O1–05–01: Long‐term patterns of low physical activity and cognitive function in mid‐life: the CARDIA Study

Abstract

Background: Few studies have investigated whether physical activity in early to mid-life is associated with cognitive function even though this may be a critical period for establishing life-long activity habits. We investigated the relationship between long-term patterns of low physical activity over 25 years with cognitive function in mid-life. Methods: In a biracial cohort of 3,375 adults, (ages 18-30 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) Study (1985-86) and followed for 25 years, physical activity was assessed at repeated visits (>3 assessments) using a validated physical activity questionnaire and cognitive function was evaluated at the end of follow-up, Year 25. A long-term pattern of low physical activity over 25 years was defined as reporting activity levels within the bottom tertile (<247 exercise units) of baseline physical activity scores for >2/3 rds of completed visits. Cognitive function was assessed using the Digit Symbol Substitution Test (DSST, standard deviation (SD)=16.16), Stroop Interference Score (SD=10.98), and Rey Auditory Verbal Learning Test (RAVLT, SD=3.27). Results: 26% of participants reported a long-term pattern of low physical activity over 25 years. Compared to more active participants, long-term patterns of low physical activity were associated with increased likelihood of significant poor cognitive performance (<1 SD below the mean) on DSST (inactive: 19% vs active: 15%, OR=1.67, 95% CI 1.30-2.13) and Stroop (inactive: 18% vs active: 11%, OR=1.47, 95% CI 1.15-1.88) but not on RAVLT, after adjusting for age, race, sex, education, smoking, body mass index, and hypertension. For those with very-low activity patterns (long-term pattern of physical activity scores <50 exercise units, 2% of participants), effects were even more pronounced (DSST: OR=2.52, 95% CI 1.34-4.75; Stroop: OR=2.24, 95% CI 1.21-4.14). Conclusions: Beginning in early adulthood, long-term patterns of low physical activity over 25 years were associated with worse mid-life executive function and processing speed. Future prevention strategies should focus on increasing physical activity across the life course.