Not getting enough physical activity can indeed affect the health of your heart, but did you know that not sleeping sufficiently or having long gaps between your sleeps may also contribute to the risk of developing heart diseases?
Researchers warn that those who work in shifts, have malfunctioning involuntary processes in the body, which could lead to an increased risk of cardiovascular disease. According to research conducted in the Northwestern University in the US, and reported by PTI, insufficient sleep and discrepancies in the circadian rhythm can be linked to adverse cardiovascular outcomes, however, the root cause is still unclear.
Researchers studied 26 healthy people, aged between 20 and 39. The participants were restricted to five hours of sleep for eight days in a sleep restriction program, with a mix of fixed bedtimes (circadian alignment) and varying bedtimes delayed by 8.5 hours, on half the duration. They found that sleep restriction combined with delayed bedtimes was associated with an increased heart rate during the day for both fixed bedtimes and delayed bedtimes groups. The heart rate was even higher at night when sleep restriction was combined with delayed bedtimes.
Participants also saw an increase in 24-hour urinary norepinephrine excretion and reduced vagal activity i.e the process which reduces your heart rate during deeper sleep phases, thereby adversely affecting the restorative effect of deep sleep for your cardiovascular health.
In addition, norepinephrine, a stress hormone, can constrict blood vessels, raise blood pressure and expand the windpipe, which results in discomfort in sleep.
“In humans, as in all mammals, almost all physiological and behavioural processes, in particular the sleep-wake cycle, follow a circadian rhythm that is regulated by an internal clock located in the brain,” said Daniela Grimaldi from Northwestern University. “When our sleep-wake and feeding cycles are not in tune with the rhythms dictated by our internal clock, circadian misalignment occurs,” she added in the findings published in Hypertension.