Expert: Joy Ramos - 5/6/2006

Question
Wow, that was a great answer. This topic is something that has a very high level of personal application for me so I'm especially interested in it.  For many years I have lived as if the day was 25 hours long rather than 24 hours long.  I've asked sleep experts about what exactly my problem may be and I never got a good answer and now I'm thinking biology experts may have a better answer for me. I have a VERY irratic sleeping habit and it has not been unusual for me to go to sleep for 4 hours over the course of 48 hours, and then suddenly sleep for 20 hours over the course of another 48 hours. For the most part, however, I would often go to bed slightly later than I have the day before regardless of what time of day it was.  I would go through what I call a "cycle" where I would sleep and wake up an average of around an hour or so later than I did the day before so that by the end of this cycle, which usually lasted somewhere around 3-4 weeks, I would have slept one less time than someone who would sleep once a night.  In your answer you mentioned that light plays a VERY BIG role.  Well the thing is that I like to be in dark rooms and dark areas with the curtains completely closed so that barely any light comes in and for the past few years I have rarely even gotten out of the house during the day.  Also, the only thing I do on any kind of normal schedule is washing up and that's really about it.  

Now to the other questions about this I wanted to ask, I was wondering if you knew of any detrimental health affects that may come from having a sleeping habit such as mine. There have been times where I've been able to sustain more of a "normal" sleeping habit but I've usually only been able to maintain this for a few weeks before reverting to my old habit. The last time I was able to do this, I noticed that my skin looked much clearer. Also, I ended up in an emergency room and was diagnosed with having gallstones a year and half ago when I was 21 years old. Could either my skin or gallbladder have been affected by my very irratic sleeping habits? Also I have a slightly different question. If I had slept more consistent amount of time but operated on a 25 hour day cycle, can it be detrimental to my health even if I am in dark rooms most of the day?  If these are not something that has an answer yet or if it's difficult to answer, I would appreciate it if you could tell me where I can read about the circadian rhythm research done on rab rats so that maybe I can at least form my own opinions.  Thank you!


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Followup To
Question -
Hi, this is a pretty specialized question and I may be totally off base here but I thought I'd give it a shot.  I've been having sleep difficulties most of my life where I naturally seem to want to go to bed about an hour later than I had gone to bed the previous day.  Interestingly, I read that "the suprachiasmatic nucleus sets the body clock to approximately 25 hours" (http://www.emedicine.com/neuro/topic444.htm) and it seemed relevant since my sleep cycle tends to function as if the day was 25 hours long instead of 24 hours long.  I was wondering if you knew why the the suprachiasmatic nucleus may set the body clock to 25 hours instead of 24 hours when, as far as I know, the day has been 24 hours or very close to it since beginning of human history.  
Answer -
Hi, James! You lucked out since the research lab I work in investigates circadian rhythms and metabolism! I work on a different topic but I asked my labmates about your question.  Actually, the average body clock is not exactly quite 24 hours but can hover between 24 and 25 hrs. A lot of studies have been done on mice and rats to investigate the different components of the system that regulates the sleep-wake cycle. You're right, the SCN is where the central pacemaker (aptly called "CLOCK") is found and regulates the sleep-wake system.  Alterting the functions of particular key components can lead to either a longer or shorter day for the lab rat. We're not sure if the same is true for humans since unfortunately, you can't really do studies like that in humans. First of all, you can't alter human genes for research purposes :) and also, it's very hard to control the living environment of humans in order to accurately record and underestand their body clocks.  For example, light plays a VERY BIG role in regulating our sleep-wake cycle.  For example in winter, when there's less outdoor light, our sleep cycles are naturally altered but we don't let that manifest itself since we all still follow the regular workday, regardless of how much light there is outside. So, as of now, it's not quite clear what genes are involved in determining a person's body clock but scientists continue to understand it a little better each day.

Answer
Hi, James. There's a lot of information that's available online. One website you can go to is: http://www.stanford.edu/~dement/circadian.html. It has several links for different kinds of information about circadian rhythms. This website is also interesting: http://www.apollolight.com/new_content/circadian%20rhythms_disorders/sleep/circa
OR
http://www.merck.com/pubs/mmanual_ha/sec3/ch31/ch31g.html
but since these are commercial company's websites, they don't cite any references for their claims so I'd be careful about believing what they say. Good luck!