By Virginia Gurley, MD, MPH
MB (Marc Braman, MD, MPH):
Our topic this session is “Healthy Sleep for Healthy Blood Pressure.” Welcome back, Dr. Gurley.
VG (Virginia Gurley, MD, MPH):
Thank you, Dr. Braman.
MB:
So, as we talk about how sleep helps our blood pressure and our heart stay healthy, it’s helpful to understand that what we’re talking about is hypertension, high blood pressure, very common amongst much of the population. It’s where the person’s blood vessels are really not in the best state of health and we end up with excess pressure inside which means that the heart has to work harder to pump the blood through the body. While it’s very common, it does significantly increase our chances of having a heart attack, having heart failure and especially, potentially, having a stroke. So, how does sleep help keep our blood pressure healthy?
VG:
Well, that’s a good question, and there are several different ways that sleep helps your blood pressure stay in the healthy range. First, many studies have shown that when we sleep, our blood pressure should decrease by at least 10% sometime between midnight and 4 am. People who have this healthy decrease in their blood pressure, especially their systolic blood pressure, which is the upper number in your blood pressure, are sometimes called “dippers”. And people in whom blood pressure does not decrease at least 10% during the early morning hours are called “non-dippers”.
MB:
Why does it matter whether you’re a “dipper” or “non-dipper?”
VG:
The dip in blood pressure during sleep seems to be very important for maintaining the health of our blood vessels, and recent studies have found that non-dippers have a significantly higher risk for heart attack, stroke, heart failure and atherosclerosis (which means inflammation and clogging of the arteries). Even people that have normal blood pressure during the day can be non-dippers, and those people have the same heart disease risks as people with high blood pressure.
MB:
Wow, that’s pretty impressive. So if I’m not getting enough quality sleep at night, the organ system that is my blood vessels really can’t rest and recover like it needs to. Even if my blood pressure is normal during the day, I could be at greater risk for heart disease and stroke. Perhaps lack of quality sleep regularly should be thought of like having high blood pressure during the day. What are some of the other ways sleep helps keep our blood pressure healthy?
VG:
The other main way healthy sleep helps blood pressure and heart health is through melatonin – that’s the brain hormone that helps trigger and maintain sleep. In other sessions, we’ve talked about how light at night blocks your brain’s release of melatonin. So, now studies are finding that the light at night that decreases melatonin (lights like room lights, computer screens, smartphone screens and alarm clock lights) this light at night also decreases the blood pressure dip. And the great news is that non-dippers can regain a healthy blood pressure dip during sleep by avoiding lights at nights and thereby restoring healthy melatonin levels.
MB:
Excellent. So, in short, we can use quality sleep as medicine as part of our treatment to treat the very common condition of high blood pressure.
Thank you, Dr. Gurley.
VG:
Thank you, Dr. Braman.
Dipper and non-dipper blood pressure 24-hour patterns: circadian rhythm-dependent physiologic and pathophysiologic mechanisms. Fabbian F, Smolensky MH, Tiseo R, Pala M, Manfredini R, Portaluppi F. Chronobiol Int. 2013 Mar;30(1-2):17-30. doi: 10.3109/07420528.2012.715872. Epub 2012 Sep 24. Review.
Blunted sleep-time relative blood pressure decline increases cardiovascular risk independent of blood pressure level–the “normotensive non-dipper” paradox. Hermida RC, Ayala DE, Mojón A, Fernández JR. Chronobiol Int. 2013 Mar;30(1-2):87-98. doi: 10.3109/07420528.2012.701127. Epub 2012 Oct 5.
Peripheral and central effects of melatonin on blood pressure regulation. Pechanova O, Paulis L, Simko F. Int J Mol Sci. 2014 Oct 8;15(10):17920-37. doi: 10.3390/ijms151017920. Review.
