Biomarker assessment of tobacco smoking exposure and risk of dementia death: pooling of individual participant data from 14 cohort studies. Issue 6 (24th January 2018)

• Record Type: Journal Article
• Authors: Batty, G David; Shipley, Martin J; Kvaavik, Elisabeth; Russ, Tom; Hamer, Mark; Stamatakis, Emmanouil; Kivimaki, Mika
• Is Part Of: Journal of epidemiology and community health. Volume 72:Issue 6(2018)
• Page Start: 513
• Page End: 515
• Publication Date: 2018-01-24
• Subjects: smoking -- dementia -- cohort studies; Public health -- Periodicals; Epidemiology -- Periodicals; 614.4
• DOI: 10.1136/jech-2017-209922
• Languages: English
• ISSNs: 0143-005X

Abstract

Abstract : Background: While there is a suggestion that self-reported tobacco smoking may be a risk factor for dementia, to date, it has not been possible to explore the thresholds at which this exposure elevates risk. Accordingly, our aim was to relate cotinine, a biomarker of tobacco smoking, to risk of dementia death. Methods: We pooled 14 prospective cohort studies that held data on cotinine (plasma or saliva), covariates and death records. Results: In the 33 032 study members (17 107 women) with salivary cotinine data, a mean duration of 8.3 years of follow-up gave rise to 135 deaths ascribed to dementia; while in 15 130 study members (7995 women) with plasma cotinine data, there were 119 dementia deaths during 14.3 years of mortality surveillance. After multiple adjustment, both plasma cotinine (per 1 SD higher cotinine; 95% CI 1.29; (1.05 to 1.59)) and salivary cotinine (1.10 (0.89 to 1.36)) were positively related to dementia risk, with stronger effects apparent for plasma. Conclusion: Our finding that plasma cotinine was related to an elevated risk of dementia death warrants testing in studies with measures of disease onset as opposed to just mortality.