A new study suggests sleeping badly could, in fact, be an early warning of serious illness. Nobuo Sasaki of Hiroshima University claims lack of rest can damage the heart by increasing harmful inflammation as well as resulting in insulin resistance.
Insufficient sleep has already been linked to a variety of health conditions ranging from cancer to dementia while one has even hinted it could lead to weight gain.
"The kind of sleep disturbances that are most risky are not well documented. Poor sleep includes too short or too long sleep, difficulty maintaining sleep," Dr. Sasaki said.
Until now, the actual cause and effect of sleeping badly, or sometimes not at all, has been hard to separate.
Some argue that trouble sleeping may be the result of emerging illness, although others with existing heart disease often report a disrupted pattern.
Dr. Sasaki and his team quizzed 12,000 people about their sleeping habits — whether they woke often, got up to use the toilet, struggled to breathe or were dogged by bad dreams.
The results found that those who took longer than 30 minutes to fall asleep were 52 percent more likely to suffer a heart attack or angina, rising to 73 percent for those reporting poor quality sleep.
Those who faced the most disturbances at night were 99 percent more likely to suffer heart attacks or angina, Dr. Sasaki's team discovered.
"Poor sleep in patients with ischaemic disease may be characterized by shorter sleep and brief moments of waking," he told a conference of heart experts in Barcelona, Spain.
"Difficulty maintaining sleep reflects an increase in sleep fragmentation — brief moments of waking up — and causes over-activity of the sympathetic nervous system and ardenocortical axis (a hormonal system that regulates stress)."
Modern life has already resulted in the average Briton having to make do with getting two hours less sleep at night than people 60 years ago.
In a previous study, British scientists found people who slept just six hours a night had waist measurements an inch greater than those enjoying nine hours.
The findings by the University of Leeds reported shorter sleep was also linked to reduced levels of good cholesterol which helps reduce fat from the body.