This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
Steroids cause: 
Select and explain. 
A. Increased TSH, B. Increased FSH, C. Prevent de-iodination, D. All of the above
C: Prevent de-iodination
Answer: C: Prevent de-iodination 
Explanation: Ans. (C) Prevent de-iodination(Ref: Katzung 11/e p670, 686)Glucocorticoids on long term use suppress the release of ACTH, GH, TSH and LH. These also inhibit the activity of 5'- deiodinase and thus inhibit the peripheral conversion of T4 to T3. These also decrease thyroid binding globulin.