This Article Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Chatterton, R. T. Search for Related Content PubMed Articles by Chatterton, R. T.

Psychological Stress and Skydiving—Author’s Response^d

Northwestern University Medical School Chicago, Illinois 60611

Dugué, in the letter above, implies that there is a significant difference between the data of his group and that published by us (1). However, the only analyte measured by both of us was cortisol in men before a parachute jump. His group found a mean increase in serum cortisol of from 504 to 582 mmol/L, P < 0.15 (2). In females the difference was even less significant. There did appear to be a hemoconcentration effect in his subjects, but it was only 2.0% (3). We also found no significant increase before the actual experience of parachuting. Assuming their initial value was actually 504 nmol/L rather than 504 mmol/L as listed, it would appear that their subjects were quite stressed at the time of the initial blood sample. This may, in part, be because blood was drawn by venipuncture, a stressful procedure for many persons.

In our case an indwelling catheter was inserted early in the day; the initial mean value at 0800 h for the parachutists on the day of the skydive was 250 nmol/L and at 1230 h was 225 nmol/L. We did include control day data on the parachutists, but only at one time during the day. The mean cortisol concentration in the parachutists themselves at 1400 h, 3–5 days before the skydive, was 226 nmol/L. Our subjects were also seated for at least 15 min before the preboarding sample was obtained. Hemoglobin measurements were not taken but, if similar to those of Dugué et al. (2), little correction for hemoconcentration would have been necessary.

Thus, we see no evidence that cortisol was increased in first-time skydivers before the actual event in either study and, to quote the conclusion of Dugué et al. (2), "cortisol, commonly used to indicate the level of stress, did not react much and is therefore not a good index of psychological stress." In fact, we found that the concentration of plasma cortisol progressively decreased significantly until mid-morning before skydiving, and we comment on this in relation to other studies in which a similar phenomenon was observed.

Footnotes

Address correspondence to: Robert T. Chatterton, Ph.D., Department of Obstetrics and Gynecology, Northwestern University Medical School, 333 East Superior Street, Chicago, Illinois 60611.

Received December 18, 1997.

References

1. Chatterton Jr RT, Vogelsong KV, Lu Y-C, Hudgens GA. 1997 Hormonal responses to psychological stress in men preparing for skydiving. J Clin Endocrinol Metab. 82:2503–2509.[Abstract/Free Full Text]
2. Dugué B, Leppänen E, Teppo AM, Fyhrquist F, Gräsbeck R. 1993 Effects of psychological stress on plasma interleukins-1 beta and 6, C-reactive protein, tumor necrosis factor alpha, anti-diuretic hormone and serum cortisol. Scand J Clin Lab Invest. 53:555–561.[Medline]
3. Dugué B, Leppänen E, Zhou H-P, Gräsbeck R. 1992 Preanalytical factors and standardized specimen collection: influence of psychological stress. Scand J Clin Lab Invest. 52:43–50.[Medline]

This Article Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Chatterton, R. T. Search for Related Content PubMed Articles by Chatterton, R. T.