The alterations of cerebral cortex thickness based on surface morphology and its correlation with smoking-related characteristics in severe nicotine addicts

Abstract

Objective: To explore the alterations of cerebral cortical thickness in severe nicotine addicts by using surface-based morphology (SBM) method and further analyzing the association of these changes with smoking-related characteristics. Methods: Data were retrospectively collected from August 2014 to August 2019 from severe nicotine addicts [aged 25 to 52(38±8)years] and 56 non-smokers healthy volunteers [aged 22 to 51(36±8)years]. All subjects underwent 3.0 T magnetic resonance scans, and FreeSurfer software was used to analyze the difference in cortical thickness between the two groups, and Pearson correlation analysis was used to explore the correlation between the nicotine dependence group and smoking-related characteristics. Results: Compared to control group, the severe nicotine dependence group had a significant reduction in the cortical thickness in 9 areas of the brain, the left cerebral cortex, including: middletemporal, precentral, superiorfrontal, insula [(2.78±0.10) mm vs (2.92±0.17) mm, (2.57±0.15) mm vs (2.70±0.14) mm, (2.63±0.18) mm vs (2.76±0.15) mm, (3.01±0.10) mm vs (3.13±0.13) mm, all P<0.01, respectively], and the right cerebral cortex including: temporalpole, rostralmiddlefrontal, superiorfrontal, postcentral, parsopercularis [(3.12±0.14) mm vs (3.26±0.19) mm, (2.71±0.16) mm vs (2.87±0.18) mm, (2.96±0.15) mm vs (3.10±0.20) mm, (2.57±0.15) mm vs (2.71±0.15) mm, (2.54±0.11) mm vs (2.65±0.15) mm, all P<0.05, respectively]. The cortical thickness of left insular was positively correlated with the initial smoking age (r=0.403,P=0.009), while the cortical thickness of the other brain regions had no significant correlation with smoking-related characteristics (all P>0.05). Conclusion: Significant alterations were observed in cortical thickness in severe nicotine addicts, and there is a correlation between the thickness of the left insular cortex and the age of initial smoking.