Melatonin as a Therapeutic Adjunct in Obstructive Sleep Apnea: A Review of Potential Benefits

Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent upper airway obstruction, leading to intermittent hypoxia, sleep fragmentation, and increased risk of cardiovascular, metabolic, and neurocognitive complications. Chronic intermittent hypoxia (CIH), a hallmark of OSA, contributes significantly to oxidative stress, systemic inflammation, endothelial dysfunction, and neuronal injury. These mechanisms underlie the development of comorbidities such as hypertension, diabetes mellitus, dyslipidemia, and cognitive impairment. While continuous positive airway pressure is the standard treatment, poor adherence highlights the need for adjunctive therapies. Melatonin, a neurohormone with potent antioxidant, anti-inflammatory, and neuroprotective properties, has emerged as a promising therapeutic agent for mitigating CIH-related complications. Preclinical studies demonstrate that melatonin reduces oxidative stress and inflammation, improves endothelial function, and ameliorates metabolic dysfunction, including insulin resistance and lipid dysregulation. Additionally, melatonin has shown potential in preventing CIH-induced cognitive decline by reducing hippocampal oxidative damage, preserving synaptic plasticity, and enhancing neurogenesis. These neuroprotective effects may counteract the cognitive impairments frequently observed in OSA patients. This narrative review examines the impact of melatonin administration on cardiovascular, metabolic, and neurocognitive sequelae of OSA, focusing on its molecular mechanisms of action and therapeutic potential. While preclinical studies provide compelling evidence for its efficacy, clinical trials are needed to establish optimal dosing, safety, and long-term benefits of melatonin therapy in OSA patients. Integrating melatonin as an adjunctive therapy may offer a novel approach to reducing the burden of OSA-related diseases.