Study: Poor sleep related to high blood pressure in children

Key takeaways:

• About 6% of children in the United States have hypertension.
• Every extra hour of sleep duration was associated with reduced odds of hypertension.

A study identified a link between poor sleep and hypertension in children and teenagers, according to findings published in Pediatrics.

Although it is commonly thought of as a disease of older adults, an estimated 6% of children have hypertension.

Because sleep has been linked to obesity, unhealthy eating, increased stress and lower quality of life, the authors of the new study hypothesized that inadequate sleep might contribute to the prevalence of pediatric hypertension.

“It was an interesting question to us since most children don’t achieve the recommended number of hours of sleep, yet sleep isn’t something that we traditionally think about when evaluating a child with high blood pressure,” Amy Kogon, MD, MPH, a nephrologist at The Children's Hospital of Philadelphia (CHOP), told Healio. “If sleep plays a role in the prevalence of hypertension in children, then that opens up a novel way to consider treatments for hypertension.”

Kogon and colleagues began their study by evaluating ambulatory blood pressure monitor records of children who were referred to the CHOP nephrology clinic for the evaluation of high blood pressure to determine if self-reported sleep duration was associated with a higher odds of hypertension.

“We reviewed the results from patients who underwent this testing,” Kogon said. “We excluded patients with a known diagnosis of hypertension, patients already taking blood pressure medications, or any medications known to be associated with high blood pressure, and patients with chronic medical conditions that are known to cause secondary hypertension.”

They recruited a cohort of 539 patients aged between 4 and 22 years and measured their blood pressure every 20 minutes while awake and every 30 minutes while asleep. Sleep duration among participants averaged 9.1 hours per night, and the average timing of sleep onset and offset were 11:06 p.m. and 8:18 a.m., respectively.

In the study, longer sleep duration was associated with better daytime blood pressure. Specifically, every extra hour of sleep duration was associated with reduced odds of hypertension while awake (OR = 0.88; 95% CI, 0.79-0.99), and staying up late was associated with a higher awake systolic blood pressure index (mean wake blood pressure/95th percentile]) (b = 0.07; 95% CI, 0.02-0.13), or worse daytime blood pressure.

These associations were consistent regardless of sex, age, BMI category and weekday status, the researchers found.

Kogon said the most surprising findings were regarding nocturnal dipping — the expected drop in blood pressure that comes during sleep — which occurred primarily in patients reporting excessive sleep duration.

“It is considered abnormal if a patient does not exhibit nocturnal dipping on their ambulatory blood pressure study,” Kogon said. “We don’t have sleep quality data or long-term sleep data to explain this finding. It’s possible that those with excessive sleep duration are not sleeping well.”

The findings of the study suggest that getting good sleep could offer new solutions to children and teenagers with high blood pressure, Kogon said, adding that sleep guidance for patients with an elevated blood pressure may be an additional tool to mitigate hypertension and its consequences.

Kogon and the other researchers are working on a related study that will “access more long-term sleep data and sleep quality to better understand how sleep is associated with hypertension in pediatrics.”

“We are also initiating trials to study whether sleep promotion can be successfully applied as a treatment for teens with hypertension,” Kogon said.