Obstructive sleep apnea is a common and serious condition which is now recognized to have multiple underlying mechanisms. Although upper airway anatomical compromise is known to be important in OSA pathogenesis, other factors may be important particularly in subgroups of patients with OSA. some patients have dysfunction in the upper airway dilator muscles; these individuals may be particularly amenable to hypoglossal nerve stimulation. Other individuals with OSA have unstable ventilatory control (elevated loop gain) which may be amenable to agents such as oxygen or acetazolamide which could stabilize breathing. High loop gain is thought be both a cause and a consequence of OSA and maybe an important predictor of failure of upper airway surgery. That is patients with normal loop gain likely have major improvements with upper airway surgical therapy as compared to those with high loop gain. An improved understanding of OSA pathogenesis may be valuable for practioners who care for afflicted patients.

Dr. Malhotra is research chief of Pulmonary, Critical Care and Sleep Medicine at UCSD. He is former President of the American Thoracic Society.
He runs a large NIH funded laboratory focused on sleep apnea pathogenesis and pathophysiology of its complications. He has published over 500 peer reviewed
Papers (300 original) since coming on faculty in 2000. He is active clinically, in research and in teaching.