HAMP and chronic obstructive pulmonary disease: Consistent with the elevation of ferritin and hepcidin by inflammation, the values for these were significantly higher in the COPD ID subgroup compared with the control ID subgroup (median ferritin 28.3 vs 10.5 μg/L, p=0.040; median hepcidin 21.4 vs 3.33 μg/L, p=0.020).