Prevalence of OSAS in asthma: The prevalence of OSAS in asthmatic patients has not yet been studied, but several studies have reported an increased prevalence of OSAS symptoms in asthmatic patients. Large epidemiologic studies demonstrated that asthma patients are more frequently report snoring. In a longitudinal study, asthma was an independent risk factor for development of snoring. OSAS symptoms are highly prevalent in clinic-based populations of well-characterized asthma patients. Polysomnography revealed high frequencies of OSAS (88% and 95.5%) in patients with difficult-to-control asthma.