Sciency Stuff Part II

Greetings Daily Dwayne Enthusiasts! The editors of The Dwayne have asked me to make another guest appearance and write a little segment about an upcoming test Tate is going to have on Tuesday. The test is called a Cortrosyn Stimulation Test (aka ACTH Stimulation Test) and it is going to help the doctors rule out possible adrenal gland and/or pituitary gland issues. This is in response to the fainting and light- headedness Tate has been experiencing. Before I start explaining the test, what it is measuring, etc.

The Cortrosyn Stimulation Test measures your cortisol levels at different intervals to determine if your adrenal glands are responding to a dose of ACTH (adrenocorticoropic hormone – say that 10 times fast) that is introduced to the body. It is a one-hour test that begins with a blood draw to test the baseline cortisol level. Then they inject a dose of ACTH into his system. After 30 minutes they take another blood sample and check his cortisol level again. And finally, another blood sample at 60 minutes for the final cortisol level test. But what pray tell do cortisol and ACTH have to do with each other? Glad you asked friend, glad you asked.

Cortisol and ACTH have a kind of symbiotic relationship. ACTH is produced in the pituitary gland in the brain while cortisol is produced by the adrenal glands that are just above your kidneys. Cortisol is most commonly known as the “fight or flight hormone” because it is released during high levels of stress and fear. Cortisol also has an effect on metabolic processes as well as the immune system in fending off infections. It works like this, when we experience stress (be it through an outside source or the stress of an infection attacking your body) the pituitary gland in the brain releases ACTH. When ACTH is introduced it prompts the adrenal gland to increase your cortisol levels. When cortisol levels rise the pituitary gland stops producing ACTH. So, this what I meant by calling it a symbiotic relationship, when working correctly they each keep the other leveled kind of like a teeter-totter. But there are diseases that can cause the adrenal gland to not produce enough (or any) cortisol. One such disease is called Addison’s Disease and can be life threatening. For the record, nobody, including the Endocrinologist, thinks Tate has Addison’s Disease but they want to make sure because low cortisol levels can cause low blood pressure, fainting and light headedness. An interesting fact that we learned in the clinic is that John F. Kennedy had Addison’s Disease which is why he would take time to lay down and rest often and also why he had a hunky permanent bronze-like tan. Addison’s Disease does that to your skin. Where was I? Oh yeah, the risks we are ruling out, there are other disorders that can affect the pituitary gland’s levels of ACTH released into the body. Cushing’s Syndrome is one such disorder that has a number of unwanted health risks associated with it. When a person has Cushing’s Syndrome the pituitary gland produces more ACTH than is needed which in turn causes the adrenal gland to produce too much cortisol. One of the common exogeneous (coming from outside your body) causes of Cushing’s Syndrome is the long-term use of glucocorticoids (Tate’s main steroid Prednisone is a glucocorticoid).

So, in running the Cortrosyn Stimulation Test they will be able to determine how Tate’s adrenal glands are responding when ACTH is introduced which will allow them to rule out some potential scary things that might be causing his fainting episodes. If the results come back unexpected there are some more tests they can run to really isolate which area (adrenal or pituitary or even the hypothalamus which produces CRH – corticotropin-releasing hormone – which can affect the pituitary’s ability to release ACTH but we won’t even go there in this update) is having the problem.

Now for the silver lining: the endocrinologist is very confident that his episodes are directly related to the prednisone and she did not seem to indicate that any lasting form of Cushing’s Syndrome was a concern. What she said was that she sees this all the time with children who have to take steroids. Her explanation was a little “dumbed-down” for us but she essentially said that the adrenal gland and pituitary glands get “lazy” when steroids are introduced for any significant amount of time. They stop functioning because the steroids are much stronger so they simply stop producing the needed hormones which can cause the symptoms that Tate is experiencing. This is not a permanent atrophy, once the steroids are no longer administered the glands will return to normal function once again. But she is expecting that we will have to give Tate hydrocortisone when he is not on prednisone to keep everything level during the rest of his maintenance phase of treatment.

So there you have it – The Cortrosyn Stimulation Test. The expected result is that he will have low cortisol levels to begin with and that the introduction of the ACTH will cause a minimum to no rise in cortisol due to the monthly steroid pulses he gets. If this occurs then they will prescribe him over the counter hydrocortisone that will give him the hormone level he needs.

Thank you all for your ongoing reading of The Dwayne. Sally puts a lot of love, effort and sometimes tears into this as a means to keep all our loved ones up to date. And a special thanks to Dr. “Smitty” Collum for loaning me his Endocrinology Diagnostics book to help with my research into the fascinating world of glands. Now to keep the book away from a certain destructive monster of a dog (did you really think I would be able to write such a long rant without mentioning him?).

Love,

Greg