‘Gift That Keeps Giving’: The Impact of GLP-1 in Asthma

This transcript has been edited for clarity. 
Akshay B. Jain, MD: Welcome back to Medscape at ADA 2024, where Dr James Kim, primary care physician from Calgary, Alberta, will be joining me, Akshay Jain, an endocrinologist from Vancouver, Canada, in deciphering the key highlights at the ADA conference and bringing our own clinical twist into what the relevance would be for people like you and I to take back to our clinics.
Welcome back, Dr Kim. 
James Kim, MBBCh, PgDip, MScCH: Thank you very much. It’s nice to be back. 
Jain: This was a diabetes conference, so obviously we are very pancreas focused. At this conference, we went outside our general area of territory, going outside of the pancreas and delving into other organ states. What I found fascinating were some data regarding the effects of incretin therapy on the lung, and in particular, some of the restrictive lung disorders.
Dr Kim, you attended these sessions as well. Can you tell us a little bit more about the results that were discussed? 
Kim: This is an interesting field. The moderator of the session went up and said that there has been no time in any previous ADA sessions where the lung issue was actually discussed. This was the first time ever.
They had some of the world leaders in this field, so it was really awesome to see them. Just to paint a picture of these obese asthmatic patients, they are challenging cases because, as you know, the main therapy for any asthmatic patient is inhaled corticosteroid.
Patients who are obese have quite a bit of a steroid resistance. Therefore, they end up being on many medications that sometimes are off label, and many end up on biologics as well. Therefore, the respiratory world has been seeking therapies for these obese asthmatic patients who are likely to be steroid resistant because these people are also likely to end up on an oral steroid as well.
Dr Jain, you know the effect of the steroids much better than I do, and it’s like a laundry list. We really don’t want our patients to be on oral steroids. 
In the past few years, GLP-1 has been studied quite extensively in the lung, especially in the world of asthma, and also in COPD. What’s really fascinating is that the GLP-1 receptors have been found to be quite abundant in the airway. Some studies show that the highest concentration of GLP-1 lies in the airway, whereas some studies have said that it’s the third most common area to find the GLP-1. 
It is not a surprise that GLP-1 is being studied in managing the airway, especially airway inflammation in asthma and COPD patients. The preliminary data have been quite encouraging. They also discussed that there are new medications coming out that seem to be incretin based, so we’ll wait to see what those studies show.
There are two current phase 3 trials being held at the moment. One is using semaglutide 2.4 mg subcutaneous and another one is using metformin to reduce the airway inflammation in these asthmatic patients and also in some COPD patients. We’ll look forward to these results.
Jain: That’s really important to note because we see that there is a high density of these receptors in the airways, and hitherto we had no idea about the overall effect. Now, we’re looking at, as you mentioned, individuals with obesity who have asthma, so there are both the restrictive and obstructive components in the lung coming into play here.
From an endocrinology perspective, I’m thinking that this could be multiple effects of the GLP-1 receptor agonists, where on one hand you’re managing the obesity and you’re working along that line, and on the other hand, it could have local anti-inflammatory effects in the lung. Hence, there could be potential improvement in the overall pulmonary function of these individuals. 
Kim: We are seeing this in primary care. Ever since I found out this information, I have started numerous patients, who are obese, asthmatic patients who do not have diabetes, on GLP-1 therapies, and their pulmonary function tests have improved significantly.
As a matter of fact, one of my personal friends is a severe asthmatic patient. She ends up being on oral steroids about three times a year. There was even one day when I saw her in one of my classes and she was dyspneic. She was short of breath. 
I introduced her to one of my colleagues who’s a respirologist and very much into the impact of the incretins and asthma, and she was started on a GLP-1 receptor agonist. She lost about 30 pounds of weight, but now she is labeled as a mild asthmatic. Her pulmonary function test is completely normal. She hasn’t touched an oral steroid for a couple of years now.
That is a huge success story and I’m seeing that even in my own clinic as well. It’s a huge win for the respiratory world.
Jain: I think from an endocrinology perspective as well, if we are initiating GLP-1 receptor agonists or medications in that class, where we use it for management of obesity, sooner or later we do hit a stage where people will plateau with their weight loss. They won’t have any additional weight loss.
We tell individuals at that time that the fact that they’re able to maintain the weight loss still means that the medication is working from the obesity perspective. For individuals who also have asthma, it would be a good point to tell them that it could still have potential effects on reducing inflammation ongoing. Hence, even though they may not be losing any additional weight, it would still be helpful to continue on these medications from a pulmonary perspective. 
Kim: Right now these pleiotropic effects of GLP-1 agents are absolutely mind-blowing. I mentioned in one of my respiratory presentations to a bunch of respirologists that diabetes is taking over the world, including the respiratory world. Well, you can imagine what their faces were like. However, they were quite impressed at that, and they were very excited with what these two phase 3 trials will show. 
Jain: I think, based on the ADA 2024 conference, GLP-1 receptor agonists continue to be the gift that keeps giving. We have the effects on diabetes, obesity, kidney function, liver protection, lungs, and Alzheimer’s. We saw some sessions about potential use in people with alcohol misuse disorder or gambling problems. Clearly, there’s a large amount of research that’s being done with these agents. 
Perhaps when you and I talk about ADA 2025, we might be able to talk about some more pleiotropic benefits outside the pancreas. Until then, please do check out our other videos from ADA 2024. Thanks for joining us again, Dr Kim.
Kim: Thank you very much for having me.