Potential protective mechanism of arousal in obstructive sleep apnea

Obstructive sleep apnea (OSA) pathophysiology is thought to be due to the interaction of traits including airway anatomy and neuromuscular control which vary between individuals. These traits include a low arousal threshold (wake easily from sleep), upper airway gain (how effectively activation of upper airway dilator muscles improves ventilation), loop gain (stability of the negative feedback chemoreflex control system) and upper airway collapsibility (anatomical predisposition to passive airway collapse) (1). While deficits in these traits and how they interact varies between individuals, generally mechanisms that increase activation of upper airway dilator muscles are considered to help protect the airway from collapse.