[Exploring the criteria for assessing hypoxemia in patients with obstructive sleep apnea from the standpoint of hypertension].

<b>Objective:</b> To determine appropriate cutoff values for evaluating hypoxemia severity in patients with obstructive sleep apnea (OSA). <b>Methods:</b> This cross-sectional study selected data from 1, 781 young patients with obstructive sleep apnea (OSA) who underwent polysomnography in the Department of Otorhinolaryngology Head and Neck Surgery of the Sixth Medical Center of PLA General Hospital from January 2015 to June 2023. The cohort included 1, 604 males and 177 females, with a mean age of (32.6±5.3) years. The relationship between the minimum arterial oxygen saturation (MSaO₂) and the prevalence of hypertension in this population was investigated. Subjects were categorized into seven groups based on MSaO₂ levels: Group 1 (MSaO₂≥90%), Group 2 (85%≤MSaO₂<90%), Group 3 (80%≤MSaO₂<85%), Group 4 (75%≤MSaO₂<80%), Group 5 (70%≤MSaO₂<75%), Group 6 (65%≤MSaO₂<70%), and Group 7 (MSaO₂<65%). The prevalence of hypertension in each group was statistically analyzed, and the chi-square test was used to identify significant differences in hypertension prevalence. The diagnostic performance of the new versus traditional grouping methods was evaluated using receiver operating characteristic (ROC) curve analysis. <b>Results:</b> Among the 1, 781 OSA patients, 915 had hypertension. The prevalence of hypertension in Groups 1 to 7 was 27.8%, 42.4%, 52.2%, 54.1%, 59.5%, 70.5%, and 75.4%, respectively. Significant differences in hypertension prevalence were observed between Group 1 and other groups, Group 2 and Groups 5-7, Group 3 and Groups 6-7, and Group 4 and Group 7(χ2=187.94,<i>P</i><0.001). After merging the groups based on MSaO₂ thresholds of≥90%, 90%>MSaO₂≥85%, 85%>MSaO₂≥75%, and MSaO₂<75%, the prevalence of hypertension in the new groups was 27.8%, 42.4%, 53.0%, and 71.2%, respectively, with significant differences between adjacent groups(χ2=178.99,<i>P</i><0.001). ROC curve analysis revealed that the area under the curve (AUC) for the new grouping method (0.676) was higher than that for the original grouping method (0.664). <b>Conclusions:</b> As hypoxemia severity increases in OSA, so does the prevalence of comorbid hypertension. Using MSaO₂ cutoff values of 90%, 85%, and 75% to categorize hypoxemia severity appears more appropriate compared to the existing guideline values of 90%, 85%, and 80%.