IGF1 and acromegaly: In fact, GH and IGF1 excess reportedly play a key role in OSAS pathogenesis in acromegaly, as it exerts direct effects on upper airway narrowing leading to mandible, maxilla, and ioid bones overgrowth, pharyngeal soft tissue swelling, and macroglossia (5), and indirect effects on cerebral breathing centres by altering the brain’s respiratory control centres (50).