P046 Symptom subtypes of obstructive sleep apnoea determined using latent class analysis have distinct comorbidity profiles

Abstract Background Three clinical phenotypes of obstructive sleep apnoea (OSA) were first described in the Icelandic Sleep Apnoea Cohort, with later studies reporting between 3-5 subtypes. We aimed to determine the optimal clustering of OSA phenotypes in an Australian cohort and determine comorbidity profiles related to the separate groups. Methods Between 2019-2024, 1282 adults from three sleep clinics completed sleep studies and 833 were diagnosed with OSA (apnoea-hypopnoea index [AHI] ≥5 events/h). Symptom and comorbidity questionnaires were completed by 785 participants. Latent class analysis was performed using 18 symptom variables. Progress to Date Four OSA symptom subtypes were identified: excessively sleepy, minimally symptomatic, disturbed sleep, and moderately sleepy. The excessively sleepy and minimally symptomatic groups were predominantly male and had severe OSA (AHI: 34.4 ± 28.6 and 29.6 ± 25.5 events/h) but differed substantially in symptom burden. The disturbed sleep group was older (58.1 ± 11.7 years), mostly male (66.7%), reported difficulty staying asleep and the least sleepiness (ESS: 4.1 ± 3.0), and had milder OSA (AHI: 24.3 ± 21.4 events/h). The moderately sleepy group was mainly female (61.3%), had the mildest OSA (AHI 18.3 ± 18.0 events/h), but reported more sleepiness (ESS: 8.0 ± 5.5), depression (40.4%), anxiety (54.4%), concentration issues, and worse insomnia, fatigue and functional outcomes. Significant differences between subtypes were observed for age, OSA severity, sleepiness, insomnia and psychiatric comorbidity (all p<.001). Intended outcome and impact These findings confirm previously established OSA symptom subtypes in an Australian population and support a personalised approach to future OSA research and clinical management.