Prevalence of comorbid obstructive sleep apnea and metabolic syndrome: syndrome Z and maxillofacial surgery implications.

PURPOSE: To determine the prevalence of the recently identified syndrome Z (SZ), which is the co-occurrence of obstructive sleep apnea (OSA; hypoxia, systemic and pulmonary hypertension, nocturnal arrhythmias) and metabolic syndrome (MetS; increased abdominal girth, hypertriglyceridemia, decreased high-density lipoprotein, hypertension, increased fasting glucose), which places the surgical patient at heightened risk of perioperative complications (myocardial infarction, stroke, pneumonia, wound infection).

MATERIALS AND METHODS: Electronic medical records of 296 male veterans were assessed for the presence of SZ using the American Academy of Sleep Medicine definition of OSA and a modified Adult Treatment Panel III definition of MetS, where obesity was defined by a body mass index of at least 30 kg/m(2) rather than by waist circumference.

RESULTS: SZ was diagnosed in 59% of patients. These individuals commonly exhibited severe OSA and least commonly mild OSA. The more severe the OSA, the more likely (60%) that patients manifested moderate (4 risk markers) or severe (5 risk markers) MetS. Furthermore, with increasing apnea-hypopnea index values, the more severe were the MetS elements.

CONCLUSIONS: The results of this study demonstrate the high prevalence rate of MetS in patients with OSA seeking treatment. Given the risk of perioperative complications, it is suggested that all patients scheduled for maxillofacial surgical procedures to treat OSA be evaluated for SZ.