Prevalence and impact of hyponatremia in chronic obstructive pulmonary disease. A systematic review and meta-analysis

Hyponatremia has been found to be associated with chronic obstructive pulmonary disease (COPD) and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). However, there is a lack of systematic evidence on the prevalence and impact of hyponatremia in COPD and AECOPD patients. We performed a systematic search on three major databases for articles published on or before 31 July 2025. We included all the studies reporting the prevalence or number of hyponatremia cases in COPD patients (stable and exacerbation) aged 18 years and above. Pooled prevalence was calculated by a random effects model using RStudio. The Joanna Briggs Institute (JBI) tool was used for quality evaluation of the included studies. In this systematic review and meta-analysis, we included 11 studies out of 284 studies retrieved in the initial search. Of these 11 studies, three were COPD studies, and eight were AECOPD studies. The pooled prevalence of hyponatremia among COPD patients was 14% (95% CI: 4%-28%), with significant heterogeneity (I² = 98.3%, p < 0.0001). The pooled prevalence of hyponatremia in AECOPD patients was 19% (95% CI: 9%-32%), with significant heterogeneity (I² = 98.8%, p < 0.0001). Most of the studies showed that hyponatremia was not associated with mortality as an outcome of AECOPD. This study found a high prevalence of hyponatremia in both COPD and AECOPD patients; however, substantial heterogeneity (I² > 98%) necessitates cautious interpretation of pooled estimates. Future studies with standardized diagnostic criteria and larger sample sizes are needed to establish more precise prevalence rates.