US research reveals that teenagers who don’t sleep enough or have poor quality sleep may be at higher risk of elevated blood pressure that could lead to cardiovascular disease in adulthood. The study is the first to examine links between high blood pressure and sleep quality in healthy adolescents.
The research appears as a paper published online before print on 18th August in Circulation, the journal of the American Heart Association (AHA). It was written by senior author Dr Susan Redline, professor of medicine and pediatrics and director of University Hospitals Sleep Center at Case Western Reserve University in Cleveland, Ohio, and colleagues.
Redline and her team carried out a cross-sectional analysis of 238 healthy 13 to 16 year olds (123 boys and 115 girls) who had not been diagnosed with sleep apnea (where breathing stops while you are asleep) or other severe problems.
They found that shorter time spent asleep, but poor sleep quality in particular, were linked to higher risk of elevated blood pressure, and that “technology” in bedrooms, such as music players, phones and computers, may be part of the problem.
For the study, there were two measuring periods, at home and in the lab. At home, the participants wore movement detectors on their wrists for five to seven days to monitor their sleep patterns. They also completed a sleep log to give estimates of sleep patterns.
In the lab, the researchers measured the participants’ sleep quality during overnight sleep, for instance using a polysomnograph machine that monitors brain function, eye and body movement and breathing. They also took 9 blood pressure readings.
Upon analysing the results Redline and colleagues found that:
- The odds of elevated blood pressure increased 3.5 times for those teenagers with low sleep efficiency and 2.5 times for those who slept less than 6.5 hours.
- These figures were unaffected by gender, body mass index (BMI) and socioeconomic status.
- Teenagers who had trouble falling asleep at night and waking up in the morning (low sleep efficiency), had an average 4 mm Hg (millimeters of mercury) higher systolic blood pressure compared to teenagers without these problems (higher sleep efficiency).
- 14 per cent of the teenagers had pre-hypertension or hypertension with blood pressures in the 90th percentile (among the top ten per cent in the country) for their height, age and gender.
- 26 per cent of the participants had low sleep efficiency and 11 per cent slept for less than 6.5 hours (extremely short sleep).
- Nearly two thirds of the teenagers with short sleep duration also had low sleep efficiency.
- 27.9 per cent of the teenagers with low sleep efficiency also had short sleep duration.
- Participants with less than 85 per cent sleep efficiency in the lab phase had nearly three times the odds of having elevated blood pressure.
Redline and colleagues concluded that:
“Poor sleep quality is associated with prehypertension in healthy adolescents.”
They said the link is not explained by “socioeconomic status, obesity, sleep apnea, or known comorbidities, suggesting that inadequate sleep quality is associated with elevated blood pressure”.
Redline suggested part of the problem was the “technological invasion of the bedroom with computers, cell phones and music”. Sending text messages or listening to music all night, with early rising for school, compresses the time left for sleep.
“Adolescents need nine hours of sleep. Parents should optimize sleep quality for their family with regular sleep and wake times and bedrooms should be kept quiet, dark and conducive to sleep,” said Redline.
The researchers said further studies were needed to find out if preventing high blood pressure in children should consider not only ways of losing weight and doing more exercise, but also how to sleep better.
“Meanwhile, pediatricians should view sleep quality and patterns as an intervenable health concern,” said Redline.
“Our data underscores the need to monitor quality and quantity of sleep as part of a child’s overall health strategy,” she added.
“Sleep Quality and Elevated Blood Pressure in Adolescents.”
Sogol Javaheri, Amy Storfer-Isser, Carol L. Rosen, and Susan Redline
Circulation Published online before print August 18, 2008.
Source: AHA, journal abstract.
Written by: Catharine Paddock, PhD