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Although systemic hypertension occurs in less than 4% of
the pediatric population, there is ample evidence that the roots
of primary hypertension extend back to childhood. In young children,
hypertension is often a sign of underlying renal or cardiac disease,
but with the rise in childhood obesity, primary hypertension is
now recognized as a frequent cause of hypertension in adolescents.
Management of systemic hypertension in the pediatric population
begins with correct blood pressure (BP) measurement using a standardized technique,
categorization using current normative standards, evaluation of
the etiology of the hypertension, and use of nonpharmacologic and
pharmacologic therapies.
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Until more recently, the prevalence of hypertension in children has
been low (1–2%). More recent data suggests, however,
that blood pressure (BP) has risen among children and adolescents
over the past decade attributable to an increase in weight in the
pediatric population.1 Longitudinal studies begun
in the 1970s in Muscatine, Iowa, and Bogalusa, Louisiana, established
a relationship between body size and BP.2,3 Although
height relates strongly to BP, weight remains a major determinant
of BP even after adjustment for height. BP increases with age throughout
childhood. Beginning with puberty, it is greater in boys than in
girls. Ethnic differences in BP have also been described in some
studies.
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Longitudinal studies have established that the pattern of BP
tracks over time. Systolic BP levels track from childhood better
than diastolic BP levels. In the Bogalusa study, 40% of
those with systolic BP and 37% of those with diastolic BP
in the upper 20% in childhood continued to have BP above
the 80th percentile 15 years later.3 Children in
Muscatine, Iowa, with systolic BP levels above the 90th percentile
for age and gender were at 2.5 times the risk for high adult BP
than children with levels at the 50th percentile.2 Initial
BP levels are the most predictive measure of the follow-up level,
especially when combined with change in weight.
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Obesity has risen dramatically in the United States. Among children and
adolescents, rates of overweight have increased from 13.9% from
1999 to 2000 to 16% from 2003 to 2004.4 In
a more recent study, it was projected that the increase in childhood
obesity in the United States will result in a significant increase in
obesity among 35-year-olds by 2020, which could then translate into
a significant increase in adult coronary heart disease.5
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Weight-related disorders such as hypertension, type 2 diabetes
mellitus, hyperlipidemia, sleep disorders, and orthopedic problems
are now commonly identified within pediatric practice. National
survey data show a rise in the prevalence of hypertension from 2.7% from 1988
to 1994 to 3.7% from 1999 to 2002.6 Prehypertension
is now reported to be present in approximately 10% of children
and adolescents. National surveys have relied, however, on measurements
of BP on a single occasion. More recent data from school-based screening
in Houston confirm a ~3% prevalence of hypertension after
measurement ...