The prevalence of OSA (defined as either AHI ≥ 10 or 15) in various medical disorders. Compared to three population-based prevalence studies [20–23], patients with Type 2 diabetes [68,69], polycystic ovary syndrome [70,72], coronary artery disease [74–76], congestive heart failure [77–79], and stroke [80–82] have a much higher prevalence of OSA. Each bar in the figure represents an individual study.