Do symptoms of sleepiness and insomnia in US veterans with obstructive sleep apnea vary by age?

Introduction: The influence of aging on the clinical presentation of obstructive sleep apnea (OSA) is not well characterized in US veterans. Our aims were to (1) examine age and established predictors of sleepiness and insomnia symptoms in veterans with OSA and (2) determine if the relationship between predictors of the Epworth sleepiness scale (ESS) and insomnia severity index (ISI) depended on age. Methods: We performed a retrospective analysis of veterans diagnosed with OSA at the Miami VA in 2014. On polysomnography (PSG) night, questionnaires were completed querying socio-demographics, insomnia (ISI), sleepiness (ESS), and self-reported sleep duration. Regression modeling was performed to explore association of variables with (1) ESS and (2) ISI. Analyses were performed in two steps: (1) variables were tested for main effects and (2) product of age and each variable found to have an association at a significance level of p < 0.10 with primary outcome were entered separately to test for interaction. Results: The sample consisted of 483 veterans (93% male, age 52 ± 13 years, 41% black, 34% Hispanic). Having a regular bed partner, higher weighted medical comorbidities, chronic pain diagnosis, and shorter sleep duration were associated with ESS. Age did not moderate the relationship between these variables and ESS. Younger age, Hispanic ethnicity, higher educational level, shorter sleep duration, mood, and pain diagnoses were each associated with the ISI. Furthermore, an age-sleep duration interaction term was associated with the ISI (b = − 0.03; p = 0.005). For all participants, there was an inverse relationship between sleep duration and ISI. However, for any sleep duration, older veterans reported lower levels of insomnia than younger veterans. Discussion: Older veterans with OSA may report lower ISI scores. Alternative assessment methods for comorbid insomnia among older individuals with OSA may be needed.