The Impact of CPAP Therapy for Obstructive Sleep Apnea Hypopnea on Cardiovascular Risk Factors: A Randomised Crossover Trial

The purpose of this study is to determine whether treatment with continuous positive airway pressure (CPAP) improves cardiovascular risk in patients with sleep apnea. Sleep apnea is a common under-diagnosed medical disorder found in approximately 4% of men and 2% of women. It is characterized by repetitive collapse of the airway during sleep, causing sleep disruption, loud snoring, choking during the night, and daytime sleepiness. Moreover, patients with sleep apnea are at high risk of developing cardiovascular disease (including strokes and heart attacks). Likely, this is because sleep apnea causes multiple adverse effects on body functions including activation of inflammation, high blood pressure, and blood vessel dysfunction; these adverse effects are all implicated in causing cardiovascular disease. We want to determine whether treatment with CPAP (a mask that fits over the nose during sleep) improves these adverse effects. If it does, this would provide strong evidence that using CPAP reduces the risks of cardiovascular disease. Given that cardiovascular disease is the major cause of death and disability in the Western World, determining whether sleep apnea therapy reduces the risks of cardiovascular disease would have immense importance.