By Linda Carroll -
NBC News
The time you go to bed can affect your risk for heart disease.
Researchers say there is a sweet spot for heart health when it comes to falling asleep: 10-11 at night.
An analysis of data from more than 88,000 adults who were followed for about six years revealed a 12% increased risk among those who went to bed between 11 and 11:59 p.m. and a 25% increased risk of develop cardiovascular disease among people who fell asleep at or after midnight.
[Most adults should not take a daily aspirin to prevent a heart attack]
Falling asleep before 10 p.m. was associated with a 24% increase, according to a report published Monday in the European Heart Journal-Digital Health.
"The body has an internal 24-hour clock, called the circadian rhythm, which helps regulate physical and mental functioning," explained one of the study's co-authors, David Plans, a neuroscientist and experimental psychologist who is a senior professor of neuroscience. Organizational at the University of Exeter, UK.
"Although we cannot conclude causality from our study, the results suggest that early or late bedtime may be more likely to alter the body clock, with adverse consequences for cardiovascular health," he noted.
To explore how different bedtime times might affect heart health, Plans and his colleagues turned to the UK Biobank, which maintains information on more than 500,000 volunteers aged 37 to 73 who were recruited between 2006 and 2010 and provided information about your demographics, lifestyles and health.
Their physical health was also evaluated.
The researchers focused on 88,926 adults, with a mean age of 61, who wore accelerometers - devices that record when a person moves - on their wrists for seven days.
Using the accelerometer data, the researchers determined the onset times of sleep and wakefulness.
[CDC analyzes 300 cases of heart problems in young people after vaccination against COVID-19]
During a median follow-up period of 5.7 years, 3,172 of the volunteers (3.6%) suffered cardiovascular events, such as strokes, myocardial infarctions, or heart failure.
Incidents were highest among people who had their sleep hours after midnight or later and lowest among those who fell asleep from 10 to 10:59 pm.
A baby of only two months has a new heart thanks to a feat of these Spanish doctors
May 19, 202101: 54
Even when various factors were taken into account - such as age, sex, length of sleep, sleep irregularity, being an early riser or night owl, smoking, body mass index, diabetes, blood pressure, cholesterol levels and socioeconomic status - falling asleep regularly at midnight or later was still associated with the increased risk of heart disease.
The increased risk was more pronounced in women who fell asleep later.
Men only had a higher heart risk when they fell asleep earlier, before 10 p.m.
[This athlete celebrated her silver medal in Tokyo in style. Now the auction so that a baby can be operated on the heart]
The new study "really reinforces what we know from a cardiovascular risk prevention standpoint: sleep is a risk factor," said Dr. Françoise Marvel, assistant professor and co-director of the Johns Hopkins Digital Health Laboratory, in Johns Hopkins School of Medicine, Baltimore.
"But there is a huge and important gap to recognize: there is no evidence at this time to suggest that improving sleep will effectively reduce cardiovascular problems, such as a heart attack or stroke," he explained.
Previous studies have suggested that the duration of sleep is important.
The new one didn't look at waking hours along with onset of sleep, but the American Heart Association's primary prevention guidelines suggest that people who sleep less than six hours are at risk for hypertension, which is a major risk factor. cardiovascular.
The study is especially "intriguing" when it comes to the findings on women, said Dr. Roxana Mehran, an interventional cardiologist and professor of medicine, cardiology, and population health science and policy at Mount's Icahn School of Medicine. Sinai in New York.
Cardiovascular disease is the leading cause of death in the United States, according to the American Heart Association.
[Type 2 diabetes skyrockets among Latino and black youth: early screening recommended]
"So we have to find out what is more or less important to prevent heart disease in women," Mehran said.
However, the findings should be taken as a grain of salt.
The new research shows an association, but it doesn't prove that falling asleep later or earlier than 10 a.m. to 11 p.m. causes heart disease.
Other factors may be the real culprits, such as stress, anxiety and depression, he said.