Intravenous iron delivers a sustained (8‐week) lowering of pulmonary artery pressure during exercise in healthy older humans. Issue 13 (3rd July 2019) - Cheng, Hung‐Yuan
Abstract: In older individuals, pulmonary artery pressure rises markedly during exercise, probably due in part to increased pulmonary vascular resistance and in part to an increase in left‐heart filling pressure. Older individuals also show more marked pulmonary vascular response to hypoxia at rest. Treatment with intravenous iron reduces the rise in pulmonary artery pressure observed during hypoxia. Here, we test the hypothesis that intravenous iron administration may also attenuate the rise in pulmonary artery pressure with exercise in older individuals. In a randomized double‐blind placebo‐controlled physiology study in 32 healthy participants aged 50–80 years, we explored the hypothesis that iron administration would deliver a fall in systolic pulmonary artery pressure (SPAP) during moderate cycling exercise (20 min duration; increase in heart rate of 30 min −1 ) and a change in maximal cycling exercise capacity ( V ˙ O 2 m a x ). Participants were studied before, and at 3 h to 8 weeks after, infusion. SPAP was measured using Doppler echocardiography. Iron administration resulted in marked changes in indices of iron homeostasis over 8 weeks, but no significant change in hemoglobin concentration or inflammatory markers. Resting SPAP was also unchanged, but SPAP during exercise was lower by ~3 mmHg in those receiving iron ( P < 0.0001). This effect persisted for 8 weeks. Although V ˙ O 2 m a x remained unaffected in the iron‐replete healthy participants studied here, this study demonstrates for the first time the ability of intravenous iron supplementation to reduce systolic pulmonary artery pressure during exercise. Abstract : Intravenous iron was administered to 16 healthy volunteers aged 50–80 years and its effects compared with 16 similar controls over 8 weeks. We observed a lowering of systolic pulmonary artery pressure during exercise in those receiving iron. This interesting change is discussed in relation to the known effects of iron on the pulmonary circulation.