How is the sleep apnea of GH excess different from the sleep apnea of thyroid hormone deficiency?
GH excess is associated with a high proportion of OSA and central sleep apnea, whereas hypothyroidism is almost uniformly associated with OSA. Up to 60% of patients with acromegaly are eventually found to have sleep apnea by PSG studies. In one series, over 30% had central sleep apnea. Endoscopy revealed little occlusive posterior tongue movement during sleep, indicating that this is not from macroglossia. The mechanism for central sleep apnea in patients with acromegaly is not clear.