Obstructive sleep apnea syndrome is associated with some components of metabolic syndrome in nonobese adults

The relationship between obstructive sleep apnea (OSA) syndrome and metabolic syndrome is far from conclusion for obesity as a confounding factor. The aim of the present study was to investigate the association between OSA and some components of metabolic abnormality in nonobese patients. We consecutively recruited nonobese subjects who underwent polysomnography and analyzed some components of metabolic abnormality in subjects with and without OSA. Multiple linear regression was used to evaluate the independent risk factor of some components of metabolic abnormality. A total of 154 subjects were enrolled and were divided to control group (45 subjects) and OSA group (113 subjects). Body mass index was no different between groups. Systolic blood pressure, triglycerides, and insulin concentration were significantly higher among OSA group compared with control group (p = 0.000, 0.043, and 0.006, respectively), and the prevalences of dyslipidemia, hypertension, and at least two of the metabolic abnormalities were significantly greater in OSA group (p = 0.003, 0.031, and 0.000, respectively). After adjusting for confounding factors, lowest O-2 saturation was the major contributing factor for elevated systolic blood pressure (p = 0.001), and independent associations were found between apnea-hypopnea index and the following parameters of metabolic abnormality: triglycerides and homeostasis model assessment of insulin resistance (all p = 0.000). Our finding was consistent with previous studies that OSA was independently associated with dyslipidemia, hypertension, and at least two of metabolic abnormalities in nonobese patients.