Tobacco smoking and brain atrophy in the elderly subjectdécembre 2014 Directeur(s) de thèse : Bernard MAZOYER Résumé de thèse
Increase in life expectancy seen during the XXth century, followed by an increase in the proportion of elderly, has placed the study of brain aging and of its accompanying diseases in the spotlight. This thesis aimed at quantifying of the impact of tobacco consumption on brain morphological aging in a large cohort of healthy elderly subjects from the Three Cities Study. We focused on the evaluation and comparison of its impact as compared to other factors known to influence brain aging, in longitudinal and cross-sectional studies. We show that tobacco smoking has mainly global effects, albeit with somme differences depending on brain tissue type, more important than that of other cardiovascular risk factors included in this study and as important as the effect of age. Also, we have found that this effect stops whe subjects quit smoking, showing that prevention among the elderly population might be of major interest. Moreover, analysis have been conducted in men and women separately, allowing us to find differential effects of tobacco consumption on the brain morphological aging in the two sexes. These original findings, that for the most part have never been repported in the literature, need to be replicated in another cohort.