growth in childhood

Question 1

5 reasons to measure growth

Answer 1

poor infant growth associated with high childhood morbidity and mortality, growth best indicator for health, demonstrate normality of growth by age and stage of puberty, identify disorders of growth, assess obesity

Question 2

how to measure length accurately for infant

Answer 2

measure length: legs straight, head and feet flat against board

Question 3

how to measure height accurately for child

Answer 3

use stadiometer/tape measure when standing

Question 4

what do centile growth charts express

Answer 4

variation within population; how many people in population are at a particular variable (e.g. height) at any age

Question 5

examples of centile charts

Answer 5

head circumference, weight, height, leg length, BMI, growth velocity, specialist charts

Question 6

describe 5th, 50th and 95th centiles

Answer 6

50th percentile is mean, 5-95th percentiles

Question 7

why measure head circumference in adult

Answer 7

reflects brain development

Question 8

guide to accurate plotting

Answer 8

plot with dot to determine if someone has dropped centiles

Question 9

height velocity calculation

Answer 9

(height now - height last visit)/(age now - age last visit); expressed in cm/yr and interval approx. 6 months

Question 10

what hormonal axis controls endocrine control of growth

Answer 10

GH-IGF-1 axis regulator of human linear growth (GH single chain peptide)

Question 11

describe GH secretion from somatotroph cells of anterior pituitary

Answer 11

pulsatile, and influenced by nutrition, sleep, exercise and stress

Question 12

describe hormonal control of growth axis

Answer 12

hypothalamus -> GHRH and somatostatin -> anterior pituitary -> GH (and GH binding protein) -> GH receptor -> GH action and IGF-1 production -> IGF-1 (liver; and IGF binding proteins) -> IGF-1 receptor -> IGF-1 action

Question 13

phases of growth

Answer 13

antenatal (most rapid phase of growth) -> infancy -> childhood -> adolescence

Question 14

what are important factors in antenatal phase of growth

Answer 14

maternal health, placenta

Question 15

describe infant initial growth

Answer 15

rapid (23-25cm in first year) as continuation of foetal growth

Question 16

what is infant growth dependent on

Answer 16

nutrition

Question 17

after 9-12 months, what hormone influences infant growth

Answer 17

GH

Question 18

describe childhood growth rates, and what drives it

Answer 18

growth rates similar in boys and girls, with GH/IGF-1 axis driving growth and nutrition having less impact

Question 19

speed of growth in height velocity at puberty, and difference between males and females

Answer 19

females undergo puberty before males (peaks at 12 vs 14); puberty, sex steroids and GH stimulate pubertal growth spurt

Question 20

what is bone age and how is it measured

Answer 20

bone maturity (membrane, cartilaginous or ossified), as X-rays only see ossified bone (gaps at growth plates seen to determine if maturing)

Question 21

what happens to bones at end of puberty

Answer 21

mature and epiphyses fuse; final part of growth occurs in spine and final epiphyses to fuse are pelvis

Question 22

4 main questions to ask about growth

Answer 22

is child too short/tall for age (could there be a problem), has puberty started/normal progression, is growth normal for stage of puberty, is child overweight/obese

Question 23

4 main lessons from centile growth charts

Answer 23

centiles are not a “normal range” (can be taller/shorter and still normal and healthy), most children set out on a centile by 2 y/o and grow on same centile during childhood, pattern of growth is more important than position on centile, child who falls significantly in centile position is not growing normally (whatever their height)

Question 24

7 causes of short stature

Answer 24

genetic, pubertal and growth delay, IUGR/SGA, dysmorphic syndromes, endocrine disorders, chronic paediatric disease (inflammation attached to cells block IGF pathway), psychosocial depravation

Question 25

causes of short stature with normal growth pattern, and consequence of IUGR

Answer 25

most short children have short parents and no medical issues; not all children with IUGR catch up completely, as growth is normal in childhood but would have “lost” some height in antenatal period

Question 26

4 criteria to think about with small child on growth chart

Answer 26

birth history and weight, parental heights, medical history, previous measurements

Question 27

mid parental centile equation

Answer 27

male (combined parents height/2)+7cms; female (combined parents height/2)-7cms

Question 28

3 endocrine problems causing abnormal growth pattern, short stature and reduced growth velocity

Answer 28

hypothyroidism, GH deficiency, steroid excess

Question 29

4 criteria to think about with small child on growth chart who isn’t growing parallel to centiles

Answer 29

full blood count, CRP, serum iron, kidney and liver function, thyroid function, coeliac screen, IGF-1, bone age

Question 30

2 investigations for endocrine cause of short stature

Answer 30

MRI pituitary, pituitary function testing

Question 31

3 syndromes causing abnormal growth despite normal hormones

Answer 31

Turner syndrome (XO), Down syndrome (T21), skeletal dysplasias

Question 32

why can significant illnesses interfere with growth

Answer 32

inflammation, poor nutrition and the effects of drugs such as steroids

Question 33

describe Turner syndrome (XO) and treatment

Answer 33

normal intelligence, short; normally don’t go into puberty so induce puberty and give GH

Question 34

describe achondroplasia

Answer 34

measure full and sitting height to give leg length (very short)

Question 35

7 chronic paediatric diseases

Answer 35

asthma, sickle cell, juvenile chronic arthritis (pro-inflammatory cytokines), inflammatory bowel disease (Crohns, coeliac), CF, renal failure, congenital heart disease

Question 36

4 causes of tall stature

Answer 36

tall parents, early puberty, syndromes e.g. Marfans, GH excess (gigantism)

Question 37

3 problems of global obesity

Answer 37

widespread, high prevalence and costly consequences

Question 38

why is obesity harmful

Answer 38

emotional and behavioural, school absence, high cholesterol, high blood pressure, pre-diabetes, bone and joint problems, breathing difficulties, increased risk of becoming overweight adutls, risk of ill-health and premature mortality in adult life

Question 39

7 complications of obesity and associated features

Answer 39

T2DM, orthopaedic problems, PCOS, CVD, psychological problems, cancer, respiratory difficulties

Question 40

BMI in children vs adult

Answer 40

varies

Question 41

prevalence of excess weight among children

Answer 41

1/5 in reception, 1/3 in year 6

Question 42

obesity prevalence by deprivation decile

Answer 42

least deproved centiles is least obesity, most deprived centiles is most obesity

Question 43

6 features of childhood obesity

Answer 43

decreased exercise, increased calorie consumption, association with increased TV watching, consumption of soft drinks, parental obesity, education and social factors

Question 44

3 syndromes associated with obesity (tend to be short also)

Answer 44

Cushing’s, Prader-Willi (parental disomy), Lawrence-Moon-Biedl

Question 45

genetics of weight: inheritance and heritability

Answer 45

high heritable trait with majority being polygenic (some rare monogenic obesity syndromes)

Question 46

5 examples of rare monogenic obesity syndromes

Answer 46

leptin deficiency, leptin receptor deficiency, POMC deficiency, PC-1 deficiency, MC4R deficiency