[Anemia in patients with severe chronic obstructive pulmonary disease, a comorbity more common than previously thought].

Chronic Obstructive Pulmonary Disease (COPD) is traditionally associated with polycythemia which results from chronic hypoxemia. Nevertheless, recent studies have shown that anemia may be more frequent than expected in patients with COPD. In this retrospective study, we investigated the prevalence of hemoglobin disorders in a cohort of 100 patients with stable, moderate to severe COPD (II to IV GOLD classification). We identified 31 % patients with anemia while only 15 % had polycythemia. Anemia was more frequent in male patients. We also demonstrated a negative correlation between hemoglobin and CRP levels (R=-0.56, p inferior to 0.0001). COPD patients with anemia had experienced a higher rate of hospitalizations for exacerbation in the previous year than those with polycythemia (p inferior to 0.05). Anemia is a frequent comorbidity in COPD; it is associated with systemic inflammation and a propensity to hospitalization for exacerbation.