5a: Growth in Childhood Flashcards
What are common measurements taken in children to dermine growth?
- head circumference
- = indicator of brain development
- weight
- height/length
- leg length
- BMI
- growth velocity
Explain the generation and meaning of centile charts
Just mean what is average:
In 50 percentile: 50% of children will be smaller, 50% will be taller
Being in low/high centiles does not have to mean to be abnormal
Explain how growth velocoty changes through childhood
- Very fast in early childhood
- Decreases and stabelises in later childhood
- Accelerates at puberty
How is growth velocety calculated and expressed?
In cm/ year
Intervals for measurement (if you are keen) are about every 6 months
Explain the endocrine controll of growth
Which factors influenct the secretion of that hormone?
Via Growth hormone that produces IGF1
- •Pulsatile secretion
–Influenced by nutrition, sleep, exercise, stress.
What are the different phases of growth?
- Antenatal
- Infancy
- Childhood
- Puberty
When is the antenatal phase of growth?
What are the most important influencing factors?
Before birth- most rapid phase of brith
Influenced mainly ba maternal health and placental status
What are the characteristics of the infancy phase of growth?
Which factors influence growth?
- Continuation of fetal growth (up to about 9-12 Month)
- Nutrition dependant (not hormonal)
- GH influence after 9-12 Months
- Rapid initial growth ( 23-25 cm in first year)
What are the characteristics of the childhood phase of growth?
Which factors influence growth?
- Post infancy to adolescence
- Growth rates in boys and girls similar
- GH/IGF-1 axis drives growth
- Nutrition less impact (in western world where there is no starvation)
What are the characteristics of growt in puberty?
Which factors influence growth?
Hormonally driven:
- sex steroids and GH
*
What are the sexual differnences in growth in puberty?
Up to puberty: only very little difference
- In puberty
- Girls
- growth spurt is at the begining of puberty
- puberty is earlier
- Boys
- growth spurt is at the end of puberty
- puberty is later
When do you stop growing?
At the end of puberty (most epiphysis close)
- final part of growth occurs in spine
- at the pelvis
How would you spot “abnormal” growth?
Low/ high percentiles don’t have to be abnormal!
- Growth pattern is the most important thing
- most children settle in centile by age 2 and follow it
- A child who falls significantly in centile position is not growing normally, whatever their height
List causes of short stature
- Genetic
- Pubertal and growth delay
- IUGR/SGA
- Dysmorphic syndromes
- Endocrine disorders
- Chronic paediatric disease
- Psychosocial depravation
Explain how genetics and IUGR can influence short stature
- Parental height can influence short stature
- just having “small genes”
- Genetic syndromes
- E.g. Turners
- Downs
- Or Skeletal dyslasias (anchondroplasia)
- IUGR children not always catch up completely
Explain endocrine problems that might lead to short stature
Endocrine problems
- hypothyroidism
- growth hormone deficiency
- steroid excess
Explain how chronic illnesses in childhood can influence growth
Many reasons e.g. Inflammatory diseases
- inflammatory mediatiors disrupt intracellular GH signaling –> reduced production of IGF1
Which chornic pedriatric diseases can e.g. lead to short stature?
- Severe forms of
- Asthma
- Sickle cell
- Cystic fibrosis
- Inflammatory diseases
- Juvenile chronic arthritis
- Inflammatory bowel disease
- Crohns disease
- Coeliac disease
- Organ failures
- Renal failure
- Congenital heart disease
What are causes of tall stature?
tall parents
early puberty
Or rarer:
- syndromes eg Marfans
- growth hormone excess
Why is obesity in childhood a problem?
It increases the risk of death and developing many comorbidities
- Type 2 diabetes
- Orthopaedic problems
- Polycystic ovarian disease
- Cardiovascular risk
- psychological problems
- Cancer
- Respiratory difficulties
Summarise the hormonal axis of Growth Hormone
What is the defninition of obesity in children and adulats?
For adults BMI of over 25 kg/m2 is overweight and over 30 kg/m2 is obese.
Children are different! Have lower BMIs!!!
(assessed via BMI centile posistion)
What are the causes of obesity?
Normally: multigenic + environmental influence
- very rare monogenic inherited syndromes
- normally involved in appetite regulation
- –Leptin deficiency
–Leptin receptor deficiency
–POMC deficiency
–PC-1 deficiency
–MC4R deficiency
