Target Audience and Goal Statement: Pediatricians, pediatric nephrologists, pediatric cardiologists, pediatric gastroenterologists, family physicians
The goal of this systematic review and meta-analysis was to assess
the prevalence of hypertension in the general pediatric population.
Question Addressed:
- What is the prevalence of hypertension in the general pediatric population?
Study Synopsis and Perspective:
How common is high blood pressure (BP) among children and adolescents
ages 19 and younger? In a systematic review and meta-analysis of 47
articles (1994-2018), researchers reported that hypertension affected 4%
of children worldwide.
Compared with the 1.9% prevalence seen in children and adolescents
with normal weight, Yajie Zhu, PhD, of the George Institute for Global
Health at the University of Oxford in England, and colleagues found a
higher prevalence of hypertension in overweight (4.99%) and obese
(15.27%) children.
- In a systematic review and meta-analysis of 47 articles, researchers
reported that hypertension affected 4% of children ages 19 and younger
worldwide.
- Note that the findings suggest that childhood hypertension is
becoming more common in the general pediatric population, representing a
considerable public health challenge.
While common hypertension varied when measured by different devices, a
trend of increasing prevalence of childhood hypertension was seen
during the study period, which spanned roughly 2 decades. Taken
together, these study findings, published in
JAMA Pediatrics,
suggest that hypertension is relatively common in children and
adolescents. Thus, pediatricians are likely to see children with
hypertension in routine clinical practice.
Hypertension in adults, which can take years to develop, is known to be a
major risk factor for more than heart disease.
Left uncontrolled,
the condition can damage the arteries, brain, kidneys, and eyes, among
many other effects on the body. About half of people with untreated
hypertension die of heart disease. Different lines of evidence have
emerged that show that hypertension has immediate
adverse effects
on the heart and brain and, if present during childhood and
adolescence, is linked to markers of subclinical atherosclerosis in
adulthood.
From a public health perspective, reliable estimates of the
prevalence of childhood hypertension could inform management of the
condition and the prevention of its consequences, as well as aid in
evidence-based health resource allocation and policy making, according
to the group.
Because BP is so variable, hypertension definitions require systolic
BP (SBP) or diastolic BP (DBP) to be persistently in the ≥95th
percentile on three separate occasions, an approach recommended for
children up to age 13 in the most recent American Academy of Pediatrics
clinical practice guidelines.
Adult guidelines for elevated BP (120-129/<80 mm Hg) and
hypertension (BP >130/80 mm Hg) are used for children ≥13 years, but
these measurements also need to be elevated persistently on three
separate occasions.
“In children, the measurement of blood pressure is relatively
complicated and unstable, so it needs to be repeated across at least
three different visits to avoid false positive cases,” Zhu told
MedPage Today.
“Until recently, reliable estimates of childhood hypertension
prevalence were lacking.” A previous meta-analysis reported the pooled
prevalence of childhood hypertension at 11.2%, for example, but that
analysis included studies with only one BP measurement.
Because studies included in the current review and meta-analysis were
performed before new guidelines became available, the researchers used
standardized definitions of hypertension based on the fourth report from
the National High Blood Pressure Education Program (
NHBPEP) working group for children and adolescents. Standardized definitions for some of the key BP metrics in this review were:
- Prehypertension: an SBP and/or DBP ≥90th percentile but <95th percentile (for age, sex, and height) or ≥120/80 mm Hg
- Hypertension: an SBP and/or DBP ≥95th percentile (for age, sex, and height) on ≥3 separate occasions
- Stage 1 hypertension: an SBP and/or DBP ≥95th percentile (for age,
sex, and height) but ≤99th percentile plus 5 mm Hg (for age, sex, and
height) on ≥3 separate occasions
- Stage 2 hypertension: an SBP and/or DBP >99th percentile plus 5 mm Hg (for age, sex, and height) on ≥3 separate occasions
To be eligible for the systematic review, studies needed to be based
on a generally representative sample of children and adolescents (≤19
years of age) and provide numerical prevalence estimates of
hypertension, prehypertension, stage 1 hypertension, stage 2
hypertension, or different phenotypes of hypertension (systolic
hypertension, diastolic hypertension, isolated systolic hypertension,
isolated diastolic hypertension, or systolic-diastolic hypertension).
Only studies that repeated BP measurements on at least three separate
occasions were included in the analysis.
More than two-thirds of the articles (68%) were published from 2010
onwards and the most commonly used device for BP measurement was a
mercury sphygmomanometer (40.4%), followed by an oscillometric
sphygmomanometer (34%). More than half the studies were conducted in
low- and middle-income countries and no single study had an excessive
influence on the pooled prevalence.
Pooled prevalence estimates for prehypertension and stage 2
hypertension in children ages 19 and younger were 9.67% and 0.95%,
respectively. During a 15-year period (2000-2015), the prevalence of
childhood hypertension across a specified age range (6 to 19 years) rose
at a relative rate of 75% to 79%. A trend of hypertension with respect
to age was also observed. In 2015, the prevalence of hypertension ranged
from 4.32% among children age 6 years to 3.28% among those age 19, and
peaked at 7.89% among children age 14.
While Zhu’s group unified the definitions of childhood hypertension
and its subtypes before pooling the prevalence estimates, they
acknowledged the presence of substantial heterogeneity. Uncertainties
for pooled prevalence estimates were increased because of the small
number of included studies for prehypertension, stage 1 hypertension,
and stage 2 hypertension in children. Researchers also noted that the
prevalence at the regional level was not optimal for the six World
Health Organization regions covered.
Source References: JAMA Pediatrics 2019; DOI: 10.1001/jamapediatrics.2019.3310
Editorial:
JAMA Pediatrics 2019; DOI: 10.1001/jamapediatrics.2019.3333
Study Highlights and Explanation of Findings:
Using 47 studies that covered urban, rural, and mixed childhood
populations in many different countries, combined with a strict
definition of hypertension, researchers were able to quantitate its
overall prevalence as 4% in children 19 years or younger. Overweight and
obese children were more likely to have hypertension than their
normal-weight counterparts. Among children ages 6 to 19, the prevalence
of hypertension increased from 75% to 79% from 2000 through 2015.
Researchers noted that, to the best of their knowledge, this was the
first systematic review and meta-analysis to explore the global
prevalence of childhood hypertension based on BP measurements on at
least three separate occasions. Study strengths included comprehensive
search strategies, a double review process, and stringent selection
criteria, increasing the chances of generalizability by selecting
studies that were conducted in the general pediatric population.
Hypertension continued to increase before the onset of puberty and
during puberty, but this may not be sustained after puberty. “This
finding is consistent with the clinical observation of adolescents with
persistently high blood pressure, especially during periods of rapid
growth in height, who can then have normal blood pressure later in
adolescence and young adulthood,” wrote Stephen Daniels, MD, PhD, of the
University of Colorado in Aurora, in an
accompanying editorial.
“It is important for adolescents with hypertension to be followed up
over time to determine which adolescents will become healthier and which
will develop persistent hypertension.”
Although the authors were not able to use the most recent definition
of hypertension, Atul Sharma, MD, and colleagues pointed out that the
use of the new clinical practice guidelines would result in elevated BP
using National Health and Nutrition Examination Survey data in a
separate
JAMA Pediatrics study. By extension, Daniels reasoned that the prevalence of hypertension might have been increased in the current analysis.
Consistent with a
prior study,
the group found systolic hypertension to be common in children and
adolescents. Daniels noted that elevated SBP is more closely associated
with left ventricular hypertrophy than DBP. Therefore, increases in SBP
might not be linked to stress and anxiety “and should be considered to
be important for further workup and potential treatment.”
BP measurements should be measured at routine health maintenance
visits, and when elevated BP is found, it is important for additional
measurements to be made to determine whether hypertension is present,
Daniels concluded.
Reviewed by
Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco
Primary Source
JAMA Pediatrics
Secondary Source
JAMA Pediatrics
