Lack of deep sleep contributes to high blood pressure

http://thechart.blogs.cnn.com/2011/08/29/study-lack-of-deep-sleep-raises-blood-pressure/?hpt=hp_bn6

August 29th, 2011

A lack of deep sleep may be one of the reasons why people develop high blood pressure. A study of older men published Monday found that those who got the least amount of deep sleep were 80% more likely to develop high blood pressure, compared to those who got longer, less interrupted sleep.

Researchers studied almost 800 men over the age of 65 who didn't have hypertension when the study started. They were given at-home sleep tests that looked at their sleep patterns and measured their non-rapid eye movement sleep, also known as "slow wave sleep," or deep sleep. Researchers monitored the men's blood pressure changes for a little more than 3 years. Results were published in Hypertension, a journal of the American Heart Association.

Previous studies have shown that when people get less than 6 hours of sleep per night, it can increase the risk of high blood pressure. If people wake-up frequently, due to sleep apnea, medications, or other health issues and cannot fall back asleep quickly, this can also negatively affect blood pressure.

"Our study shows for the first time that poor quality sleep, reflected by reduced slow wave sleep, puts individuals at significantly increased risk of developing high blood pressure, and that this effect appears to be independent of the influence of breathing pauses during sleep," explains study author Dr. Susan Redline, Professor of Sleep Medicine at Brigham and Women's Hospital and Beth Israel Deaconess Medical Center at Harvard Medical School in Boston.

Experts often refer to slow wave sleep as the time when the body is restoring its energy reserves: Blood pressure goes down, breathing slows and the heart rate drops. People usually fall into deep sleep during the early part of the night.

Redline says this new research suggests that if your blood pressure doesn't drop sufficiently while you're sleeping, it may damage your blood vessels. Too little deep sleep may also cause parts of the brain that control the release of a number of hormones and other substances related to maintaining proper blood pressure to work less efficiently.

[...]

..