Men who get the least deep sleep each night have a higher risk of hypertension, new research shows.
Rahav Segev for The New York Times
Earlier studies have tied chronic sleep disorders and low levels of sleep to greater risks of heart disease and obesity, and even reduced life span. But the new study, published in the journal Hypertension, is one of the first to find that it’s not just how much you sleep, but the the quality of your nightly slumber that can affect your risk for high blood pressure.
The goal of the study, carried out by researchers at Harvard Medical School and elsewhere, was to look specifically at the slow-wave stages of sleep, which make up about 90 minutes to two hours of a normal night’s rest and represent the deepest hours of sleep. To study the effect of deep sleep on health, the scientists followed 784 healthy men who were part of an ongoing sleep study and did not have signs of high blood pressure at the start of the research. During the three-and-a-half year study, the men had their blood pressure checked at various times, and their levels of slow-wave sleep were monitored at home by a machine.
After controlling for a number of variables, the researchers found that the men who spent the least time in slow-wave or deep sleep were the most likely to develop high blood pressure. Although a night of normal sleep should consist of about 25 percent slow-wave sleep, the men in the study who were at highest risk for hypertension managed to enjoy deep sleep for no more than 4 percent of their total sleep each night.
Read more:
http://well.blogs.nytimes.com/2011/08/31/lack-of-deep-sleep-tied-to-hypertension/