First growth reference curves for Tunisian children and adolescents

Abstract

A growth chart is a powerful graphical tool displaying children's growth patterns. The aim of this study was to develop growth reference curves appropriate for Tunisian children. The collection of data from this cross-sectional study was conducted on 4358 healthy subjects (2182 girls and 2176 boys) in three pediatric centers and 15 schools. Smoothed growth curves were estimated using the LMS method. The smoothed percentile curves for height, weight, sitting height (SH), and leg length (LL) increase rapidly during the 1st years of life and then progress slowly until 18 years. However, the sitting height-to-height ratio (SHTHR) curves decrease sharply before the age of 4 and then stabilize in both sexes. In addition, the comparison between boys and girls indicated that the values are very similar at most ages. Except during puberty, the values in boys increase (P<0.0001) for the weight, height, SH, and LL parameters and decline (P<0.0001) in the SHTHR compared to the values in girls. The growth rate curves presented two remarkable velocity peaks: the first appears during the 1st years of life and the second at puberty. Height gains at the last stage of growth (puberty) are around 15.45% of final height for boys and 15.52% for girls. This study showed a number of discrepancies for certain age groups when comparing the median weight and height values with those of the World Health Organization, the National Center for Health Statistics, and Algerian references in both sexes. Conclusion: The smoothed percentile curves for weight and height will be useful to access the general growth of Tunisian children. Furthermore, the SH, LL, and SHTHR curves can be used to monitor body proportions during childhood.

Full text

Research
paper
First
growth
reference
curves
for
Tunisian
children
and
adolescents
H.
Ghouili
a,b,
*,
N.
Ouerghi
a,c
,
A.
Boughalmi
a
,
A.
Dridi
a
,
F.
Rhibi
d
,
A.
Bouassida
a
a
Research
Unit,
Sportive
Performance
and
Physical
Rehabilitation,
High
Institute
of
Sports
and
Physical
Education
of
Kef,
University
of
Jendouba,
Kef,
Tunisia
b
Faculty
of
Sciences
Bizerte,
University
of
Carthage,
Bizerte,
Tunisia
c
University
of
Tunis
El
Manar,
Faculty
of
Medicine
of
Tunis,
Rabta
Hospital,
LR99ES11,
1007
Tunis,
Tunisia
d
Movement,
Sport,
Health
and
Sciences
laboratory
(M2S).
UFR/APS,
University
of
Rennes
2,
France
1.
Introduction
Physical
growth
and
bone
maturation
are
essential
processes
for
well-being.
They
can
be
indicators
of
genetic
variations,
environmental
factors,
or
pathological
processes
[1].
Growth
assessment
is
important
for
monitoring
health
status,
and
healthcare
professionals
need
to
keep
an
eye
on
children’s
development
patterns.
They
have
guidelines
that
help
them
assess
whether
a
child’s
growth
is
within
the
normal
range
or
has
an
abnormality
requiring
early
intervention
[2].
In
clinical
practice,
physical
growth
is
assessed
by
anthropometric
parameters.
Weight
and
height
measurements
are
the
main
indicators
for
assessing
the
quality
of
nutrition
and
growth
in
children
and
adolescents
[3].
Other
indicators
related
to
size
(sitting
height
[SH]
and
leg
length
[LL])
are
commonly
used
as
indices
of
dysmorphic
development
[4].
A
growth
chart
is
a
powerful
graphical
tool
displaying
the
growth
pattern
of
groups
of
children
and
individuals
[5].
This
curve
has
become
an
important
tool
in
child
health
screening
and
pediatric
clinical
assessment
[6].
During
the
1960s
and
1970s,
two
sets
of
data
were
frequently
used
as
a
growth
reference:
the
Harvard
growth
curves,
developed
in
the
United
States,
and
later
the
Tanner
growth
curves
produced
in
Great
Britain.
At
the
end
of
the
1970s,
the
World
Health
Organization
(WHO),
recognized
the
inadequacy
of
the
Harvard
reference
and
sought
to
identify
a
set
of
anthropometric
data
specific
to
developing
a
new
international
growth
reference
[7].
In
1977,
WHO
established
new
growth
curves
from
a
study
based
on
specific
criteria
to
select
a
well-
nourished
population
and
used
more
developed
techniques
to
smooth
the
curves
[8].
The
last
curves
constructed
by
WHO
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
A
R
T
I
C
L
E
I
N
F
O
Article
history:
Received
13
July
2020
Received
in
revised
form
30
December
2020
Accepted
16
March
2021
Available
online
xxx
Keywords:
Children
Height
Leg
length
LMS
method
Sitting
height
Weight
A
B
S
T
R
A
C
T
A
growth
chart
is
a
powerful
graphical
tool
displaying
children’s
growth
patterns.
The
aim
of
this
study
was
to
develop
growth
reference
curves
appropriate
for
Tunisian
children.
The
collection
of
data
from
this
cross-sectional
study
was
conducted
on
4358
healthy
subjects
(2182
girls
and
2176
boys)
in
three
pediatric
centers
and
15
schools.
Smoothed
growth
curves
were
estimated
using
the
LMS
method.
The
smoothed
percentile
curves
for
height,
weight,
sitting
height
(SH),
and
leg
length
(LL)
increase
rapidly
during
the
1st
years
of
life
and
then
progress
slowly
until
18
years.
However,
the
sitting
height-to-height
ratio
(SHTHR)
curves
decrease
sharply
before
the
age
of
4
and
then
stabilize
in
both
sexes.
In
addition,
the
comparison
between
boys
and
girls
indicated
that
the
values
are
very
similar
at
most
ages.
Except
during
puberty,
the
values
in
boys
increase
(P
<
0.0001)
for
the
weight,
height,
SH,
and
LL
parameters
and
decline
(P
<
0.0001)
in
the
SHTHR
compared
to
the
values
in
girls.
The
growth
rate
curves
presented
two
remarkable
velocity
peaks:
the
first
appears
during
the
1st
years
of
life
and
the
second
at
puberty.
Height
gains
at
the
last
stage
of
growth
(puberty)
are
around
15.45%
of
final
height
for
boys
and
15.52%
for
girls.
This
study
showed
a
number
of
discrepancies
for
certain
age
groups
when
comparing
the
median
weight
and
height
values
with
those
of
the
World
Health
Organization,
the
National
Center
for
Health
Statistics,
and
Algerian
references
in
both
sexes.
Conclusion:
The
smoothed
percentile
curves
for
weight
and
height
will
be
useful
to
access
the
general
growth
of
Tunisian
children.
Furthermore,
the
SH,
LL,
and
SHTHR
curves
can
be
used
to
monitor
body
proportions
during
childhood.

C
2021
French
Society
of
Pediatrics.
Published
by
Elsevier
Masson
SAS.
All
rights
reserved.
Abbreviations:
WHO,
World
Health
Organization;
NCHS,
National
Center
for
Health
Statistics.
*Corresponding
author
at:
High
Institute
of
Sports
and
Physical
Education
of
Kef,
University
of
Jendouba,
Tunisia.
E-mail
address:
hatemghouili@gmail.com
(H.
Ghouili).
G
Model
ARCPED-4945;
No.
of
Pages
11
Available
online
at
ScienceDirect
www.sciencedirect.com
https://doi.org/10.1016/j.arcped.2021.03.011
0929-693X/

C
2021
French
Society
of
Pediatrics.
Published
by
Elsevier
Masson
SAS.
All
rights
reserved.
Please
cite
this
article
as:
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.,
First
growth
reference
curves
for
Tunisian
children
and
adolescents,
Archives
de
Pe
´diatrie,
https://doi.org/10.1016/j.arcped.2021.03.011

comprised
the
standard
curve
established
in
2006
from
combined
studies
(longitudinal
and
cross-sectional
studies)
and
recruited
healthy
infants
and
children
from
six
sites
in
Brazil,
Ghana,
India,
Norway,
Oman,
and
the
United
States.
The
longitudinal
study
was
based
on
1737
children
(894
boys
and
843
girls)
aged
from
birth
to
2
years
and
the
cross-sectional
study
was
based
on
6669
children
(3450
boys
and
3219
girls)
aged
from
2
years
to
5
years
[9].
Then
the
reference
curves
for
children
and
adolescents
(5–19
years)
were
created
in
2007.
This
reference
recruited
the
same
sample
used
for
the
construction
of
the
original
NCHS
charts,
combining
three
data
sets
[10].
However,
there
is
increasing
evidence
questioning
the
universal
applicability
of
these
WHO
standards.
A
number
of
authors
have
shown
that
the
children
of
their
countries
are
longer
and
heavier.
Conversely,
for
others,
the
children
were
shorter
and
lighter
[11].
Thus,
the
WHO
standard
curves
cannot
eliminate
the
need
for
local
growth
references
[11].
It
is
more
reliable
to
compare
the
pattern
of
a
child’s
growth
to
the
group
model
of
children
from
the
same
population.
In
this
sense,
several
countries
have
established
their
own
weight
and
height
reference
curves
[12]
and
the
SH
and
LL
curves
were
also
implemented
[13].
In
Tunisia,
the
only
references
used
are
those
of
the
WHO
standard
curves
[9].
Therefore,
the
aim
of
this
study
was
to
present,
for
the
first
time,
growth
reference
curves
specific
to
Tunisian
children
aged
1–18
years.
2.
Subjects
and
methods
2.1.
Subjects
The
method
and
recruitment
of
the
subjects
in
this
cross-
sectional
study
have
been
presented
previously
[14].
In
summary,
the
anthropometric
data
were
collected
between
November
2012
and
May
2013.
The
selection
of
the
sample
of
children
aged
0–18
was
established
using
a
stratified
random
analysis
technique.
We
divided
Tunisia
into
three
large
areas
according
to
their
geographic
locations:
north,
center,
and
south.
We
randomly
selected
three
pediatric
centers
from
24
pediatric
centers
in
Tunisia
(one
center
chosen
per
area).
Regarding
the
selection
of
schools,
we
randomly
selected
three
governorates
(one
governor-
ate
in
each
area)
from
24
governorates
in
Tunisia.
Then
we
contacted
the
regional
Board
of
Education
in
the
selected
governorates
through
the
research
unit.
After
the
study
was
accepted,
all
schools
that
had
all
levels
of
education
and
the
average
number
of
students
per
class
exceeded
25
students
were
included
in
the
draw
list.
Finally,
we
randomly
selected
five
schools
per
area
(two
primary
schools,
two
preparatory
schools,
and
one
secondary
school).
Children
whose
parents
refused
to
participate
or
who
had
chronic
diseases
were
excluded
from
this
study.
2.2.
Anthropometric
parameters
Anthropometric
measurements
were
taken
by
six
well-trained
examiners
using
standard
anthropometric
techniques
[3].
Weight
and
length
(for
children
under
2
years
who
are
unable
to
stand
independently)
or
height
(for
children
over
2
years
and
adoles-
cents)
were
measured
by
the
specialists
in
pediatrics.
These
measurements
have
been
described
in
detail
in
the
previous
studies
[14,15].
Regarding
the
measurement
of
SH
in
infants,
the
legs
are
placed
in
the
vertical
plane
forming
a
right
angle
with
the
trunk
and
the
cursor
(mobile
part)
of
the
horizontal
height
rod
is
fixed
at
the
level
of
the
buttocks
during
the
measurement
(Fig.
1).
The
measuring
tool
is
a
horizontal
rod
available
in
pediatric
centers.
For
the
measurement
of
SH
in
children
and
adolescents,
subjects
are
seated
on
a
table
placed
in
front
of
the
stadiometer.
The
dimensions
of
this
table
are
built
according
to
the
recom-
mendations
of
Cameron
(1982)
[16].
The
subject
puts
his
back,
buttocks,
and
occipitals
in
contact
with
the
vertical
plane
of
the
wall.
The
knees
form
right
angles
(908),
the
hands
are
on
the
thighs
and
the
head
positioned
in
the
Frankfurt
plane
(Fig.
2).
The
measurement
of
SH
is
calculated
by
subtracting
the
height
of
the
table
from
the
total
height
taken
when
the
subject
is
seated.
The
measurement
was
noted
using
a
Seca
206
portable
stadiometer
(Hamburg,
Germany)
to
the
nearest
0.1
cm.
LL
was
calculated
for
each
subject
as
the
subtraction
of
SH
(cm)
from
height
(cm).
SHTHR
was
SH
(cm)
divided
by
height
(cm).
Fig.
1.
Sitting
height
measurement
in
infant
[34].
Fig.
2.
Sitting
height
measurement
in
children
and
adolescents
[34].
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
G
Model
ARCPED-4945;
No.
of
Pages
11
2

2.3.
Statistical
analysis
The
differences
between
boys
and
girls
in
weight,
height,
SH,
LL,
and
SHTHR
were
analyzed
using
the
one-factor
ANOVA
statistical
tool
with
a
significance
level
equal
to
P
<
0.05.
The
relationship
between
height
and
SH
and
SHTHR
was
estimated
using
the
Pearson
correlation
coefficient
(r).
Generally,
the
velocity
of
growth
is
presented
in
different
years.
It
was
calculated
by
the
variation
of
the
measured
weight
(kg),
height
(cm),
SH
(cm),
and
LL
(cm)
of
two
successive
years
[17].
The
onset
of
puberty
varies
from
one
individual
to
another
and
also
between
countries.
We
chose
the
ages
of
10
and
12
[18]
for
boys
and
girls,
respectively.
This
allowed
us
to
compare
height
gains
during
puberty
of
Tunisian
children
with
other
references.
In
the
present
study,
we
analyzed
each
data
set
using
the
LMS
method
[19],
which
provides
curves
in
smoothed
percentiles
(C3,
C10,
C25,
C50,
C75,
C90,
and
C97)
according
to
three
curves
called
L
(lambda),
M
(mu),
and
S
(sigma).
The
M
and
S
curves
correspond
to
the
median
and
the
coefficient
of
variation
at
each
age,
while
the
L
curve
expresses
the
power
necessary
to
transform
the
data
into
a
normal
distribution.
The
points
of
each
curve
in
percentiles
were
obtained
using
the
formula:
C
100
a
¼
Mð1
þ
LSZ
a
Þ
1
L
where
Z
a
is
the
deviation
of
the
normal
equivalent
for
the
surface
of
the
tail
a
.
All
statistical
analyses
were
performed
using
SPSS
software
version
24.0
(Chicago,
IL,
USA).
LMS
Chart
Maker
Pro
software
version
2.3
(The
Institute
of
Child
Health,
London,
UK)
was
used
to
smooth
the
curves
in
percentiles,
by
sex
and
age.
3.
Results
This
study
was
conducted
on
4647
Tunisian
infants,
children,
and
adolescents.
They
were
recruited
from
three
randomly
selected
governorates
in
three
large
areas
of
Tunisia:
1762
subjects
Table
1
Mean
values
with
standard
deviation
(SD)
of
weight,
height,
sitting
height
(SH),
leg
length
(LL),
and
sitting
height-to-height
ratio
(SHTHR)
by
age
group
and
sex.
Age
group
(years)
Boys
N
Weight
(kg)
Height
(cm)
SH
(cm)
LL
(cm)
SHTHR
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
0–0.99
76
7.55
2.33
65.63
10.93
43.03
4.27
22.59
10.66
0.67
0.10
1–1.99
70
12.30
2.08
82.94
7.21
49.11
4.62
33.87
8.78
0.60
0.08
2–2.99
76
14.95
2.12
94.86
7.88
52.00
4.17
42.86
7.73
0.55
0.06
3–3.99
47
16.85
2.26
102.96
5.58
54.68
4.04
48.28
6.67
0.53
0.05
4–4.99
65
18.96
2.61
110.11
5.36
57.51
4.23
52.63
6.54
0.52
0.04
5–5.99
69
20.16
2.56
114.03
5.55
59.39
4.99
54.61
7.75
0.52
0.05
6–6.99
144
23.50
3.23
121.2**
6.20
62.60
4.22
58.58
7.34
0.52
0.04
7–7.99
149
26.07
3.95
126.04
5.71
64.15
3.50
61.88
6.69
0.51
0.04
8–8.99
168
29.21
4.74
131.43
6.05
65.63
4.12
65.79
7.41
0.50
0.04
9–9.99
160
31.33
4.82
136.89**
7.18
66.86
4.66
70.11**
8.96
0.49
0.04
10–10.99
139
34.54
6.16
141.80
7.11
70.04
4.96
71.78
8.72
0.49
0.04
11–11.99
131
39.14
6.55
147.31
7.83
72.77
4.45
74.51
9.14
0.50
0.04
12–12.99
87
41.18
8.34
150.82
7.98
74.67
6.13
76.15
9.86
0.50
0.05
13–13.99
108
46.79
9.09
158.41
10.36
77.27
5.36
81.15***
11.47
0.49
0.05
14–14.99
104
51.55
8.59
164.15***
8.41
81.45
4.75
85.09***
16.38
0.48
0.09
15–15.99
152
56.03
8.95
167.59***
6.15
83.88
6.52
83.69***
9.13
0.50
0.04
16–16.99
148
60.37***
9.80
172.40***
6.37
88.59*
6.84
83.85***
9.27
0.51
0.04
17–17.99
158
65.46***
11.39
175.41***
5.79
89.40**
7.06
86.03***
9.23
0.51
0.04
18–18.99
125
69.30***
13.49
176.75***
6.43
88.17
6.04
88.61***
8.60
0.50
0.04
Age
group
(years)
Girls
N
Weight
(kg)
Height
(cm)
SH
(cm)
LL
(cm)
SHTHR
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
0–0.99
66
7.36
2.11
65.14
7.89
43.61
4.36
21.52
6.63
0.68
0.09
1–1.99
72
11.82
1.52
81.89
5.53
50.00
3.63
31.81
6.58
0.61
0.06
2–2.99
62
14.48
1.89
93.79
6.29
53.39*
3.73
40.35
6.19
0.57
0.05
3–3.99
61
16.50
1.88
103.18
4.73
55.49
3.73
47.66
5.61
0.54
0.04
4–4.99
78
18.94
2.06
110.55
5.93
57.31
3.68
53.21
6.39
0.52
0.04
5–5.99
83
20.79
3.21
115.58
8.16
60.04
3.85
55.61
9.18
0.52
0.06
6–6.99
149
23.30
4.05
119.83
7.35
61.91
3.21
57.92
7.85
0.52
0.04
7–7.99
156
25.85
4.63
126.01
6.44
63.83
3.19
62.15
7.02
0.51
0.04
8–8.99
165
28.63
4.47
130.96
6.59
65.49
3.65
65.84
8.72
0.50
0.05
9–9.99
127
31.21
5.49
135.55
5.65
68.67**
3.87
66.87
6.54
0.51**
0.03
10–10.99
150
34.07
6.75
141.73
6.99
70.67
3.97
71.01
7.77
0.50
0.04
11–11.99
122
38.86
8.47
147.32
8.30
72.33
4.26
74.99
9.44
0.49
0.04
12–12.99
94
43.49*
7.08
152.47
7.45
77.07**
5.23
75.36
8.42
0.51
0.04
13–13.99
105
48.99*
8.06
157.12
6.13
80.11***
4.86
77.02
7.77
0.51**
0.04
14–14.99
121
53.5*
7.88
160.26
5.28
81.13
4.40
79.15
6.76
0.51***
0.03
15–15.99
145
55.00
8.11
162.31
4.65
84.66
5.34
77.66
7.06
0.52***
0.04
16–16.99
109
56.16
8.58
162.18
5.14
87.22
5.22
75.00
7.05
0.54***
0.03
17–17.99
161
56.36
8.80
164.47
5.59
88.48
6.47
75.99
7.80
0.54***
0.04
18–18.99
156
58.14
10.07
165.53
6.08
87.49
6.18
78.03
9.01
0.53***
0.04
Difference
between
boys
and
girls
at
each
age
group
*
P
<
0.01.
**
P
<
0.001.
***
P
<
0.0001.
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
G
Model
ARCPED-4945;
No.
of
Pages
11
3

were
from
Bizerte
governorate
(northern
area),
1702
subjects
were
from
the
Monastir
governorate
(central
area),
and
1183
subjects
were
from
the
Gabes
governorate
(southern
area).
Among
them,
3%
of
schoolchildren
and
14%
of
children
under
6
years
refused
to
participate
in
the
study;
1%
of
the
subjects
suffered
from
chronic
diseases
and
were
excluded.
Of
the
total
number
of
children
measured,
4358
(2182
girls
and
2176
boys)
participated
in
this
study.
All
15
schools
(six
primary
schools,
six
preparatory
schools,
and
three
secondary
schools)
were
randomly
selected
in
the
three
governorates
from
a
total
of
185
schools.
These
schools
had
all
levels
of
study
and
the
number
of
students
per
class
exceeded
25.
Table
1
presents
height,
weight,
SH,
LL,
and
SHTHR
as
a
mean
and
standard
deviation
(SD)
by
age
group
and
gender.
It
also
shows
the
difference
between
the
values
for
girls
and
boys
at
each
age
group.
Tables
2–6
present
the
values
of
L,
M,
S,
and
the
different
percentiles
of
the
anthropometric
parameters
(weight,
height,
SH,
LL,
and
SHTHR)
according
to
age
and
gender.
The
median
weight
values
range
from
10.38
kg
to
65.27
kg
at
the
age
of
18
in
boys
and
9.88
kg
to
55.98
kg
in
girls.
Regarding
the
median
height,
the
values
change
from
74.26
cm/73.81
cm
(boys/girls)
to
176.27
cm/
164.23
cm
at
18
years.
In
addition,
the
raw
data
of
the
weight
and
height
measurements
show
a
significant
difference
(P
<
0.001)
at
the
age
of
18
between
girls
and
boys
(Table
7).
The
SH
values
vary
from
46.75
cm/47.11
cm
(boys/girls)
to
89.91
cm/88.08
cm
at
18
years.
However,
LL
values
range
from
28.11
cm/26.78
cm
to
87.39
cm/77.30
cm
at
18
years.
Moreover,
the
raw
data
show
that
the
LL
values
are
significantly
higher
than
SH
(P
<
0.0001)
during
the
1st
year
of
life
in
both
genders
(Table
7).
Figs.
3–5
illustrate
the
smooth
percentile
curves
of
weight,
height,
SH,
LL,
and
SHTH
for
girls
and
boys.
Weight
curves
increase
continuously
with
age
except
that
in
girls
the
values
tend
to
stabilize
starting
at
15
years
of
age.
Height
and
SH
curves
increase
sharply
during
the
1st
year.
However,
the
LL
curves
increase
sharply
until
the
age
of
5
years.
Then
they
increase
slightly
until
puberty.
LL
curves
reach
a
steady
state
very
early
(12
years)
compared
to
the
height
curves
(14
years)
and
SH
curves
(17
years)
in
girls.
In
boys,
the
values
of
these
curves
tend
to
increase
after
the
age
of
18.
On
the
other
hand,
the
SHTHR
curves
decrease
sharply
before
the
age
of
4
and
then
stabilize
in
both
genders.
The
50th
percentile
weight
values
are
very
similar
for
both
sexes
before
the
age
of
12.
Then
the
values
for
girls
become
higher
with
a
significant
difference
(P
<
0.001)
for
12–15
years.
After
the
Table
2
L,
M,
S,
and
percentile
values
for
weight
(cm)
for
Tunisian
children
aged
1–18
years.
Age
(years)
Boys
Girls
L
M
S
P3
P10
P25
P50
P75
P90
P97
L
M
S
P3
P10
P25
P50
P75
P90
P97
1
0.68
10.38
0.15
7.62
8.47
9.36
10.38
11.43
12.41
13.39
0.93
9.88
0.11
7.80
8.46
9.13
9.88
10.64
11.32
12.00
2
0.39
13.87
0.14
10.51
11.52
12.60
13.87
15.21
16.49
17.81
0.85
13.47
0.1
1
10.63
11.52
12.44
13.47
14.51
15.46
16.40
3
0.21
16.11
0.14
12.41
13.51
14.69
16.11
17.63
19.09
20.63
0.71
15.52
0.11
12.32
13.31
14.35
15.52
16.72
17.82
18.93
4
0.09
17.70
0.13
13.76
14.92
16.18
17.70
19.34
20.93
22.63
0.53
17.58
0.12
13.91
15.04
16.22
17.58
18.99
20.30
21.64
5
0.03
19.23
0.13
15.07
16.29
17.62
19.23
21.00
22.73
24.59
0.27
19.72
0.13
15.38
16.68
18.07
19.72
21.48
23.15
24.89
6
0.20
21.56
0.13
16.99
18.31
19.77
21.56
23.55
25.53
27.69
0.09
21.75
0.14
16.71
18.17
19.78
21.75
23.95
26.13
28.49
7
0.41
24.54
0.13
19.30
20.78
22.45
24.54
26.92
29.35
32.05
0.55
24.01
0.15
18.40
19.94
21.72
24.01
26.69
29.51
32.78
8
0.60
27.17
0.14
21.26
22.90
24.78
27.17
29.95
32.87
36.22
0.88
26.64
0.16
20.53
22.17
24.09
26.64
29.74
33.17
37.37
9
0.74
29.58
0.15
23.07
24.85
26.91
29.58
32.75
36.14
40.14
1.07
29.08
0.16
22.49
24.23
26.30
29.08
32.54
36.47
41.46
10
0.84
32.23
0.15
24.97
26.93
29.22
32.23
35.85
39.82
44.60
1.15
31.56
0.16
24.22
26.13
28.43
31.56
35.55
40.19
46.27
11
0.88
35.69
0.16
27.33
29.56
32.19
35.69
39.96
44.72
50.58
0.91
35.14
0.18
26.20
28.53
31.34
35.14
39.93
45.44
52.52
12
0.85
39.08
0.17
29.56
32.09
35.08
39.08
44.01
49.54
56.41
0.21
40.05
0.18
28.70
31.84
35.44
40.05
45.40
50.96
57.28
13
0.84
42.74
0.17
32.16
34.96
38.29
42.74
48.24
54.42
62.12
0.29
45.81
0.16
33.20
36.91
40.96
45.81
51.05
56.12
61.47
14
0.92
47.75
0.16
36.52
39.50
43.04
47.75
53.56
60.07
68.18
0.16
50.72
0.15
37.98
41.71
45.80
50.72
56.08
61.31
66.86
15
1.01
52.63
0.15
40.96
44.07
47.75
52.63
58.63
65.35
73.69
0.29
53.57
0.15
41.16
44.67
48.62
53.57
59.19
64.91
71.28
16
1.03
56.93
0.15
44.38
47.72
51.68
56.93
63.40
70.64
79.66
0.56
54.93
0.15
42.48
45.93
49.88
54.93
60.83
67.02
74.15
17
0.96
61.24
0.15
47.44
51.12
55.47
61.24
68.31
76.19
85.92
0.67
55.55
0.15
43.01
46.45
50.42
55.55
61.60
68.06
75.61
18
0.78
65.27
0.16
49.86
54.00
58.86
65.27
73.03
81.55
91.87
0.74
55.98
0.15
43.36
46.80
50.80
55.98
62.16
68.81
76.69
Table
3
L,
M,
S,
and
percentile
values
for
height
(cm)
for
Tunisian
children
aged
1–18
years.
Age
(years)
Boys
Girls
L
M
S
P3
P10
P25
P50
P75
P90
P97
L
M
S
P3
P10
P25
P50
P75
P90
P97
1
1.56
74.26
0.07
65.62
68.09
70.84
74.26
78.14
82.10
86.57
2.24
73.81
0.06
64.87
67.88
70.77
73.81
76.71
79.20
81.57
2
1.99
88.94
0.06
80.00
82.55
85.40
88.94
92.96
97.08
101.73
2.20
88.09
0.06
78.29
81.57
84.73
88.09
91.29
94.07
96.72
3
1.88
99.60
0.05
90.65
93.25
96.10
99.60
103.48
107.38
111.67
2.30
99.02
0.05
88.72
92.17
95.49
99.02
102.39
105.30
108.08
4
1.36
106.85
0.05
98.01
100.63
103.47
106.85
110.51
114.06
117.84
2.48
107.15
0.05
96.47
100.05
103.50
107.15
110.62
113.61
116.45
5
0.66
112.34
0.04
103.50
106.18
109.03
112.34
115.82
119.12
122.52
2.50
113.34
0.05
102.35
106.04
109.59
113.34
116.91
120.00
122.93
6
0.13
117.68
0.04
108.57
111.38
114.32
117.68
121.15
124.38
127.66
2.15
118.20
0.05
107.10
110.77
114.36
118.20
121.89
125.12
128.20
7
0.06
123.35
0.04
113.72
116.70
119.81
123.35
126.99
130.35
133.75
1.47
122.94
0.05
111.84
115.43
119.01
122.94
126.80
130.23
133.58
8
0.29
128.67
0.04
118.50
121.62
124.90
128.67
132.59
136.25
140.00
0.78
128.11
0.05
116.91
120.45
124.07
128.11
132.18
135.86
139.53
9
0.90
133.85
0.05
123.11
126.35
129.80
133.85
138.14
142.23
146.51
0.34
133.32
0.05
121.87
125.44
129.14
133.32
137.60
141.52
145.47
10
1.19
138.93
0.05
127.54
130.94
134.59
138.93
143.58
148.07
152.81
0.27
138.74
0.05
126.78
130.51
134.36
138.74
143.23
147.35
151.51
11
0.95
144.01
0.05
131.79
135.46
139.38
144.01
148.95
153.68
158.65
0.43
144.42
0.05
131.90
135.82
139.85
144.42
149.06
153.32
157.58
12
0.37
149.04
0.05
135.92
139.92
144.14
149.04
154.17
159.00
163.97
0.60
149.96
0.05
137.38
141.34
145.40
149.96
154.58
158.79
162.98
13
0.22
154.74
0.05
141.03
145.29
149.71
154.74
159.90
164.66
169.47
0.51
154.86
0.04
143.01
146.73
150.55
154.86
159.22
163.20
167.17
14
0.76
160.79
0.04
147.51
151.71
155.99
160.79
165.61
169.98
174.32
0.00
158.64
0.04
148.06
151.35
154.76
158.64
162.61
166.27
169.97
15
1.48
165.70
0.04
153.65
157.54
161.43
165.70
169.92
173.68
177.35
0.93
161.07
0.03
151.73
154.59
157.60
161.07
164.69
168.09
171.58
16
2.13
169.84
0.03
158.75
162.37
165.96
169.84
173.62
176.95
180.16
2.14
162.41
0.03
153.79
156.38
159.15
162.41
165.89
169.23
172.75
17
2.22
173.64
0.03
162.84
166.37
169.86
173.64
177.33
180.56
183.69
3.43
163.32
0.03
154.86
157.34
160.05
163.32
166.90
170.45
174.30
18
1.68
176.27
0.03
165.26
168.82
172.38
176.27
180.10
183.51
186.83
4.61
164.23
0.03
155.60
158.08
160.83
164.23
168.08
172.02
176.48
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
G
Model
ARCPED-4945;
No.
of
Pages
11
4

Table
4
L,
M,
S,
and
percentile
values
for
sitting
height
(SH)
(cm)
for
Tunisian
children
aged
1–18
years.
Age
(years)
Boys
Girls
L
M
S
P3
P10
P25
P50
P75
P90
P97
L
M
S
P3
P10
P25
P50
P75
P90
P97
1
1.36
46.75
0.08
39.43
41.81
44.17
46.75
49.27
51.50
53.67
0.16
47.11
0.07
40.96
42.84
44.82
47.11
49.49
51.72
54.01
2
1.20
50.80
0.08
43.15
45.61
48.08
50.80
53.49
55.88
58.22
0.13
51.87
0.07
45.64
47.53
49.53
51.87
54.33
56.66
59.07
3
1.07
53.68
0.08
45.97
48.44
50.93
53.68
56.43
58.90
61.32
0.31
54.47
0.06
48.37
50.21
52.17
54.47
56.90
59.21
61.61
4
0.95
56.17
0.07
48.47
50.92
53.40
56.17
58.94
61.44
63.92
0.44
56.41
0.06
50.46
52.25
54.16
56.41
58.79
61.05
63.42
5
0.83
58.59
0.07
50.94
53.36
55.83
58.59
61.38
63.90
66.41
0.56
58.42
0.06
52.64
54.38
56.24
58.42
60.74
62.95
65.26
6
0.72
61.11
0.07
53.53
55.91
58.36
61.11
63.89
66.43
68.96
0.66
60.68
0.05
55.05
56.75
58.55
60.68
62.93
65.08
67.32
7
0.61
63.30
0.06
55.77
58.13
60.56
63.30
66.09
68.65
71.20
0.73
62.74
0.05
57.19
58.86
60.64
62.74
64.96
67.08
69.30
8
0.54
64.74
0.06
57.19
59.55
61.98
64.74
67.55
70.12
72.71
0.77
64.55
0.05
58.94
60.63
62.43
64.55
66.80
68.95
71.19
9
0.47
66.16
0.06
58.53
60.91
63.37
66.16
69.02
71.64
74.29
0.78
66.79
0.05
60.92
62.69
64.57
66.79
69.14
71.39
73.74
10
0.38
68.46
0.06
60.61
63.05
65.58
68.46
71.42
74.16
76.92
0.72
69.27
0.05
62.97
64.87
66.89
69.27
71.79
74.21
76.73
11
0.28
71.32
0.06
63.19
65.70
68.32
71.32
74.42
77.28
80.19
0.61
71.46
0.05
64.70
66.74
68.91
71.46
74.17
76.75
79.45
12
0.22
73.70
0.06
65.30
67.89
70.60
73.70
76.92
79.90
82.93
0.42
74.39
0.06
67.03
69.26
71.63
74.39
77.32
80.09
82.96
13
0.19
76.08
0.06
67.36
70.05
72.86
76.08
79.43
82.54
85.71
0.15
77.97
0.06
69.92
72.38
74.97
77.97
81.11
84.06
87.09
14
0.19
79.18
0.07
69.94
72.78
75.76
79.18
82.73
86.03
89.39
0.14
80.72
0.06
72.03
74.70
77.50
80.72
84.06
87.16
90.31
15
0.24
82.62
0.07
72.56
75.66
78.90
82.62
86.47
90.05
93.69
0.41
83.24
0.06
73.78
76.72
79.77
83.24
86.80
90.07
93.38
16
0.32
85.89
0.07
74.89
78.29
81.83
85.89
90.09
93.99
97.95
0.66
85.76
0.07
75.40
78.65
81.99
85.76
89.59
93.08
96.57
17
0.39
88.14
0.07
76.47
80.08
83.84
88.14
92.58
96.69
100.86
0.83
87.41
0.07
76.34
79.84
83.41
87.41
91.44
95.09
98.72
18
0.41
88.91
0.07
77.00
80.68
84.52
88.91
93.44
97.62
101.86
0.90
88.08
0.07
76.70
80.31
83.98
88.08
92.20
95.92
99.60
Table
5
L,
M,
S,
and
percentile
values
for
leg
length
(LL)
(cm)
for
Tunisian
children
aged
1–18
years.
Age
(years)
Boys
Girls
L
M
S
P3
P10
P25
P50
P75
P90
P97
L
M
S
P3
P10
P25
P50
P75
P90
P97
1
0.71
28.11
0.19
18.43
21.39
24.51
28.11
31.85
35.33
38.87
1.24
26.78
0.15
18.45
21.31
24.08
26.78
29.41
31.99
34.51
2
0.51
38.99
0.15
28.50
31.67
35.04
38.99
43.14
47.06
51.09
1.18
37.26
0.13
27.20
30.62
33.97
37.26
40.50
43.69
46.85
3
0.42
46.41
0.13
35.63
38.89
42.36
46.41
50.69
54.72
58.87
1.18
44.58
0.12
33.78
37.44
41.04
44.58
48.07
51.51
54.92
4
0.41
50.56
0.12
39.59
42.91
46.44
50.56
54.89
58.97
63.17
1.19
50.47
0.11
38.91
42.82
46.68
50.47
54.21
57.90
61.55
5
0.41
53.45
0.12
42.20
45.62
49.24
53.45
57.87
62.02
66.29
1.17
54.85
0.11
42.71
46.81
50.86
54.85
58.79
62.68
66.53
6
0.43
56.32
0.12
44.67
48.22
51.97
56.32
60.88
65.15
69.53
1.16
57.39
0.11
44.95
49.15
53.30
57.39
61.43
65.44
69.40
7
0.46
59.87
0.12
47.59
51.34
55.30
59.87
64.65
69.12
73.69
1.15
59.95
0.10
47.19
51.49
55.74
59.95
64.11
68.23
72.32
8
0.50
63.80
0.12
50.59
54.64
58.89
63.80
68.90
73.67
78.52
1.12
63.33
0.10
50.10
54.55
58.96
63.33
67.67
71.97
76.25
9
0.56
67.72
0.12
53.35
57.77
62.40
67.72
73.23
78.35
83.56
1.09
66.30
0.10
52.61
57.20
61.77
66.30
70.81
75.29
79.75
10
0.63
70.76
0.12
55.45
60.18
65.11
70.76
76.58
81.96
87.41
1.05
69.32
0.10
55.07
59.84
64.59
69.32
74.04
78.74
83.44
11
0.69
73.24
0.12
57.24
62.20
67.36
73.24
79.27
84.82
90.41
0.99
72.80
0.10
57.86
62.84
67.82
72.80
77.79
82.78
87.77
12
0.76
75.78
0.12
59.20
64.38
69.72
75.78
81.95
87.61
93.28
0.93
75.16
0.10
59.87
64.94
70.04
75.16
80.31
85.48
90.66
13
0.85
78.78
0.12
61.72
67.08
72.59
78.78
85.04
90.74
96.42
0.89
76.23
0.10
60.83
65.92
71.05
76.23
81.44
86.69
91.97
14
0.94
81.49
0.11
64.20
69.68
75.26
81.49
87.75
93.41
99.01
0.87
76.64
0.10
61.20
66.30
71.44
76.64
81.88
87.17
92.50
15
0.99
83.11
0.11
65.79
71.31
76.89
83.11
89.33
94.92
100.45
0.86
76.76
0.10
61.30
66.40
71.55
76.76
82.01
87.31
92.65
16
1.03
84.11
0.11
66.81
72.33
77.92
84.11
90.30
95.85
101.32
0.84
77.03
0.10
61.52
66.63
71.80
77.03
82.32
87.66
93.05
17
1.07
85.39
0.11
68.11
73.65
79.22
85.39
91.52
97.01
102.40
0.83
77.16
0.10
61.62
66.73
71.91
77.16
82.47
87.84
93.27
18
1.14
87.39
0.10
70.20
75.73
81.28
87.39
93.43
98.82
104.10
0.81
77.30
0.10
61.72
66.84
72.03
77.30
82.63
88.03
93.50
Table
6
L,
M,
S,
and
percentiles
values
for
sitting
height-to-height
ratio
(SHTHR)
for
Tunisian
children
aged
1–18
years.
Age
(years)
Boys
Girls
L
M
S
P3
P10
P25
P50
P75
P90
P97
L
M
S
P3
P10
P25
P50
P75
P90
P97
1
0.25
0.63
0.08
0.54
0.57
0.59
0.63
0.67
0.70
0.74
0.40
0.64
0.08
0.55
0.58
0.61
0.64
0.68
0.71
0.74
2
0.07
0.58
0.08
0.49
0.52
0.54
0.58
0.61
0.64
0.67
0.16
0.59
0.08
0.51
0.53
0.56
0.59
0.62
0.65
0.68
3
0.17
0.54
0.08
0.46
0.49
0.51
0.54
0.57
0.60
0.63
0.54
0.55
0.08
0.48
0.50
0.52
0.55
0.58
0.61
0.64
4
0.37
0.53
0.08
0.45
0.47
0.50
0.53
0.56
0.58
0.61
0.74
0.53
0.08
0.46
0.48
0.50
0.53
0.55
0.58
0.61
5
0.50
0.52
0.08
0.44
0.47
0.49
0.52
0.55
0.58
0.61
0.79
0.52
0.07
0.45
0.47
0.49
0.52
0.54
0.57
0.60
6
0.54
0.52
0.08
0.44
0.47
0.49
0.52
0.55
0.57
0.60
0.74
0.51
0.07
0.45
0.47
0.49
0.51
0.54
0.57
0.59
7
0.52
0.51
0.08
0.44
0.46
0.48
0.51
0.54
0.57
0.59
0.64
0.51
0.07
0.45
0.47
0.49
0.51
0.54
0.56
0.59
8
0.49
0.50
0.08
0.43
0.45
0.48
0.50
0.53
0.56
0.58
0.54
0.50
0.07
0.44
0.46
0.48
0.50
0.53
0.55
0.58
9
0.46
0.50
0.08
0.42
0.44
0.47
0.50
0.52
0.55
0.58
0.41
0.50
0.07
0.44
0.46
0.48
0.50
0.53
0.55
0.57
10
0.41
0.49
0.08
0.42
0.44
0.46
0.49
0.52
0.55
0.57
0.24
0.50
0.07
0.44
0.46
0.48
0.50
0.52
0.55
0.57
11
0.35
0.49
0.08
0.42
0.44
0.46
0.49
0.52
0.55
0.58
0.03
0.50
0.07
0.43
0.45
0.47
0.50
0.52
0.54
0.57
12
0.29
0.49
0.09
0.42
0.44
0.46
0.49
0.52
0.55
0.58
0.17
0.50
0.07
0.43
0.45
0.47
0.50
0.52
0.55
0.57
13
0.22
0.49
0.09
0.42
0.44
0.46
0.49
0.52
0.55
0.58
0.35
0.50
0.07
0.44
0.46
0.48
0.50
0.53
0.55
0.57
14
0.16
0.49
0.09
0.42
0.44
0.47
0.49
0.52
0.55
0.58
0.51
0.51
0.07
0.44
0.46
0.48
0.51
0.53
0.56
0.58
15
0.09
0.50
0.08
0.42
0.45
0.47
0.50
0.53
0.56
0.58
0.65
0.52
0.07
0.45
0.47
0.49
0.52
0.54
0.57
0.59
16
0.03
0.50
0.08
0.43
0.45
0.48
0.50
0.53
0.56
0.59
0.78
0.53
0.07
0.46
0.48
0.50
0.53
0.55
0.58
0.60
17
0.04
0.51
0.08
0.43
0.45
0.48
0.51
0.54
0.56
0.59
0.90
0.53
0.07
0.46
0.48
0.51
0.53
0.56
0.58
0.61
18
0.10
0.50
0.08
0.43
0.45
0.48
0.50
0.53
0.56
0.59
1.02
0.53
0.08
0.46
0.48
0.51
0.53
0.56
0.59
0.61
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
G
Model
ARCPED-4945;
No.
of
Pages
11
5

age
of
15,
the
50th
percentiles
intersect
and
the
values
for
boys
increase
with
a
highly
significant
difference
(P
<
0.0001)
at
16–17
years
(Table
1,
Fig.
6).
The
medians
of
height
in
both
sexes
are
almost
identical
in
most
age
groups.
After
14
years,
boys’
values
rose
compared
to
those
of
girls
with
a
highly
significant
difference
(P
<
0.0001)
(Table
1,
Fig.
6).
The
smooth
median
SH
curves
in
both
sexes
overlap.
According
to
Table
1
and
Fig.
6,
the
SH
values
for
girls
are
greatest
at
12–13
years
(P
<
0.001),
while
at
16–17
years
the
SH
values
for
boys
rise
(P
<
0.001).
The
trend
median
curves
for
LL
and
SHTHR
are
very
similar
in
most
age
groups
in
both
genders.
After
the
age
of
13,
the
LL
values
for
boys
are
higher
(P
<
0.001)
and
the
SHTHR
values
for
girls
are
higher
(P
<
0.001)
(Table
1,
Fig.
6).
The
50th
percentile
of
weight
in
Tunisian
boys
is
higher
compared
to
the
NCHS,
WHO,
and
Algerian
references
at
1–
11years.
After
11
years,
it
crosses
with
that
of
the
NCHS
reference
and
at
13
years
it
approaches
the
50th
percentile
of
the
Algerian
reference.
For
girls,
the
50
th
percentile
is
higher
than
those
of
the
three
references.
At
9
years,
it
overlaps
with
those
of
the
NCHS
and
Algerian
references
(Fig.
7).
The
median
height
curve
in
Tunisian
boys
is
greater,
especially
at
2–6
years
in
comparison
with
the
three
references.
Between
12
and
18
years,
it
shifts
down
compared
to
the
NCHS
and
WHO
references
and
approaches
the
median
of
the
Algerian
reference.
However,
the
median
curve
for
Tunisian
girls
is
higher
between
the
ages
of
2
and
9
years,
then
it
approaches
the
NCHS
and
WHO
references
and
becomes
higher
than
the
Algerian
reference
beginning
at
the
age
of
14
(Fig.
7).
Table
7
The
raw
data
in
two
ages
groups
(1–1.99
and
18–18.99
years)
and
the
smoothed
50
th
percentile
values
at
1
year
and
18
years
of
the
parameters
weight,
height,
sitting
height
(SH),
leg
length
(LL),
and
sitting
height-to-height
ratio
(SHTHR)
according
to
sex.
Raw
Data
Smoothed
data
(Median)
1–1.99
years
18–18.99
years
One
year
18
years
Boys
Girls
Boys
Girls
Boys
Girls
Boys
Girls
Mean
(SD)
Range
Mean
(SD)
Range
Mean
(SD)
Range
Mean
(SD)
Range
Weight
(kg)
12.30
(2.08)
7.71
19.13
11.82
(1.52)
9.18–15.92
69.30
a
(13.49)
46.02

97.82
58.14
(10.07)
39.01

85.15
10.38
9.88
65.27
55.98
Height
(cm)
82.94
(7.21)
67.00

107.00
81.89
(5.53)
70.00

96.00
176.75
a
(6.43)
163.00

196.00
165.53
(6.08)
150.00

183.00
74.26
73.81
176.27
164.23
SH
(cm)
49.11
b
(4.62)
39.00
-
60.00
50.00
b
(3.63)
43.00

58.00
88.17
(6.04)
76.00

102.00
87.49
(6.18)
73.00

102.00
46.75
47.11
88.91
88.08
LL
(cm)
33.87
(8.78)
7.00

61.00
31.81
(6.58)
18.00

50.00
88.61
a
(8.60)
68.00

109.00
78.03
(9.01)
54.00

103.00
28.11
26.78
87.39
77.30
SHTHR
0.60
(0.08)
0.40

0.89
0.61
(0.06)
0.47

0.75
0.50
(0.04)
0.43

0.60
0.53
a
(0.04)
0.42

0.64
0.63
0.64
0.50
0.53
SD,
standard
deviation.
a
P
<
0.0001;
difference
between
boys
and
girls.
b
P
<
0.0001;
difference
between
SH
and
LL.
Fig.
3.
Smoothed
percentile
curves
for
weight
and
height
for
boys
and
girls.
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
G
Model
ARCPED-4945;
No.
of
Pages
11
6

The
maximum
shift
of
the
median
weight
curve
reaches–
5.17
kg/+2.17
kg
(boys/girls)
compared
to
that
of
the
NCHS,
+1.77
kg/+1.99
kg
compared
to
the
WHO
curve,
and
+2.34
kg/
+2.34
with
the
Algerian
weight
curve
(Table
8).
In
height,
the
maximum
shift
reaches
17.30
cm/18.22
cm
(compared
to
the
NCHS
reference),
+3.52
cm/+4.42
cm
(compared
to
the
WHO
reference),
and
+2.33
cm/+4.09
cm
(compared
to
the
Algerian
reference)
(Table
9).
4.
Discussion
The
assessment
of
weight,
height,
and
different
body
segments
is
very
important
in
monitoring
children’s
growth.
The
objective
of
this
study
was
to
develop
reference
curves
for
weight,
height,
SH,
LL,
and
SHTHR
for
Tunisian
children
and
adolescents.
The
general
trend
in
weight
and
height
curves
shows
an
increase
over
time
into
adulthood.
Regarding
the
median
height
curves,
boys
become
taller
than
girls.
This
can
be
explained
by
the
different
roles
of
androgens
and
estrogens
in
the
regulation
of
growth
velocity
and
bone
maturation
in
both
sexes
during
the
pubertal
growth
spurt
[20].
The
comparison
of
the
values
of
the
median
percentiles
in
Tunisian
children
with
those
of
the
NCHS,
WHO,
and
Algerian
references,
the
latter
in
the
same
geographical
region
(North
Africa),
brought
out
discrepancies
at
certain
time
intervals.
This
can
be
linked
to
various
factors:
genetic
factors,
environmental
factors
including
diet
and
climatic
conditions,
socioeconomic
status,
and
social
stability
[21,22].
Analyzing
the
change
in
velocity
in
weight
and
height
is
fundamental
to
assess
children’s
growth.
Growth
disorders
can
be
manifested
by
certain
endocrine
and
metabolic
diseases
[23].
Two
growth
peaks
have
been
identified,
the
most
remarkable
during
the
1st
years
of
life
and
the
other
at
puberty
[17].
Our
data
show
that
the
peaks
of
velocity
in
weight
after
the
1st
years
in
boys
and
girls
are
3.49
kg/year
and
3.58
kg/year,
respectively.
During
puberty,
the
peaks
reach
the
values
of
5.01
kg/year
at
14
years
and
5.76
kg/year
at
13
years.
In
1966,
Tanner
et
al.
published
the
first
graphs
of
growth
velocity
in
English
children
[24].
These
references
remain
the
most
frequently
used
worldwide
until
today
Fig.
4.
Smoothed
percentile
curves
for
sitting
height
and
leg
length
for
boys
and
girls.
Fig.
5.
Smoothed
percentile
curves
for
sitting
height-to-height
ratio
for
boys
and
girls.
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
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(xxxx)
xxx–xxx
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Model
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of
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7

[17],
presenting
velocity
peaks
of
weight
in
the
1
st
years
of
life
at
3.33
kg/year
in
boys
and
3.32
kg/year
in
girls.
In
adolescence,
the
velocity
peaks
are
around
6.30
kg/year
(14
years)
and
5.99
kg/year
(12.5
years).
For
height
in
our
references,
after
the
1st
year
the
growth
velocity
peaks
reached
14.68
cm/year
in
boys
and
14.28
cm/year
in
girls.
At
puberty,
they
are
around
6.04
cm/year
(14
years)
and
5.67
cm/year
(11
years)
in
girls
and
boys,
respectively
[24].
However,
the
height
curves
reported
by
Tanner
(1966)
presented
as
velocity
peaks
in
0.87
years
14.50
cm/year
and
15.90
cm/year
in
boys
and
girls,
respectively.
At
adolescence,
the
peaks
are
7.30
cm/year
and
6.38
cm/year
[24].
Another
study
conducted
by
Tanner
(1985)
in
North
America
identified
other
height
velocity
peaks:
9.50
cm/year
(boys)
and
8.30
cm/year
(girls)
at
ages
11.50
and
13.50
years
[25].
A
small
deviation
was
observed
between
the
weight
and
height
velocity
peaks
of
our
reference
and
those
of
the
Tanner
curves
made
in
1966,
despite
the
different
tools
investigated
and
the
approach
used:

the
measurement
dates
(the
1960s
vs.
2012–2013),
when
there
was
a
change
in
diet
with
more
recent
foods
genetically
modified
due
to
changes
in
technology
[26];

the
comparison
of
a
longitudinal
study
with
a
cross-sectional
study;
the
cross-sectional
study
could
not
reflect
the
actual
rate
of
growth
in
weight
and
height
[27];

the
techniques
for
smoothing
curves
are
more
developed
today
[28]
compared
to
the
smoothing
techniques
used
in
the
1960s
[24].
Height
gains
during
puberty
are
15.45%
and
15.52%
of
final
height
in
boys
and
girls,
respectively.
Several
references
have
shown
similar
percentages.
In
Algeria,
the
gains
are
15.66%
and
14.79%
[12].
In
the
WHO
international
reference,
they
are
estimated
at
around
16%
and
15%
[10].
The
gains
reported
in
Argentina
are
16%/16%
[29].
In
Colombia,
the
percentages
are
slightly
lower
(14%/13%).
This
may
be
linked
to
the
precocious
puberty
of
their
children
[29].
The
assessment
of
body
proportions
is
very
important
in
the
diagnosis
of
growth
disorders.
SH,
LL,
and
SHTHR
are
among
the
parameters
most
widely
used
by
pediatricians
to
detect
dispro-
portionate
growth.
According
to
the
values
of
the
smoothed
median
curves,
we
found
a
difference
in
the
changes
in
trunk
height
and
leg
length.
This
corresponds
to
the
different
velocity
Fig.
6.
Comparisons
between
boys
and
girls
in
50th
percentiles
for
weight,
height,
sitting
height,
leg
length,
and
sitting
height-to-height
ratio.
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
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(xxxx)
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of
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8

peaks
reached,
in
particular
during
the
1st
years
of
life.
SH
velocity
peaks
are
4.05
cm/year
(boys)
and
4.76
cm/year
(girls)
while
LL
velocity
peaks
are
10.88
cm/year
(boys)
and
10.48
cm/year
(girls).
Consequently,
we
deduce
that
the
legs
grow
faster
than
the
trunk
from
1
year
of
age
to
puberty.
In
this
sense,
various
studies
conducted
in
different
countries
such
as
England
and
Turkey
have
shown
that
the
change
in
body
height
is
mainly
due
to
the
increase
in
the
length
of
the
legs
rather
than
that
of
the
trunk
[13,30].
At
puberty,
the
velocity
peaks
of
SH
and
LL
are
very
similar:
3.43
cm/
year
in
boys
and
3.57
cm/year
in
girls
versus
3
cm/year
in
boys
and
3.48
cm/year
in
girls.
However,
other
studies
have
shown
that
all
sections
of
the
body
participate
in
pubertal
thrust,
but
this
involves
the
height
of
the
trunk
more
than
the
lower
limbs
[31].
In
addition,
according
to
the
analysis
of
the
median
SHTHR
curve,
the
values
decrease
with
age
from
0.63
and
0.64
to
0.50
and
0.53
in
boys
and
girls,
respectively.
This
means
that
the
leg
length
increases
without
exceeding
half
of
the
body
height
in
adulthood.
The
same
result
was
found
in
2005
in
German
children:
the
SHTHR
values
decline
from
0.68
in
childhood
to
0.52
at
puberty
[4].
The
ratio
in
Turkish
children
varies
from
0.56
(boys)
and
0.55
(girls)
at
6
years
to
0.53
and
0.54
at
18
years
[30].
The
final
proportions
of
the
legs
of
Tunisian
children
are
higher
than
those
of
Japanese
children
[32]
(boys:
89.81
cm
vs.
80.80
cm;
girls:
88.07
cm
vs.
74.50
cm)
and
those
of
German
children
[4]
(boys:
89.81
cm
vs.
89.14
cm;
girls:
88.07
cm
vs.
81.06
cm).
This
confirms
the
idea
that
populations
of
African
origin
have
significantly
longer
leg
lengths
than
those
of
the
populations
of
Asian
and
European
origins
[33].
Fig.
7.
Comparisons
the
50th
percentiles
for
weight
and
height
of
Tunisian
children
with
those
of
the
NCHS,
WHO,
and
Algeria.
Table
8
Shifts
of
the
50th
percentile
of
weight
(kg)
of
Tunisian
reference
with
the
NCHS,
WHO,
and
Algerian
references
in
the
different
age
groups
among
boys
and
girls.
Boys
Girls
Age
Tunisia
NCHS
Shift
WHO
Shift
Algeria
Shift
Tunisia
NCHS
Shift
WHO
Shift
Algeria
Shift
1
10.38
10.10
+0.28
9.65
+0.73
9.88
9.57
+0.31
8.95
+0.94
2
13.87
12.34
+1.53
12.15
+1.71
13.47
11.80
+1.67
11.48
+1.99
3
16.11
14.62
+1.49
14.34
+1.77
15.52
14.10
+1.42
13.85
+1.67
4
17.70
16.69
+1.01
16.35
+1.35
17.58
15.96
+1.62
16.07
+1.51
5
19.23
18.67
+0.56
18.34
+0.90
19.72
17.66
+2.06
18.22
+1.50
6
21.32
20.69
+0.63
20.51
+0.81
20.85
+0.47
21.58
19.52
+2.06
20.16
+1.41
19.50
+2.08
7
24.54
22.85
+1.69
22.89
+1.65
22.59
+1.95
24.01
21.84
+2.17
22.37
+1.63
21.90
+2.11
8
27.17
25.30
+1.87
25.42
+1.76
24.92
+2.25
26.64
24.84
+1.80
25.03
+1.61
24.30
+2.34
9
29.58
28.13
+1.45
28.11
+1.47
27.89
+1.69
29.08
28.46
+0.62
28.20
+0.87
26.95
+2.13
10
32.23
31.44
+0.79
31.16
+1.07
30.86
+1.37
31.56
32.55
0.99
31.86
0.29
30.44
+1.12
11
35.69
35.30
+0.39
33.87
+1.82
35.14
36.95
1.81
34.70
+0.44
12
39.08
39.78
0.70
37.41
+1.67
40.05
41.83
1.78
39.28
+0.77
13
42.74
44.95
2.21
41.81
+0.93
45.81
46.10
0.29
44.07
+1.74
14
47.75
50.77
3.02
47.25
+0.50
50.72
50.28
+0.44
48.55
+2.17
15
52.63
56.71
4.08
52.89
0.26
53.57
53.68
0.11
51.78
+1.79
16
56.93
62.10
5.17
57.44
0.51
54.93
55.89
0.96
53.78
+1.15
17
61.24
66.31
5.07
60.54
+0.70
55.55
56.69
1.14
54.95
+0.60
18
65.27
68.88
3.61
62.93
+2.34
55.98
56.62
0.64
55.63
+0.35
+:
shift
up;

shift
down.
H.
Ghouili,
N.
Ouerghi,
A.
Boughalmi
et
al.
Archives
de
Pe
´diatrie
xxx
(xxxx)
xxx–xxx
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Model
ARCPED-4945;
No.
of
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9

The
strong
point
of
this
study
is
that
it
is
the
first
to
investigate
the
construction
of
growth
curves
specific
to
Tunisian
children
and
adolescents.
Nevertheless,
it
also
has
several
limitations:
The
number
of
cross-sectional
data
measurements
taken
during
the
1st
years
of
life
may
be
too
low.
It
is
difficult
to
describe
accurately
the
rapid
change
in
growth
rate
during
this
period.
Therefore,
it
is
very
useful
to
base
future
studies
on
longitudinal
data
from
a
very
large
representative
sample,
in
order
to
establish
standard
percentile
curves
specific
to
Tunisian
children.
These
curves
can
help
pediatric
specialists
to
better
detect
growth
disorders
at
an
early
age.
5.
Conclusion
The
curves
presented
in
this
study
are
national
reference
curves
based
on
measurements
of
subjects
recruited
from
three
major
areas
(north,
center,
and
south)
in
Tunisia.
We
believe
that
these
curves
could
be
added
to
the
clinical
tools
of
pediatric
centers.
The
weight
and
height
percentile
curves
will
be
useful
to
access
the
general
growth
in
Tunisian
children.
However,
the
SH,
LL,
and
SHTHR
curves
could
be
used
to
monitor
body
proportions
during
childhood.
The
official
use
of
these
curves
requires
validation
by
pediatricians
and
public
health
specialists
after
testing
their
reliability
on
Tunisian
children.
Disclosure
of
interest
The
authors
declare
that
they
have
no
competing
interest.
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Shifts
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Boys
Girls
Age
Tunisia
NCHS
Shift
WHO
Shift
ALGERIA
Shift
Tunisia
NCHS
Shift
WHO
Shift
Algeria
Shift
1
74.26
61.20
+13.06
75.75
1.49
73.81
59.60
+14.21
74.02
0.20
2
88.94
72.40
+16.54
87.82
+1.13
88.09
70.60
+17.49
86.42
+1.67
3
99.60
82.30
+17.30
96.08
+3.51
99.02
80.80
+18.22
95.05
+3.97
4
106.85
92.30
+14.55
103.33
+3.52
107.15
91.40
+15.75
102.73
+4.42
5
112.34
100.50
+11.84
109.96
+2.38
113.34
99.10
+14.24
109.42
+3.92
6
117.68
107.40
+10.28
115.95
+1.73
116.14
+1.54
118.20
106.20
+12.00
115.12
+3.07
114.11
+4.09
7
123.35
114.20
+9.15
121.73
+1.61
121.02
+2.33
122.94
112.80
+10.14
120.81
+2.13
119.56
+3.38
8
128.67
120.60
+8.07
127.27
+1.41
126.38
+2.29
128.11
119.60
+8.51
126.56
+1.55
125.10
+3.01
9
133.85
126.70
+7.15
132.57
+1.28
131.92
+1.93
133.32
125.40
+7.92
132.49
+0.83
130.79
+2.53
10
138.93
132.60
+6.33
137.78
+1.15
137.10
+1.83
138.74
130.90
+7.84
138.64
+0.11
136.92
+1.82
11
144.01
137.70
+6.31
142.65
+1.36
141.83
+2.18
144.42
136.30
+8.12
144.46
0.04
143.36
+1.06
12
149.04
142.80
+6.24
149.08
0.04
146.85
+2.19
149.96
142.50
+7.46
151.23
1.27
149.36
+0.60
13
154.74
148.70
+6.04
155.43
0.69
152.90
+1.84
154.86
148.70
+6.16
156.01
1.15
154.19
+0.67
14
160.79
154.50
+6.29
163.18
2.40
159.75
+1.04
158.64
155.20
+3.44
159.79
1.15
157.49
+1.15
15
165.70
162.50
+3.20
168.96
3.25
165.84
0.14
161.07
161.40
0.33
161.67
0.60
159.44
+1.63
16
169.84
170.00
0.16
172.63
2.80
170.14
0.30
162.41
165.10
2.69
162.47
0.06
160.34
+2.07
17
173.64
176.40
2.76
175.16
1.52
172.67
+0.97
163.32
165.80
2.48
162.85
+0.46
160.56
+2.76
18
176.27
180.00
3.73
176.14
+0.12
174.13
+2.14
164.23
166.40
2.17
163.06
+1.17
160.69
+3.54
+:
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