A silent epidemic of hypertension -- commonly known as high blood pressure -- may be affecting the long-term health of as many as 1.5 million American children, according to a new study released Tuesday.
The research, which is slated to appear in the upcoming issue of the Journal of the American Medical Association, looked at existing medical records of more than 14,000 children aged 3 to 18.
Researchers found that while 507 of these children and adolescents had high blood pressure, such a diagnosis had only been made in 131 of them -- suggesting that nearly three out of four cases of hypertension went undiagnosed.
Such a percentage could have big implications if they are reflected in the general population as researchers believe.
"There are approximately 2 million children in the country aged 3 to 18 who have high blood pressure, or hypertension," said lead study author Dr. David Kaelber of the Boston Children's Hospital.
Extrapolating from the study's findings, he said, only about 500,000 of these cases will be detected.
"This means that there are 1.5 million of these children that neither they, nor their parents, nor their clinicians know they have high blood pressure," Kaelber said.
Doctors not affiliated with the study said the research underscores a significant problem.
"I really think this article emphasizes the importance of doing blood pressure monitoring in children," said Dr. Tom Edwards, a pediatric cardiologist at the Cleveland Clinic. "There seems to be a significant difference between what we think the incidence of hypertension is and its correct incidence."
And if left unchecked, the problem could get worse.
"The epidemic of childhood obesity has made hypertension much more common," said Dr. Goutham Rao, clinical director of the Weight Management and Wellness Center at the Children's Hospital of Pittsburgh.
"Roughly 30 percent of overweight and obese children are hypertensive," Rao said. "As more and more children become obese, hypertension will become an increasingly common problem."
But why are pediatricians missing so many cases of high blood pressure?
As any child who has been to the doctor's office can attest, a blood pressure check is a routine part of any pediatric examination. However, the recent study shows that the data obtained through these checks is not always used in the best way possible to determine whether or not a child has high blood pressure.
This is due in part to the fact that "normal" blood pressure ranges for children vary greatly according to height, age and sex of the child -- far too many values for doctors to know by heart.
"The American Academy of Pediatrics has released guidelines for the detection and treatment of hypertension, but these are cumbersome to use," Rao said. "Doctors need easy-to-use tools to detect elevation of blood pressure."
"Even as a board-certified pediatric physician I don't know all of these values," Kaelber added. "There are literally hundreds of them."
Moreover, even if the doctor notes an abnormally high blood pressure reading at a single checkup, it takes three of these high readings on separate doctor visits to make a diagnosis of pediatric hypertension.