Serum omentin levels in patients with obstructive sleep apnea.

Background: Obstructive sleep apnea syndrome (OSAS) is associated with increased rates of cardiovascular diseases (CVD). The basic mechanisms involved in the increased cardiovascular risk of OSAS remain unclear. Recent discoveries of fat-secreted substances which serve endocrine roles improve our understanding of the relationship between OSAS, CVD, and the metabolic syndrome. In this study, we aimed to examine associations between omentin levels and OSA.

Methods: Forty-six newly diagnosed OSA patients and 35 non-apneic controls were enrolled in this study. Demographical data, cigarette smoking status, previous history of chronic diseases including CVD and metabolic diseases and drugs, and habits were obtained using a standardized questionnaire. All patients underwent polysomnographic evaluation. Omentin was measured the following morning.

Results: The mean age was 48.1 ± 12.5 (24-74) years in the OSA group and 42.8 ± 14.1 (21-69) years in the control group. Of the 81 patients, 46 (34 males and 12 females) were classified as having OSA and 35 patients (20 males and 15 females) as control. Plasma levels of omentin were found to be markedly higher in OSA patients (570.8 ng/ml) than in the control group (432.0 ng/ml; p < 0.001). In addition, plasma levels of omentin were found to be high in all OSA subgroups than in controls. The plasma omentin levels were significantly correlated only with age in patients with OSA.

Conclusions: We conclude that circulating omentin levels are elevated in OSA patients. To the best of our knowledge, this is the first clinical study that demonstrated the association between omentin and OSA.