Does Melatonin Improve Neurocognitive Function, Cardiovascular Outcomes and Control of Breathing in Untreated Obstructive Sleep Apnea?

Intermittent hypoxia (low oxygen), sleep fragmentation and restriction are characteristic of obstructive sleep apnea (OSA) and cause mental deficits and cardiovascular disease (CVD). Melatonin (MLT) is a hormone with sleep promoting properties and the investigators have found 7 days 10mg MLT treatment significantly increases sleep consolidation in untreated OSA. Thus, melatonin could improve mental function. MLT also has potent antioxidant, anti-inflammatory and anti-hypertensive properties. In humans with CVD and metabolic disorder exogenous MLT improves a wide range of cardio-metabolic outcomes. In rat models of OSA, MLT completely blocks intermittent hypoxia induced cardiovascular damage and brain cell death. Intermittent hypoxia also induces lasting changes in the neural control of breathing, which worsens OSA. Experimentally antioxidants block the induction of changes to neural control of breathing. Thus MLT may also normalize the control of breathing and reduce the severity of OSA. Given these findings, the hypothesis is that MLT will improve mental function, cardiovascular outcomes and control of breathing in untreated OSA.