Iron Deficiency in COPD Associates with Increased Pulmonary Artery Pressure Estimated by Echocardiography.

OBJECTIVES

Iron deficiency (ID) might augment chronic pulmonary hypertension in chronic obstructive pulmonary disease (COPD). This observational study investigates the association between ID and systolic pulmonary artery pressure estimated by echocardiography in non-anaemic COPD outpatients.

METHODS

Non-anaemic COPD patients (GOLD II-IV) with no history of cardiovascular disease were recruited from outpatient clinics. Iron deficiency was defined as ferritin<100μg/L. Pulmonary artery pressure was estimated from the tricuspid regurgitation maximum velocity (TR V). Tricuspid regurgitation V indicative of pulmonary hypertension was considered present for values ≥ 2.9 m/s.

RESULTS

In a total of 75 included patients, 31 (41%) had ID. These patients had a significantly higher TR V (3.02 vs. 2.77 m/s, p=0.01) and lower diffusion capacity of carbon monoxide (40% vs. 50% of predicted, p<0.01), though similar in age, sex, pack years, FEV and high-sensitive CRP (p>0.05). Ferritin inversely correlated with TR V in ID patients (-0.37 (p=0.04)). The prevalence of TR V ≥ 2.9 m/s was twice as high in patients with ID (58% vs. 29%) and odds ratio of pulmonary hypertension in ID (compared to no ID) was 3.3 (95% CI 1.3-8.6, p=0.015).

CONCLUSION

Iron deficiency in non-anaemic COPD patients was associated with a modest increase in systolic pulmonary artery pressure and limitation of diffusion capacity.