FIGURE 1.

Variation with altitude of iron indices, haematological parameters and cardiopulmonary physiological variables. Sea-level data were acquired immediately prior to infusion of iron or saline. Data are plotted as mean±sem. The p-values given are for the interaction between group and altitude, that is, whether iron administration altered the change from sea level to maximum altitude. S_pO2: peripheral oxyhaemoglobin saturation; SVI: stroke volume index; T_Sat: transferrin saturation; Hb: haemoglobin concentration; sTfR: soluble transferrin receptor; CI: cardiac index; RIMP and LIMP: RV and LV indices of myocardial performance (combined measures of the efficiency of ventricular filling and ejection; higher values indicate more significant impairment); Epo: erythropoietin; RVSP: right ventricular systolic pressure; PVR: pulmonary vascular resistance; TAPSE: tricuspid annular planar systolic excursion.