The Journal of the Arkansas Medical Society Med Journal June 2020 | Page 12

EDITORIAL PANEL: Chad T. Rodgers, MD, FAAP | Elena M. Davis, MD, MPH | Shannon Edwards, MD | William L. Mason, MD | J. Gary Wheeler, MD, MPS
Pediatric Osteoporosis
Management is Critical
LAURA J. HOBART-PORTER, DO, FAAPMR
Osteoporosis is a condition
commonly ascribed to
elderly people, but it can
also be a serious condition in
children. The incidence of pediatric
osteoporosis is not known, but
there are several disease processes
that place children at higher risk.
Appropriate management of
pediatric osteoporosis is critical,
given that 90% of bone density
is determined by puberty, and
consequences for missing it can be
debilitating and life long. 1
Bone development begins in fetal
life and is influenced by maternal
factors including substance exposure
(smoking, caffeine, alcohol), vitamin
D deficiency, activity level, intrauterine
growth restriction and diabetes,
all of which adversely influence bone
development. As a child develops,
prematurity, genetics, diet, mobility,
chronic disease and medications also
convey an increased risk of lower
bone density. 2,3
The primary means of assessing
bone density in children remains
pediatric dual-energy X-ray
absorptiometry (DXA). For children,
studies should be ordered at a
facility capable of controlling for
age and stature for a more accurate
measurement. Children should
be able to lie flat on an exam
table. Significant contractures, hip
dislocation and the presence of
orthopedic instrumentation limit
the data that DXA can collect. There
are no reliable norms for children
under age 3. Children weighing less
than 20 kg. or smaller than 115 cm.
may not have references available
for their size, rendering data of little
utility. Consistent measurement
approaches from year to year allow
reliable monitoring of disease
progression. Measure DXA annually
in at-risk populations. 3
There are other means of
assessment beyond DXA, but lack
of age and stature-related norms
makes interpretation difficult. Plain
radiographs can be used to estimate
bone density in younger children,
but this is a highly subjective
method without normative data.
Quantitative computed tomography,
quantitative ultrasonography and
magnetic resonance imaging offer
an assessment of bone structure
in addition to bone density itself. 3
However, these are most often
employed in research settings. Lack
of normative data is a limitation in
the pediatric population.
In 2013, the International Society
of Clinical Densitometry published
a Pediatric Position Statement,
delineating the differences between
adult and pediatric osteoporosis.
Osteopenia in adults is defined as
DXA Z-score between -1 and -2.5;
osteoporosis is defined as DXA
less than 2.5. In children, a Z-score
less than -2 is called “low bone
density,” not osteopenia. Z-scores
less than or equal to -2 with clinically
significant fracture(s) meet criteria
for osteoporosis. The Society defines
clinically significant fractures as
one or more vertebral compression
fractures, two or more long bone
fractures by age 10, or three or more
long bone fractures up to age 19. 2
When low bone density (LBD) is
identified, it is important to address
the etiology. Laboratory tests of
alkaline phosphatase, osteocalcin,
type I procollagen, calcium, phosphate
and vitamin D-25OH can
help determine if LBD is related to a
modifiable risk factor. Low vitamin D
levels are common within pediatric
populations. Levels less than 20 ng/
mL are considered low; borderline
low is less than 30. Children with
disabilities that contribute to LBD
may need vitamin D levels ranging
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