Too little or too much sleep tied to death risk

By Amy Norton

NEW YORK (Reuters Health) - Adults who routinely get too little or too much sleep may die sooner than those who get the standard 8 hours each night, a study suggests.

Researchers found that among nearly 10,000 UK adults followed for 17 years, those who starting sleep less each night during the early part of the study were more likely to die of heart disease or stroke than those who kept catching 7 or 8 hours of sleep.

On the other hand, those whose typical sleep time increased beyond 8 hours were at elevated risk of dying from non-cardiovascular causes.

The study, published in the medical journal Sleep, did not pinpoint the reason for the findings.

However, past research suggests that chronic sleep deprivation can be hard on the cardiovascular system. Sleep is a time for the body to recoup, which includes drops in blood pressure and heart rate that ease the daily strain on the heart, explained Dr. Jane E. Ferrie of the University College London, the lead researcher of the new study.

In addition, she told Reuters Health, some studies have linked sleep deprivation to poorer appetite control and blood-sugar regulation, which can affect body weight and the risk of type 2 diabetes. This, in turn, could potentially increase a person's odds of developing heart disease.

It's possible that study participants who started sleeping less were in poorer health; certain conditions, such as any disorder that causes chronic pain, might curtail a person's sleep, Ferrie pointed out.

The study participants were asked about pre-existing illnesses at the outset, but it's possible that some had underlying health problems that were missed, according to Ferrie.