[stylist] off-topic, final circadian post

[Chris Kuell]

Steve,

You didn't address your post to me, but I'll assume you meant it for me. I 
don't have the time or the energy to research the original papers, but much 
of what I'm going to write is considered common knowledge. I'm going to 
present a simplified scenario which I hope will suffice to answer your 
question.

Forget about blindness and blind people for the next minute. What I'm 
talking about here is the sighted world. If you were to take 100 random, 
healthy,  sighted people and lock them in a dark room for a week, feeding 
them and keeping them comfortable, what you would find is their sleep cycle, 
their circadian clocks, get disturbed. Not every person, some to a lesser or 
higher extent than others, but in a statistically significant way, their 
sleep cycles would be off.

Now, if you were to do a complete, detailed blood work-up before and after 
the above experiment, one thing you would notice is that after darkness, or 
in the post-experiment bloodwork, many, but not all, of the people's 
melatonin levels were reduced. You could then, which has been done, re-do 
the experiment, this time giving the experimental subjects melatonin 
supplements, and check their sleep patterns. Again, it wouldn't be 100%, but 
to a significant extent, you would see that their sleep cycles were better 
than      in the first, no supplement experiment. Hence, it's safe to 
conclude that sunlight affects the production of melatonin, and and 
melatonin has something to do with setting the biological circadian clock. 
You could also do further experiments to verify that sunlight entering the 
eye triggers melatonin production, and this has been proven. However, things 
are a little more complicated, because the human body is a remarkable thing. 
Most of our melatonin comes from the pineal gland, which is triggered by 
sunlight. But in the absence of sunlight, we can also produce small amounts 
of melatonin in our bone marrow and a couple other ways, to lesser extents, 
which I don't remember at the moment. That's why not everyone would suffer 
from a disrupted sleep cycle, some would a little, and some would a lot.

When this was first discovered, melatonin was used to try to adjust people 
who had sleep cycles that were out of whack. It is still used commonly today 
for travelers to fight jet lag, which is another way to throw your sleep 
cycle off. It doesn't work for everyone, not everyone needs it, and some 
people experience side effects. This doesn't change the biological fact that 
melatonin plays an important role in the human circadian cycle.

Okay, now lets consider Joe, a seemingly healthy blind guy who hasn't been 
sleeping well. so badly, in fact, that he goes to a doctor to seek help. 
There could be any number of reasons Joe isn't sleeping well. He could have 
apnea, a badly deviated septum, acid reflux, he likes a cup of coffee at 
10:00 p.m., his job and his wife and his kids are driving him nuts, he's 
worried about next month's mortgage payment, he never exercises and eats 
crap all day, he's got bed bugs, and so on. There are any number of reasons 
he might not be sleeping. When he walks into the office, the doctor greets 
him, asks him why he's there and begins asking questions to best determine 
what to do about it. The doctor will likely discuss no caffeine 5 hours 
before bed, practice good sleep hygiene, take up meditating to reduce 
stress, try to eat right and exercise regularly, etc... The doctor, fully 
aware of the above-mentioned experiments, might also suggest Joe try a 
melatonin supplement. After all, there have also been experiments performed 
on blind people which show that a significant number of blind people are 
somewhat deficient in melatonin.

In my view, this is a reasonable course of action. It's easy, it's not 
dangerous, and it's very inexpensive. Melatonin costs about 3 cents per 
pill--you can't get much cheaper than that. Should the doctor enlist Joe 
into a detailed sleep study to determine if he has apnea, restless leg 
syndrome, or a neurological viral infection? Realistically speaking, sleep 
studies cost thousands of dollars, Joe may or may not have good health 
insurance, but either way it's a very costly procedure which may be entirely 
unnecessary. I realize in you and Peter's case, it was necessary, but 
medicine, especially in the early diagnostic stage,  is often a matter of 
statistics and practicality. I relate it to an old Mustang I used to drive, 
and still own. When the engine was running rough, I'd try the 'easy' fixes 
first. Adjust the mixture in the carb, check the points and spark plugs, 
maybe replace the distributor cap. You don't overhaul the engine unless you 
have to.

Anyway, I hope this makes some sense to you. If not, I've failed, but either 
way we should probably give the topic a rest.

Peace,

chris