# GLP-1 Drugs and Asthma Risk: Read the Severity Column, Not the Headline

By Nora Bissett, Pricing Editor (https://glpwatchdog.org/authors/nora-bissett) | Published: 2026-08-21 | Updated: 2026-11-01

Canonical page: https://glpwatchdog.org/research/glp1-and-asthma-risk

> A cohort of people with type 2 diabetes found an adjusted hazard ratio of 0.67 for developing asthma on a GLP-1, but the association weakened as severity rose and disappeared at cases requiring intubation.

## Key points

- Taiwan national cohort, 2011-2015: 1,345 GLP-1-treated people out of 1,936,512 with type 2 diabetes, mean follow-up 2.92 years.
- Adjusted hazard ratio for developing asthma: 0.67 overall.
- By severity: 0.55 without exacerbations, 0.83 for status asthmaticus, 0.96 (CI crossing 1) for cases requiring intubation.
- The paper dates its data 2011 to 2015, before semaglutide's first FDA approval in December 2017, yet reports a semaglutide subgroup; the class-effect claim is an inference.

A cohort study of people with type 2 diabetes reported that those taking a GLP-1 were less likely to develop asthma, with an adjusted hazard ratio of 0.67.[1] Read one row further and the picture gets more complicated. The association was strongest for the mildest asthma and weakest for the most severe, and at the severest endpoint of all, cases requiring a breathing tube, it vanished. That pattern deserves more of your attention than the headline number.

## What the study found

Researchers used Taiwan’s National Health Insurance database from 2011 to 2015, excluding anybody who already had asthma. Out of a cohort of 1,936,512 people with type 2 diabetes, **1,345** were treated with a GLP-1 receptor agonist. Mean follow-up was 2.92 years.[1]

*Adjusted hazard ratios for developing asthma, by severity. Below 1 favors GLP-1 use.[1]*

| Endpoint | HR | 95% CI |
| --- | --- | --- |
| Asthma overall | 0.67 | 0.45–0.76 |
| No acute exacerbations | **0.55** | 0.37–0.62 |
| With acute exacerbations | 0.59 | 0.39–0.66 |
| Status asthmaticus | 0.83 | 0.56–0.93 |
| Requiring endotracheal intubation | **0.96** | 0.65–1.09 |

The authors describe this as a protective trend across severity levels, except in cases requiring intubation. That is accurate, but the same column also reads as a gradient that weakens steadily the sicker the endpoint gets, until at the top it is indistinguishable from no effect at all.

> **A real protective drug effect usually gets more visible at severe endpoints, not less.** A gradient running the other way is the signature of confounding by indication. People well enough to be started and kept on an injectable differ from people who are not, and that difference shows up most where illness is most severe. The finding may still be real, but this study cannot yet tell the two explanations apart.

## What 1,345 people means

The exposed group is 1,345 out of nearly two million. New-onset asthma in adults with diabetes is uncommon, so the number of asthma cases inside that exposed group will be small, and the confidence intervals reflect it. However large the database, the drug arm here is smaller than many single-center trials.

The years matter too. The paper gives its study period as January 1, 2011 to December 31, 2015,[1] two years before the FDA first approved semaglutide, in December 2017,[2] and well before tirzepatide. Yet its table of results by individual drug includes a semaglutide subgroup.[1] The paper does not explain how, so the per-drug results are hard to interpret. For the drugs most people are prescribed today, the authors’ suggestion of a class effect remains an inference.

## And COPD, where the studies are observational

COPD is usually paired with asthma when this question is raised. It has its own records, and the asthma result cannot stand in for them. A US insurance-claims study of people with COPD and type 2 diabetes matched 32,107 pairs and found fewer moderate or severe flare-ups after starting a GLP-1 than after starting a DPP-4 inhibitor, with a hazard ratio of 0.86, over a median of 145 days on treatment.[3] A 2025 review of flare-ups in people with both conditions pooled nine observational studies and retrieved no randomized trials.[4] The comparison drug matters: against metformin, a Japanese cohort found no clear difference (hazard ratio 1.07, 95% CI 0.87–1.32).[5]

The one randomized trial we found in COPD gave 40 people with obesity liraglutide 3.0 mg or placebo for 40 weeks and measured lung function, not flare-ups. Forced vital capacity and symptom scores improved; FEV1 and walking distance did not change significantly.[6]

## What to do with it

- No GLP-1 is approved to prevent or treat asthma, and nothing here suggests taking one for that reason.
- This is a single retrospective cohort with 1,345 exposed people and no randomization.
- The severity gradient runs in the direction that confounding would produce, which is the main reason to hold the result loosely.
- If you have asthma and are considering a GLP-1 for weight or diabetes, this is not a reason for concern either, since the study found no signal of harm.
- Inhaled therapy is not something to change on the strength of a records study. That is a conversation with whoever manages your asthma.

For the airway condition where a GLP-1 does hold an approved indication and a randomized trial, see [Zepbound for sleep apnea](https://glpwatchdog.org/research/zepbound-for-sleep-apnea).

## Frequently asked questions

### Do GLP-1 drugs reduce asthma risk?

One retrospective cohort of people with type 2 diabetes reported an adjusted hazard ratio of 0.67 for developing asthma among GLP-1 users. It is observational, the exposed group was 1,345 people, and the association weakened as asthma severity increased.

### Why does the severity gradient matter?

Because it runs the wrong way for a real drug effect. The hazard ratio was 0.55 for asthma without exacerbations, 0.83 for status asthmaticus, and 0.96 with a confidence interval crossing 1 for cases needing intubation. A protective effect usually becomes clearer at severe endpoints, not fainter.

### Is it safe to take a GLP-1 if I have asthma?

This study excluded people who already had asthma, so it does not answer that directly. It found no signal of increased asthma risk or severity. Any decision about your asthma treatment belongs with the clinician managing it.

### What about COPD?

The flare-up evidence is observational and mostly in people who also have type 2 diabetes. A large US claims study found fewer moderate or severe flare-ups after starting a GLP-1 than a DPP-4 inhibitor (hazard ratio 0.86), while a Japanese cohort found no clear difference against metformin. A 40-person liraglutide trial measured lung function rather than flare-ups.

## References

1. Cheng YS, Chung CH, Kuo SM, et al. Glucagon-like peptide-1 receptor agonists linked to a reduced risk of developing asthma among patients with type 2 diabetes. Therapeutic Advances in Endocrinology and Metabolism. 2025. PMID: 41425689. https://pubmed.ncbi.nlm.nih.gov/41425689/
2. U.S. Food and Drug Administration Drugs@FDA: OZEMPIC (semaglutide), NDA 209637, original approval December 5, 2017. FDA Drugs@FDA database. 2017. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=209637
3. Ray A, Paik JM, Wexler DJ, et al. Glucose-Lowering Medications and Risk of Chronic Obstructive Pulmonary Disease Exacerbations in Patients With Type 2 Diabetes. JAMA Internal Medicine. 2025. PMID: 39928303. DOI: 10.1001/jamainternmed.2024.7811. https://pubmed.ncbi.nlm.nih.gov/39928303/
4. Pirera E, Di Raimondo D, D'Anna L, Tuttolomondo A. Efficacy of SGLT2 Inhibitors, GLP-1 Receptor Agonists, DPP-4 Inhibitors, and Sulfonylureas on Moderate-to-Severe COPD Exacerbations Among Patients with Type 2 Diabetes: A Systematic Review and Network Meta-Analysis. Pharmaceuticals. 2025. PMID: 41011208. DOI: 10.3390/ph18091337. https://pubmed.ncbi.nlm.nih.gov/41011208/
5. Kimura Y, Jo T, Inoue N, et al. Association of novel antihyperglycaemic drugs versus metformin with COPD exacerbations. ERJ Open Research. 2025. PMID: 40432813. DOI: 10.1183/23120541.00757-2024. https://pubmed.ncbi.nlm.nih.gov/40432813/
6. Altintas Dogan AD, Hilberg O, Hess S, et al. Respiratory Effects of Treatment with a Glucagon-Like Peptide-1 Receptor Agonist in Patients Suffering from Obesity and Chronic Obstructive Pulmonary Disease. International Journal of Chronic Obstructive Pulmonary Disease. 2022. PMID: 35237033. DOI: 10.2147/COPD.S350133. https://pubmed.ncbi.nlm.nih.gov/35237033/

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Cite as: GLP Watchdog, Nora Bissett, "GLP-1 Drugs and Asthma Risk: Read the Severity Column, Not the Headline", published 2026-08-21, updated 2026-11-01. https://glpwatchdog.org/research/glp1-and-asthma-risk

Canonical HTML page: https://glpwatchdog.org/research/glp1-and-asthma-risk

Medical disclaimer: Nothing here is medical advice. We report on this subject; we do not treat anyone. Whether to begin a medication, supplement, or treatment, whether to adjust it, and whether to stop are questions for a clinician licensed to answer them, who knows your history.