<prompt> What is the most common cause of obstructive sleep apnea?Craniofacial abnormalitiesHypothyroidismAlcoholismAcromegaly  <response>: Craniofacial abnormalities are common in O.S.A in non-obese patients and children. Non structural risk factors for OSA include: Obesity, central fat distribution Male sex, middle age Alcohol use, sedative use, smoking Supine sleep position 