Association between Cognitive Reserve Indicator and Chronic Disease-Free Survival: A Large Community-Based Longitudinal Study

Background Cognitive reserve (CR) has been linked to dementia and might be a predictor of aged-related outcomes. However, the association between CR and risk of other chronic diseases and mortality remains unclear. Objectives We aimed to investigate the association of CR with survival free from major chronic diseases. Design, Setting and Participants This community-based longitudinal study used data from the UK Biobank. A total of 412,509 participants (mean age 55.71 +/- 8.10) free of major chronic disease (including dementia, diabetes, cardiovascular diseases, chronic obstructive pulmonary disease, and cancer) completed the baseline examination between 2006 to 2010 and were followed for changes in health status. Measurements Latent class analysis was used to generate an indicator of CR (categorized as low, moderate, or high) based on education, occupation, television viewing time, confiding, social connection, and leisure activities. Major chronic diseases and survival status were ascertained through self-reported history and/or linkages to medical and death records. Chronic disease-free survival was defined as survival without any of the aforementioned chronic diseases. Effect modifications and interactions between the CR indicator and sex, age, and lifestyle factors (including smoking status, alcohol consumption, physical activity, and body mass index) were explored. Results Over a median follow-up of 12.49 (interquartile range 11.42-13.41, range 0.01-15.87) years, 112,190 (27.2%) participants died or developed at least one chronic disease. High CR indicator was associated with lower risk of chronic disease/death (hazard ratio 0.82, 95% confidence interval: 0.80-0.83) compared to low CR indicator. Chronic disease-free survival was prolonged by 1.33 (1.21-1.44) years among participants with high CR compared to low CR indicator. Furthermore, the association between the CR indicator and chronic disease-free survival was strengthened among individuals aged <60 years and current smokers. Conclusion High CR indicator is associated with a lower risk of chronic disease/death and may prolong chronic disease-free survival. Our findings underscore the importance of CR-enhancing lifestyle and experiences in health longevity, especially for younger individuals and current smokers.