Growth in Childhood Flashcards
what is documented in the “Red Book” (UK)?
documentation of child growth parameters
- Height
- weight
- head circumference (brain development)
- BMI
- leg length
what is (poor) growth in infancy associated with?
as its an indicator of health
associated with increased morbidity and mortality
what are centile charts used for?
for cumulative height – the total of all the growth they have done up until now
what is height/growth velocity?
how fast a child is growing in cm/year
(many short children grow at a normal speed)
–>height now-height last time
divided by age now-age last time
what are the influences on normal growth?
o Events before birth
– i.e. poor foetal growth, LBW, etc.
o Medical issues in childhood – i.e. malnutrition, chronic disease.
o Genetic factors.
o Randomness
– presence of multiple genes and the environment.
when is the fastest phase of growth?
0-2 years
the child falls into their centile by age 2
when does growth stop?
when the epiphyses fuse at the end of puberty
what is the impact on height on those who start puberty late?
fall behind in height development
what is growth velocity at infancy? what is this dependent on?
23-25 cm per year
nutrition dependent
when does GH become the dominant driving force of growth?
9-12 months
what is the most important growth factor? what is it stimulated by?
growth hormone (GH) GHRH (pulsatile release mainly overnight)
what inhibits GH?
somatostatin
what is the effect of GH that directly influences growth?
IGF1 production
where is IGF1 produced?
in the liver and epiphyseal plates
what may cause short stature?
o Poor nutrition.
o Chronic paediatric disease e.g. asthma, sickle cell, IBD
o Endocrine causes
– GH deficiency, TSH/T4 deficiency.
o Genetic disorders affecting bone growth
– achondroplasia, Turner’s & Down’s syndrome.
o Psychological distress and neglect.
how do chronic paed diseases cause small stature?
inflammatory disease causes the formation of mediators that block the intracellular signals that lead to the formation of IGF1
how does IGF1 cause growth of the skeleton?
osteoblasts at the epiphyses are stimulated to cause bone growth
what causes tall stature?
o Syndromes of overgrowth
– e.g. Marfan’s syndrome, Soto syndrome.
o GH excess from pituitary tumour.
o Precocious puberty
– early puberty but they can also be short as adults as puberty stops earlier.
normal factors:
- tall parents
what are causes of short stature despite having normal hormones?
- Turners (XO)
- Downs (T21)
- skeletel dysplasia
- significant illness
- inflammation
- poor nutrition
- burns
- achondroplasia (short sub-ischial length)
what is the midparental centile?
the average adult height centile to be expected for all children of these parents. It incorporates a regression adjustment to allow for the tendency of very tall and short parents to have children with less extreme heights.
what investigations can be done to investigate short stature?
- CRP
- serum Fe
- LFTs, kidney function
- TFTs
- coeliac screen (absorption issues)
- IGF1 levels
- bone age (maturity)
- MRI of pituitary
what are the parameters for being overweight and obese for adults? how does this compare for children?
BMI >25kg/m2 overweight, BMI >30kg/m2 is obese.
in an adult BMI of 20 would be very good, but in a child that would be considered obese. BMI changes with age and its lower than that of adults
what is a big complication of obesity?
T2DM and therefore CVD
what is the Barker Hypothesis?
adverse nutrition in early life, including prenatally as measured by birth weight, increased susceptibility to the metabolic syndrome which includes obesity, diabetes, insulin insensitivity, hypertension, and hyperlipidemia
birth weight link to risk of death due to metabolic disease
how does the age of T2DM diagnosis affect prognosis?
the earlier the age of diagnosis, the more aggressive the microvascular complications and the prognosis is worse
why do people become obese?
- intake>expenditure
- polygenetic inheritance (monogenic obesity is rare)
- leptin deficiency (rare)
- leptin receptor deficiency (rare)
- POMC def (MSH also affected)
- MC4R def
