关键词: 睡眠呼吸暂停, 阻塞性；瘦素；食欲素；生长激素释放肽；多导睡眠监测

Abstract: Background　Obstructive sleep apnea-hypopnea syndrome（OSAHS）is a common clinical sleep disorder.The concentration of metabolic hormones and the obesity，a major risk factor for OSAHS，may trigger abnormal sleep-related events in patients with OSAHS，but the causes are still unclear.and there are few studies exploring the relationship of leptin，orexin，and Ghrelin with polysomnography（PSG）parameters in patients with OSAHS.Objective　 To explore the influencing factors of the severity of OSAHS，and the correlation of serum leptin，orexin，Ghrelin and metabolic and PSG parameters in patients with OSAHS.Methods　We enrolled 58 patients with PSG diagnosed OSAHS from December 2017 to December 2018 from the Sleep Medicine Center，Shengjing Hospital of China Medical University.According to the apnea-hypopnea index（AHI），they were divided into mild group（5 times / h≤AHI≤15 times / h，n=6），moderate group（15 times/h<AHI≤30 times / h，n=11）and severe group（AHI>30 times / h，n=41）.PSG was conducted at the night of admission day and on the next early morning，peripheral arterial blood was drawn.The concentration of leptin，orexin，and Ghrelin were tested by ELISA.General clinical data were collected，including sex，age，BMI，history of smoking，drinking，hypertension，diabetes，and chronic rhinitis，neck，waist and hip circumferences，pre-sleep and morning systolic and diastolic blood pressures，total time in bed，total sleep time，AHI，total number of microarousals，number of microarousals lasting for longer than 15 seconds，microarousal index，the percent of the total time with oxygen saturation level lower than 90%（T90%），the lowest oxygen saturation，arterial partial pressure of oxygen（PaO2），arterial partial pressure of carbon dioxide（PaCO2），fasting blood glucose，total cholesterol，triacylglycerol，high-density lipoprotein，low-density lipoprotein，leptin，Ghrelin，and orexin levels.Ordinal Logistic regression analysis was used to explore the influencing factors of OSAHS severity .Spearman's rank correlation or Pearson correlation analysis was used to explore the associations of metabolic and clinical related parameters.Results　 The mild，moderate and severe groups showed statistically significant differences in AHI，microarousal index，T90% and the lowest oxygen saturation（P<0.05）.Ordinal logistic regression analysis showed that T90%〔OR=1.138，95%CI（1.026，1.262）〕was an independent factor associated with the severity of OSAHS（P<0.05）.Leptin level was positively correlated with BMI（r=0.482），waist circumference（r=0.429），hip circumference（r=0.576），and pre-sleep systolic blood pressure（r=0.261），but was negatively correlated with PaO2（P<0.05）.Ghrelin level was negatively correlated with smoking history（rs=-0.273），drinking history（rs=-0.309），pre-sleep systolic blood pressure（r=-0.391）and diastolic blood pressure（r=-0.282）（P<0.05）.Orexin was negatively correlated with total time in bed（r=-0.320，P<0.05）.Conclusion　T90% is a simple indicator that could effectively identity people at high risk of OSAHS，which is of some guiding significance to the evaluation of OSAHS severity.The interaction of factors such as hypoxia and obesity can promote the increase of leptin concentration in OSAHS patients，and induce the onset of leptin resistance，resulting in metabolic disorders.Orexin may play a role in maintaining wakefulness.Ghrelin plays a certain role in the physiological process of regulating blood pressure，which may provide a new idea or direction for the prevention，diagnosis and treatment of OSAHS patients cardiovascular diseases.Sleep fragmentation shortens the duration of sleep，and promotes the increase of orexin levels in the body，leading to higher risk of developing obesity.

Key words: Sleep apnea, obstructive；Leptin；Orexin；Ghrelin；PSG