Abstract
The Low Dose (1 μg) ACTH Stimulation Test (LDST) is useful in the evaluation of the Hypothalamic-Pituitary- Adrenal (HPA) axis. The effect of physiological stressors on its accuracy is not known. We examined the effect of prior exercise on the assessment of the HPA axis with the low dose ACTH stimulation test. Twenty-six healthy male subjects had baseline cortisol levels drawn at two-hour intervals on the initial day of the study. On day two, the LDST was performed at rest. On day three, subjects exercised by completing stage I-V of a Bruce treadmill protocol, followed by the LDST after one hour of rest. We found that mean peak cortisol levels at 30 and 60 minutes after the LDST did not differ between the day of exercise and the day of rest. The mean maximal change in cortisol levels at 30 and 60 minutes also did not differ. However, mean baseline cortisol levels before exercise began were higher on the day of exercise than on the rest day (p<0.001). Mean ACTH levels at these times were not significantly different (p=0.09). The adrenal response to a LDST test is not affected by prior physiologic stress in the form of exercise in nonsedentary adult males.
Highlights
The low dose (1 μg) Adreno-Cortico Tropic Harmone (ACTH) stimulation test (LDST) is useful in the evaluation of the hypothalamicPituitary-Adrenal (HPA) axis
The LDST produces lower elevations in serum cortisol compared to the SDST and is affected to a greater degree by many variables
We have shown that prior exercise in healthy, active, adult males has no effect on peak cortisol or maximal change in cortisol achieved with the LDST
Summary
The low dose (1 μg) Adreno-Cortico Tropic Harmone (ACTH) stimulation test (LDST) is useful in the evaluation of the hypothalamicPituitary-Adrenal (HPA) axis. The appealing characteristic of the LDST is that it produces lower cortisol elevations than the Standard Dose (250 μg) ACTH Stimulation Test (SDST) which may make it a more sensitive test in mild disease [3,4,5,6,7,8,9,10,11]. Given that the LDST produces smaller elevations in serum cortisol, a number of variables which have not been fully elucidated may affect its accuracy. Exercise of sufficient intensity and duration may produce a different response to HPA axis testing [17,18,19]. Establishing the impact of exercise on the LDST would assist in determining its applicability in different patient populations and clinical settings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
