Elevated C-reactive protein to albumin ratio levels increase COPD risk: Study

A recent study published in the BMC Pulmonary Medicine unveiled a strong link between the C-reactive protein to albumin ratio (CAR) and chronic obstructive pulmonary disease (COPD). This discovery highlights CAR as a critical biomarker in assessing the risk and progression of this life-threatening respiratory condition.

COPD affects millions globally and is known for its progressive nature and significant health impact. While CAR has already been recognized as a marker for various diseases, its association with COPD has remained understudied until now. This new cross-sectional analysis offers valuable insights into this relationship.

The study analyzed data from 24,627 adult participants enrolled in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2010. COPD was identified based on self-reported information, and logistic regression analysis was utilized to evaluate the relationship between CAR and COPD.

This research adjusted the analysis for potential confounding factors to ensure accurate results. Subgroup and sensitivity analyses were also conducted by offering additional layers of validation and confirming the consistency of the findings. These rigorous methodologies ensured the reliability and robustness of this study.

Of the participants, a total of 1,809 were identified as having COPD. The study revealed that elevated CAR levels were significantly associated with a higher risk of COPD. After accounting for various confounding variables, the odds ratio (OR) for the CAR-COPD association stood at 1.37 (95% confidence interval [CI], 1.12–1.69; P = 0.003).

Further analysis compared individuals in the lowest CAR tertile (T1) and the ones in the highest tertile which showed even stronger results. The adjusted OR was 1.39 (95% CI, 1.17–1.65; P < 0.001), which indicated a substantial increase in COPD risk among individuals with elevated CAR levels. These findings were reinforced by the subgroup and sensitivity analyses, which demonstrated the stability and consistency of the observed relationship.

These results underline the potential of CAR as a vital marker for identifying individuals at higher risk of COPD. By incorporating CAR analysis into routine medical assessments, physicians could improve early detection and targeted interventions for this condition. This research marks a significant step forward in understanding the underlying mechanisms linking inflammation and protein levels to COPD. Further investigations encourage to explore the role of CAR in disease progression and to develop preventive strategies aimed at reducing the global burden of COPD.

Reference:

Ao, T., Huang, Y., Zhen, P., & Hu, M. (2025). Association between C-reactive protein to albumin ratio and chronic obstructive pulmonary disease: a cross-sectional study. In BMC Pulmonary Medicine (Vol. 25, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1186/s12890-024-03469-w