Introduction: The European Space Agency conducted an astronaut selection campaign in 2008-09 which attracted over 8000 applicants. Of those, 45 made the final assessment stage: the medical examination (MEX). This retrospective, observational study reports exercise and fitness data, lipid profiles and other results of interest from the blood and urine samples of this niche subpopulation.
Methods: All the applicants that reached the MEX completed a Bruce protocol test and a standard blood draw (12 h of fasting, water intake was ad libitum) was collected together with a 24-h urine collection. All the results were compared to either a comparative population or reference range.
Results: The applicants had comparable fitness levels to the 90th percentile of their age group. The lipid profiles were observed to be within the 'optimal' or 'desirable' ranges. Bilirubin and creatinine clearance were measured at 1.2 (+/- 0.40) mg x dl(-1) and 131.0 (+/- 25.81) ml x min(-1), respectively, and both were shown to be significantly higher than their respective normative ranges, while urinary creatinine (0.65 (+/- 0.19) g x L(-1)) was significantly lower than the reference range.
Discussion: Overall, the results from the Bruce protocol and lipid profile show that the final round applicants were in good health and physically active. The most likely cause of the elevated bilirubin and creatinine levels was 'last-minute' exercise conducted by the final round applicants before the MEX and the low levels of urinary creatinine may be attributed to drinking high quantities of water with an associated hypovolemia, diluting the urine.