A Study Of Chemical Sensitivity In Patients With Obstructive Sleep Apne

Part 1 The determinants of chemosensitivity in patients with obstructive sleep apneaObjective:This study aimed to investigate the mechanism of abnormal chemosensitivity in patients with obstructive sleep apnea(OSA).Methods:Men with OSA admitted to the sleep center of our hospital from December 2020 to May 2021 were enrolled.Their medical histories were collected.They finished the questionnaires,polysomnography,vascular endothelial function test,rebreathing test,and pulmonary ventilation function.Fasting peripheral blood was collected and sent to the clinical laboratory of our hospital for the detection of metabolism biomarkers.Hypercapnic ventilatory response under hyperoxia conditions(Hyperoxia-HCVR)reflects the central chemosensitivity.Hypercapnic ventilatory response under hypoxia conditions(Hypoxia-HCVR)reflects overall chemosensitivity.Results:A total of 77 men with OSA were enrolled in this study.Univariate linear regression analysis showed that age,obesity,and hypertension were positively associated with Hyperoxia-HCVR.Age,obesity,hypertension,reactive hyperemia index,fasting blood glucose and glycosylated hemoglobin were positively correlated with Hypoxia-HCVR.Multivariate linear regression analysis found significant positive relationship between hypertension and central and overall chemosensitivity after adjusting for age,OSA severity,excessive daytime sleepiness,abdominal obesity,and diabetes.Conclusions:In OSA patients,elevated central and overall chemosensitivity were associated with hypertension.Part 2 The determinants of chemosensitivity in obstructive sleep apnea patients with hypertensionObjective:This study aimed to explore the mechanism of elevated chemosensitivity in OSA patients with hypertension.Methods:Heart rate variability(HRV)was calculated over 5 min records of the RR series.The differences in clinical characteristics and HRV variables between OSA patients and OSA patients with hypertension were analyzed.Factors associated with chemosensitivity were analyzed in OSA patients with hypertension.Results:Compared with OSA patients,OSA patients with hypertension had increased body mass index,obesity percentage,and neck circumference,more serious nocturnal hypoxia,and lower time-domain variables and frequencydomain variables.Univariate linear regression analysis showed that central chemosensitivity was negatively correlated with approximate entropy in OSA patients with hypertension.Conclusions:Elevated central chemosensitivity might be associated with weak adaptability of the cardiac autonomic nervous system in OSA patients with hypertension.Part 3 Clinical characteristics and chemosensitivity of patients with positional obstructive sleep apneaObjective:This study aimed to investigate the clinical characteristics and chemosensitivity of patients with positional obstructive sleep apnea(POSA).Methods:The polysomnography of OSA patients admitted to the sleep center of our hospital from October 2012 to October 2018 was retrospectively analyzed.The Amsterdam Positional OSA Classification(APOC)was used as the diagnosis criteria of POSA.The clinical characteristics of POSA patients and non-positional obstructive sleep apnea(NPOSA)patients were compared.The comparison of chemosensitivity between POSA patients and NPOSA patients among 77 male OSA patients included in the first part was conducted.Results:In the retrospective study,53.76%of OSA patients met the diagnostic criteria of APOC,and the prevalence of POSA in females was higher than that in males.The apnea hypopnea index(AHI)and nocturnal hypoxia in POSA patients were lower than those in NPOSA patients,and the AHI and nocturnal hypoxia in APOC I group was the lowest.According to the APOC,there was no significant difference in central and overall chemosensitivity between POSA and NPOSA groups.Conclusions:According to the APOC,patients with POSA had less severe OSA and lower degree of nocturnal hypoxia,which was remarkable in the APOC I group.In male OSA patients,there was no significant difference in central and overall chemosensitivity between POSA and NPOSA patients.