Obstructive Sleep Apnea in World Trade Center Responders
Condition: Obstructive Sleep Apnea
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Interventional

Summary: 
      The goal of the study is to examine the possible underlying causes of sleep apnea (a disorder
      in which there are problems with breathing during sleep) in World Trade Center Responders.
      The study will look at the relationship between sleep apnea and various nose and throat
      conditions. Specifically, the study will look at upper airway disease (problems with the nose
      and throat), nasal inflammation, and nasal resistance (the amount of airflow through the
      nose). Subjects will have a physical exam and answer questions about nasal symptoms and
      sleeping problems. Nasal lavage (washing the inner nasal passages) will be performed on the
      subjects and markers of inflammation will be measured in the lavage fluid. Rhinomanometry
      (measuring the airflow through the nose) will also be performed to measure the degree of
      airflow obstruction. All subjects will be asked to perform in-home sleep apnea monitoring.
      Those subjects who are diagnosed with sleep apnea will test two treatment methods. Sleep
      apnea is treated by using a CPAP (continuous positive airway pressure) device. This device
      blows air into a mask worn by the patient during sleep. The two treatment methods that will
      be tested are the fixed pressure CPAP (pressure is constant during use) and CPAP-flex
      (pressure decreases when the subject exhales). Patients will be randomly assigned to one
      treatment method for one month then crossed to the other treatment method for the next month.
      The investigators will determine if patients with certain nasal conditions (high nasal
      resistance) are more likely to use CPAP-flex rather than CPAP.
    

Detailed description: 
      Following the World Trade Center (WTC) disaster, an estimated 40,000 individuals were exposed
      to significant amounts of dust while working in rescue, recovery and debris removal. A
      significant number of these responders have reported least one new or worsened upper airway
      respiratory symptom when examined in 2004 with 50% of responders continuing to have symptoms
      of chronic rhino-sinusitis or upper airway disease (UAD) in 2007. In addition, about 50% of
      those with UAD referred to our sleep center reported new onset snoring on their
      questionnaires immediately following their exposure and had unusually high prevalence of
      obstructive sleep apnea (OSA) that did not appear to be related to obesity, which is the
      usual risk factor for OSA. This suggests to us that mechanisms other than obesity may be
      important in the pathogenesis of OSA in these subjects. Given their chronic nasal symptoms
      they also provide a unique opportunity to examine the relationship between nasal pathology
      and OSA and test if nasal symptoms reported by the subjects in the WTC Health Program (WTCHP)
      are an indicator of increased nasal resistance due to nasal inflammation resulting from
      exposure to the WTC dust. Positive Airway Pressure (CPAP) is the standard therapy for OSA but
      despite its efficacy has poor adherence. Subjects with high nasal resistance (such as
      responders with UAD and OSA) may experience additional pressure during expiration at the
      upper airway resulting in greater difficulty in tolerating CPAP therapy than those who do not
      have high nasal resistance. Reduction of excess expiratory positive pressure by the modality
      known as Cflex™ during CPAP therapy (CPAPFlex) may improve comfort and adherence in these
      subjects without compromising CPAP efficacy. In the present proposal we will study responders
      enrolled at the Environmental and Occupational Health Sciences Institute of Robert Wood
      Johnson Medical School (RWJMS) and the NYU School of Medicine Clinical Center of Excellence
      at Bellevue Hospital
    

Intervention name(s): Standard CPAP; CPAP - Flex
Intervention type(s): Device; Device
Intervention description(s): Use of the REMstar Auto A-Flex in standard CPAP therapy mode; Use of Philips Respironics REMstar Auto A-Flex in C-Flex mode
Other intervention name(s): Philips Respironics REMstar Auto A-Flex; Philips Respironics REMstar Auto A-Flex
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: World Trade Center (WTC); nasal symptoms; nasal inflammation; CPAP