High Eosinophil Counts in COPD Patients Tied to Increased Risk of Heart Failure and Kidney Disease: Study Shows

The researchers analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES) covering 2013 to 2018. The study focused on 614 adults diagnosed with COPD, categorizing them based on their blood eosinophil counts (BEC): those with levels below 300 cells/μL and those with levels at or above this threshold.

The study led to the following findings:

• Patients with elevated eosinophil counts (≥300 cells/μL) had a significantly higher prevalence of extrapulmonary comorbidities than those with lower counts.
• 85.3% of individuals in the high-eosinophil group had at least one extrapulmonary condition versus 71.4% in the low-eosinophil group.
• After adjusting for potential confounders, high eosinophil levels were associated with a two-fold increase in the odds of having any extrapulmonary comorbidity (OR 2.03).
• Elevated eosinophil counts were linked to a 69% higher risk of congestive heart failure (OR 1.69).
• High eosinophil levels were also associated with nearly double the risk of renal dysfunction (OR 1.95).
• There was no significant association between eosinophil levels and pulmonary comorbidities.
• The findings suggest that eosinophilic inflammation may play a role in systemic health issues beyond the respiratory system.

“Our analysis indicates that higher eosinophil counts in COPD patients may serve as a signal for non-respiratory complications, particularly involving the cardiovascular and renal systems,” noted the authors.

To strengthen their findings, the researchers conducted sensitivity analyses using additional eosinophil cutoffs, which consistently confirmed the association between rising eosinophil levels and increased risk of extrapulmonary disease.

The authors emphasized the potential clinical implications of these results, suggesting that therapies targeting eosinophilic inflammation might benefit lung function and help mitigate broader health risks in COPD patients. However, they called for further prospective studies to explore causal pathways and determine how best to incorporate eosinophil monitoring into comprehensive COPD management strategies.

"The study highlights the importance of viewing COPD as a systemic disease and not just a condition of the lungs, especially when elevated eosinophil levels are present," the authors concluded.

Reference:

Chen, H., Hu, X., He, C. et al. Association of blood eosinophil counts with pulmonary and extrapulmonary comorbidities in patients with chronic obstructive pulmonary disease: data from NHANES 2013–2018. BMC Pulm Med 25, 256 (2025). https://doi.org/10.1186/s12890-025-03734-6