159 The Role of Education on the Association between OSA and Cognitive Functions in Middle-age and Older Adults
Abstract Introduction A weak relation between an increase in education and improved health knowledge was observed among those who attended college, but not among those whose highest educational level attainment was high school (Altindag, Cannonier, & Mocan, 2014). Alachantis and colleagues (2005) had applied cognitive reserve theory (Stern, 2002) to help explain why OSA patients with higher intelligence scores perform well on cognitive tasks. The resource substitution theory (RST; Ross & Mirowsky, 2006) posits that higher education compensates for background disadvantages rather than magnifying background advantages. The goals of the current study were to examine the interaction between educational level and obstructive sleep apnea (OSA) on cognitive functions such as verbal fluency, psychomotor vigilance, executive functions, visuospatial ability, and attention span and to determine whether the results would support the RST. Methods One hundred and nine participants (47 ApneaLinkTM -screened controls and 62 untreated OSA patients) participated in the study and completed the Wisconsin Card Sorting Test, WAIS-III digit span and block design, semantic and phonemic fluency tests, and a psychomotor vigilance task. Subjective sleep (PSQI and ESS) and health measures (depression, anxiety, mood disturbance, diabetes, hypertension) were assessed. A hierarchical regression was conducted to test for the additional variance explained by the interaction term even after accounting for the covariates. Results In semantic fluency and visuospatial ability tasks, patients with higher education performed better than patients with high school or less education. This moderation effect of education was not observed for the control group. A significant interaction effect was not observed for vigilance, phonemic fluency, attention span, or executive functions although education was a significant predictor for all cognitive tasks. Conclusion The resource substitution theory was supported as the benefit of education seemed more crucial for OSA patients than for controls, specifically in semantic fluency and visuospatial ability. This benefit of higher education contributing to larger cognitive reserves in patients with OSA helped buffer some cognitive deficits but not for others, but this buffer no longer works when the cognitive demand gets larger. Support (if any) A grant from the Center for Integrative Research on Cognitive Neural Science, Southern Illinois University Carbondale was received.