title: Sex-related and tissue-specific effects of tobacco smoking on brain atrophy: assessment in a large longitudinal cohort of healthy elderly.
abstract: We investigated the cross-sectional and longitudinal effects of tobacco smoking on brain atrophy in a large cohort of healthy elderly participants (65-80 years). MRI was used for measuring whole brain (WB), gray matter (GM), white matter (WM), and hippocampus (HIP) volumes at study entry time (baseline, N = 1451), and the annualized rates of variation of these volumes using a 4-year follow-up MRI in a subpart of the cohort (N = 1111). Effects of smoking status (never, former, or current smoker) at study entry and of lifetime tobacco consumption on these brain phenotypes were studied using sex-stratified AN(C)OVAs, including other health parameters as covariates. At baseline, male current smokers had lower GM, while female current smokers had lower WM. In addition, female former smokers exhibited reduced baseline HIP, the reduction being correlated with lifetime tobacco consumption. Longitudinal analyses demonstrated that current smokers, whether men or women, had larger annualized rates of HIP atrophy, as compared to either non or former smokers, independent of their lifetime consumption of tobacco. There was no effect of smoking on the annualized rate of WM loss. In all cases, measured sizes of these tobacco-smoking effects were of the same order of magnitude than those of age, and larger than effect sizes of any other covariate. These results demonstrate that tobacco smoking is a major factor of brain aging, with sex- and tissue specific effects, notably on the HIP annualized rate of atrophy after the age of 65.
authors.affiliation: Life Sciences, University of Bordeaux, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Centre National de la Recherche Scientifique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Commisariat à l'Energie Atomique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Duriez
authors.affiliation: Life Sciences, University of Bordeaux, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Centre National de la Recherche Scientifique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Commisariat à l'Energie Atomique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Crivello
authors.affiliation: Life Sciences, University of Bordeaux, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Centre National de la Recherche Scientifique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France ; Commisariat à l'Energie Atomique, Neurofunctional Imaging Group (GIN) UMR5296 Bordeaux, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Mazoyer
keywords: MRI; aging; brain atrophy; gray matter; hippocampus; sex; tobacco; white matter