New research published in the journal Scientific Reports has shown that getting just 90 minutes less of sleep per night damages the cells that line the blood vessels in women.
The randomized crossover study included 35 healthy women who normally got 7–8 hours of sleep per night. The study lasted 12 weeks in total. For six weeks of the study, the women slept as usual while their sleep was monitored using wrist-worn sleep trackers. For the other six weeks of the study, they were required to go to bed 1.5 hours later than usual while waking up at the same time. This requirement was meant to mimic real-life conditions in which sleep might be delayed due to typical life obligations, such as chores or childcare. Throughout the study, the health of the participants’ endothelial cells, the cells that line the blood vessels, was monitored. Previous research in animal models has shown that shortened sleep duration damages the endothelial cells. Damage to endothelial cells is one of the steps in the development and progression of heart disease.
The results of the study showed that after six weeks, the relatively mild sleep restriction caused greater oxidative stress (leading to more damage) in the women’s endothelial cells. Additionally, their endothelial cells had weakened antioxidant responses to prevent the damage.
The authors of the study noted that this is some of the first evidence showing that relatively minor sleep restriction can directly lead to the development of heart disease. While many previous studies have indirectly tied sleep restriction to heart disease, this randomized controlled study showed a direct link between mild sleep deprivation and damage to blood vessel cells that could lead to heart disease.