COPD assessment test score and serum C-reactive protein levels in stable COPD patients

Abstract

Background

An eight-item questionnaire of the COPD assessment test (CAT) is widely used to quantify the impact of COPD on the patient’s health status. C-reactive protein (CRP) is associated with disease severity and adverse health outcomes of patients with COPD. This study aimed to evaluate the relationship between CAT score and serum CRP levels in stable COPD patients.

Methods

We evaluated the medical records of 226 patients with CAT and serum CRP measured within a week at Samsung Medical Center between October 2013 and October 2015.

Results

Serum CRP levels had a significantly positive relationship with CAT score (Spearman’s r=0.20, P=0.003). Patients with elevated serum CRP levels (>0.3 mg/dL) were significantly more likely to have CAT scores of ≥14. The adjusted odds ratio for elevated serum CRP levels in total CAT score was 1.06 (95% confidence interval, 1.02–1.09). Among CAT components, cough (adjusted P=0.005), phlegm (adjusted P=0.001), breathlessness going up hills/stairs (adjusted P=0.005), low confidence leaving home (adjusted P=0.002), and feeling low in energy (adjusted P=0.019) were independently associated with elevated serum CRP levels.

Conclusion

In stable COPD patients, serum CRP levels were independently associated with total CAT score and CAT components related to respiratory symptoms, confidence leaving home, and energy.

Keywords:

• chronic obstructive pulmonary disease assessment test
• C-reactive protein
• quality of life
• inflammation

Supplementary material

Table S1 Clinical characteristics according to serum CRP levels

Acknowledgments

The authors would like to thank Soohyun Kim for electronic medical record development for this study. This study was supported by the Samsung Medical Center Foundation for Medical Research (SMO1140211).

Disclosure

The authors report no conflicts of interest in this work.