Relation Between Smoking Status and Subjective Cognitive Decline in Middle Age and Older Adults: A Cross-Sectional Analysis of 2019 Behavioral Risk Factor Surveillance System Data.

Background: Smoking status may influence subjective cognitive decline (SCD); however, few studies have evaluated this association.

Objective: To assess whether smoking status is associated with SCD among middle age and older adults, and to determine if this association is modified by sex at birth.

Methods: A cross-sectional analysis was conducted using data from the 2019 Behavioral Risk Factor Surveillance System (BRFSS) survey to analyze the relationship between SCD and smoking status (current, recent former, and remote former). Eligible respondents included participants 45 years of age or older who responded to the SCD and tobacco questions of interest. Survey-weighted Poisson regression models were employed to estimate the crude and adjusted prevalence ratios (cPR/aPR) and corresponding 95% confidence intervals (CI) of the association between smoking status and SCD. A Wald test was computed to determine the significance of the interaction term between smoking status and sex (α= 0.05).

Results: There were 136,018 eligible respondents, of which approximately 10% had SCD. There was a graded association between smoking and SCD, with the greatest prevalence of SCD among current smokers (aPR = 1.87; CI: 1.54, 2.28), followed by recent former smokers (aPR = 1.47; 95% CI: 1.02, 2.12), and remote former smokers (aPR = 1.11; 95% CI: 0.93, 1.33) each compared to never smokers. There was no evidence of effect modification by sex (p interaction = 0.73).

Conclusion: The consistency of smoking as a risk factor for objective and subjective cognitive decline supports the need for future studies to further the evidence on whether changes to smoking status impacts cognition in middle age.