For this analysis, researchers assessed sleep patterns in 1,752 people living in the Corinthia region of Greece using a standard questionnaire.They ranged in age from 40 to 98 years, with a mean age of 64 years old
Participants were then divided into one of four groups based on self-reported sleep duration: normal (seven to eight hours a night), short sleep duration (six to seven hours a night), very short sleep duration (less than six hours a night) or long sleep duration (greater than eight hours a night).
At the time of the study, each participant also underwent ultrasound imaging to measure the thickness of the inner part of the arterial wall.
Thickening of the arterial walls reflects plaque buildup and is associated with an increased risk of stroke and other cardiovascular events.
The researchers found that even after accounting for other known risk factors for heart disease or stroke, people who slept less than six hours or more than eight hours a night had significantly greater odds of having plaque buildup in the walls of their carotid arteries–a 54 per cent and 39 per cent increase, respectively–compared with those who got seven or eight hours of shut eye.