Children and adolescents who regularly sleep a few hours may be at greater risk of developing hypertension, a new study suggests. The results could change the way doctors talk to children and their parents about this condition.
An analysis of data from more than 500 children and adolescents with hypertension revealed a relationship between hours of sleep shorter than recommended and hypertension, according to the study, published in the scientific journal Pediatrics.
Although childhood hypertension has decreased, the Centers for Disease Control and Prevention (CDC) estimated that 1 in 7 youth between the ages of 12 and 19 has hypertension.
The study doesn't prove that reducing sleep causes high blood pressure, but doctors don't often think about sleep when they counsel parents about high blood pressure, said the study's lead author, Dr. Amy Kogon, an associate professor at the University of California. Perelman School of Medicine of the University of Pennsylvania. The study data comes from children and adolescents seen at a clinic at Children's Hospital of Philadelphia, where Kogon is a pediatric kidney specialist.
“We typically focus on things like diet and exercise,” Kogon said. “This is another thing parents may want to think about, especially if the child has hypertension.”
The main risk factors for hypertension in children and adolescents are being overweight, lack of physical activity and an inadequate diet, according to the American Heart Association.
Most middle and high school children in the United States do not get enough sleep. In fact, according to the CDC, nearly 60% of middle school students and more than 70% of high school students don't get enough sleep.
Up to a third of primary school children sleep less than recommended, according to Kogon.
The number of hours that children and adolescents should sleep depends on their age. The American Academy of Sleep Medicine recommends:
- From 10 to 13 hours per night for children under 6 years old.
- From 9 to 12 hours per night for children from 6 to 12 years old.
- From 8 to 10 hours per night for children from 13 to 18 years old.
- From 7 to 9 hours per night for those over 18 years old.
Controlling blood pressure at an early age is important because the longer you have high blood pressure, the greater your risk of developing heart disease, explained Dr. Barry Love, director of the congenital cardiac catheterization program at Mount Sinai's Kravis Children's Heart Center.
“We know that hypertension is associated with the early onset of coronary heart disease and stroke,” added Love, who was not involved in the new study. “We believe that damage to blood vessels occurs over time.”
For the new study, researchers examined the medical records of 539 children, with an average age of 14.6 years, who were referred to pediatric kidney clinics because of high blood pressure readings. The children were questioned about when they went to bed and when they got up in the morning. They were also asked to wear ambulatory blood pressure measuring devices, which took readings every 20 minutes while awake and every 30 minutes while sleeping.
The further sleep duration moved away from recommended levels, the more likely children were to suffer from high blood pressure during the day. Children who went to bed late were also more likely to suffer from hypertension. The results were consistent regardless of the age, sex and Body Mass Index (BMI) of the minors.
Sleeping too much was also linked to blood pressure problems. Normally, blood pressure decreases by about 10% during sleep, but this was less likely when children slept more hours than recommended.
Why don't children sleep?
According to a national survey from CS Mott Children's Hospital at the University of Michigan, anxiety causes sleep problems for 25% of children ages 1 to 6. These children were less likely to have bedtime routines and more likely to skip videos or television shows, their parents reported in the survey, which was made public Monday.
Another possible cause of sleep problems: It is estimated that 59% of minors do not turn off their electronic devices at night.
It's not so much the light from the devices that causes problems, but what children see in them. Apps like TikTok and Instagram can ruin sleep because they are “hard to put down and are also stimulating,” Kogon added.
Reading a book on a device, for example, “is probably not the same as browsing social media,” Kogon said.
Parents should not allow children to have cell phones in the room at night. He also suggests that they not have any type of electronic devices or televisions in their bedrooms, Kogon said.
Dr. Mariana Bedoya, assistant professor of allergy, immunology, pulmonology and sleep medicine at Monroe Carell Jr. Children's Hospital at Vanderbilt University in Nashville, Tennessee, added that other ways to help improve sleep include:
- Give up caffeine at least six hours before bedtime.
- Maintain regular sleep schedules.
- Avoid naps in older children.
“I tell patients not to change their sleep schedule by more than an hour and a half or two hours on the weekend,” said Bedoya, who was not involved in the new study.
Love mentioned that it is difficult for children to get enough sleep these days. “There are so many things that distract them from sleep.”
