Efficacy of Continuous Positive Airway Pressure in Reducing Oxidative Stress in Individuals With Sleep Apnea
Condition: Sleep Apnea Syndromes; Oxidative Stress; Cardiovascular Diseases
MeSH terms: Apnea; Sleep Apnea Syndromes; Cardiovascular Diseases
Study type: Interventional

Summary: 
      Sleep-disordered breathing (SDB) is a condition in which a person experiences frequent
      breathing pauses during sleep, also known as sleep apnea. There is evidence that the
      recurrent sleep arousal and associated shortage of oxygen in the body may increase risk for
      cardiovascular disease (CVD). It is believed that treatment with continuous positive airway
      pressure (CPAP) may reduce certain risk factors for heart disease, including markers of
      inflammation and oxidative stress. This study will evaluate the effectiveness of CPAP in
      reducing CVD risk factors in people with SDB.
    

Detailed description: 
      It is estimated that 18 million Americans are affected by SDB. SDB involves repeated sleep
      arousal caused by breathing difficulties. These frequent sleep disruptions may cause a person
      to experience daytime drowsiness, impaired mental functioning, and trouble concentrating or
      staying alert. SDB is also associated with an increased risk of certain cardiovascular
      diseases, such as high blood pressure and heart disease. Researchers believe that increased
      oxidative stress and inflammation associated with SDB may play a role in the physiologic
      pathway linking SDB and CVD. However, more information on the SDB-CVD relationship is needed
      to be able to identify risk factors for CVD and to discover the best means of treatment.
      CPAP, a current treatment for SDB, acts by delivering air through a mask during sleep. CPAP
      helps improve overnight breathing and quality of sleep and may, in turn, decrease oxidative
      stress and associated CVD risks. This study will compare the effectiveness of CPAP versus
      placebo CPAP in reducing CVD risk factors, such as oxidative stress markers, in people with
      SDB.

      Participation in this study will last between 2.5 and 4 months and will include four to five
      study visits. During the first study visit, participants will undergo a CPAP titration study,
      which will involve appropriate CPAP mask fitting and an overnight sleep test to determine the
      best CPAP pressure, as well as a lower placebo pressure, for each participant. Participants
      will also be provided educational information on diet, sleep, and the use of CPAP as a
      treatment for sleep apnea. After the titration study, participants will be asked to wear
      their fitted CPAP mask every night for the next 2 weeks, during which they will use the lower
      (placebo) pressure one week and use the higher pressure the other week. During this time, a
      technician will contact participants every 3 to 4 days to address any questions or problems
      with the CPAP equipment.

      One month later, participants who were able to tolerate and use CPAP most nights will attend
      Visit 2. This second visit will include an overnight sleep study without wearing the CPAP
      mask; blood and saliva collection; cheek brushing for genetic material; tests on diabetes,
      artery stiffness, and circulation; body fat measurements; and questionnaires. Participants
      will then be randomly assigned to use either the higher pressure CPAP or the lower pressure
      CPAP for 8 weeks. Visit 3 will occur 1 week after beginning CPAP treatment and will include a
      fasting blood test. During treatment, participants will be periodically contacted by a
      technician to check on equipment status.

      Upon completing treatment, participants will undergo repeat tests from Visit 2, except that
      they will wear the CPAP mask in the overnight sleep test. This fourth study visit will mark
      the completion of treatment for participants assigned to the lower pressure CPAP.
      Participants assigned to the higher pressure CPAP will be asked to use CPAP for 4 more weeks.
      These participants will return at the end of the 4 weeks for a final visit, which will
      include a repeat sleep study and other testing.
    

Intervention name(s): Continuous Positive Airway Pressure (CPAP); Sham CPAP
Intervention type(s): Device; Device
Intervention description(s): Participants will use the higher pressure CPAP, as determined by an in-laboratory attended titration study, every night for 12 weeks.; Participants will use the lower pressure CPAP every night for 8 weeks.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Sleep-Disordered Breathing