Changes in Sleep Affect the Heart

Lack of sleep and an abnormal sleep cycle may increase the risk of heart disease. This study involved 26 healthy people who were restricted to five hours of sleep per night for eight days with either fixed bedtimes or bedtimes delayed by 8.5 hours on half the nights. The researchers found the changes in sleep resulted in higher daytime heart rates, with the greatest effect when sleep was both shortened and delayed. Additionally, they observed that abnormal sleep patterns increased the levels of a stress hormone called norepinephrine that is known to narrow blood vessels, raise blood pressure, and expand the windpipe. Hypertension, June 2016