Recent research carried out by the University of Chicago, and published in Journal of the American Medical Association, has revealed that if you do not get enough sleep, then your arteries are more likely to harden. This commonly leads to the development of heart disease. Hardened arteries, caused by calcification, was evident in 1 in 3 people that had less than five hours sleep a night. One extra hour per night reduced calcification to 1 in 10.
The research data was gathered after studying a group of volunteers who measured sleep patterns by keeping a sleep diary and filling out questionnaires. Quality of sleep was also taken into account. The subjects underwent two CT scans five years apart, which monitored the increase in calcium in the heart’s arteries.
At the start of the study, the none of the subjects had any calcification in their arteries. At the end of the study, five years later, 61 of them had developed hardened arteries. This calcification appeared to be linked with lack of sleep. Subjects that regularly had more than seven hours sleep appeared to have the lowest risk of developing hardened arteries.
According to Dr Diane Lauderdale, the head of research at the University of Chicago, there are several possible explanations for the link that they found. One possible reason is that there could be a currently unknown factor that increases calcification in a person deprived of sleep. Another possible reason could be the effect of high blood pressure. Blood pressure in known to increase the likelihood of calcification and blood pressure goes down during sleep.
An alternative reason could be the stress factor, and specifically the working of a stress hormone like cortisol, which has been tied to decreased sleep and increased calcification.
Medical and scientific responses to the research:
“Although there are constant temptations to sleep less, there is a growing body of evidence that short sleep may have subtle health consequences. Although this single study does not prove that short sleep leads to coronary artery disease, it is safe to recommend at least six hours of sleep a night.” Dr Diane Lauderdale, the head of research at the University of Chicago.
“It is not yet clear quite how sleep affects our heart disease risk, but this study adds to previous research suggesting that getting enough sleep may help to keep our heart and circulation healthy. Sleep is essential for our body’s ability to repair itself and with the party season in full flow, it is important to try and get enough rest. Drinking alcohol late at night and getting up early can mean we’re not getting enough quantity, or quality, of sleep.” Ellen Mason, the British Heart Foundation