Abstract

Have you ever dreamed of being an astronaut? Exploring outer space sounds exciting, and astronauts get to do that. However, going into space can lead to health problems. The lack of gravity has a negative impact on bones, called bone loss. Astronauts try to compensate for bone loss with a lot of exercise – both in space and on Earth. But even exercising doesn’t prevent bone loss in some cases. We wanted to find out what factors affect bone loss. We also wanted to find a way to predict bone loss in astronauts before spaceflight. 

We analyzed the leg and arm bones of 17 astronauts before and after a space mission. We also looked for markers of bone change in their blood and urine. 

We found out that bone loss happens quickly in space. The longer the space mission, the bigger the problem. More exercise before spaceflight predicted greater bone loss! Elevated markers of bone metabolism before flight also predicted greater bone loss.