Blood pressure in teens predicts hypertension

By Anthony J. Brown, MD

NEW YORK (Reuters Health) – Adolescents with blood pressure
in the pre-hypertension range are at increased risk for
developing full-blown hypertension within two years, according
to a new report.

The findings, presented here Friday at the annual meeting
of the American Society of Hypertension, indicate that roughly
7 percent of teens with pre-hypertension will progress to fixed
hypertension each year.

“In adults, current blood pressure is known to be the
strongest predictor of future blood pressure,” researcher Dr.
Bonita Falkner, from Thomas Jefferson University in
Philadelphia, told Reuters Health. “Less is known about the
association in adolescents due to a limited amount of follow-up
data and the individual variability in blood pressure seen in
this age group.”

The current study involved an analysis of data for 8533
adolescents entered in the National Childhood Blood Pressure
database. The subjects had blood pressure measurements taken on
two occasions, two years apart.

Based on the initial measurement, subjects were classified
into one of three blood-pressure groups: normal (less than the
top 90 percent by age, sex, and height), pre-hypertensive (in
the top 90 to 95 percent), and hypertensive (in the top 95 to
100 percent). The researchers then looked at how the group
distributions changed after two years.

In boys, 5 percent of those who had normal blood pressure
at the first measurement were hypertensive by the second
measurement, while 31 percent of those who were hypertensive at
the first measurement were hypertensive at the second. In
girls, the corresponding figures were 4 percent and 26 percent.

Fourteen percent of boys and 12 percent of girls who were
pre-hypertensive initially moved to the hypertensive group at
follow-up.

In boys, their body mass index or BMI — weight in relation
to height — played a role in predicting future blood pressure.
“The boys who either stayed hypertensive or became hypertensive
were the ones who had a high BMI initially or who gained weight
in the 2-year interval,” Falkner explained.

In girls, age was linked to blood pressure at follow-up.
“The older the girl was with high blood pressure at initial
measurement, the more likely they would still have high blood
pressure at follow-up,” she said.

“The findings indicate that children with high blood
pressure readings are at increased risk for hypertension,”
Falkner emphasized. “This age group is a good entry point for
preventive interventions known to have a beneficial effect,
such as weight reduction, physical activity, and dietary
changes.”