(NaturalNews) Think that hypertension is a condition which strikes only adults and those more advanced in their years? Think again.
Recent research conducted at the Case Western Reserve University in Cleveland, Ohio, has suggested that lack of sleep as well as poor sleep quality can cause elevated blood pressure levels in healthy adolescents. These associations could not be explained by being overweight, socioeconomic status, sleep apnea, or known comorbidities.
About Blood Pressure, Hypertension and Prehypertension
Blood pressure is the measurement of the force of blood acting against the walls of our arteries and varies throughout the day. When blood pressure levels remain elevated over a sustained period of time, one then has "high blood pressure", medically referred to as "hypertension".
So what's the big deal about high blood pressure? It is potentially dangerous because it causes the heart to overwork, and also contributes to the hardening of one's arteries. Risks of suffering heart disease and stroke – two of the top killers in the US – are thus increased. Other health conditions, for example congestive heart failure, kidney disease and blindness, can also result from hypertension.
"Prehypertension", on the other hand, is a term used to describe the state whereby one does not have high blood pressure right now, but is likely to get it in the future. In other words, your blood pressure is high, but not quite high enough yet to qualify for an official diagnosis of hypertension. Prehypertension in adolescents was what the Case Western study looked at.
According to the American Heart Association, a whopping 73 million people in the US aged 20 and above are estimated to have high blood pressure; that is about one in every three adults. In 2004, the death rates from hypertension for every 100,000 people were 15.7 for white males, 51.0 for black males, 14.5 for white females and 40.9 for black females. In that year, high blood pressure killed 54,707 people in the US alone.
Perhaps not one of the top killers, but when you consider that hypertension also directly leads to other diseases, then the potential dangers are far greater. In addition, the figures are rising significantly too. From 1994 to 2004, the death rate from high blood pressure went up 26.6 percent, while the actual number of deaths increased by 56.1 percent.
Details and Findings of Study
The recent study, the first of its kind in terms of drawing a link between not getting enough sleep and blood pressure levels in healthy adolescents, consisted of a cross-sectional analysis of data from the Cleveland Children's Sleep and Health Study. In total, the study covered 238 adolescents aged 13 to 16. The participants were not known to have sleep apnea, severe comorbidities or other health conditions.
The study, published in the August 2008 issue of Circulation: Journal of the American Heart Association, assessed sleep duration and efficiency at the homes of the teenagers for three to seven nights. The participants maintained a daily sleep log, and also wore a wrist device which measured their movement to determine their sleep and wake patterns.
In addition, they spent one night in a clinical sleep laboratory, where, on top of the earlier mentioned assessments, their blood pressure levels were measured a total of nine times over two days. In the research facility, an overnight polysomnography was also made; according to Wikipedia, a polysomnography "is a multi-parametric test used in the study of sleep", and the test result is termed a polysomnogram.
The study team reported that healthy teenagers who had less than 6.5 hours of sleep a night were 2.8 times more likely to have elevated blood pressure levels, when compared to those who had more hours of sleep. Those with low sleep efficiency, on the other hand, were 4.5 times more likely to have prehypertension.
Sleep efficiency could be broadly defined as sleep quality. It took into account factors such as having difficulty falling asleep or staying asleep, and was measured using an actigraphy-defined objective measure. An actigraphy is a method of monitoring human rest-activity cycles. Low sleep efficiency was benchmarked at below or equal to 85%.
After the data was adjusted for gender, body mass index and socioeconomic status, the relatively higher risks of prehypertension were 2.5 times for lack of sleep and 3.5 times for low sleep efficiency.
Further, adjusted analyses revealed that those with low sleep efficiency had an average 4mm Hg higher systolic blood pressure (the figure usually placed at the top of blood pressure measurements) than those who had good sleep.
The study was supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.
Sufficient Sleep for Adolescents
How much sleep do adolescents actually need? And why are they not getting enough?
According to the NHLBI's Your Guide to Healthy Sleep, children of school-going age and adolescents need at least 9 hours of sleep every night. According to the guide, hormonal influences during puberty tend to affect the biological clocks of adolescents. They are thus more likely to go to bed later at night, and want to sleep in longer in the morning.
This sleep-wake schedule does not correspond with the early start times of most high schools, and hence results in most teenagers only getting an average of 7 to 7.5 hours of sleep per night. This figure more or less tallies with what the recent Case Western study found, with participants sleeping an average of 7.7 hours each night.
Hypertension and Prehypertension in Adolescents
Another study by Case Western last year, which looked at a total of 14,187 children and adolescents aged 3 to 18, had found that hypertension and prehypertension were often undiagnosed. The study found that those who were older, taller, were obese, or had more frequent and greater magnitudes of abnormal blood pressure measurements were more likely to be diagnosed.
Of those studied, out of 507 who had hypertension, only 131 (26%) had a diagnosis of hypertension or increased blood pressure documented in the electronic medical record. As for prehypertension, out of 485 who had the condition, only 55 (11%) had the corresponding diagnosed recorded in the same database.
What this means is that there are scores of young people walking around who are given clean bills of health, but who in fact have hypertension or prehypertension.
If the young ones are often having trouble falling asleep, getting up several times or for long periods during the night, having sleepy spells during the day, or having difficulty concentrating, then it is possible that they are not having enough sleep, or are having poor sleep.
Other studies have already linked poor and lack of sleep to health problems in adults. Now we know that poor sleep affects even the young ones, in a very tangible way.
When we add everything up, we have a not-so-desirable recipe – adolescents not getting enough sleep, poor and lack of sleep causing hypertension and other health problems, hundreds of undiagnosed and thus unmanaged cases of adolescents suffering from hypertension or prehypertension, as well as high blood pressure leading to many killer diseases and even being a direct cause of death.
And, compared with twenty or even ten years ago, teenagers today have even more reasons to stay awake late into the night. Decades ago, there were no computers, no internet, and very little, if any, late night television. Add to that the stress and pressures of increased workloads in school, as well as the nutritional fiasco which is our modern diet of refined foods, and the problem gets a lot bigger.
As Whitney Houston sings in her 80s hit "Greatest Love of All", she believes that "children are our future". They most certainly are, and if we don't sit up, take note and do something now, our future is going to be one potential big health disaster.