Insomnia Linked To High Blood Pressure

Main Category: Sleep / Sleep Disorders / Insomnia
Also Included In: Hypertension
Article Date: 21 Jun 2008 - 6:00 PDT

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Insomniacs who sleep fewer than five hours a night are five times more likely to suffer hypertension than people who sleep well, according to a major study that highlights the growing concerns over links between sleep problems and serious illness.

"Given the link between stress hormones and high blood pressure we decided to investigate the hypothesis that people who suffer low sleep efficiency are more likely to suffer from hypertension," commented lead investigator Dr Alexandros Vgontzas.

With his colleagues at Penn State College of Medicine, in Hershey, Pennsylvania, he studied the link between sleep problems and raised blood pressure in 1,741 people. The randomly selected volunteers were classed as either normal sleepers, those who had difficulty sleeping or as insomnia sufferers.

Participants were also grouped according to their sleep efficiency - the total number of hours they slept; the top 50 per cent slept for more than 6 hours during the night; the middle quartile 5 - 6 hours and the bottom quartile less than 5 hours.

The results suggested that a combination of low total sleep duration and insomnia - waking up in the night or having difficulty getting to sleep on a chronic basis - were very strongly linked to hypertension. Most strikingly, those with sleeping problems who slept fewer than five hours a night were five times more likely to have hypertension. In contrast, those who slept well for more than hours were not at raised risk of high blood pressure.

Significantly, the researchers found that participants with insomnia who were nonetheless able to sleep for more than 6 hours a night were only slightly more at risk from hypertension, suggesting that a combination of sleeping difficulties and low total sleeping hours was key in raising the risk of high blood pressure.

"This suggests that the medical impact of insomnia has been greatly underestimated," commented Dr Alexandros Vgontzas. "I think that the association with depression and anxiety is fairly well established but we're behind in studying the physical effects of sleep problems."

He conceded that measuring the blood pressure in the subjects for only one night was a limitation of the study, but added, "There is a lot of work to be done but I find this data very exciting and promising."

Other delegates at the meeting suggested investigating whether treating the patients' insomnia lowered their blood pressure.

Evidence of a link between reduced deep sleep and another serious illness, Type 2 diabetes, also emerged at the meeting.

Dr Esra Tasali and colleagues at the University of Chicago Medical School found that decreased slow-wave sleep in healthy adults markedly lowered their sensitivity to insulin. Resistance to the effects of this hormone is thought to be a major contributor to Type 2 diabetes.

Dr Tasali stated that there was "an increased risk of diabetes following reduction of sleep quality", and that this might lead to a vicious circle in which the effects of insulin resistance further harmed sleep quality.

Leading sleep expert Dr Thomas Roth, of the Henry Ford Hospital in Detroit, said the results from both studies underlined the growing interest in the physical effects of insomnia.

"There is now great interest in this field and this will continue as new evidence emerges of a link between sleep problems and diseases such as insulin resistance and diabetes."

Written by Michael Day, sponsored by sanofi-aventis

SLEEP 2008 - Baltimore