By Virginia Gurley, MD, MPH
MB (Marc Braman, MD, MPH):
Our topic this session is “Diabetes, Sleep and Cardiovascular Health.” So, welcome, Dr. Gurley.
VG (Virginia Gurley, MD, MPH):
Thank you, Dr. Braman.
In prior sessions, we talked about the benefits of sleep for diabetes (appetite, weight, stress, stress hormones, glucose control, etc) and in other ones we talked about the benefits of sleep for healthy blood pressure and heart. Are there any differences in how sleep benefits blood pressure and heart health for people with diabetes?
Getting eight hours sleep gives an even bigger boost to blood pressure and heart health for people with diabetes. So, one of the reasons is when a person has diabetes, not getting enough sleep is even more damaging to the heart and blood vessels. That’s because when there’s too much sugar in the blood, there’s also too much sympathetic tone, which is your fight or flight part of your nervous system and that also increases your blood pressure.
Ok, so this is in addition to night time blood pressure being too high because of light exposure at night and lowered melatonin?
That’s right. Normally, and even in people that have high blood pressure, blood pressure drops during sleep, so that the cardiovascular system can rest and restore. But, recent studies are finding that in people with diabetes who don’t sleep enough, instead of blood pressure dropping at night, their blood pressure is even higher at night than it is during the day and this is very hard on the heart and blood vessels and it may be why some people with diabetes develop blood vessel damage not only in the heart, but also in the brain, eyes and kidneys.
Wow, that’s actually a really big deal. I didn’t realize blood pressure could go up at night in some of these situations. So this sounds like some really good reasons for anyone with diabetes to get at least 7 – 8 hours of sleep. Anything else?
Yes, we’ve talked previously about diabetes research on avoiding light at night so that melatonin release in the brain can increase and that also increases blood sugar control. So, it turns out that boosting melatonin release by avoiding light at night also helps reverse the blood pressure rise during sleep so that the normal drop in blood pressure during sleep is restored.
Ok, so I know we’re going to get some of these questions. Do melatonin supplements help reverse the blood pressure rise during sleep too?
They do, yes. But melatonin supplements can also increase blood sugar during sleep, especially if someone eats close to bedtime, so if a person is going to take melatonin supplements, it’s important not to eat for at least 3-4 hours before taking the supplement at bedtime. And, because the benefits of melatonin are strongly controlled by when you actually take it, it’s safest to increase your melatonin by simply avoiding too much light at night by turning down lights, avoiding screens that are backlit like computers and smartphones and television.
Excellent. So we actually have a lot of control over these factors, this physiology, and managing our conditions or diseases. We can use sleep as medicine for vascular health and diabetes. That is really good news! Thank you, Dr. Gurley.
Thank you, Dr. Braman.
Effect of diabetes mellitus on sleep quality. Surani S, Brito V, Surani A, Ghamande S. World J Diabetes. 2015 Jun 25;6(6):868-73. doi: 10.4239 wjd.v6.i6.868. Review.
Differences in circadian time structure of diastolic blood pressure between diabetes mellitus and essential hypertension. Matteucci E, Della Bartola L, Giampietro O. Diabetol Metab Syndr. 2012 Dec 17;4(1):51. doi: 10.1186/1758-5996-4-51.
The Angiotensin-melatonin axis. Campos LA, Cipolla-Neto J, Amaral FG, Michelini LC, Bader M, Baltatu OC. Int J Hypertens. 2013;2013:521783. doi:10.1155/2013/521783. Epub 2013 Jan 8.