The Effects of Obesity and Obstructive Sleep Apnea on Inflammation and Heart Disease
Condition: Sleep Apnea Syndromes; Inflammation
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Inflammation
Study type: Interventional

Summary: 
      Obstructive sleep apnea (OSA) is a serious sleep disorder in which a person's breathing is
      restricted during sleep. Obese individuals with OSA are at an increased risk of inflammation
      and heart conditions, but it is unknown whether this risk is related to the effects of OSA or
      obesity. This study will evaluate whether OSA or obesity plays the primary role in
      inflammation related to heart disease. The study will also determine the independent effects
      of OSA and obesity on insulin resistance and blood vessel function.
    

Detailed description: 
      OSA is a common sleep disorder that is characterized by a brief collapse of the upper airway
      during sleep. This blockage prevents air from flowing properly into the lungs and causes
      pauses in breathing. If left untreated, OSA can cause high blood pressure, memory problems,
      weight gain, impotency, and headaches. It is also associated with an increased risk of
      inflammation-related heart conditions. Obesity is common among individuals with OSA and it
      may also be associated with inflammation. It is not known, however, whether the increased
      risk of heart problems is caused primarily by the inflammatory effects of OSA or obesity.

      The most common treatment for OSA is continuous positive airway pressure (CPAP) therapy, in
      which a mask is worn over the nose during sleep. Air flows through the mask to maintain a
      level of pressure that keeps the throat open. The most common treatment for obesity is weight
      loss. This study will determine the primary cause of heart-related inflammation by evaluating
      the individual and combined effects of CPAP therapy and a weight loss program in treating
      obese individuals with OSA. The study will also determine the independent effects of these
      therapies on insulin resistance and blood vessel function (arterial stiffness, central
      arterial pressures).

      This study will enroll obese individuals with moderate to severe OSA for a total of 24 weeks.
      Potential participants will first take part in an overnight sleep study at the University of
      Pennsylvania sleep lab. Sensors will monitor body functions during the night, including brain
      and muscle activity, eye movement, heart rate, breathing effort, air flow, and blood oxygen
      levels. Eligible participants will then be randomly assigned to CPAP therapy, a weight loss
      program, or a combination of the two. Participants in the weight loss program will receive
      weekly dietary counseling and will be encouraged to decrease caloric intake and increase
      physical activity. Participants receiving CPAP therapy will use a CPAP machine each night
      while they sleep. Study visits for all participants will occur at baseline and Weeks 6, 12,
      and 24. Blood will be collected to measure levels of triglycerides, high-density lipoprotein
      (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and levels of C-reactive
      protein (CRP), which is an inflammation biomarker. Insulin resistance will be evaluated using
      a glucose tolerance test, and blood vessel function will be evaluated using a brachial artery
      reactivity test in which artery size and blood flow will be measured with an ultrasound.
    

Intervention name(s): Weight Loss Program; CPAP therapy
Intervention type(s): Behavioral; Device
Intervention description(s): Participants in the weight loss program will receive weekly dietary counseling and will be encouraged to decrease caloric intake and increase physical activity.; Participants receiving CPAP therapy will use a CPAP machine each night while they sleep.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Sleep Apnea; C-Reactive Protein; Obesity; Insulin Resistance; Arterial stiffness