C-reactive protein in patients with COPD, control smokers and non-smokers.
BACKGROUND
Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels.


METHODS
Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements.


RESULTS
Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05).


CONCLUSIONS
CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.
Pinto-Plata
V M
VM
Pulmonary and Critical Care Division, Caritas St Elizabeth's Medical Center, Tufts University School of Medicine, Boston, MA 02135, USA. vpinto@copdnet.org
Müllerova
H
H
Toso
J F
JF
Feudjo-Tepie
M
M
Soriano
J B
JB
Vessey
R S
RS
Celli
B R
BR
D000305:Adrenal Cortex Hormones / Q000009:adverse effects; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000097:blood / Q000150:complications*; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D012907:Smoking / Q000009:adverse effects / Q000097:blood*; D014797:Vital Capacity / Q000502:physiology
D000305:Adrenal Cortex Hormones; D002097:C-Reactive Protein