Proteinuria in fighter pilots after high +Gz exposure

Exposure to high gravitational forces acting along the body axis towards the feet (+Gz) causes considerable strain on several organ systems, including the kidneys. During +Gz tolerance studies without anti-G suits, significant amounts of protein and hyaline casts were found in 17 of 20 fighter pilots after centrifugation. The G load alternated between 3.5 and 5.5 G. Mean time in the centrifuge was 15 min. For comparison we examined another group of 19 fighter pilots after air combat maneuver training with anti-G suits. None showed proteinuria. The proteinuria most likely indicates a severely depressed renal blood flow during centrifugation.