Gray matter volumes of insular subregions are not correlated with smoking cessation outcomes but negatively correlated with nicotine dependence severity in chronic smokers

摘要

The insula, a cortical region that integrates heterogeneous signals about internal states and contributes to executive functions, has been implicated as an important role in the maintenance of nicotine dependence. Previous studies have indicated that insula damage may contribute to quitting smoking successfully, but few studies have examined whether quitting successfully is related to cortical structural integrity of insular subregions before smoking cessation treatment. Moreover, although prior researches have shown group differences in insular cortex structure in chronic cigarette smokers compared to nonsmokers, less is known about how cortical structural integrity of insular subregions relate to smoking behaviors in smokers. This study, therefore, aimed to (1) further explore the association between the cortical structural integrity of insular subregions prior to the target quit date and the treatment outcomes of smoking cessation therapy; and (2) further evaluate how the cortical structural integrity of insular subregions are related to smoking behaviors. In the present study, a total of 83 smokers and 41 nonsmokers were enrolled and high-resolution structural magnetic resonance images were acquired from all participants. After a 12-week smoking cessation treatment, 28 smokers succeeded in quitting smoking, 46 failed, and 9 were unable to be contacted. Our analysis showed that gray-matter volume of bilateral anterior insula were negatively correlated with nicotine dependence scores. However, the smoking cessation outcomes showed no correlations with the gray-matter volume and seed-based structural covariance network of insular subregions prior to smoking cessation. The present study further clarified the more precise roles of the insular cortex in smoking behaviors, which might improve the understanding of the mechanism in the nicotine dependence.