This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
At what time of the day GH levels are highest:September 2007 
Select and explain. 
A. 2 hours after sleep, B. 2 hours before sleep, C. Evening, D. Early morning
A: 2 hours after sleep
Answer: A: 2 hours after sleep 
Explanation: Ans. A: 2 hours after sleepGH is synthesized and secreted from the anterior pituitary gland in a pulsatile manner throughout the day; surges of secretion occur at 3- to 5-hour intervals. The largest and most predictable of these GH peaks occurs about 2 hours of deep sleep, otherwise there is wide variation between days and individuals.