Moderate to severe obstructive sleep apnea during REM sleep as a predictor of metabolic syndrome in a Korean population.

ABSTRACT

PURPOSE: Metabolic syndrome is a cluster of metabolic abnormalities including obesity, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hyperglycemia. Obstructive sleep apnea (OSA) is known to be associated with metabolic syndrome. However, it remains uncertain which sleep parameters of OSA are associated with metabolic syndrome. We aimed to clarify the relationship between sleep variables and the presence of metabolic syndrome in patients with OSA. METHODS: We prospectively recruited patients who visited the institute for the evaluation of sleep-disordered breathing. All patients underwent overnight polysomnography and sleep questionnaires. They were diagnosed with metabolic syndrome according to the 2007 consensus definition by the International Diabetes Federation. We applied multivariate logistic regression models to predict the presence of metabolic syndrome with variables related to sleep parameters. RESULTS: A total of 85 patients (43 men) were enrolled. The mean age (± standard deviation) was 52.0 ± 14.3 years. Metabolic syndrome was diagnosed in 39 (46%) patients. Patients with metabolic syndrome had a significantly higher apnea-hypopnea index (AHI) compared with patients without metabolic syndrome. An AHI greater than 15/h during REM sleep was a significant independent predictor of metabolic syndrome (adjusted OR, 7.08; 95% CI, 1.60-31.41; p = 0.010) after adjusting for age, body mass index, and non-REM AHI ≥ 15/h. In partial correlation analysis, REM AHI was significantly associated with the presence of metabolic syndrome after adjusting for age and BMI (r = 0.229, p = 0.042). CONCLUSION: Korean patients with OSA frequently had comorbid metabolic syndrome. Moderate to severe OSA during REM sleep may be a predictor of metabolic syndrome.