A study has found that people who suffer from insomnia have heightened nighttime blood pressure, which can lead to cardiac problems. The researchers measured the 24-hour blood pressure of people with insomnia compared to those who sleep soundly.

"Over many years, chronic insomnia can have negative effects on the hearts of otherwise healthy individuals," says lead author Paola A. Lanfranchi. "Whereas blood pressure decreases in regular sleepers and gives their heart a rest, insomnia provokes higher nighttime blood pressure that can cause long-term cardiovascular risks and damage the heart."

Insomnia is a common sleep complaint that is characterized by a chronic difficulty falling or staying asleep. Insomnia affects up to 48 percent of the population at some point in their lives, and symptoms of insomnia can be caused by a variety of biological, psychological and social factors. 

As part of the study, the scientific team recruited 13 otherwise healthy chronic insomniacs and 13 good sleepers. Subjects spent 40 hours in the sleep laboratory: two nights for adaptation and one for monitoring followed by the intervening day.

"Blood pressure cycles are mainly linked to the sleep-wake cycle," says co author Jacques Montplaisir. "Since blood pressure is heightened among insomniacs, those with overt cardiac disease are particularly at risk for progression of the disease."
References:
1. Paola A. Lanfranchi, Marie-Hélène Pennestri, Lorraine Fradette, Marie Dumont, Jacques Montplaisir. Nighttime Blood Pressure in Normotensive Subjects With Chronic Insomnia: Implications for Cardiovascular Risk. Sleep. 2009 Jun 1;32(6):760-6. PMID: 19544752.