Association Between Smoking and Cognitive Function Based on Atrial Fibrillation Status: The Tromsø Study

Abstract

<p>Background: According to World Health Organization (WHO), the global tobacco smoking prevalence is 22.3% (36.7% for men and 7.8% for women). Cigarette smoking is a risk factor for cancer, cardiovascular diseases, and cognitive decline. The association of smoking and cognitive decline is well documented. Whitehall II Cohort study, Doetinchem Cohort study and many other studies have found that smoking and cognitive decline are associated to each other. As shown by many studies atrial fibrillation (AF) is also the risk factor for cognitive decline. <p>Purpose of the study: The main aim of this study is to identify the association between smoking and cognitive function based on AF status. <p>Method: This is a longitudinal study with 3305 participants included from Tromsø6 and Tromsø7 study. SPSS version 26 was used for all the analyses. Means and standard deviation (SD) were calculated for continuous variables whereas number and proportions were presented for categorical variables. T-test and chi-square test were used to calculate the difference between groups. ANCOVA analysis was used to calculate the mean cognitive score among different groups according to smoking habit and AF status. Cognitive test scores were subtracted from Tromsø7 to Tromsø6 to find out the differences in cognitive test scores from Tromsø6 to Tromsø7. Mean change in test scores from Tromsø6 to Tromsø7 was estimated with ANCOVA analysis in three different models. Covariates included in the analysis were baseline test scores, age, sex, education, smoking, physical activity, hypertension, total cholesterol, HDL cholesterol, BMI, myocardial infarction, and HbA1c. <p>Results: Cognitive function was found to be improved in Tromsø over about 9 years and there was decline in smoking habit. After adjusting for the covariates (model 1, 2 and 3) the result showed that smoking was significantly associated with cognitive decline as shown by digit-symbol coding test and tapping test among those without AF. <p>Conclusion: Smoking is significantly associated with cognitive decline among people without AF as measured by digit-symbol coding test and tapping test.