growth in childhood Flashcards
why do we measure growth
poor growth is associated with high childhood morbidity and mortality
best indicator of ehalth
demonstration of normality of growth by age and stage of puberty
identify disorders of growth
assess obesity
how do you measure height *
when child ois lying down - legs straight head and feet flat against a board
or stood up
what is a centile chart *
a way of expressing variation within a population
they are cumulative
based on surveyrs of large numbers of children - use UK based and those from WHO that look at international population
age on x axis, height on y
growth measurements that are taken *
HC
weight
height/length
leg length
BMI
growth velocity
specialist charts
statistical distribution of height *
normally distributed
can have short and tall normals
people have to grow along a centile
why do we measure head circumference
children’s heads have fontenelles so head growth reflects brain growth
if head not growing = brain not growing
if sudden growth suggest hydrocephaly/bleed
when skull fuses dont measure head circumference anymore
describe height velocity chart *
expressed in cm/year
slow down at birth (very fast in utero)
increase in puberty because of GH and sex steroids
describe the hormonal control of growth *
GH-IGF-1 axis is the regulator of human linear growth
GH is a single chain polypeptide produced bvy somatotrophs in anterior pit - pulsitile secretion
cause production of IGF1 at growth plates and liver
IGF1 is what causes you to grow
what effects the production of GH *
nutrition
sleep
exercise
stress
describe the GH-IGF1 axis *
GRHR and somatostatin released from hypothalamus
act on the pituitary - GH released from ant pit and is bound to GH binding protein
GH act on GH receptor = GH action = IGF1 production
IGF is bound to IGF binding proteins
IGF1 acts on IGF1 receptor
growth in antenatal phase and factors that effect it *
most rapid phase
maternal health and placenta are the most important factors
growth in infancy and the factors that effect it *
rapid growth addition of 23-25cm in year 1
continuation of fetal growth
nutritionally dependant
no GH until 9-12 months
describe growth in childhood and the factors that effect it *
childhood is post-infancy to adolescence
boys born slightly bigger but growth rate in childhood is equal
GH/IGF1 axis drives growth - nutritions less important (as long as not malnurished)
describe growth in puberty *
under control of sex steroids and GH
stimulate the pubertal growth spurt
happen in early puberty in girls and late puberty in boys
describe bone age *
bones develop as cartilage then mature
IGF1 acts in the growth plates = osteoblasts get active and make bone
when stop growing, the growth plates fuse - happens at end of puberty
final part opf growth occurs to the spune and final epiphyses to fuse are in the pelvis
what do you look for when assessing someone’s growth *
are they too short or tall for age - could there be a problem
has puberty started and is it progressing normally
is growth normal for the stage of puberty
is the child overweight or obese
what can you learn by assessing growth*
centiles are not normal range - can be taller/shorter than the centile lines and still be completely normal
most children are on a centile by 2yrs and grow on same throughout childhood
patterns of growth are more important that the position on the centiles - most tall/short people are healthy and grow in a normal pattern
a child who falls significantly in a centile is not growing normally
what are the causes of short stature *
genes
pubertal growth delay - girl normally 8-13, boy 9-13.5 - if delay you dont get the normal growth spurt
IUGR/SGA - 85% people catch up to normal
dysmorphic syndromes - down’s/turner’s/skeletal dysplasias (something wrong in genes for bone)
endocrine disorders - GH deficiency/hypothyroid/steroid excess
chronoc paediatric disease - inflammation effects growth - inflammatory mediators block the intracellular signalling of GF = dont grow
psychosocial depravation - reduce GH pulsitility = reduced GH = reduced IGF1
drugs - steroids
poor nutrition
describe short stature (*
children have a normal growth pattern and mo medical problem
usually the children of short parents
not all children with IUGR catch up completely - growth will be normal in childhood but they have lost some growth in the antenatal period
what do you do if someone is below the centiles (
look at birth history and weight
parental heights
medical history
previous measurements
describe the mid-parental centile *
used to adjust the graph of centiles to the parents height
investigations if someone is dropping off the centiles (
FBC - look if infection, CRP, serum iron
liver and kidney function
thyroid func
coeliac screen
IGF 1
bone age
MRI pit
describe Turner’s *
normal intelligence
short
dont enter puberty
describe achondroplasia *
measure full height and sitting height - subtract sitting height from full to find leg length
have normal sitting weight but short leg length