Hemolysis contributes to anemia during long-duration space flight

Area of Science:

• Space medicine
• Hematology
• Physiology

Background:

• Anemia in astronauts has been observed since early space missions.
• The underlying mechanisms of spaceflight-induced anemia remain poorly understood.

Purpose of the Study:

• To investigate the mechanisms contributing to anemia in astronauts during space flight.
• To determine the effects of microgravity on red blood cell parameters.

Main Methods:

• Analysis of hemoglobin degradation products (carbon monoxide, iron) in 14 astronauts during 6-month International Space Station missions.
• Assessment of erythrocytic effects (hemolysis, reticulocytosis, hemoglobin) one year post-flight.

Main Results:

• Space flight was associated with persistently increased levels of hemoglobin degradation products.
• Increased hemolysis, reticulocytosis, and hemoglobin levels were observed during and after space missions.
• These findings indicate a significant impact on red blood cells due to space travel.

Conclusions:

• Microgravity appears to induce hemolysis, a primary effect contributing to space flight anemia.
• Space flight anemia is likely a hemolytic condition.
• Findings support the need for screening and monitoring of astronauts and space tourists for hemolytic anemia.