Trace element and hormonal responses during flight aptitude test.

BACKGROUND

The purpose of this study was to determine how trace metal and hormone levels change during stressful flight tests. The relationship between the hormonal response and flying performance was also investigated.

METHODS

Urinary zinc (Zn), copper (Cu), noradrenaline (NAd), adrenaline (Adr), and saliva cortisol (Cs) levels were determined in 67 pilot applicants and compared with NAd, Adr, and Cs levels in 30 instructor pilots during 4 flight tests.

RESULTS

Applicants had significantly decreased Zn concentrations following flight, but Cu concentrations remained unchanged. NAd, Adr, and Cs concentrations significantly increased following flight; the average ratio (post-/pre-flight) of the hormonal levels of the applicants was 1.52 (NAd), 3.57 (Adr), and 2.80 (Cs) compared with 1.86 (Adr) in instructors (NAd and Cs concentrations were not significantly changed in instructors following flight). Multiple regression analyses of post-flight levels of Zn for the hormonal levels revealed that Zn levels correlated significantly (p < 0.05) negatively with Adr levels. Hormonal responses for the best-rated and worst-rated applicant groups were greater than in the other groups, and post-flight levels of NAd and Adr in the best-rated group tended to return more rapidly to pre-flight levels.

CONCLUSION

Flight test stress causes pilot applicants to change levels of urinary Zn, NAd, Adr, and Cs. Post-flight Zn decrement was likely related to an increase in Adr, suggesting that circulating Zn is sequestered by the liver in situations that induce hormonal changes.