The Effect of Stressful Diagnostic Studies and Surgery on Anterior Pituitary Hormone Release in Man

Abstract

The hormonal response of the anterior pituitary was studied in 10 normal males undergoing treadmill exercise testing, in 5 male patients undergoing diagnostic gastroscopy, and in 8 male patients undergoing elective surgery under general anaesthesia. Serum TSH was depressed below the baseline value at 2 and 3 h post-treadmill exercise, at 1, 2 and 3 h post-gastroscopy and from 10 min through 2 h post-surgery. Serum triiodothyronine was depressed below the baseline value at 10 min through 2 h post-surgery. Serum prolactin, growth hormone and cortisol were elevated by all three stressful procedures. Both gastroscopy and surgery resulted in an elevation of serum luteinizing hormone levels. There was no significant change in serum FSH levels in any of the three procedures. The post-stress depression in TSH levels could result from the suppressive effect at the hypothalamic-pituitary level of high serum levels of cortisol generated by the stress of the procedures.

The effects of maximal aerobic exercise on cortisol and thyroid hormones in male field hockey players

“…Our results were consistent with other reports suggesting that hemoconcentration could be a cause of changes in circulating TSH and fT3 (Krotkiewski et al, 1984;Sowers et al, 1977;Schmid et al, 1982).…”

“…In this study, cortisol concentration significantly increased immediately after exercise. High serum levels of cortisol generated by the stress procedure might also contribute to the post-stress (exercise) depression of TSH levels (Sowers et al, 1977).…”

Effect of Treadmill Exercise on Circulating Thyroid Hormone Measurements

“…The hemoconcentration results contradicted some reports that no apparent Hct changes were found [11,14]. However, our results were consistent with other reports [7,9,[13][14][15][16] suggesting that hemoconcentration could be a cause of changes in circulating TSH. High serum levels of cortisol generated by the stress procedure might also contribute to the post-stress (treadmill exercise) depression of TSH levels [7].…”

“…While data has been reported on effects of exercise on the TH metabolism, the results have been inconsistent or even contradictory [4,[6][7][8][9][10][11]. These divergent results may be due to differences in the intensity of work, duration of exercise, frequency and design of the training program, and to differences in gender and age of the subjects.…”

“…These divergent results may be due to differences in the intensity of work, duration of exercise, frequency and design of the training program, and to differences in gender and age of the subjects. In addition, different duration of studies, timing of sampling after exercise and methodological factors in hormonal assay and data analysis may also be responsible for the discrepancies [4,[6][7][8][9][10].…”