Abstract

Sleep-disordered breathing (SDB) affects hormones via a number of mechanisms. On the other hand, hormones and endocrine states induce, aggravate or alleviate SDB. Finally, nasal continuous positive airway pressure (CPAP) therapy influences hormone secretion. The direct and indirect effects of hormones and endocrine disorders on sleep and breathing are mediated via several pathways. The male gender and the postmenopausal state are risk factors that link the sex-hormones to the pathophysio-logy of SDB. Sleep apnoea is common in acromegaly, hypothyroidism or Cushing’s syndrome. Recent studies suggest that SDB may not only complete the clinical picture but play a central role in the pathophysiology of obesity, leptin resistance and the metabolic syndrome. Unfortunately, due to the lack of well-documented epidemiological studies most prevalence estimates are based on small study populations and also limited because of different definitions of SDB. Much of our current knowledge on the interactions between hormones and obstructive sleep apnoea syndrome (OSAS) is based on intervention studies with nasal CPAP. Changes in the levels of several hormones have been interpreted to be related to SDB or associated sleep disturbance, if they consistently respond to on-off nasal CPAP interventions. Hormonal changes are potential mediators to link SDB with various comorbidities. Better understanding of hormones and breathing may open new perspectives in developing strategies to prevent, alleviate or cure sleep-disordered breathing and its systemic consequences.