[Obstructive sleep apnea syndrome(OSAS)and bone.]

Obstructive sleep apnea syndrome(OSAS)is a sleep disorder characterized by repetitive upper airway collapse during sleep, causing frequent hypoxia and sleep disturbance. Known risk factors of OSAS include obesity, male sex and smoking. OSAS has been linked to various comorbidities such as hypertension, cardiovascular diseases and diabetes. Recent evidence also indicates that OSAS is associated with vitamin D insufficiency, increased bone resorption and bone loss. Thus, although increased fracture rate has not been demonstrated, OSAS is now recognized as a risk factor of osteoporosis. This review will summarize the recent reports about bone metabolic abnormalities in OSAS.