Quitting Smoking Early Halves Risk of COPD in Adults with High Genetic Risk

In the largest study to date examining risk factors for lung disease, researchers showed that people at high genetic risk for developing chronic obstructive pulmonary disease (COPD) can cut that risk in half if they stop smoking in early adulthood.

The study examined 24 million genetic variants and concluded that those with the highest risk are 3.7 times more likely to develop COPD than those in the lowest risk group. Smoking further aggravates the risk, so much so that more than two-thirds of smokers in the high-risk group are likely to develop the condition.

The study, “Genome-wide association analyses for lung function and chronic obstructive pulmonary disease identify new loci and potential druggable targets,” involved participants from 13 countries and appeared in the journal Nature Genetics.

Researchers examined two groups of more than 144,000 individuals in what is known as a genome-wide association study (GWAS). This type of approach allows researchers to study links between genes and a disease without any preconceived theories, and often gives surprising insights into the genetic risk of disease.

By making sure to include people with extremely poor or good lung function, researchers nearly doubled the number of factors known to be linked to lung health. This increased resolution may lead to new ways of treating diseases such as COPD, particularly since some of the newly identified genes are already explored in other conditions.

“Our findings point to proteins that will help guide the development of new drugs and to proteins that are targets for drugs already tested for different diseases,” Martin Tobin, a professor at Britain’s University of Leicester — and one of two senior researchers who led the study — said in a press release. “This indicates that repurposing drugs already tested for different diseases could be one way to improve treatments for COPD.”

“Given how common COPD is, we know surprisingly little about the reasons why one individual develops the condition whilst another does not,” added the University of Nottingham‘s Ian Hall, the study’s second co-senior author. “The study of genetic variation between individuals provides a powerful way to understand these mechanisms which underlie disease risk, which in turn will provide a stimulus for drug development.”

Since COPD does not exclusively affect smokers, and not all smokers develop the condition, the team focused especially on understanding how a person’s genetic makeup affects risk in smokers and non-smokers separately.

“COPD has a devastating effect on the lives of people who live with it, and on their loved ones and carers,” said Ian Jarrold, head of research at the British Lung Foundation. “Understanding how COPD develops and progresses is key to the discovery of new effective treatments and for using existing treatments more effectively. This work represents an important step towards this, and may also lead to better prevention, earlier diagnosis and earlier treatment of COPD.”

Added Tobin: “As a result of this work, we can now better predict who will develop COPD – opening up the possibility of using this information in prevention (such as for targeting smoking cessation services).”