Longitudinal brain-age predictions comprising long-duration spaceflight missions.

Area of Science:

• Neuroscience
• Space Medicine
• Radiology

Background:

• Understanding the physiological effects of space travel on the human body is crucial.
• Long-duration spaceflight poses unique challenges to astronaut health, including potential impacts on the brain.

Purpose of the Study:

• To investigate the effects of long-duration spaceflight on brain aging in astronauts.
• To compare brain aging in spacefarers (ROS cosmonauts and ESA astronauts) with Earth-bound controls.

Main Methods:

• Structural MRI scans were acquired pre-flight, post-flight, and during follow-up.
• Machine learning models were employed to estimate brain age from MRI data.
• Data from Russian (ROS) and European (ESA) astronauts and matched controls were analyzed.

Main Results:

• A significant difference in brain aging was observed between spacefarers and controls, particularly in the ESA cohort (ß = 0.63).
• In the ROS cohort, a difference was noted between pre- and post-flight scans, with post-flight brain age being approximately 0.842 years greater than pre-flight.
• Machine learning models demonstrated good to excellent reliability (ICC) across MRI sessions.

Conclusions:

• Long-duration spaceflight appears to influence human brain aging.
• Further research is warranted to fully elucidate the neurobiological consequences of space travel.