Effect of GLP-1RA on blood eosinophil levels in adults: a real-world study

Wu, Y., Lin, Y., Wu, J. et al.  BMC Pulm Med (2026). https://doi.org/10.1186/s12890-026-04469-8

Abstract

Background

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used for glycemic control and weight management, especially semaglutide. Potential benefits of GLP-1RAs in asthma, especially in eosinophilic phenotypes, prompt growing scientific interest.

Objective

To investigate the impact of semaglutide on eosinophilic inflammation and to identify clinical and metabolic determinants of eosinophil reduction after treatment.

Methods

We conducted a retrospective, single-center study in Shanghai, China. Eligible subjects were those first prescribed semaglutide in our outpatient clinic. Demographic characteristics, complete blood counts, and lipid profiles before and after semaglutide treatment were collected from electronic medical records. Subgroup analyses were stratified using a blood eosinophil count (BEC) cut-off of 150/µL and a BMI threshold of 28 kg/m². Multiple linear regression analysis was employed to identify factors influencing the reduction in eosinophil counts.

Results

Among 371 participants included in the final analysis, BEC decreased significantly from 160(150)/µL at baseline to 110(100)/µL after semaglutide treatment (P < 0.001), and eosinophil percentage declined from 2.20(1.80)% to 1.60(1.40)% (P < 0.001). The proportion of individuals with eosinophil counts < 150/µL increased from 44.20% to 65.79%. Eosinophil reduction occurred in both baseline eosinophil < 150/µL and eosinophil ≥ 150/µL groups. The percentage reduction in eosinophil count was greater in the BMI-low group than in the BMI-high group (− 31.58% vs. −21.04%, P = 0.037). Multiple linear regression identified baseline eosinophil count as the only independent predictor of eosinophil reduction after treatment.

Conclusions

GLP-1RA, semaglutide treatment significantly reduced BECs regardless of baseline levels, with a more pronounced effect observed in non-obese individuals. Higher baseline eosinophil levels independently predicted greater treatment-induced reductions after adjustment for BMI and lipid parameters.

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