Grant: Sleep and Circadian Rhythms: Operating Grant

RATIONALE: The rise in obesity in Canadian children has led to a rise in childhood obstructive sleep apnea (OSA). OSA is caused by a blockage of the airway, resulting in pauses in breathing during sleep. In young children, enlarged tonsils and adenoids are removed to treat OSA. This surgery is often unsuccessful in obese adolescents, and the more common treatment for OSA in this group is similar to the treatment of OSA in adults - nightly Positive Air Pressure (PAP) therapy using a face mask. Obese children may have a number of health problems, such as resistance to insulin, a hormone responsible for blood sugar control. Insulin resistance (IR) causes high levels of sugar in the blood. A blood test called the homeostasis model assessment of insulin resistance (HOMA-IR) is used to assess this condition. IR leads to future health problems, including diabetes and heart disease. Thus, the concern is that together, obesity, OSA, and IR may greatly increase the risk for early health problems and premature death. Fortunately, PAP therapy in adults significantly improves IR and heart health. We predict that PAP treatment for obese youth with OSA will improve measures of obesity-related diseases. OBJECTIVES: We will determine whether, in obese children with OSA, increased usage of PAP over one year leads to a greater improvement in measures of health. METHODS: From 4 Canadian hospitals, we will recruit obese 8 to 16 year-olds with OSA who will undergo PAP therapy. HOMA-IR, blood pressure and heart rate and quality of life (questionnaires) will be measured at the start of PAP treatment and again one year later. IMPORTANCE: When OSA is treated in obese adults, they suffer from fewer health problems and live longer. Our study is the first to examine in children measures of health before and after treatment for OSA. Our study will generate knowledge both about obesity-related health risks and improvements brought about by PAP therapy specifically in obese children.