The Role of Physical Activity in the Association Between Smoking Status and Cognitive Function : A Cross-Sectional Study Based on NHANES 2011-2014

Abstract

Abstract Objectives The aim of this study is to examine the relationship between physical activity, smoking status and cognitive function, and to test the potential moderating role of physical activity. Methods This cross-sectional study used data on smoking status, cognitive function and physical activity from 1735 participants aged 60 years and older in NHANES from 2011 to 2014. Linear and logistic regression models were used to assess the association between smoking status and cognitive function. Mediation and moderation analyses were conducted to examine the role of physical activity in this association. Results Former smokers scored on average 2.090 points higher on the Digit Symbol Substitution Test (DSST) compared to never smokers (95% CI 0.755, 3.472; P < 0.05), while logistic regression showed that current smokers had an odds ratio (OR) of 0.629 for cognitive impairment compared to never smokers (95% CI 0.421, 0.941). No significant associations were observed between smoking status and CERAD and AFT. Moderation analysis showed that leisure-time physical activity significantly attenuated the effect of smoking on DSST scores in current smokers compared to never smokers (β = -2.014, P < 0.05). Conclusion There was a significant correlation between smoking status, physical activity and DSST scores.Although the mediating effect of leisure-time physical activity in the association between smoking status and cognitive function is not significant, it attenuates the decline in DSST scores in current smokers.