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Impact of Cigarette Smoking and Its Interaction with Hypertension and Diabetes on Cognitive Function in Older Americans

Restifo D, Zhao C, Kamel H, Iadecola C, Parikh NS

Journal of Alzheimer's disease : JAD, 2022

3,007 participants

Abstract

BACKGROUND: The detrimental impact of tobacco smoking on brain health is well recognized.

OBJECTIVE: To evaluate whether smoking acts synergistically with hypertension and diabetes to influence cognitive performance.

METHODS: We performed a cross-sectional analysis using the US National Health and Nutrition Examination Survey. Participants were tested for serum cotinine, a validated cigarette smoking/exposure biomarker, and had standardized blood pressure and hemoglobin A1c measurements. Participants were administered four cognitive tests: Digit Symbol Substitution (DSST), Animal Fluency, Immediate Recall, and Delayed Recall. Multivariable linear regression models adjusted for demographics and confounders evaluated the association of cotinine with cognition. Interaction testing evaluated effect modification by hypertension, diabetes, and their continuous measures (systolic blood pressure and hemoglobin A1c).

RESULTS: For 3,007 participants, mean age was 69.4 years; 54% were women. Using cotinine levels, 14.9% of participants were categorized as active smokers. Higher cotinine levels were associated with worse DSST performance when modeling cotinine as a continuous variable (β, -0.70; 95% CI, -1.11, -0.29; p < 0.01) and when categorizing participants as active smokers (β, -5.63; 95% CI, -9.70, -1.56; p < 0.01). Cotinine was not associated with fluency or memory. Effect modification by hypertension and diabetes were absent, except that cotinine was associated with worse…

How strong is the evidence?

Evidence Hub reads this as a cross-sectional, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause. Reported size: 3,007 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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