Background: Emerging work suggests that chronic smoking may have deleterious neurocognitive effects. Physical activity has been shown to maintain or improve cognitive function. Thus, it stands to reason that physical activity may moderate the relationship between smoking and cognitive function among older adults. This has yet to be fully evaluated, which was this studys purpose. Methods: Data from the 1999-2002 NHANES were employed (N = 2,144; 60-85 yrs). Cognitive function was assessed from the Digit Symbol Substitution Test. Moderate-to-vigorous physical activity (MVPA) and smoking were assessed via self-report. Results: In a multiplicative interaction model, the interaction term of physical activity and smoking on cognitive function was not significant (βadjusted = -0.41; 95% CI: -3.11 to 2.28; P=0.75). However, smokers who were physically active had better cognitive function than smokers who were not physically active. Conclusion: Physically active smokers had better cognitive function than their less active smoking counterparts.
Key words: Epidemiology; elderly; executive function; NHANES; smoking