CPAP Therapy Restores Circadian Rhythms, Normalizes Melatonin & Cortisol Levels in Obstructive Sleep Apnea Patients, New Research Shows
Groundbreaking studies reveal that continuous positive airway pressure (CPAP) treatment not only alleviates breathing difficulties associated with obstructive sleep apnea (OSA) but also significantly improves hormonal regulation, specifically restoring disrupted melatonin and cortisol concentrations. These findings offer a deeper understanding of the systemic effects of OSA and the potential for complete recovery with effective treatment. millions suffer from OSA-estimated to affect over 1 billion adults globally-and frequently enough experience secondary hormonal imbalances impacting sleep, metabolism, and overall health.
OSA is characterized by repeated interruptions in breathing during sleep, leading to oxygen deprivation and fragmented sleep architecture. This disruption profoundly impacts the body’s natural circadian rhythms, the internal biological clock governing hormone release and other vital functions. Consequently, individuals with OSA frequently exhibit altered levels of melatonin, a hormone crucial for sleep regulation, and cortisol, a stress hormone with a distinct diurnal pattern. Recent research demonstrates that CPAP therapy can effectively address these hormonal imbalances,offering a pathway to improved physiological well-being.
A 2013 study by KM, Targosz A, et al. published in J Physiol Pharmacol investigated the relationship between melatonin, omentin, and OSA, suggesting a complex interplay between these factors in the syndrome’s pathology. Further investigation in 2017 by Barnaś M, et al. in Pol Arch Intern Med directly examined melatonin concentrations in OSA patients before and after CPAP treatment. Their findings showed that CPAP therapy influenced diurnal and nocturnal serum melatonin levels.
The impact of external factors on melatonin and cortisol is also significant. Research published in Sleep Med in 2002 by Shilo L, et al., demonstrated that coffee consumption can disrupt melatonin secretion. similarly, Burke TM, et al. in Sci Transl med (2015) detailed the effects of caffeine on the human circadian clock, both in vivo and in vitro. These findings underscore the importance of considering lifestyle factors alongside medical interventions.
Cortisol levels are also frequently dysregulated in OSA. A systematic review by Tomfohr LM, et al.in Sleep Med rev (2012) assessed the association between OSA and cortisol levels, while Hansen AM, et al. (psychoneuroendocrinology, 2012) found a correlation between salivary cortisol and sleep problems in civil servants. Backhaus J, et al. (Psychoneuroendocrinology, 2004) reported that sleep disturbances correlate with decreased morning awakening salivary cortisol.
More recent long-term studies confirm the restorative effects of CPAP. Gaspar LS, et al.in EBioMedicine (2021) showed that long-term CPAP treatment ameliorates biological clock disruptions in OSA patients. Building on this,research published in sci Rep in 2025 by Gabryelska A,et al., assessed the effect of CPAP on the circadian clock signaling pathway, providing further evidence of its positive impact on hormonal regulation. These advancements highlight the potential for CPAP therapy to not only treat the symptoms of OSA but also to restore fundamental physiological processes, improving the long-term health and quality of life for affected individuals.
