Growth, Endocrine and Metabolism Flashcards

1
Q

What are the most common chronic diseases in childhood?

A

1) Asthma
2) Cerebral Palsy
3) Type 1 DM

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2
Q

List some types of diabetes found in children

A

1) T1DM (95%)
2) T2DM (1-2%)
3) MODY
4) Steroid induced DM
5) CF related DM

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3
Q

What is MODY?

A

Maturity-onset diabetes of the young

Monogenic = single gene defects of pancreatic SUR1 and Kir6.2 sub units of K+ channels in beta cells leading to impaired insulin secretion

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4
Q

What is the inheritance pattern of MODY?

A

Autosomal dominant

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5
Q

Which 2 groups of children tend to suffer steroid induced DM?

A

Post-transplant

Oncology

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6
Q

What is aetiology of T1DM?

A

Some evidence of genetic implication but often no FHx (FHx much more common in T2DM)

Children often develop T1DM after unknown trigger such as viral infection or diet

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7
Q

What gene is implicated in T1DM?

A

HLA DR3 and DR4

human leukocyte antigen

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8
Q

What is the pathophysiology of type 1 diabetes?

A

T-cell mediated autoimmune destruction of beta cells in pancreatic islets of Langerhans

Results in inability to secrete insulin therefore inability of cells to uptake blood glucose leading to hyperglycaemia

This results in a catabolic state with increased glycogenolysis, gluconeogenesis and lipolysis

Hyperglycaemia exceeds renal threshold leading to dehydration and electrolyte loss by osmotic diuresis

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9
Q

What is the % chance if one identical twin has T1DM that the other twin will also?

A

30%

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10
Q

In T1DM there is beta-cell destruction. At what % mass destruction does presentation usually occur?

A

50% (early) - 90% (late)

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11
Q

What is the peak age of onset of T1DM?

A

Age 5-7yrs (but increasing in toddlers) and just before the onset of puberty

Esp during winter (implying potential of preceding viral infection)

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12
Q

What are the four T’s aimed to improve early recognition of T1DM?

A

Thirst
Toilet
Tired
Thin

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13
Q

How does T1DM present?

A
Several weeks of polyuria
Lethargy
Polydipsia
Weight loss
\+/- infection / poor growth / ketosis
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14
Q

What are the effects of insulin?

A

Insulin = anabolic

Responsible for tissue build up = glycogen, protein and fat synthesis

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15
Q

What are the effects of insulin on:

1) Skeletal muscle
2) Liver
3) Adipose tissue?

A

1) Skeletal muscle
- Increased glycogenesis
- Increased protein synthesis

2) Liver
- Increased glycogenesis
- Decreased gluconeogenesis

3) Adipose tissue
- Increased adipogenesis
- Decreased lipolysis

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16
Q

What is catabolism?

A

Tissue break down:

  • Glycogenolysis
  • Gluconeogenesis
  • Protein catabolism
  • Lipolysis

Thus insulin deficiency = catabolism

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17
Q

How is T1DM confirmed?

A

Signs of hyperglycaemia AND:

Random blood glucose at or above 11mmol/L
or fasting blood glucose at or above 7mmol/L

OR

No symptoms but raised blood glucose on 2 occasions

Oral glucose tolerance tests (OGTT) rarely required in children

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18
Q

What antibodies are checked for when investigating T1DM?

A

Islet cell autoantibody, anti-insulin antibody, antiGlUAD antibody and anti-IA2

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19
Q

What is the most common regime of managing T1DM?

A

Mixture of rapid acting and long acting insulin injected subcutaneously depending on daily insulin requirement

  1. 5-1 units/kg/24hr = prepubertal
  2. 5/units/kg/24hr = pubertal
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20
Q

How is insulin injected and why are different sites used?

A

Subcutaneously into arms, thighs and abdomen

To avoid lipohypertrophy

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21
Q

Which hormones increase / decrease glucose levels?

A

Increase:
- Insulin

Decrease = counter-regulatory hormones:

  • Glucagon
  • Cortisol
  • Oestrogen
  • Testosterone
  • GH
  • Adrenaline / noradrenaline
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22
Q

Why do continuous SC insulin pumps have diurnal variations in their basal dose (as well as bolus during mealtimes)?

A

Due to the diurnal variation of counter-regulatory hormones GH and cortisol

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23
Q

List three other methods of managing T1DM

A

1) Short-acting basal bolus with meals and long-acting at night
2) Multidose regime using insulin pen
3) Continuous subcutaneous pump with basal bolus (pump)

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24
Q

Below what mmol/L is considered hypoglycaemic in a diabetic pt?

Why is this not the same in an individual who does not suffer from DM?

A

<4mmol/L (4 = floor)

Those without DM may have blood glucose lower than this, however this is not as concerning as the body will identify this and their pancreatic insulin secretion will be adjusted accordingly

Those with DM are receiving exogenous insulin and thus will hypo further = more concerning

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25
Q

How can exogenous and endogenous insulin be differentiated ie if someone has had a hypo, what could you measure to identify if this was from injected insulin or from what the body has produced?

A

Insulin is produced in the body as a pre-insulin attached to C-peptide which is cleaved

High levels of C-peptide indicate high endogenous insulin

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26
Q

What OGTT is diagnostic of T1DM?

A

At or above 11mmol/l

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27
Q

What HbA1c is diagnostic of T1DM?

A

At or above 6.5% or 48mmol

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28
Q

What is given in hypoglycaemia?

A

If conscious:
- Lucozade, jam, jelly babies, glucose tablets eg lift

If unconscious:
- Glucagon (good as works fast)

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29
Q

Give an example of a rapid and long acting insulin

A

Aspart or Novorapid = rapid acting

Detemir (Levemir) = long acting

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30
Q

What is the ‘honeymoon period’?

A

A period post diagnosis where insulin requirement is low

This is because there is still some pancreatic beta cells functioning

Period can vary from months to sometimes years - aim is to prolong this period for as long as possible

Greater pancreatic function at presentation = longer honeymoon period

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31
Q

List some pros of continuous insulin pumps

A
Great for compliance
Fewer injections
Increased lifestyle flexibility
Accurate delivery
Fewer hypos
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32
Q

List some cons of continuous insulin pumps

A

Cost
Risk of superficial infections
Pump failure can lead to DKA
Inconvenience of wearing an external pump / cosmetic

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33
Q

What should blood glucose be first thing in the morning?

A

4-7mmol/L

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34
Q

What often tends to happen with insulin requirements after initial use?

A

They increase after ‘honeymoon’ period

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35
Q

What is DKA?

A

Leading cause of mortality in childhood DM

Either absolute or relative insulin deficiency

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36
Q

What is absolute insulin deficiency in a child with DKA?

A

Previously undiagnosed T1DM or pt noncompliant with their insulin

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37
Q

What is relative insulin deficiency in a child with DKA?

A

Stress causes a rise in counter-regulatory hormones with relative insulin deficiency

eg catecholamines, glucagon, cortisol, growth hormone (eg in sepsis)

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38
Q

What is the pathophysiology of DKA?

A

Insulin deficiency

Inappropriate gluconeogenesis and liver glycogenolysis occur compounding the hyperglycaemia, causing hyperosmolarity and leading to polyuria, dehydration and loss of electrolytes

Accelerated catabolism from lipolysis of adipose tissue leads to increase in free fatty acid circulation which are oxidised by the liver and turn to ketone bodies = metabolic acidosis

Potassium moves from intracellular to extracellular space to exchange with the hydrogen ions that accumulate. Many of these extracellular potassium is eliminated in urine = hypokalaemia

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39
Q

What vicious cycle occurs in DKA? How can it be broken?

A

Vomiting often occurs, compounding the stress and dehydration

= Can only be broken by providing insulin and fluids

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40
Q

When is DKA more common?

A

Children <5yr

Children whose families have poor access to medical care

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41
Q

What is the DKA triad?

A

1) Hyperglycaemia
2) Acidaemia
3) Ketonaemia

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42
Q

How does DKA present?

A

1) Dehydration
2) Lethargy, confusion
3) Polyuria +/- polydipsia
4) Glucosuria
5) Weight loss
6) Abdo pain +/- vomiting (may mimic surgical abdo)
7) Kussmaul’s respirations
9) Ketoic breath
9) Shock / coma
10) Cerebral oedema

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43
Q

Why is polyuria a feature of DKA?

A

Secondary to osmotic diuresis

44
Q

Why is polydipsia a feature of DKA?

A

Hypovolaemia stimulates the thirst receptors in CNS

45
Q

What investigations are performed for DKA?

A
Immediate:
1) Capillary blood glucose
2) Capillary blood ketones
(or urinary ketones)
3) Capillary or venous pH and bicarbonate

Also:

4) Renal function (U&Es, eGFR, creatinine)
5) Urine dipstick
6) FBC
7) ECG
8) Check for infection eg blood an urine cultures, CXR etc

46
Q

What is Kussmaul’s respirations?

A

Deep, fast breathing associated with metabolic acidosis

Body is trying to blow off as much carbon dioxide as possible

47
Q

Is fever normal for DKA?

A

No - seek source of sepsis

48
Q

What are other causes of metabolic acidosis?

A

1) Overdose eg salicylates
2) Lactic acidosis
3) AKI
4) Septicaemia

49
Q

What are the biochemical markers of DKA?

A

Acidosis:

Blood pH <7.3 or bicarb <18mmol/L

> or = to 7.1 is mild or moderate

< 7.1 is severe

Ketonaemia:

Blood beta-hydroxybutyrate >3mmol/L

or +++urine dipstick

50
Q

What are the most common causes of death in DKA?

A

1) Cerebral oedema - mortality of 25% and is more common in younger children
2) Hypokalaemia - monitor ECG
3) Aspiration pneumonia - NG tube if reduced GCS

51
Q

How is DKA managed?

A

ABCDE

NG if reduced GCS / risk of aspiration

Fluids - BSPED guidelines
+ (potassium)

Replace fluids and potassium 1-2hrs before starting insulin

52
Q

How is insulin given in DKA?

A

IV infusion 0.05-0.1 units/kg/hour

Initial bolus not recommended

Continuous SC insulin pumps should be stopped while IV infusion is given, but long acting insulin treatment may be continued

53
Q

What is the fluid management in DKA?

A

If shocked:
10ml/kg bolus 0.9& NaCl with 20mmol/L K+

If not shocked:
Maintenance fluid + deficit correction over 48hrs

54
Q

What are the maintenance fluids in the management of DKA?

A

Risk of cerebral oedema so reduced volume:

If under 10kg: 2ml/kg/hr
If 10-40kg: 1ml/kg/hr
If over 40kg: fixed volume 40ml/hr

55
Q

How are deficit fluids calculated in DKA?

A

Deficit fluids = % dehydration x weight x 10

Mild to moderate (pH 7.1-7.3) = 5% dehydration

Severe (pH<7.1) = 10% dehydration

56
Q

What is mannitol?

What is failure to thrive (FTT)?

A

An osmotic diuretic

It elevates blood plasma osmolality, resulting in enhanced flow of water from tissues (eg brain and CSF) into interstitial fluid and plasma

aka faltering growth = descriptive term

Interruption in the expected rate of growth compared with other children of similar age and sex during early childhood

57
Q

What is failure to thrive (FTT)?

A

aka faltering growth = descriptive term

Interruption in the expected rate of growth compared with other children of similar age and sex during early childhood

58
Q

What may potassium levels be DKA?

A

There is a depletion in total body potassium

However, initial serum K values may be normal/high due to the transcellular shift caused by ketoacidosis

This masks the deficit which is uncovered once insulin has commenced

  • Ensure all fluids contain 40mmol/L potassium chloride (unless evidence of renal failure)
59
Q

What are some complications of DKA?

A

1) Cerebral oedema
2) Hypoglycaemia
3) Hypokalaemia
4) Systemic infections
5) Aspiration pneumonia
6) VTE
7) Appendicitis
8) Others - pneumothorax, interstitial pulmonary oedema, hyperosmolar hyperglycaemia non-ketotic coma

60
Q

How is cerebral oedema avoided in DKA?

A

Mannitol 20% 0.5-1g/kg over 10 to 15 minutes

OR hypertonic sodium chloride

Half maintenance fluids

61
Q

What is weight faltering?

A

Weight falling through centile spaces, low weight for height or no catch-up from a low birth weight

62
Q

What is growth faltering?

A

Crossing down through length/height centile(s) as well as weight. A low height centile or less height than expected from parental heights

63
Q

What age group does FTT usually refer to?

A

Young children and babies (rather than older children/adolescents)

64
Q

What % of weight/growth falters have an organic cause? What is the most common cause?

A

5%

Mostly due to undernutrition relative to child’s specific energy requirements - often multifactorial including problems such as diet and feeding behaviour that resolve with targeted advice

65
Q

When should a premature baby have reached ‘normality’ for:
Head circumference
Weight
Height

A

Head circumference: 18 months
Weight: 24 months
Height: 40 months

= thus some premature babies with very low birth weight may not catch up until 5/6yrs

66
Q

Is it normal for a baby to lose weight early in life?

A

Yes - normal for a baby to lose up to 10% body weight in first few days of life which is rapidly regained (but more slowly in BF babies)

67
Q

What is ‘corrected age’?

A

Used for premature babies

Baby’s chronological age minus the number of weeks they were premature

Eg a baby born 12 weeks ago at 32 weeks gestation is treated as a 4 week old baby

68
Q

When should corrected age be considered?

A

1) Growth
2) Nutritional needs
3) Feeding - solids / cow’s milk
4) Developmental milestones

= For infants <37 weeks until 24 months

69
Q

What maternal factors during pregnancy may cause a baby to be small for date? (5)

A

1) Smoking
2) Alcohol
3) Use of medications
4) Recreational drugs esp amphetamines and cocaine
5) Any illness during pregnancy
6) Infections eg TORCH

+ Any cause of placenta insufficiency

70
Q

What conditions have specific reference charts?

A

Down’s syndrome

Turner’s syndrome

71
Q

What is plotted on a growth chart?

A

Height
Weight
Head circumference

72
Q

What are some postnatal causing there to be failure of adequate nutrition? (4)

A

1) Lack of appetite may occur with IDA, CNS pathology or chronic infection
2) Inability to suck or swallow eg CNS / muscular disorders
3) Vomiting
4) GOR and oesophagitis

73
Q

What physical problems may cause feeding problems postnatally? (4)

A

1) Cleft palate
2) Hypotonia
3) Microthagnia
4) Prader-Willi syndrome

74
Q

What are some prenatal factors causing faltering growth (baby)?

A

1) Prematurity
2) IUGR
3) Chromosomal abnormalities

75
Q

What may lead to poor absorption or metabolism of nutrients in children? (5)

A

1) GI disorders eg CF, coeliac and chronic diarrhoea
2) CKD or renal tubular acidosis
3) Endocrine eg hypothyroidism, DM, hypopituitarism
4) Inborn errors of metabolism
5) Chronic infection eg congenital HIV, TB, parasites

76
Q

What may cause an increased metabolic demand in a child?

A

1) Hyperthyroidism
2) Chronic cardiac or rest disease eg HF, asthma, bronchopulmonary dysplasia
3) CKD
4) Malignancy

77
Q

What investigations are done for FTT?

A
FBC
Urinalysis
Urine culture
U&amp;Es and creatinine
LTFs inc total protein and albumin
Coeliac screen
Prealbumin = nutritional marker

+ specific tests eg HIV, sweat test, stools for parasite, TB testing

78
Q

What is ambiguous genitalia?

A

A birth defect in which the outer genitals do not have the typical appearance on either a boy or a girl

Ambiguous genitalia = a form disorder of sexual development (DSD)

79
Q

What 3 categories can sex differentiation be divided into?

A

1) Chromosomal sex or karyotype
- 46, XX
- 46, XY
- Variants

2) Gonadal sex
- Presence of testis or ovary

3) Phenotypic sex
- External genitalia
- Internal structures

80
Q

What is virilisation?

A

A condition in which women develop masculine physical traits eg male-pattern hair growth

81
Q

What causes virilsation of 46, XX?

A

1) Congenital adrenal hyperplasia (CAH)
2) Prenatal exposure to male hormones eg medication
3) Tumours

82
Q

What causes under-virilisation of 46, XY?

A

1) Androgen insensitivity syndrome (most common)
2) Defective testosterone production = Leygic cell hypoplasia
3) Defective testosterone metabolism = 5-alpha-reductase deficiency

83
Q

What is CAH?

A

Enzyme defects mean there is decreased cortisol and aldosterone, and increased androgens

Main cause is 21-hydroxylase enzyme deficiency

84
Q

What is the inheritance pattern of CAH?

A

Autosomal recessive

85
Q

How may ambiguous genitalia present in females?

A

Clitoral hypertrophy

Variable fusion of labia

86
Q

How may ambiguous genitalia present in males?

A

Severe hypospadias
Bifid scrotum
Bilateral undescended testes

87
Q

What is hypospadias?

A

A congenital defect in which the opening of the urethra is on the underside of the penis instead of the tip

88
Q

What investigations may be done for ambiguous genitialia?

A

Pelvis USS

Karyotyping

89
Q

Until what point do male and female embryos develop in a similar manner?

A

7 weeks gestation

90
Q

What is Rokitansky syndrome?

A

= Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome

Under-developed womb, or no womb, cervix or upper vagina

Ovaries and external gent normal

91
Q

What are the most common DSDs?

A

1) Klinefelter syndrome
2) Turner syndrome
3) Mixed gonadal dysgenesis
4) Congenital adrenal hyperplasia (CAH)
5) Androgen insensitivity syndrome
6) Cryptochordism

92
Q

What is Klinefelter syndrome?

A

47,XXY

93
Q

How may Klinefelter syndrome present?

A
Tall stature
Gynecomastia
Small testes
Azoospermia
Learning difficulties
94
Q

What is Turner syndrome?

A

45,XO

95
Q

How may Turner syndrome present?

A
Webbed neck
Low hairline
Short stature
Streak ovaries
Coarcatation of the aorta
Learning difficulties
96
Q

How may CAH present?

A

Low aldosterone = unable to retain enough sodium (salt)

This means too much sodium is lost in urine = ‘salt-wasting’

Excess ACTH mean that excessive androgens are produced, causing virilisation of female infants (or hyperandrogenaemia if not classic form)

97
Q

When is CAH detected? If not what would they electrolytes / hormones would they present with?

A

Newborn screen

If not present with hyponatraemia, hyperkalaemia, low alldosterone, high androgens

98
Q

What is the management of CAH?

A

Glucocorticoids (cortisol)
Mineralocorticoids (aldosterone)
Salt for infants

99
Q

What is the inheritence and mutation of androgen insensitivity syndrome?

A

X-linked recessive

Androgen receptor gene mutation

100
Q

How may androgen insensitivity syndrome present?

A

Wide phenotypic spectrum

1) Complete androgen receptor resistance:
- Female phenotype with bilingual inguinal hernias OR
- Primary amenorrhoea and scanty pubic hair

2) Partial androgen receptor resistance
- Ambiguous genitalia with labial masses OR
- Male with infertility, decreased pubic hair or beard growth and gynecomastia

101
Q

What investigations re done for androgen insensitivity syndrome?

A

Age-approprate testosterone levels

Elevated LH and FSH

Normally formed testes

Absent/vestigial Mullerian structures

Variable presence of Wolffian ducts

102
Q

What is the treatment for androgen insensitivity syndrome?

A

Hormone replacement therapy

+/- gonadectomy

103
Q

What is cryptochordism?

A

The testes is not in the scrotum and is not descended by 4 months old

104
Q

How common is cryptochordism?

A

Most common congenital abnormality in boys

2-4% of term male infants

105
Q

What are some complications of cryptochordism?

A

Inguinal hernia
Testicular torsion / trauma
Subftertility
Malignant transformation

106
Q

What may hormone levels be in Klinefelter syndrome?

A

High FSH and LH
Low AMH and inhibin B
Low testosterone

107
Q

What is the management of cryptochordism?

A

Orchidopexy = surgically moving testes into the scrotum

Or removal of dysgenic testes

Hormonal therapy (hCG / GnRH) may help testicular descent