0453 The Effects Of Ambient Temperature Changes On The Severity Of Obstructive Sleep Apnea And Autonomic Nervous System Among Adult Patients

Abstract

Introduction: Obstructive sleep apnea (OSA) is a prevalence sleep breathing disorder and could lead to high cardiovascular morbidity and mortality. There are different treatment ways, and lifestyle modifications have been tested however the effect is limited. Moreover, the relationship between the sleep environment and OSA severity remains obscure. The objective of this study is to investigate if the sleep ambient temperature (Ta) will affect the severity and autonomic nervous system among OSA patients. Methods: OSA participants (n=8) with the mean age was 31 years old were enrolled in this study. The 7‐day sleep diary includes home ambient temperature and apnea‐hypopnea index (AHI) will record. Participants will be required to stay in an experimental room with three Ta, including a relatively colder (Ta 16degreeC), a comfortable (Ta 26degreeC) and a warmer (Ta 30degreeC) circumstances in random order. The changes in sleep‐related and respiratory parameters will be evaluated by the polysomnography and wireless oximeter. ECG and the EEG signals were further used to analyze the heart rate variability (HRV) and the cortical activities, respectively. Results: In the autonomic nerves system, the HF represents the parasympathetic activity increased in Ta 16degreeC (p<0.05) and the LF/ HF and LF% represent the sympathetic activity arose in Ta 30degreeC (p<0.05). On the other hand, the respiratory data showed Ta 30degreeC would have higher AHI during REM stage (AHI‐REM) (p<0.05), supine posture (p<0.05) and lowest overnight mean SpO2 both in the REM and NREM stages (p<0.05). The temperature difference from Ta 26degreeC showed correlation with AHI‐REM (Pearson's correlation: 0.487, p<0.05) and NREM‐mean SpO2 (Pearson's correlation: ‐0.55, p<0.05). Conclusion: Compared with Ta 26degreeC, untreated OSA patients have higher parasympathetic activity and lower sympathetic activity at Ta 16degreeC, but higher sympathetic activity and more severe AHI at Ta 30degreeC.