Intravenous Iron Replacement Improves Exercise Tolerance in COPD: A Single-Blind Randomized Trial

Abstract Introduction Iron deficiency affects exercise capacity because of the critical role iron plays in the optimal functioning of skeletal muscle metabolism. We hypothesized that intravenous iron may improve exercise tolerance, quality of life (QoL), and daily physical activity (DPA) in patients with chronic obstructive pulmonary disease (COPD). Methods This was a placebo-controlled, single-blind, parallel-group, randomized clinical trial. Iron deficiency was defined as a ferritin level  Results We included 66 patients, 44 (66.7%) in the intervention group and 22 (33.3%) in the placebo group. Among patients receiving ferric carboxymaltose, 23 (52.3%) achieved the primary endpoint compared to 4 (18.2%) in the placebo group [p = 0.009; relative risk 3.12, (95% CI, 1.19–8.12)]. CAT score decreased −3 (−6.0–1.3) points from baseline in the intervention group (p = 0.007), in contrast to placebo group [−1 (−4.0–2.3) points, p = 0.236] with no differences in DPA and adverse events in both groups. Conclusions Iron replacement improved exercise capacity and QoL in stable COPD patients with iron deficiency. The treatment was well tolerated. Clinical Trial registration EudraCT 2016-001238-89.