Heritability And Environment Effect On Cigarette Smoking And Alcohol Use For Adolescent Twins In Qingdao City

Objective: To determine the prevalence of cigarette smoking and alcohol use inadolescents twins. To examine the relative contribution of genetic andenvironmental influences on cigarette smoking and alcohol use amongadolescents twins.Methods: Subject to zygosity identification, cigarette smoking and alcohol usewere studied for 334 pairs Monozygotic twins, 280 pairs Dizygotic twins pairs,aged 10 to 16 who participate in this study voluntarly. The adolescents' twinsand their parents were asked to complete the questionnaire for substance use.Stratified estimators,logistic Regression and Holzinger methods were usedtogetherly to analysis.Results: The ratio of experminet smoking was 18.0% in male, 12.3% in female.The ratio of current smoking was 5.50% in male, 2.70% in female.Male twinswas higher than female in smoking, it's significance different in experimentand current smoking (x~2=7.681,P＜0.01; x~2=6.462,P＜0.05). The heritabilityestimated of current smoking was 13.3±2.80%, 27.8±2.45% in male. Themodel of stratified odds ration estimators has comfirmed that familial effectswas significance in twins smoking (x~2M-H=63.87, P＜0.001), with evidence for asignificant contribution of heritability and environmental correlation (x~2G×E=74.22,P＜0.001). Logistic regression suggested that familial effects, heritabilityand environment correlation effect was also significance in smoking(OR=2.81,95% CI 0.29-4.226;OR=3.17 95% CI 1.34-8.56); The ratio ofexperminet drinking was 17.8% in male, 11.2% in female. The ratio of currentdrinking was 13.3% in male, 5.2% in female. Male twins was higher thanfemale twins in drinking, it's significance different in experiment and current drinking (x~2=10.826, P＜0.05; x~2=14.412,P＜0.01).The heritability estimated ofcurrent drinking was 18.2±2.97%, 26.1±3.31% in male twins.Familialclustering,common environment and specific environment was significance inadolescent twins alcohol drinking by stratified odds ration estimators (x~2=31.244,P＜0.001;x~2=43.62, P＜0.001). Logistic regression was also significantcontribution of familial,additive genetic, shared and non-shared environment intwins' drinking (OR=3.24, 95%CI 0.123-4.470; OR=31.23, 95%CI 1.690-57.39;OR=3.524 95% CI 0.288-43.087;OR=3.54 95% CI 2.085-6.010).Conclusion: The adolescents' sustance use had been on lower agedcurrently.Familial aggregation had effected on cigarette smoking and alcoholuse significantly. The correlation of genetics and environment had also effecton cigarette smoking and alcohol use. Suggest that health promotion will becarried out to prevent and control the adolescents' substance use.