C-reactive protein levels and survival in patients with moderate to very severe COPD.
BACKGROUND
Serum levels of C-reactive protein (CRP) are increased in patients with COPD and correlate modestly with variables predictive of outcomes. In epidemiologic studies, CRP level is associated with all-cause mortality in patients with mild-to-moderate disease.


OBJECTIVE
To determine if CRP levels are associated with survival in patients with moderate to very severe COPD in comparison with other well-known prognostic parameters of the disease.


METHODS
In 218 stable patients with COPD, we measured baseline serum CRP level, BODE (body mass index, obstruction, dyspnea, and exercise capacity) index and its components, arterial oxygenation (Pao(2)), inspiratory capacity (IC) to total lung capacity (TLC) ratio, and Charlson comorbidity score. We followed up the patients over time and evaluated the strength of the association between the variables and all-cause mortality.


RESULTS
During the follow-up time (median, 36 months; 25th to 75th percentiles, 24 to 50 months), 54 patients (25%) died. CRP levels were similar between survivors and the deceased (median, 3.8 mg/L; 95% confidence interval, 1.9 to 8.1; vs median, 4.5 mg/L; 95% confidence interval, 2.1 to 11.5; p = 0.22) and was not significantly associated with survival.


CONCLUSIONS
In this population of patients with clinically moderate to very severe COPD, the level of CRP level was not associated with survival compared with other prognostic clinical tools such as the BODE index, modified Medical Research Council scale, 6-min walk distance, percentage of predicted FEV(1), IC/TLC ratio < 0.25, and Pao(2). Other long-term studies of well-characterized patients with COPD could help determine the exact role of CRP levels as a biomarker in patients with clinical COPD.
de Torres
Juan P
JP
Respiratory Research Unit, Departments, Hospital Ntra Sra de Candelaria, Tenerife, Spain. Electronic address: jupa65@hotmail.com.
Pinto-Plata
Victor
V
Pulmonary and Critical Care Department, Caritas St Elizabeth's Medical Center, Boston, MA.
Casanova
Ciro
C
Pulmonary, Departments, Hospital Ntra Sra de Candelaria, Tenerife, Spain.
Mullerova
Hanna
H
GlaxoSmithKline, Worldwide Epidemiology Department, London, UK.
Córdoba-Lanús
Elizabeth
E
Respiratory Research Unit, Departments, Hospital Ntra Sra de Candelaria, Tenerife, Spain.
de Fuentes
Mercedes Muros
MM
Biochemical Analysis, Departments, Hospital Ntra Sra de Candelaria, Tenerife, Spain.
Aguirre-Jaime
Armando
A
Respiratory Research Unit, Departments, Hospital Ntra Sra de Candelaria, Tenerife, Spain.
Celli
Bartolome R
BR
Pulmonary and Critical Care Department, Caritas St Elizabeth's Medical Center, Boston, MA.
D000368:Aged; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000145:classification / Q000401:mortality; D012720:Severity of Illness Index; D016019:Survival Analysis
D002097:C-Reactive Protein