Why do some people quit smoking easily while others struggle? Study reveals a genetic link

Researchers have identified genetic variants that may affect how well individuals respond to varenicline, a drug used for smoking cessation.

A study has identified genes that could play a role in how the anti-smoking drug varenicline helps individuals quit the habit. Varenicline, widely used to aid smoking cessation, mimics nicotine by binding to specific proteins in brain cells, blocking the rewarding effects of smoking and reducing cravings. It is commonly available in India under varied brand names, including Champix.

Genes influence varenicline’s success in quitting smoking

However, researchers, including those from the University of Leicester, UK, said that the drug does not work for everyone. "Our study is the first to scan the entire genome to look for genes linked to successfully stopping smoking using varenicline," lead researcher Kayesha Coley, University of Leicester, said.

The study, published in the journal Nicotine and Tobacco Research, looked at health records from databases, such as the UK Biobank, to identify people who quit smoking with varenicline and those who did not. A genetic analysis revealed variants -- small changes in one's DNA -- that were related to a person being able to successfully quit cigarettes using varenicline.

What study reveals

"We provide initial insights into the biological underpinnings of varenicline-aided smoking cessation through implicating genes involved in various processes, including gene expression," the authors wrote. The findings help improve our understanding of how one responds to varenicline, even as more studies are needed, the authors added.

The genes give us some useful insights into the diverse biological processes at play, but the next step is to confirm our findings with even larger studies, Coley said. The participants for the study were a part of the 'Extended Cohort for E-health, Environment and DNA' (EXCEED) study, based at the University of Leicester.

The genetic analysis was also performed on health records of people from other national and international cohort studies, including those from Estonia, which have also collected genetic data.