Author Identifier (ORCID)
Abstract
Background: The contribution of dietary sodium to asthma development remains unclear, particularly for adult-onset disease. We examined associations between estimated 24-h urinary sodium excretion, table salt use and incident asthma in a large prospective cohort.
Methods: We analysed 420 041 adults aged 40–69 years without prior asthma. Incident asthma was ascertained through linked health records. Urinary sodium was estimated using the INTERSALT equation from spot urine samples. Frequency of adding salt at the table was self-reported. Associations were evaluated using multivariable Cox proportional hazards models with adjustment for sociodemographic, lifestyle and clinical factors.
Results: Over a median 10.9-year follow-up, 11 927 participants developed asthma. Compared with the lowest quintile, the highest quintile of estimated urinary sodium was associated with increased asthma incidence (hazard ratio (HR) 1.50, 95% CI 1.41–1.59). Associations were stronger in females (HR 1.55, 95% CI 1.44–1.68) than males (HR 1.28, 95% CI 1.17–1.39; p-heterogeneity=0.0011) and in individuals with low eosinophil counts <300 cells·µL−1 (HR 1.55, 95% CI 1.43–1.66) compared with those ⩾300 cells·µL−1 (HR 1.24, 95% CI 1.10–1.40; p-heterogeneity=0.0017). Associations were also stronger in never-smokers (HR 1.64, 95% CI 1.51–1.79) than former (HR 1.46, 95% CI 1.33–1.60) or current smokers (HR 1.16, 95% CI 1.00–1.36; p-heterogeneity=0.0008). Frequent table salt use (“always” versus “never/rarely”) was associated with higher asthma incidence (HR 1.28, 95% CI 1.19–1.37), with no meaningful subgroup differences.
Conclusions: Higher estimated urinary sodium excretion and frequent table salt use were associated with greater asthma incidence. Stronger associations in women and individuals with low eosinophil counts suggest potential phenotype-specific susceptibility. Randomised studies are warranted to test whether sodium reduction lowers asthma risk in these subgroups.
Keywords
dietary sodium, asthma incidence, urinary sodium excretion, table salt use, adult-onset asthma, eosinophils
Document Type
Journal Article
Date of Publication
7-1-2026
Article Number
01654-2025
E-ISSN
23120541
Volume
12
Issue
4
Publication Title
ERJ Open Research
Publisher
European Respiratory Society
School
Nutrition and Health Innovation Research Institute / School of Medical and Health Sciences
Funding Information
This research was in part funded by the Co-Centre for Sustainable Food Systems (funded by Science Foundation Ireland, UK Research and Innovation and the Department of Agriculture, Environment and Rural Affairs). N.P. Bondonno is funded by a National Health and Medical Research Council Early Career Fellowship (grant number APP1159914), Australia.
Funding received from the National Health and Medical Research Council (NHMRC)
APP1159914
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Kronsteiner-Gicevic, S., Thompson, A. S., Gaggl, M., Cassidy, A., Bondonno, N. P., Lim, C. J., Breyer-Kohansal, R., & Kühn, T. (2026). Urinary sodium, table salt use and incidence of late-onset asthma in females and males: Evidence from a large prospective cohort. ERJ Open Research, 12(4), 01654–02025. https://doi.org/10.1183/23120541.01654-2025