Results : We confirmed the importance of the 4 main factors influencing SC : ( 1 ) environmental factors , ( 2 ) genomic factors , ( 3 ) gene-environment interactions , and ( 4 ) evidence -based interventions .
The model demonstrates the complex network of factors influencing SC .
Background : Smoking behaviour is a major public health problem worldwide .
Several sources have confirmed the implication of genomic factors in smoking behaviour .
These factors interact both with environmental factors and interventions to develop a certain behaviour .
Objectives : Describing the environmental and genomic factors as well as the interventions influencing smoking cessation  ( SC ) and developing a working model incorporating the different factors influencing SC were our main objectives .
Prenatal Smoke Exposure and Genomic DNA Methylation in a Multiethnic Birth Cohort
Background : Exposure to prenatal tobacco smoke ( PTS )  has been associated with a number of health outcomes in the offspring , including some childhood cancers . Lower levels of genomic DNA methylation have also been associated with several types of cancers . We investigated whether PTS was associated with global DNA methylation levels in the offspring . Methods : Our sample was drawn from a birth cohort of women born between 1959 and 1963 in New York City ( n = 90 ) . We measured  methylation of repetitive elements ( Sat2 , Alu , LINE-1 )  from peripheral blood granulocytes . We combined prospect ively collected data on PTS with adult epidemiologic data and blood sample s collected in 2001 to 2007 ( mean age , 43 years ) . We used linear regression to assess the association between PTS and repetitive element methylation . Results : Thirty-six percent of mothers smoked during pregnancy . We observed an inverse association between PTS and Sat2 methylation . This inverse association remained even after adjustment for potential mediators including child environmental tobacco smoke exposure , birth size , postnatal weight and height changes , and adult smoking status and alcohol intake ( β = −0.22 , 95 % confidence interval = −0.40 to −0.03 for ever exposed to PTS vs. never exposed using models of log-transformed methylation levels ) . PTS exposure was not statistically significantly associated with LINE-1 or Alu methylation . Conclusions : PTS exposure , measured at the time of pregnancy and not retrospectively reported , was associated with a decrease in Sat2 methylation but not LINE-1 or Alu methylation . Impact : If replicated in larger studies , this study supports a persistent effect of PTS on DNA methylation levels , as measured by Sat2 , in adulthood . Cancer Epidemiol Biomarkers Prev ; 20(12 ) ; 2518–23 . © 2011 AACR
Results : We confirmed the importance of the 4 main factors influencing SC : ( 1 ) environmental factors , ( 2 ) genomic factors , ( 3 ) gene-environment interactions , and ( 4 ) evidence -based interventions .
The model demonstrates the complex network of factors influencing SC .
Background : Smoking behaviour is a major public health problem worldwide .
Several sources have confirmed the implication of genomic factors in smoking behaviour .
These factors interact both with environmental factors and interventions to develop a certain behaviour .
Objectives : Describing the environmental and genomic factors as well as the interventions influencing smoking cessation  ( SC ) and developing a working model incorporating the different factors influencing SC were our main objectives .