Prevalence and symptoms of occult sleep disordered breathing among older veterans with insomnia.

STUDY OBJECTIVES: To determine the prevalence of occult sleep disordered breathing (SDB) and describe the relationship between classic SDB symptoms (e.g., loud snoring) and occult SDB in older veterans with insomnia.

METHODS: We analyzed baseline survey and in-home sleep study data for 435 veterans (mean age = 72.0 years [SD 8.0]) who had no known history of SDB, met International Classification of Sleep Disorders 2(nd) Edition criteria for insomnia, and were enrolled in a behavioral intervention trial for insomnia. Variables of interest included apnea-hypopnea index (AHI) ≥ 15, age, race/ethnicity, marital status, body mass index (BMI), insomnia subtype (i.e., onset, maintenance, or terminal), self-reported excessive daytime sleepiness, snoring, and witnessed breathing pause items from the Berlin Questionnaire. We computed the frequency of AHI ≥ 15 and assessed whether each classic SDB symptom was associated with an AHI ≥ 15 in 4 separate multivariate logistic regression models.

RESULTS: Prevalence of AHI ≥ 15 was 46.7%. Excessive daytime sleepiness (adjusted odds ratio 1.63, 95% CI 1.02, 2.60, p = 0.04), but not snoring loudness, snoring frequency, or witnessed breathing pauses was associated with occult SDB (AHI ≥ 15). Insomnia subtypes were not significantly associated with occult SDB (p > 0.38).

CONCLUSIONS: In our sample of older veterans with insomnia, nearly half had occult SDB, which was characterized by reported excessive daytime sleepiness, but not loud or frequent snoring or witnessed breathing pauses. Insomnia subtype was unrelated to the presence of occult SDB.