- Duration and quality of sleep are crucial for maintaining optimal cardiovascular health
- People who sleep less than 6 hours at night are more likely to develop atherosclerosis than those who sleep 7-8 hours, without fragmentation of sleep
- This can prevent the development of cardiovascular disease
Good quality and adequate amount of sleep are very important for optimal cardiovascular health, a new study suggests. People who sleep between 7 to 8 hours at night are at a far lesser risk of cardiovascular disease (CVD) than those who sleep for less than 6 hours.
The new PESA CNIC-Santander Study indicates that poor quality sleep increases the risk of atherosclerosis, which causes plaque build-up on the inner walls of the arteries throughout the body. This can significantly elevate the risk of CVD. The study was jointly led by Dr. Valentin Fuster, MD, PhD, and José M. Ordovás, PhD.
Dr. Fuster is the currently the General Director at the National Center for Cardiovascular Research or Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain. He is also a Professor of Medicine and Cardiology at Mount Sinai and Director, Zena and Michael A. Wiener Cardiovascular Institute, Mount Sinai, New York, USA. He is also the Editor-in-Chief of JACC.
The study has been published in the Journal of the American College of Cardiology (JACC).
Study BackgroundThe study is based on the premise that cardiovascular health could be maintained by factors other than conventional preventive strategies such as a healthy diet, daily physical activity, and medications. One of these factors is sleep and its role in preventing CVD. In this regard, Ordovás said: "There are two things we usually do every day: eat and sleep. We've known for many years the relation between good nutrition and cardiovascular health; however, we don't know as much the relation between sleep and cardiovascular health." Therefore, it follows that the role of sleep should be evaluated as one of the interventions to fight CVD.
What Were the Drawbacks of Previous Studies?Previous studies suffered from the following drawbacks:
- Studies included patients with health problems such as sleep apnea, which can cause bias
- Studies relied solely on questionnaires for obtaining information on sleep, which is not as accurate as direct measurements
- Studies stressed that lack of sleep increased CVD risk through indirect risk factors like blood pressure, blood glucose, inflammation, and obesity
- Direct risk factors like atherosclerosis were not studied
What's New in the Current Study?Some of the unique features of the new study include the following:
- Study was much larger, which included almost 4,000 participants
- Study focused on a healthy population
- Study used actigraphs to gather objective data on sleep. An actigraph is a small device worn on the wrist that continuously measures activity or movement
- First study to show that objectively measured sleep is independently linked to atherosclerosis throughout the body and not just in the heart
Study ProcedureThe study population was divided into the following four groups based on sleep duration:
- Sleep duration: < 6 hours
- Sleep duration: 6-7 hours
- Sleep duration: 7-8 hours
- Sleep duration: > 8 hours
- The study included 3,974 participants with an average age of 46 years
- None of the participants suffered from heart disease
- Two-thirds of the population were males
- Prevalence and progression of subclinical cardiac lesions were detected by 3D cardiac ultrasound and cardiac computed tomography (CT) scanning
- Sleep patterns of the participants were recorded for 7 days by an actigraph
Study FindingsThe following major study findings were noted:
- There was a 27 percent more likelihood of developing atherosclerosis in those who slept < 6 hours at night than those who slept for 7-8 hours
- There was a 34 percent more likelihood of developing atherosclerosis in those who had poor quality sleep than those who had good quality sleep. Quality of sleep depends on the frequency of waking up at night and frequency of movements during sleep
- Sleep duration > 8 hours increases the risk of atherosclerosis, especially in women
Concluding RemarksThe impact of sleep duration and quality of sleep in atherosclerosis was evaluated. This revealed that participants who slept less than 6 hours per night or experienced a fragmented sleep pattern, had more cholesterol plaques compared to those who slept longer without any interruption. Therefore, this study indicates that sleep duration and quality are of vital importance in cardiovascular health.
In this regard, Fuster concludes: "Medicine is entering into a fascinating phase. Until now we have tried to understand the cardiovascular disease. But thanks to studies like PESA CNIC- Santander, we are starting to understand health."
Funding SourceThe study was funded by a public-private-partnership (PPP) between the Spanish Government (through the Carlos III Institute of Health) and the Pro CNIC Foundation, which includes 13 Spanish private companies.
- Association of Sleep Duration and Quality with Subclinical Atherosclerosis - (http://www.onlinejacc.org/content/73/2/134)