aging endocrine system and acth stim test Flashcards
What are common effects of aging on the endocrine system?
Decreased hormone production and secretion, altered hormone metabolism and biological activity, decreased responsiveness of target tissues to hormones, and alterations in circadian rhythm.
What is a common endocrine disease associated with aging?
Hypothyroidism.
How can aging lead to hypercalcemia?
Increased calcium levels can contribute to osteoporosis.
What is a consequence of decreased sex hormones in aging individuals?
Decreased libido.
How does aging affect catecholamine secretion?
There may be an increased secretion of catecholamines, which can lead to hypertension (HTN).
How does aging affect insulin sensitivity and glucose tolerance?
Aging is associated with decreased sensitivity to insulin and increased glucose tolerance, potentially leading to diabetes.
What is the purpose of the ACTH stimulation test?
To measure how well the adrenal glands respond to adrenocorticotropic hormone (ACTH).
What does ACTH do?
It is a hormone produced in the pituitary gland that stimulates the adrenal glands to release cortisol.
What is the procedure for the ACTH stimulation test?
Blood levels of ACTH and cortisol are drawn, synthetic ACTH is administered, and then ACTH and cortisol levels are redrawn after 30 minutes, 60 minutes, or both, depending on the amount of ACTH given.
What cortisol level indicates a normal response in a healthy individual?
Cortisol levels should increase above 18-20 μ/dl within 60 minutes on a stimulation test.
What does it indicate if cortisol does not rise during the stimulation test?
In Addison’s disease, both cortisol and aldosterone levels are low, indicating that the adrenal glands are the problem.
How do early stages of secondary adrenal insufficiency affect test results?
The adrenal glands will still stimulate hormone production in response to synthetic ACTH, resulting in a normal stimulation test.
What happens in secondary adrenal insufficiency due to exogenous steroid use?
Over time, the adrenal glands will atrophy, cortisol production will fail, and patients will fail the stimulation test.
