Impact of intravenous iron or exogenous erythropoietin on hemoglobin mass, exercise performance, and acute mountain sickness during altitude acclimatization.

Neither intravenous iron nor EPO treatment improved hemoglobin mass, exercise performance, or symptoms of acute mountain sickness during high-altitude exposure.

Summary and findings

This study evaluated the effects of intravenous iron and erythropoietin (EPO) on hemoglobin mass, exercise performance, and acute mountain sickness (AMS) during a 14-day altitude exposure at 3,094 m. Thirty-nine participants received either a placebo, iron, or EPO treatment. The findings indicated no significant differences in hemoglobin mass or exercise performance among the treatment groups.

Abstract

Chronic exposure to high altitude leads to increases in hemoglobin mass (Hbmass), which may improve exercise performance and decrease acute mountain sickness (AMS) symptoms. We evaluated the influence of intravenous iron or erythropoietin (EPO) treatment on Hbmass, exercise performance, and AMS during a 14-day exposure to 3,094 m. Thirty-nine participants (12 F) completed the study conducted in Eugene, Oregon [sea level (SL), 130 m] and Leadville, Colorado (3,094 m). Participants were dosed with either a placebo (saline; <i>n</i> = 13), iron [Fe(III)-hydroxide sucrose 200 mg, 2 times; <i>n</i> = 14], or EPO (epoetin alfa 50 IU/kg, 3 times/wk; <i>n</i> = 12) at SL for ∼3.5 wk. Hbmass, exercise performance, and AMS symptoms were measured at SL before treatment and on <i>days 1</i>, <i>2</i>, <i>7</i>, <i>13</i>, and <i>14</i> at altitude. Absolute Hbmass (g) increased from SL and <i>day 1</i> to <i>day 13</i> (<i>P</i> < 0.0001) with no differences between treatment groups (<i>P</i> = 0.3868). Five-kilometer run times were slower at altitude compared with SL (<i>P</i> < 0.0001) and did not improve over the 14-day period at altitude for any group (<i>P</i> > 0.05). Hike times improved with acclimatization from <i>day 2</i> to <i>day 14</i> (<i>P</i> = 0.0018) in all groups, independent of treatment. The incidence and severity of AMS remained low across all participants and time points, regardless of treatment. In the current study and dosing, intravenous iron and EPO did not lead to improvements in Hbmass, exercise performance, or AMS with rapid ascent and residence at 3,100 m.<b>NEW & NOTEWORTHY</b> We investigated the influence of iron or erythropoietin treatment on hemoglobin mass, exercise performance, and acute mountain sickness (AMS) during a 14-day exposure to 3,094 m. With the given drug doses of iron [Fe(III)-hydroxide sucrose 200 mg, 2 times over 4 wk] and erythropoietin (epoetin alfa 50 IU/kg, 3 times/wk for 3 wk), we observed no differences in hemoglobin mass, aerobic exercise performance, or symptoms of AMS between groups relative to a placebo.

Limitations

Not reported in abstract.

Elsewhere in the Erythropoietin (EPO) corpus