Urinary tobacco-specific nitrosamine 4-(methylnitrosamino)- 1-( 3-pyridyl)-1-butanol (NNAL) and cognitive functioning in older adults: The National Health and Nutrition Examination Survey 2013-2014

Abstract

Introduction: Tobacco contains carcinogens called tobacco-specific nitrosamines. Among the tobacco-specific nitrosamines, is nicotine-derived nitrosamine ketone (NNK) which produces the metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanol (NNAL). We aimed to examine the association between urinary tobaccospecific NNAL and cognitive functioning among older adults. Methods: A total of 1673 older adults aged .60 years from the National Health and Nutrition Examination Survey 2013.2014 were included. Urinary tobacco-specific NNAL was analyzed in the laboratory. Cognitive functioning was measured using the Consortium to Establish a Registry for Alzheimer's Disease Word Learning subtest (CERAD-WL) immediate and delayed memory tests, the Animal Fluency test (AFT), and the Digit Symbol Substitution Test (DSST). Test-specific and global cognition z-scores were calculated based on means and standard deviations of the cognitive test scores. Multivariable linear regression models were constructed to examine the independent association between quartiles of urinary tobacco-specific NNAL and cognitive test-specific and global cognition z-scores controlling for age, sex, race/ethnicity, education level, depressive symptoms, body mass index, systolic blood pressure, urinary creatinine, hypertension, diabetes, alcohol use, and smoking status. Results: About half of the participants (mean age 69.8 years) were female (52.1%), non-Hispanic White (48.3%), and completed some college and above (49.7%). Multivariable linear regression results showed that participants in the 4th quartile (highest quartile) of urinary NNAL, compared with those in the 1st quartile (lowest quartile), had lower DSST z-scores (β= -0.19; 95% CI: -0.34. -0.04). Conclusions: Tobacco-specific NNAL was negatively associated with processing speed, sustained attention, and working memory in older adults.