Smoking initiation PRS were calculated for 7,859 young adults. A total of 878 (30%) had ever used e-cigarettes at 24 years, and 150 (5%) were regular e-cigarette users at 24 years. The researchers looked for positive associations of similar magnitude between smoking initiation PRS and both smoking initiation and ever e-cigarette use by the age of 24 years, which would show that a genetic predisposition to smoking initiation is associated with an increased risk of e-cig use.
The compiled data did indeed find such an association. “Our results indicate that there may be a shared genetic aetiology between smoking and e-cigarette use, and also with socioeconomic position, externalising disorders in childhood, and risky behaviour more generally. This indicates that there may be a common genetic vulnerability to both smoking and e-cigarette use, which may reflect a broad risk-taking phenotype.”
Second hand-smoke damage lasts generations
Meanwhile, a 2020 study published in Frontiers in Immunology, found that smoking and/or being exposed to second-hand smoke during pregnancy, may have damaging effects that last for generations.
The study indicated that the risk from second hand smoke is likely to extend further than previously assumed, affecting even the offspring of any fetus that has been exposed. “Second-hand cigarette smoke exposure during pregnancy has damaging effects that could last for generations,” said Hitendra Chand, a biomedical researcher at the Herbert Wertheim College of Medicine.
Researchers from the Chand lab and the Lovelace Respiratory Research Institute, conducted the study on animal models, and were surprised to find adverse effects in second-generation animals that had never been exposed to the smoke. “We observed a smoke-related defect in the enzymes that produce hydrogen sulfide, a vital signal transmitter [messenger] that helps regulate organ development,” said Chand. “And the smoke-induced defect in these enzymes was transmitted to second-generation [grandchildren] animals.”
The researchers added that these enzymes could potentially serve as a biomarker for determining the future susceptibility of asthma in children. Additionally, these findings have significant implications in raising further awareness against the risks of smoking.