By Virginia Gurley, MD, MPH
MB (Marc Braman, MD, MPH):
I’m Dr. Marc Braman, and our topic this session is “Sleep is Key to Physical Health”. Dr. Gurley, thank you for joining us and sharing your expertise.
VG (Virginia Gurley, MD, MPH):
My pleasure!
MB:
We talked in an earlier session about how important sleep is to mental and emotional health. Today let’s talk about how sleep affects our physical health. What are the most important effects sleep has on physical health?
VG:
That’s a hard question, because sleep affects so many key activities in the body, and because almost every week research studies are uncovering new benefits of sleep. But of all the ways sleep affects your physical health, I’d say the most important are how it helps your stress hormones, your blood pressure, heart functioning, appetite, body weight, fat metabolism, and inflammation.
MB:
That’s a really long list! And I see how these are all related to whether or not a person has or could develop cardiovascular and metabolism related conditions, like high blood pressure, obesity, high cholesterol, diabetes, heart disease and more. It sounds like sleep could protect against developing these diseases and well as probably be part of treating them. Yes?
VG:
Yeah, there are many studies showing that not enough sleep increases your risk for developing these conditions. For example, with appetite, studies have shown that after just one night of short sleep people will eat between 300 and 500 more calories the day after getting only 4 hours of sleep than they eat after sleeping 8 hours.
MB:
That’s a pretty big difference. So have any studies been done to look at how sleep affects weight gain and obesity?
VG:
Yes, quite a few studies have found that the risk of being over weight or obese is higher in people who don’t get 7-8 hours of sleep at night. Other studies have shown that not enough sleep makes it harder for your body to handle sugar, and this seems to increase the risk for developing diabetes.
MB:
Wow, so what this is showing us, the science is showing us that sleep seems to be at least one of the causes of these multi-factorial “conditions” that we have today. Has anyone done a study on whether increasing sleep time could be an effective part of treating obesity or diabetes?
VG:
That’s a great question. There is at least one study underway in Australia that’s looking at sleep as a treatment for obesity. And, there is a different study where melatonin, (which is produced in the brain during sleep) taken as a supplement, improved blood sugar control in patients with diabetes. So it definitely can help.
MB:
Interesting, we will look forward to seeing the results of this study. And I know there’s at least one prescription medication officially approved for diabetes treatment that actually works on brain chemistry typically controlled by sleep. What about blood pressure? How does sleep help your blood pressure?
VG:
Well, first of all when you lie down, your heart and blood vessels get a break from gravity and don’t have to work so hard to keep blood flowing to your brain and organs. And then, as sleep gets deeper, your blood pressure drops even further. But when sleep is shortened, that extra drop in blood pressure is lost, and that seems to be one of the first steps to developing high blood pressure during the day.
MB:
So when you don’t get a good quality 7-8 hours of sleep, it’s like your blood vessels don’t get to relax as much as they should?
VG:
Yes, that’s a good way of thinking about it. And when sleep is cut short, it’s not just your blood vessels that don’t get the relaxation they need, your heart rate also stays higher. So your heart isn’t getting the break it needs.
MB:
Higher blood pressure, higher heart rate, higher blood sugar…I can see how all these effects of not getting enough sleep could increase risk for heart disease and diabetes. What about sleep and inflammation?
VG:
Yeah, very similar to how short sleep leads to your body getting stuck in active fight or flight mode with increased heart rate, increased blood pressure, increased blood sugar, not enough sleep also seems to shift your immune system so the part that creates inflammation is overactive too.
MB:
So in essence our inflammation system needs to calm down and sleep also. So now I see how sleep ties into all the key factors in metabolism-related and cardio vascular diseases. And the good news is making time and lifestyle changes for high quality sleep is something that almost all of us can do.
Thank you so much, Dr. Gurley.
VG:
Thank you, Dr. Braman.
The impact of sleep deprivation on food desire in the human brain. Greer SM, Goldstein AN, Walker MP. Nat Commun. 2013;4: 2259. doi:10.1038/ncomms3259.
Interacting epidemics? Sleep curtailment, insulin resistance, and obesity. Lucassen EA, Rother KI, Cizza G. Annals of the New York Academy of Sciences. 2012; 1264: 110-134. doi:10.1111/j.1749-6632.2012.06655.x.
Efficacy and safety of prolonged-release melatonin in insomnia patients with diabetes: a randomized, double-blind, crossover study.Garfinkel D, Zorin M, Wainstein J, Matas Z, Laudon M, Zisapel N. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2011. 4: 307-313. doi:10.2147/DMSO.S23904.
