Association between risk of obstructive sleep apnea, inflammation and cognition after 45 years old in the Canadian Longitudinal Study on Aging

Background: The association between obstructive sleep apnea and cognitive functioning is not yet fully understood and could be influenced by factors such as sex, age and systemic inflammation. We deter-mined the sex-and age-specific association between obstructive sleep apnea risk and cognitive per-formance, and the influence of systemic inflammation on this association. Methods: We included 25,899 participants from the Canadian Longitudinal Study of Aging compre-hensive cohort, aged 45-85 years (51% women). We conducted sex-and age-specific (45-59; 60-69; >70) general linear models between obstructive sleep apnea risk and cognitive scores, and tested the moderating and mediating effects of high-sensitivity C-reactive protein levels. Obstructive sleep apnea risk was estimated by combining the STOP and whole-body fat percentage. Cognitive tests assessed episodic verbal memory, executive functions and psychomotor speed. Levels of high-sensitivity C-reactive protein were obtained through blood samples. Results: Higher obstructive sleep apnea risk was associated with poorer episodic memory in women aged 45-59 years, and poorer executive function (p < 0.05 on multiple tests) in women aged 45-59 and 60-69 years. No such association was found in men. High-sensitivity C-reactive protein levels mediated some associations between obstructive sleep apnea risk and executive function in women and men aged <70 years.Conclusions: Being at high-risk for obstructive sleep apnea is associated with poorer cognition in women aged <70 years. These associations were partly mediated by systemic inflammation. These results un-derscore the importance of obstructive sleep apnea diagnosis, treatment and appropriate follow-up, particularly in middle-aged women who might already show signs of early cognitive impairments.(c) 2022 Elsevier B.V. All rights reserved.