- A large US study has found that adults with type 2 diabetes taking GLP 1 receptor agonists had a slightly higher risk of developing chronic cough than those on several other second line diabetes medicines.
- The increased risk was seen even after accounting for reflux disease, which is already known to be more common on GLP 1 drugs.
- The study shows an association only and does not prove that GLP 1 drugs cause cough, but anyone on these medicines who develops a persistent cough should discuss it with their diabetes or prescribing team.
Researchers from the University of Southern California examined electronic medical record data from 70 health care organisations.
They identified adults with type 2 diabetes who had been prescribed a GLP 1 receptor agonist and compared them to adults who were prescribed other second line diabetes medicines, including DPP 4 inhibitors, SGLT2 inhibitors and sulfonylureas.
More than 400,000 people were in the GLP 1 group and more than 1.6 million were in the comparison group.
The researchers used statistical matching to balance factors such as age, sex and other health conditions and then followed people over time to see who went on to receive a new diagnosis of chronic cough.
- Daily GLP1 pill helps people lose around 10% of their body weight
- Growing evidence that GLP-1 drugs make type 2 diabetes remission possible
- GLP-1 receptor agonists can reduce mortality in people with type 2 diabetes
What they found
People taking a GLP 1 receptor agonist had a modest but statistically significant increase in the risk of being diagnosed with chronic cough compared with those taking other non GLP 1 second line medicines overall, and compared with those taking DPP 4 inhibitors or sulfonylureas.
In the initial analysis there was no clear difference compared with SGLT2 inhibitors.
The team then repeated the analysis after excluding people who already had a diagnosis of gastro oesophageal reflux disease.
Reflux is more common in people on GLP 1 drugs and can itself cause cough. After removing these patients, GLP 1 users had a higher risk of chronic cough than all comparison groups, including SGLT2 inhibitors.
The authors are clear that this is an observational cohort study.
It can show a link between GLP 1 use and a new diagnosis of chronic cough, but it cannot prove that GLP 1 drugs directly cause the cough. Other factors may still be involved and further research is needed to understand the mechanism and the true size of any risk.
What this means if you use a GLP 1 medicine
GLP 1 receptor agonists, such as semaglutide and liraglutide, are widely used to treat type 2 diabetes and for weight management and remain very effective treatments for many people.
If you are taking a GLP 1 medicine you should not stop it suddenly on your own.
If you develop a cough that lasts for several weeks, especially if it disturbs your sleep, affects day to day life or is associated with breathlessness, chest pain or unexplained weight loss, you should speak to your diabetes team or the clinician who prescribed the medicine.
