Posted by blueboy on June 9, 2008, at 6:52:41
In reply to time of day of symptoms, posted by bissie66 on May 22, 2008, at 14:29:30
I was writing an article on cortisol yesterday and thought maybe a comment on it might be interesting in this context.
Cortisol is similar to adrenaline, and is in fact manufactured in the adrenal glands, but acts more as a daily regulator than as an emergency source of energy. It is longer lasting and slower acting than adrenaline. High levels tend to break down fat and keep blood sugar high, and keep us alert.
It lowers immunity (think "cortisone", a substance that imitates cortisol and is used to reduce auto-immune disfunction) and is harmful in a number of ways when stress keeps cortisol levels high for too long. Low cortisol periods are needed for the body to repair itself: build bone and muscle, fight off disease, and who knows what all.
Anyway, normal cortisol fluctuation may be useful to keep in mind when you are trying to figure out what's going on with your mood and energy level at a particular time of day. Assuming a full night's sleep (@ 7-8 hours), levels are usually lowest about 3-5 hours after you go to sleep. They start to rise before you wake up and max out in midmorning. Then they slowly decline.
Stress causes some degree of cortisol release, similar to adrenaline but longer-lasting. It seems likely, to me, that this is partly responsible for some of the bad effects of long-term stress, especially the tendency to catch colds.
That's all I really know. It's obvious to me that I have a less active period after lunch and a more active period starting around 7 pm, but I don't know what causes this, whether my cortisol doesn't decrease in a straight line or whether other energy regulatory functions.
Also, maybe this is why I sleep better after I get a lot of exercise -- my body needs to repair itself and so something in my brain signals the adrenal gland to hold off on the cortisol a bit longer.
poster:blueboy
thread:830527
URL: http://www.dr-bob.org/babble/20080606/msgs/833723.html