Background: The sleep disturbances are common at high altitudes. This study aimed to determine the prevalence and predictors of obstructive sleep apnea at high altitudes.
Methods: This   cross-sectional observational study was conducted from March 2018 to June    2018 to assess the predictors of obstructive sleep apnea based on Berlin, Stop-Bang and Epworth sleepiness scale questionnaire from adult population of Taif City at an altitude of 1879 m from sea level in Saudi Arabia.
Results:  Of 1002   participants, the majority (614 participants, 61.3%) was males and the mean± SD age of participants was 30.6± 10.3 years (Range 11 - 67 years). In this study 24.9% participants were found to be at a high risk of having sleep apnea. Male gender, older age and smoking were found to be significantly associated with higher risk of sleep apnea according to Berlin, Stop-Bang and Epworth sleepiness scale questionnaire. Diseases found to be associated with a high risk of developing sleep apnea included hypertension (p<0.001), hyperlipidemia (p<0.001), diabetes (p<0.001), psychological disorders (p<0.001) and asthma (p<0.001) .On the other hand, cardiac disorders were found to have an insignificant effect on sleep apnea (p=0.076) in this study. Almost one-third of the participants (34.9%; 95% CI= 32.0% to 37.9%) were found to have an abnormal level of daytime sleepiness according to Epworth Sleepiness Scale (ESS). These results were comparable to the previous studies at low altitude.
Conclusions: Our study demonstrated that the predictors of OSA at high altitudes are comparable to those at low altitudes.