Poor sleep can actually kill you

According to a new study from the European Society of Cardiology, poor sleep can lead to heart disease. Lack of quality sleep may be a sign of a serious cardiovascular issue such as ischaemic heart disease and stroke. Researchers conducted a study of almost 13,000 people to determine if there are distinguishable sleep disturbance patterns associated with each of these heart conditions.

“Poor sleep is associated with cardiovascular diseases such as ischaemic heart disease and stroke but the kind of sleep disturbances that are most risky is not well documented,” said lead researcher Dr Nobuo Sasaki. “‘Poor sleep’ includes too short or too long sleep, difficulty falling asleep, and difficulty maintaining sleep.”

In order to investigate the different patterns of sleep disturbance between the two conditions, the researchers analyzed 12,876 residents of Hiroshima, Japan, who were scheduled for a regular health check. 773 of the patients had a history of ischaemic heart disease, while 560 patients had a history of stroke. The remaining 11,543 had no cardiovascular disease.

The team evaluated sleep habits of the patients using the Pittsburgh Sleep Quality Index (PSQI), a self-reporting survey about sleep quality which produces seven component scores. These scores measure aspects of sleep such as sleep duration, sleep quality, difficulty in maintaining sleep, and use of sleeping pills.

The experts calculated a global PSQI score which ranged from 0 to 21 for each patient using the sum of the seven component scores. Higher scores indicated poorer sleep quality. These “poor sleep” ratings were found in 52 percent of patients with ischaemic heart disease and 48 percent of patients with a history of stroke.

“The proportion of people suffering from sleep disturbances is around 1.5-fold higher among patients with previous ischaemic heart disease or stroke compared to those with no history of cardiovascular disease,” explained Dr. Sasaki.

“Interestingly only patients with ischaemic heart disease reported difficulty maintaining sleep and short sleep duration,” he continued. “Difficulty maintaining sleep reflects an increase in sleep fragmentation, which refers to brief moments of waking up and causes overactivity of the sympathetic nervous system and adrenocortical axis.”

The findings of the study will be presented today at the Congress of the European Society of Cardiology in Barcelona, Spain.

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By Chrissy Sexton, Earth.com Staff Writer