post natal growth Flashcards
what does normal growth within childhood depend upon
- good general health
- normal nutrition and genetics
- adequate nutrition
- caring environment
abnormal growth disorders
- genetic
- endocrine
- cartilage or bone
- general chronic disease
early detection and treatment of the underlying condition is key in ensuring children reach their potential
phases of growth (karlberg graph)
infant
- rapid growth at birth
- declining rapidly over the first 2 years (less GH dependent)
childhood
- constant annual growth (GH dependent)
puberty
- rapid growth dependent on sex steroids and increased GH release
Mid-parental height
an estimate/guide to height potential based solely on parents height
for boys
= (dads height + (mums height + 13cm))/2
for girls
= (dads height - 13cm) + mums height)/2
MPH range is +/- 8cm
height velocity
- HV differentiates normal variant short stature from pathological short stature
- ideally calculated over 6-12 month interval (reduces measurement error)
- ‘normal’ lies within 25-75% centile
- tracks over time
- HV curve is shaped differently in children with delayed or early puberty
HV sex differences
puberty peak growth is early in girls than boys
short stature
- common clinical presentation
- a symptom or a variant NOT a disease
- may represent a variant of normal growth
- may indicate pathology
- normal SS still grows with normal HV
short stature history taking
- mother and fathers heights (MPH measured)
- family Hx delayed puberty
- menarche >14 yrs in females
- continued growth after high school in males
- look at other siblings child development records
- symptoms of underlying illness
- etc e.g. medication taking
bone age
- imprecise picture matching (xray)
- 1 year intervals
- predicted adult height from bone age
- hand used as it has many long bones
normal variant short stature
- familial SS
- constitutional delay of growth and development (CDGD)
- account for >95% of children who present with SS
- hallmark = normal HV
differences between FSS and CDGD
e.g. birthweight, family Hx, late childhood HV, bone age, puberty, final height
birthweight = normal family history = both late childhood HV = slow for CDGD bone age = delayed for CDGD puberty = delayed for CDGD final height = FSS short (CDGD normal)
what increases growth hormone secretion
- sleep
- exercise
- stress
- hypoglycaemia
- amino acids
- malnutrition
- sex steroids
what decreases growth hormone secretion
- obesity
- psychosocial deprivation
GH axis
- GHRH from the hypothalamus acts on the pituitary to release growth hormones
- these GH act on adipose tissue, stomach and liver
- liver releases IGF-1
growth hormone actions
metabolic
- inhibits glucose uptake and promotes glycogenolysis (anti-insulin)
- stimulates protein synthesis
- promotes lipolysis
IGF-1
- major post-natal growth promoting factor
- principally produced in the liver (endocrine) and bone (paracrine, autocrine)
- insulin-like (promoting glucose, lipid and A.A uptake)
- cell proliferation and differentiation
estrogens affect on growth
- effects skeleton and body composition
- has a greater effect than testosterone on skeleton
- responsible for epiphyseal maturation/closure in both sexes
if theres no E2 growth plates dont fuse and growth doesnt stop
intrauterine growth retardation / small for gestational age
IUGR/SGA
- very common
- birthweight <10th PC for gestational age
- catch-up growth above 3rd PC usually occurs by 6 mnths of age but may drag for 2 yrs
- SS by 2yrs usually associated with short final height
- on average dont reach MPH
turners syndrome
- consider in all girls with unexplained SS or height below MPH range
- commonest feature is short for MPH
- 50% will only present with SS
- may also present with poor HV or delayed puberty
clinical presenting of Turner syndrome
- neck webbing
- hand and foot edema as an infant
- wide spaced nipples
- increased carrying angle
- cardiac abnormalities
- renal/urinary tract abnormalities
may just present with SS or failure to enter puberty
investigations for Turner syndrome
karyotype = typically 45XO
- normal TFT
- elevated FSH and LH: primary gonadal failure
what determines growth
- genetics
- general health
- hormonal milieu
- nutrition
- caring environment
normal causes of short stature
familial SS
- short parents
congenital delay of growth and development
- delayed puberty
abnormal causes of short stature
presents with poor height velocity
- many systemic illnesses e.g. renal failure
- hormone deficiency e.g. GH, thyroid
- dysproportionate: the skeletal dysplasias
- small for gestational age / IUGR
what promotes IGF-1 production and what inhibits it?
normal levels of insulin and normal nutrition are essential for the normal hepatic IGF-1 production
malnutrition or poorly controlled diabetes inhibit hepatic IGF-1 production
