 Obstructive Sleep Apnea OSA is a common chronic disorder and the most common of all sleep disorders. OSA can occur in any age group, but prevalence increases between middle and older age. Over the last two decades the prevalence of sleep disordered breathing seems to be increasing in both men and women, likely due to increasing rates of obesity. Relative increases reported are between 14 and 55 depending on the subgroup. For men, the current prevalence estimates of moderate to severe sleep-disordered breathing are 10 for 30 to 49 year-olds and 17 for 50 to 70 year-olds. For women, the corresponding prevalence estimates are 3 and 9. 