Key result
Exposure to 2,400m altitude is linked to increased hematocrit, RBC aggregation, and pulmonary hemodynamic parameters.
Why the study?
Blood rheology and pulmonary hemodynamic parameters have never been explored together during acclimatization to moderate altitude.
Does exposure to moderate altitude alter blood rheology and pulmonary hemodynamics in athletes?
Observational (n=17)
Does exposure to moderate altitude alter blood rheology and pulmonary hemodynamics in athletes?
Early altitude exposure increases blood viscosity and pulmonary pressures, with pulmonary hemodynamic changes persisting even after blood viscosity normalizes at 5 days.
May warrant caution for athletes at moderate altitude; leaves open whether viscosity drives persistent pulmonary changes.
Blood rheology and hemodynamic parameters have never been explored together during acclimatization to altitude. This study aimed to investigate changes in blood rheology parameters and pulmonary hemodynamics during the first days of real moderate altitude exposure.Seventeen athletes were tested at sea-level, 20 hours after their arrival at 2,400 meters of altitude (H1) and five days later (H2). Blood was sampled to analyze red blood cell (RBC) aggregation, blood viscosity and hematocrit. Pulmonary arterial pressure (PAP), pulmonary capillary pressure (Pcap) and pulmonary vascular resistance (PVR) were assessed by echocardiography.We observed a rise in hematocrit, blood viscosity, RBC aggregation, PAP, Pcap and PVR between sea-level and H1. In H2, RBC aggregation, hematocrit, PAP, Pcap and PVR remained different compared to sea-level and no difference was observed between H1 and H2. Blood viscosity decreased in H2 and returned to sea-level values.Our results suggest that hemoconcentration occurring within the first hours of altitude exposure increased blood viscosity, which contributed to the changes in pulmonary hemodynamic. When blood viscosity decreased in H2, no change occurred in pulmonary hemodynamic parameters suggesting that hypoxic pulmonary vasoconstriction was still present. The elevated RBC aggregation observed after in H2 could participate in the increase of Pcap.
No takes yet. Share an insight, caveat, or question.
Raberin et al. (2019) conducted an observational in Exposure to moderate altitude (n=17). Exposure to moderate altitude (2,400 meters) vs. Sea-level was evaluated on Changes in blood rheology parameters and pulmonary hemodynamics. Exposure to 2,400 meters altitude in 17 athletes increased hematocrit, RBC aggregation, and pulmonary hemodynamic parameters over 5 days, with an initial rise in blood viscosity.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: