The study also revealed that the damage to cholinergic neurons was closely associated with the accumulation of hypoxia-inducible factor 1α (HIF-1α) within cells [32], suggesting that hypoxia caused by nocturnal sleep disturbances poses a significant threat to cholinergic neurons in patients with obstructive sleep apnea (OSA). Here, HIF1A is linked to obstructive sleep apnea syndrome.