Clinical, polysomnographic, and psychological profiles across questionnaire-defined symptom groups in obstructive sleep apnea

Obstructive sleep apnea (OSA) has heterogeneous symptom presentations that are not fully captured by the apnea–hypopnea index (AHI). We aimed to identify demographic, polysomnographic, and psychological profiles across four questionnaire-defined symptom groups in OSA patients. This retrospective cross-sectional study included 789 treatment-naïve patients with OSA (AHI ≥5 events/h) who underwent overnight polysomnography and neuropsychological assessment between May 2021 and August 2025. Participants were classified into four symptom-groups: low symptom burden, poor sleep quality only, excessive daytime sleepiness (EDS) only, and combined poor sleep quality and EDS, using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Multinomial logistic regression was used to identify factors associated with these symptom-groups, with the low symptom burden group as the reference. Results showed that the poor sleep quality only symptom-group was most prevalent (49.0%), followed by the low symptom burden group (29.8%), the combined group (14.3%), and the EDS-only group (6.8%). Female sex, lower BMI, altered sleep continuity and sleep-stage distribution were associated with the poor sleep quality only group, whereas younger age, shorter sleep onset latency and a shorter maximum hypopnea duration were associated with the EDS-only group. Higher PHQ-9 and CFS scores were consistently associated with all three higher symptom-burden groups (all P < 0.001), with the largest effect estimates observed for the combined group. Higher GAD-7 scores were also associated with the poor sleep quality only and combined groups, whereas the association between GAD-7 score and the EDS-only group was less precise and only nominally significant. Several additional sleep-stage, stage- or position-specific respiratory, and limb-movement associations were nominal and should be considered hypothesis-generating. Several conventional hypoxemia measures, including TST90, mean oxygen desaturation, and mean nocturnal oxygen saturation, were not significantly associated with any symptom-group in the primary adjusted analyses. The overall pattern was generally similar in the sensitivity analyses, although several nominal associations were attenuated. Overall, questionnaire-defined OSA symptom groups differed in demographic, polysomnographic, and psychological characteristics that were not fully captured by AHI alone, supporting multidimensional clinical assessment while considering the need for independent validation.