Sleep and Metabolic Syndrome

On average, human beings spend approximately one third of their life sleeping. Many individuals are chronically sleep deprived, while many individuals with primary sleep illnesses, such as obstructive sleep apnea (OSA) are unaware of their condition; as a result, without treatment, they suffer from serious negative physical, neurobehavioral and metabolic consequences. Obstructive sleep apnea is now a well recognized chronic disorder that leads to multiple cardiovascular and metabolic complications.

During the last decades there has been a mounting body of data that established a better characterized link between OSA and insulin resistance, diabetes mellitus and/or metabolic syndrome. Likely mechanistic mediators of this connection are intermittent hypoxia and sleep fragmentation. Through sympathetic system activation, oxidative stress, hypoxia/re-oxigenation, systemic inflammation, production of harmful adipokines from metabolically active visceral fat and complex endocrine changes, sleep apnea and obesity lead to a vicious cycle of abnormal glucose metabolism, which likely contributes to an increase in cardiovascular morbidity and mortality. When appropriate, physicians should have a low threshold to assess sleep apnea, as effective therapy is readily available (CPAP, mandibular advancement devices, etc). In this chapter we will summarize and analyze the most current data in this rapidly growing field of sleep medicine.