I sleep-a lot. Now, my definition of "a lot" has changed over the years. "A lot" in high school meant sleeping until noon, maybe even later. Why my mother let me do that is still beyond me. However, according to this research I am about to 'blog', maybe I should now thank her! "A lot" is now relative to how many hours others get compared to me. Still, I think my slew of former roommates would agree that I take sleeping to another level. I mean, I am OUT solid for eight hours every night. In the college dorms, I totally missed a fire alarm. I am NOT joking. I have slept through hurricanes and tornadoes. Thunder does not phase me, and things that keep others awake like the television, kids, lights, and to-do lists only challenge me to sleep better! For the record, I always win that challenge.
Suffice it to say that we have probably all heard the ol' rule: "Doctors recommend eight hours of sleep per night." Parents are inundated with regulations and warnings related to how much sleep a child needs. Children are oh-so-deprived of superfluous slumber parties, instead usually succumbing to their rooms at a time likely not chosen by them. Well, a study* performed at the University of Chicago Medical Center actually showed that suppressing deep sleep decreased insulin sensitivity, thus reducing glucose tolerance. In non-medical-jargon-because-this-means-nothing-to-me English?
If you do not sleep long enough and sleep well , you are risking developing type 2 diabetes!
This group has previously published** that the amount of sleep played a role in glucose tolerance, but now they are reporting that the quality of that sleep matters too! Most people have heard of the Rapid Eye Movement (REM) stage of sleep. This stage is preceded by non-REM (NREM) sleep in 4 distinct stages***. Stages 1 and 2 are the "light" sleep where one drifts in and out and can be easily awoken. Stages 3 and 4 are where I excel! Sleep is so deep that brain waves are extremely slow (called delta waves), and this is the cycle where some sleepwalk, nightmares occur, and being awoken is difficult. In this study, the scientists kept their subjects sleeping but used a method of acoustic stimuli delivery to prevent subjects from ever entering stages 3 and 4. They measured glucose and insulin after regular sleep for two nights and suppressed deep sleep for three nights and re-measured. Comparing the results, they found this reduced glucose tolerance and decreased insulin sensitivity.
Pretty relevant and interesting. Lucky for me, I sleep absurdly well. In fact, if there was an award for who sleeps the best, I'd win. I mean, not that my sleep is cocky or anything. It's just that my sleep knows it can rock diabetes. That's all. (There's your shout out, Catherine!)
So for all of you chocoholics, you should exercise. But, if you don't, at least sleep. And sleep well.
*This article was published in the Proceedings of the National Academy of Science (PNAS) and is available to the public at http://www.pnas.org/content/105/3/1044.long. For those who are unfamiliar with scientific and medical journals, PNAS is well respected and represents the journal of an elite group of doctors, engineers, and scientists.
**This article is also available to the public at http://jap.physiology.org/cgi/content/abstract/99/5/2008?ijkey=a4610ad4ed2a7a1bbb3bdf28bfd2887fd1de5817&keytype2=tf_ipsecsha.
***A great source for easy-to-understand sleep stages can be found at http://www.sleepdex.org/stages.htm.