Abstract
Background and Aims: The variable that most strongly predicts the degree of nicotine addiction is the quantity of cigarettes smoked per day. A variety of studies have reported a high heritability of nicotine dependence. However, no data exist for any population of Latin Americans, who exhibit different degrees of racial mixing. Therefore, the present analytic, cross-sectional study was conducted.
Methods: Smokers were included (n=515) and classified based on their consumption of cigarettes per day (cpd) as: light smokers (1-10 cpd, LS, n=328) and heavy smokers (≥20 cpd, HS, n=187). Additionally a group of non-smokers (NS, n=192), who were clinically healthy volunteers, were included. A genotyping microarray measuring 384 SNPs was employed in the CHRNA2 to CHRNA7, CHRNA10, CHRNB2 to CHRNB4 and NRXN1 genes, including 37 informative ancestry markers. The Eigensoft, Haploview, PLINK, EPIDAT v3.1, SPSSv15, and Epi-info v7.0.3 software programs were used for this analysis.
Results: Twenty-one SNPs in six genes were identified with statistically significant differences; NRXN1 and CHRNA5 are the genes with the most associated SNPs (7 and 6, respectively). Comparing LS vs. NS, the p-values were found to be between 7.85E-03 and 5.84E-07, and the OR values were between 2.13 and 4.28; in HS vs. NS, these values ranged from 8.23E-04 to 1.45E-10, with the lowest OR being 2.88 and the highest being 7.99.
Conclusions: In the Mexican Mestizo population, smoking and, in particular, a greater consumption of cigarettes are influenced by polymorphisms in genes NRXN1, CHRNA3, CHRNA5, and CHRNB4.
- Copyright ©ERS 2015