Brain Structure Alterations in Respect to Tobacco Consumption and Nicotine Dependence: A Comparative Voxel-Based Morphometry Study

Abstract

The main purpose of this study is to examine the lifetime tobacco consumption and the degree of nicotine dependence related gray matter (GM) and white matter (WM) volume alterations in young adult-male smokers. Fifty-three long-term male smokers and 53 well-matched male healthy non-smokers participated in the study, and the smokers were respectively categorized into light and heavy tobacco consumption subgroups by pack-years and into moderate and severe nicotine dependence subgroups using the Fagerström Test for Nicotine Dependence (FTND). Voxel-based morphometry analysis was then performed, and ANCOVA analysis combined with subsequent post hoc test were used to explore the between-group brain volume abnormalities related to the smoking amount and nicotine dependence. Light and heavy smokers displayed smaller GM and WM volumes than non-smokers, while heavy smokers were found with more significant brain atrophy than light smokers in GM areas of precuneus, inferior and middle frontal gyrus, superior temporal gyrus, cerebellum anterior lobe and insula, and in WM areas of cerebellum anterior lobe. However, the contrary trend was observed regarding alterations associated with severity of nicotine dependence. Severe nicotine dependence smokers rather demonstrated less atrophy levels compared to moderate nicotine dependence smokers, especially in GM areas of precuneus, superior and middle temporal gyrus, middle occipital gyrus, posterior cingulate and insula, and in WM areas of precuneus, posterior cingulate, cerebellum anterior lobe and midbrain. The results reveal that the nicotine dependence displays a dissimilar effect on the brain volume in comparison to the cigarette consumption. Our study could provide new evidences to understand the adverse effects of smoking on the brain structure, which is helpful for further treatment of smokers.

Keywords: FTND score; nicotine dependence; pack-years; smoking; voxel-based morphometry.

FIGURE 1

Regions with smaller gray matter volumes in 23 moderate nicotine dependence smokers and 30 severe nicotine dependence smokers than in non-smokers. This image shows the overlap (orange) regions of the smaller gray matter in 23 moderate nicotine dependence smokers (red) and 30 severe nicotine dependence smokers (yellow) than in 53 nonsmokers. Overall thresholds of significance were set at P < 0.05 (AlphaSim corrected). The (top row) shows four axial slices, whereas the (bottom row) shows three sagittal slices. 1, cerebellum anterior lobe; 2, insula; 3, middle occipital gyrus; 4, posterior cingulate; 5, caudate body; 6, precuneus; 7, thalamus.

FIGURE 2

Regions with smaller white matter volumes in 23 moderate nicotine dependence smokers and 30 severe nicotine dependence smokers than in non-smokers. This image shows the overlap (orange) regions of the smaller white matter in 23 moderate nicotine dependence smokers (red) and 30 severe nicotine dependence smokers (yellow) than in 53 non-smokers. Overall thresholds of significance were set at P < 0.05 (AlphaSim corrected). The (top row) shows one axial slice and three coronal slices, whereas the (bottom row) shows three sagittal slices. 1, cerebellum anterior lobe; 4, posterior cingulate; 7, thalamus; 8, midbrain.

FIGURE 3

Regions with smaller gray matter volumes in 26 light smokers and 27 heavy smokers than in non-smokers. This image shows the overlap (orange) regions of the smaller gray matter in 26 light smokers (red) and 27 heavy smokers (yellow) than in 53 non-smokers. Overall thresholds of significance were set at P < 0.05 (AlphaSim corrected). The (top row) shows four axial slices, whereas the (bottom row) shows three sagittal slices. 1, cerebellum anterior lobe; 2, superior temporal gyrus; 3, insula; 4, putamen; 5, middle occipital gyrus; 6, lingual; 7, Pallidum; 8, posterior cingulate; 9, thalamus; 10, caudate body; 11, precuneus; 12, inferior frontal gyrus.

FIGURE 4

Regions with smaller white matter volumes in 26 light smokers and 27 heavy smokers than in non-smokers. This image shows the overlap (orange) regions of the smaller white matter in 26 light smokers (red) and 27 heavy smokers (yellow) than in 53 non-smokers. Overall thresholds of significance were set at P < 0.05 (AlphaSim corrected). The (top row) shows three coronal slices and one axial slice, whereas the (bottom row) shows three sagittal slices. 1, cerebellum anterior lobe; 8, thalamus; 9, posterior cingulate; 13, midbrain.