Insomnia bad for the heart

TORONTO - Insomniacs have heightened blood pressure (BP) during the night, which can cause cardiac problems, says a new study.

The investigation, which measured the 24-hour BP of insomniacs compared to sound sleepers, was conducted by researchers from the University of Montreal (UM) and the University of Laval.

“Over many years, chronic insomnia can have negative effects on the hearts of otherwise healthy individuals,” says study co-author Paola A. Lanfranchi, professor at the UM Faculty of Medicine.

“Whereas blood pressure decreases in regular sleepers and gives their heart a rest, insomnia provokes higher night time blood pressure that can cause long-term cardiovascular risks and damage the heart,” says Lanfranchi.

The findings are important given that insomnia, which is a chronic difficulty falling or staying asleep, affects up to 48 percent of the population at some point in their lives.

As part of the study, the team recruited 13 otherwise healthy chronic insomniacs and 13 good sleepers. Subjects spent 40 hours in the sleep lab: 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, professor at the UM Department of Psychiatry.

“Since blood pressure is heightened among insomniacs, those with overt cardiac disease are particularly at risk for progression of the disease.”

These findings were published in the journal Sleep.