New Practice Guidelines To Be Issued
Average Blood Pressure Levels On Rise Among
American Children/Teenagers
Systolic and diastolic blood pressure levels for children
and teenagers have risen substantially since 1988,
according to a new study supported by the National
Heart, Lung, and Blood Institute (NHLBI), part of
the National Institutes of Health. The study links
part of the rise to a concurrent increase in the prevalence
of overweight and obesity.
The study–“Trends in Blood Pressure Among
Children and Adolescents”–appears in the
May 5, 2004 issue of The Journal of the American
Medical Association (JAMA). The study was conducted
by researchers at Tulane University in New Orleans,
LA, and the NHLBI in Bethesda, MD.
This summer, the NHLBI and the National High Blood
Pressure Education Program, which it coordinates,
will release updated clinical practice guidelines
on high blood pressure in children and adolescents.
The guidelines, presented in summary form on May 1,
2004 at the annual meeting of the Pediatric Academic
Societies (PAS) in San Francisco, include revised
blood pressure tables and updated recommendations
for lifestyle and drug therapies.
“The obesity-related rise in blood pressure
among American children is a serious health issue,”
said NHLBI Acting Director Dr. Barbara Alving. “We
need to take steps to reverse this trend. One key
step is to give physicians tools that can help them
deal with this problem, which is why we’re issuing
these new guidelines.”
“The increases found by the JAMA study
in children’s average blood pressures may seem
small, but they can have serious consequences,”
said Dr. Jeffrey Cutler, Senior Advisor, NHLBI Division
of Epidemiology and Clinical Applications, and co-author
of the JAMA paper. “Previously published
data indicate that, for each 1- to 2-millimeter of
mercury rise in their systolic blood pressure, children
face a 10 percent greater risk of developing hypertension
as a young adult.”
High blood pressure is a major risk factor for heart
disease and the chief risk factor for stroke.
The new blood pressure trends study in JAMA
involved 5,582 children ages 8-17, who were part of
the 1988-94 and 1999-2000 National Health and Nutrition
Examination Surveys (NHANES). In both surveys, the
children were about 50 percent male, 16-17 percent
black, and 9-12 percent Mexican-American. The mean
age for both groups was just under 13 years.
In 1988-94, the children’s average systolic
blood pressure was 104.6 mm Hg and their average diastolic
pressure was 58.4 mm Hg. In 1999-2000, the children’s
average systolic pressure was 106 mm Hg and their
average diastolic was 61.7 mm Hg.
In 1988-94, 11.7 percent of the children were overweight;
in 1999-2000, 16.3 percent were overweight. Overweight
is defined by body mass index (BMI), which is a measure
of weight relative to height. Overweight children
and teenagers have a BMI that falls in the 95th percentile
or higher on age- and gender-specific growth charts,
compiled by the Centers for Disease Control and Prevention.
The systolic and diastolic blood pressure increases
between the two surveys were large and occurred for
all age and race/ethnic groups, and both genders.
The systolic pressure increased by 1.4 mm Hg and the
diastolic by 3.3 mm Hg from 1988-94 to 1999-2000.
Even after adjusting for BMI, systolic and diastolic
blood pressures were 1 and 2.9 mm Hg higher, respectively,
in 1999-2000, compared with 1988-94. This suggests
that lifestyle factors other than overweight, such
as physical activity and specific dietary nutrients,
were also involved in the trends.
Further, systolic and diastolic blood pressures increased
with age for all race/ethnic groups and both genders.
For children ages 8-12, yearly systolic and diastolic
blood pressure increases were greater for girls, compared
with boys. For adolescents ages 13-17, yearly blood
pressure increases were greater for boys, compared
with girls.
The new clinical practice guidelines due for release
this summer reflect new data from the 1999-2000 NHANES.
The data have been added to the childhood blood pressure
database and reexamined to develop revised normative
blood pressure tables. The updated tables now include
the 50th, 90th, 95th, and 99th percentiles of blood
pressure by sex, age, and height.
Hypertension in youngsters is based on the range of
blood pressures in healthy children. The new guidelines
continue to define normal blood pressure as the systolic
and diastolic blood pressures that are less than the
90th percentile for that sex, age, and height. To
be consistent with the latest blood pressure guidelines
for adults,1 the
guidelines for children include a prehypertension
category. Children with a systolic or diastolic pressure
equal to or greater than the 90th percentile but less
than the 95th percentile are considered prehypertensive.
Hypertension continues to be defined as a systolic
or diastolic pressure equal to or greater than the
95th percentile.
The new guidelines describe hypertension and prehypertension
as significant health issues in the young due to the
marked increase in the prevalence of overweight children.
Overweight and high blood pressure are components
of the insulin resistance syndrome, a combination
of multiple risk factors for cardiovascular disease
and type 2 diabetes. Therefore, the guidelines call
for a comprehensive assessment of cardiovascular risk
factors. The new guidelines, noting the association
of high blood pressure and overweight with sleep apnea,
also suggest that a history of sleeping patterns should
be obtained in a child with hypertension.
Treatment for children with high blood pressure usually
consists of lifestyle changes, including weight management,
physical activity, and dietary changes. Drug therapy
is used if needed. The revised guidelines incorporate
recent research and present updated recommendations
for lifestyle approaches, such as dietary changes
for children and adolescents who have prehypertension
as well as hypertension. Revised drug recommendations
include dosage recommendations for many of the newer
drugs studied in recent clinical trials.
“We want to give our children the best possible
start in life,” said Alving. “That means
insuring they have a healthy blood pressure and weight.
We need to teach them to be physically active and
to follow a heart-healthy eating plan. Otherwise,
we may be giving them an early start on heart disease.”
To arrange an interview about this study, contact
the NHLBI Communications Office at (301) 496-4236.
Tables from the new clinical practice guidelines on
hypertension in children and adolescents are available
at www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.htm.
NHLBI press releases and other materials are available
online at www.nhlbi.nih.gov
1Seventh Report of the Joint National Committee
on the Prevention, Detection, Evaluation and Treatment
of High Blood Pressure (JNC 7) |