ranging from 0 to 28. Higher scores indicate greater insomnia severity. Scores ≥10 indicate clinically significant insomnia. |
| Waist Circumference (cm) | From baseline to the end of the intervention at 8 weeks | Waist circumference measured using a non-elastic tape measure. |
| Hip Circumference (cm) | From baseline to the end of the intervention at 8 weeks | Hip circumference measured using a non-elastic tape measure. |
| Neck Circumference (cm) | From baseline to the end of the intervention at 8 weeks | Neck circumference measured using a non-elastic tape measure. |
| Muscle Mass (kg) | From baseline to the end of the intervention at 8 weeks | Muscle mass assessed using bioelectrical impedance analysis (BIA). |
| Body Fat Percentage (%) | From baseline to the end of the intervention at 8 weeks | Body fat percentage assessed using bioelectrical impedance analysis (BIA). |
| Bone Mass (kg) | From baseline to the end of the intervention at 8 weeks | Bone mass assessed using bioelectrical impedance analysis (BIA). |
| Body Water Percentage (%) | From baseline to the end of the intervention at 8 weeks | Body water percentage assessed using bioelectrical impedance analysis (BIA). |
| Fatigue Severity | From baseline to the end of the intervention at 8 weeks | Fatigue severity will be assessed using the Fatigue Severity Scale (FSS). The FSS consists of 9 items scored from 1 to 7. Higher scores indicate greater fatigue severity. Mean scores ≥4 indicate clinically significant fatigue. |
| Peripheral Muscle Strength | From baseline to the end of the intervention at 8 weeks | Peripheral muscle strength (quadriceps, biceps brachii, and handgrip strength) will be assessed using a hand-held dynamometer and handgrip dynamometer. Higher values indicate greater muscle strength. |
| Physical Activity Level | From baseline to the end of the intervention at 8 weeks | Physical activity level will be assessed using a pedometer. Average daily step count (steps/day) will be recorded. Higher values indicate greater physical activity. |
| Health-related quality of life (Functional Outcomes of Sleep Questionnaire, FOSQ) | From baseline to the end of the intervention at 8 weeks | Quality of life will be assessed using the Functional Outcomes of Sleep Questionnaire (FOSQ). The questionnaire consists of 26 items with total scores ranging from 4 to 16. Lower scores indicate greater impairment in sleep-related quality of life. |
| Patient Global Impression of Change | At the end of the intervention (8 weeks) | Perceived clinical improvement will be assessed using the Patient Global Impression of Change (PGIC). The scale ranges from 1 (very much improved) to 7 (very much worse). Lower scores indicate greater perceived improvement. |
Countries
Turkey (Türkiye)
Contacts
CONTACTMelis Usul, PhD student
CONTACTGökşen Kuran Aslan, Professor
PRINCIPAL_INVESTIGATORMELİS USUL
Istanbul University - Cerrahpasa
STUDY_DIRECTORGökşen Kuran Aslan, Professor
Istanbul University - Cerrahpasa
STUDY_CHAIREsen Kıyan, Professor
Istanbul University Faculty of Medicine
STUDY_CHAIRZeynep Banu Güngör, Professor
Istanbul University - Cerrahpasa
Outcome results
None listed