0556 Comorbid Insomnia & Sleep Apnea Is Linked to Worse Sleep & Function vs OSA Alone in Older Veterans with No PAP Use

Abstract Introduction Many patients with obstructive sleep apnea (OSA) discontinue positive airway pressure (PAP) over time. Insomnia symptoms frequently co-occur with OSA and are common in older adults. Comorbid insomnia and sleep apnea (COMISA) is associated with greater sleep disturbance, impaired daytime functioning, and worse quality of life vs OSA (or insomnia) alone. Whether COMISA vs OSA alone is associated with greater impairment in sleep quality and sleep-related function among older patients and no /limited PAP use is unknown. Methods Veterans with moderate or severe OSA (apnea-hypopnea index AHI 15) and no/limited objective current PAP use (prescribed 1 year ago) completed Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep (FOSQ-10) questionnaires. T-tests and age-adjusted regression analyses were used to compare participants who met DSM-5 diagnostic criteria for chronic insomnia disorder and sleep apnea (COMISA) vs OSA alone. Results In 128 veterans (Mage=64.6 years, 89% male, 19.5% Hispanic, 35.9% Black, 9.4% American Indian/Alaska Native, mean comorbidity index=5.5, BMI=32.2) with no/limited PAP use, COMISA (n=77, mean ISI=13.3) was associated with worse PSQI 7.8 vs 10.9, ESS 7.6 vs 9.6 and sleep-related function (FOSQ-10 15.6 vs 14.1) vs OSA alone (n=51, mean ISI=8.9) (all P.05) despite no differences in AHI. Conclusion Among veterans with moderate-to-severe OSA and no/limited current PAP use, those with comorbid insomnia disorder (COMISA) have worse sleep quality, more daytime sleepiness and worse sleep-related function. These findings suggest that efforts to address insomnia disorder in addition to PAP use may be particularly important among older veterans with COMISA who do not use their prescribed PAP. Support (if any) VA, NIH/NHBLI