PURPOSE: To study the relationship among obesity-associated obstructive sleep apnea (OSA), insulin resistance and hyperinsulinemia.
METHODS: Polysomnography was examined during sleep, and insulin sensitivity index (ISI), fasting plasma insulin (FINS), fasting plasma glucose (FPG), fasting C peptide (FCP), HbAlc, total cholesterol (TC), triglyceride (TG) and high density lipoprotein-cholesterol (HDL-C) were examined in 60 obesity-associated OSA syndrome patients and 20 normal control volunteers.
RESULTS: FPG, HbAlc, FINS, FCP, TC, TG were significantly higher in the OSA syndrome group than those in the control group. There were also significantly differences in these variables among the mild, moderate and severe group of OSA syndrome. HDL-C was significantly lower in the severe OSA syndrome group than that in the control group. ISI was significantly negative correlated to apnea hypopnea index (AHI), the frequency of more than 4% decrease of transcutaneous saturation of oxygen (SpO2), and the duration of less than 90% of SpO2. However ISI was significantly positive correlated to the baseline of SpO2 before sleep, the minimum value of SpO2 and the mean value of SpO2 during sleep. The correlation between FINS and above parameters was opposite to that of ISI. Multiple stepwise regression analysis showed that body mass index was the first risk factor and AHI was the second risk factor contributing to the development of insulin resistance and hyperinsulinemia.
CONCLUSION: AHI, apnea duration and severity of SpO2 decrease are the important factors contributing to the hyperlipidemia and abnormal glucose metabolism in OSA patients.
CLINICAL IMPLICATIONS: OSA is an important risk factor for the development of insulin resistance and hyperinsulinemia independent of obesity and age.
DISCLOSURE: Yanbin Zhou, None.