Summary Using a sample of 2925 stroke-free participants drawn from a national population-based study, we examined cross-sectional associations of obstructive sleep apnea risk (OSA) with cognition and quality of life and whether these vary with age, while controlling for demographics and co-morbidities. Included participants from the REasons for Geographic And Racial Differences in Stroke Study were aged 47-93. OSA risk was categorized as high or low based on responses to the Berlin Sleep Questionnaire. Cognitive function was assessed with standardized fluency and recall measures. Depressive symptoms were assessed with the four-item Center for Epidemiologic Studies Depression Scale. Health-related Quality of Life (HRQoL) was assessed with the Medical Outcomes Study Short Form-12 (SF-12). MANCOVA statistics were applied separately to the cognitive and quality of life dependent variables while accounting for potential confounders (demographics, co-morbidities). In fully adjusted models, those at high risk for OSA had significantly lower cognitive scores (Wilks’ Lambda = 0.996, F(3, 2786) = 3.31, p < .05) and lower quality of life (depressive symptoms and HRQoL) (Wilks’ Lambda = 0.989, F(3, 2786) = 10.02, p < .0001). However, some of the associations were age-dependent. Differences in cognition and quality of life between those at high and low obstructive sleep apnea risk were most pronounced during middle age, with attenuated effects after age 70.

Introduction: Using a subsample from the national REasons for Geographic And Racial Differences in Stroke (REGARDS) study, we examined the associations of obstructive sleep apnea (OSA) with cognition and quality of life and whether these associations vary with age while controlling for other demographic factors and comorbid medical conditions. Methods: Stroke-free participants with complete data on OSA risk, cognition, and quality of life as of October 2010 were included (N =2,925; ages 47-93, 43% men, 35% black, 65% white). OSA risk was defined as high or low based on responses to the Berlin Sleep Questionnaire (BSQ). Cognitive function was assessed with three validated fluency and recall measures; quality of life was assessed with the 4-item Center for Epidemiological Studies-Depression (CESD-4) scale and the Medical Outcomes Study Short Form-12 (SF-12). MANCOVA statistics were applied to the cognitive and quality of life outcomes separately while accounting for potential confounders (age, sex, race, education, diabetes and dyslipidemia). Body mass index and hypertension were taken into account as part of the BSQ definition of OSA risk. Results: In fully adjusted models, those at high risk for OSA had significantly lower cognitive scores (p < .05) and lower quality of life (depressive symptoms and SF-12) (p < .0001) than those at low risk. Some of the associations were age-dependent, such that younger participants with high OSA risk had worse cognitive and quality of life scores than both younger participants with low OSA risk and older participants with high OSA risk. Discussion: Lower cognitive function and lower quality of life in those at high risk for sleep apnea remained after accounting for potentially confounding factors in a population-based sample. These relationships were more pronounced during middle age, with attenuated effects after age 70. It may be of particular importance to detect and treat OSA in younger adults.