Endocrinology || Flashcards
What type of diabetes do most children have?
Type 1 requiring insulin
What are the causes of type 2 diabetes in children (3)?
- Obesity and increasing insulin resistance
2 Higher incidence in certain ethnic groups e.g. Asian/black children - Positive family history
What is the presentation of type 1 diabetes?
- Common (3)
- Less common (3)
How is it different to adults?
Unlike adults, children only present with a few weeks of symptoms
Common:
- Polyuria
- Polydipsia
- Weight loss
Less common:
- Secondary enuresis
- Skin sepsis
- Candida and other infections
Why is it important to diagnose type 1 diabetes early?
To avoid diabetic ketoacidosis
How is type 1 diabetes diagnosed in a child (3)?
Confirmed in a symptomatic child by finding a markedly raised random blood glucose (>11.1 mmol/L), glycosuria and ketosis
If in doubt:
1. Fasting blood glucose >7mmol/L
or
2. A raised HbA1c
What is the late presentation of T1DM or diabetic ketoacidosis (8)?
- Smell of acetone on breath
- Vomiting
- Dehydration
- Abdominal pain
- Hyperventilation due to acidosis (Kussmaul breathing)
- Hypovolaemic shock
- Drowsiness
- Coma and death
What are the essential early investigations of diabetic ketoacidosis (7)?
- Blood glucose(>11.1 mmol/L)
- Blood ketones (>3.0 mmol/L)
- Urea and electrolytes, creatinine (dehydration)
- Blood gas analysis (severe metabolic acidosis)
- Evidence of a precipitating cause e.g. infection (blood and urine cultures performed)
- Cardiac monitor for T-wave changes of hypokalaemia
- Weight (compare with recent clinic weight to ascertain level of dehydration)
What is the immediate management of diabetic ketoacidosis if they are hyperglycaemic, ketoacidotic, clinically dehydrated and/or vomiting, drowsy or clinically acidotic (5)?
- Urgent hospital admission
- Fluids
- if in shock, initial resus with 0.9% saline.
- then dehydration should be corrected gradually over 48 hours (too rapid rehydration can lead to cerebral oedema)
- Monitor fluid in/output, blood glucose hourly, blood ketones (1-2 hourly), electrolytes, creatinine and acid-base status 2-4 hourly, and neurological state - Insulin infusion started after iv fluids running for 1 hour
- Monitor blood glucose hourly (aim for gradual reduction) - Potassium replacement started as soon as maintenance fluids are started (displacement from cells in exchange for H+ ions)
- Cardiac monitoring and 2-4 hour plasma potassium measurement until it is stable - Abx if diabetic ketoacidosis was precipitated by an intercurrent infection
What is the medical management of type 1 diabetes (4)?
- Insulin
-most children are started on a continuous subcutaneous insulin pump
or
-a multiple daily injection regimen (basal-bolus) with rapid-acting insulin given before each meal plus long-acting insulin in late evening and/or before breakfast to provide background basal insulin - Blood glucose monitoring
- Record should be kept in a diary or transferred from the memory of the blood glucose meter - Blood ketone testing mandatory during illness or when control is poor
- Measurement of HbA1c should be checked 4x a year
What are the insulin injection sites (4)?
Why is rotation of the injection sites necessary?
Anterior and lateral aspects of the thigh, buttocks and abdomen
Needs to be rotated to prevent lipohypertrophy or more rarely, lipoatrophy
What blood glucose levels do people aim for with treatment of T1DM?
4-7mmol/L
What does the HbA1c indicate?
The overall diabetes control over the previous 6-12 weeks
What is the initial non-medical management of T1DM (2)?
- Intensive educational programme needed for parents and child
- Basic understanding of the pathophysiology of diabetes
- Injection of insulin: technique and sites
- Blood glucose (finger prick) monitoring
- Healthy diet
- Encouragement to exercise regularly
- Sick-day rules
- Recognition and treatment of hypoglycaemia
- Psychological impact of a lifelong condition
- Where to get help/advice 24 hours a day - Diet
- Encouraged to eat a healthy diet and insulin doses to match carbohydrate intake
- High in fibre for sustained release of glucose
What are the aims of long term management of T1DM (7)?
- Normal growth and development
- Maintaining as normal a home and school life as possible
- Good diabetes control through knowledge and good technique
- Encouraging children to become self-reliant but with adult supervision until they are able to take responsibility
- Anticipating and minimising hypoglycaemia
- To maintain a HbA1c of less than 48mmol/mol (6.5%)
- Helping adolescents to deal with the biological, psychological and social factors with their diabetes.
What are the long-term complications of diabetes (2)?
- Macrovascular - hypertension, coronary heart disease, cerebrovascular disease
- Microvascular - retinopathy, nephropathy, neuropathy
What are the problems that can interfere with diabetes control (7)?
- Unhealthy diet
- Infrequent blood glucose testing
- Illness - viral illness common in the young
- Exercise - vigorous or prolonged planned exercise requires reduction in insulin dose and increase in carbohydrate intake
- Eating disorders
- Family disruption
- Inadequate family support
Who needs to be involved with the management of a child’s diabetes (3)?
- Parents
- Diabetes team
- School
How does the school help to manage the diabetes of a child (3)?
- Managing dietary needs
- Knowing what to do if child becomes hypoglycaemic
- For younger children, help is needed to test blood glucose. calculate and give the prelunch insulin injection or bolus from the pump
What are the short-term complications of T1DM (2)?
- Hypoglycaemia
2. Diabetic ketoacidosis
What are the causes of hypoglycaemia in children? 1. In neonatal period (1) 2. Beyond the neonatal period Fasting (2) Non-fasting (6)
- Transient neonatal hypoglycaemia in neonates is common due to exposure to high levels of insulin in utero in mothers with diabetes or glucose intolerance
Beyond the neonatal period:
Fasting:
- Insulin excess
- Excess exogenous insulin
- b-cell tumours
- Drug-induced
- Autoimmune (insulin receptor antibodies)
- Beckwith syndrome - Without hyperinsulinaemia
- Liver disease
- Ketotic hypoglycaemia of childhood
- Inborn errors of metabolism
- Hormonal deficiency
Reactive/nonfasting:
- Galactosaemia
- Leucine sensitivity
- Fructose intolerance
- Maternal diabetes
- Hormonal deficiency
- Aspirin/alcohol poisoning
What is the definition of hypoglycaemia?
Plasma glucose <2.6 mmol/L
but most will experience symptoms by below 4mmol/L
What are the clinical features of hypoglycaemia (4)?
What are the dangers of hypoglycaemia (2)?
- Sweating
- Palor
- CNS signs of irritability, headache, seizures and coma
- May complain of hunger, tummy ache, sweatiness, feeling faint or dizzy
Can lead to seizures and coma
What are the investigations done for hypoglycaemia?
- Blood (3)
- Urine (2)
Blood
- Glucose-sensitive strips with a meter
- Confirm hypoglycaemia with lab blood glucose
- Growth hormone, IGF-1, Cortisol, Insulin, C-peptide, Fatty acids, Ketones, Glycerol, Branched-chain amino acids, acylcarnitine profile, lactate, pyruvate
First urine after hypoglycaemia
- Organic acids
- Consider saving blood and urine for toxicology, e.g. salicylate, sulphonylurea
What is the treatment of hypoglycaemia?
In hospital (1)
Not in hospital (2)
- In hospital: iv infusion of glucose (max of 5ml/kg of 10% glucose bolus followed by 10% glucose infusion)
or
If not in hospital:
2. Orally if early stages - easily absorbed glucose in tablets or sugary drink or oral glucose gels can be absorbed from the buccal mucosa.
or
3. In severe cases with reduced consciousness, glucagon im injection and then carers should give the child some food (usually a biscuit or sandwich) to prevent the blood glucose dropping again.
Why are infants more prone to hypoglycaemia?
What needs to be avoided in infants to prevent hypoglycaemia?
Infants have high energy requirements and relatively poor reserves of glucose from gluconeogenesis and glycogenesis.
They are at risk of hypoglycaemia with fasting, so should never be starved for more than 4 hours e.g. preoperatively
What is the definition of short stature in children?
Height below the 2nd centile (i.e. 2 SD below the mean)
What is a sensitive indicator of growth failure?
Measuring height velocity
How do you measure height velocity?
2 accurate measurements at least 6 months, but preferably a year apart allow calculation of height velocity in cm/year
This is plotted at the midpoint in time on a height velocity chart
What must the height centile of a child be compared with (2)?
- Weight centile
2. Estimate of his/her genetic expected height calculated from the height of his/her parents
What are normal or non-pathological causes of short stature (4)?
- Familial
- Constitutional delay in growth and puberty
- Small for gestational age and extreme prematurity
- Inadequate nutrition (rare)
What are pathological causes of short stature? Long-term illness (5) Psychosocial deprivation Endocrine (3) Chromosomal disorder/syndromes (4)
Long-term illnesses
- Coeliac disease
- Crohn’s disease
- Chronic kidney disease
- CF
- Congenital heart disease
- Psychosocial deprivation
- Endocrine
- Hypothyroidism (usually autoimmune thyroiditis)
- Growth hormone deficiency - rare (may be isolated e.g. Laron syndrome or secondary to wider pituitary dysfunction)
- Cushing syndrome (usually iatrogenic)
Chromosomal disorder/syndromes
- Down syndrome
- Turner syndrome
- Noonan syndrome
- Russell-Silver syndrome
What can be the causes of pituitary dysfunction in children leading to growth hormone deficiency (4)?
NTK
- Congenital midfacial or midline defects
- Craniopharyngioma
- Hypothalamic tumour
- Trauma e.g. head injury, meningitis and cranial irradiation
What are the symptoms of a craniopharyngioma (3)?
NTK
- Abnormal visual fields (usually bitemporal hemaniopia)
- Optic atrophy
- Papilloedema on fundoscopy
What is Laron syndrome?
How are GH levels affected?
NTK
Condition due to defective GH receptors resulting in GH insensitivity
Patients have high GH levels but low levels of the downstream active product of GH known as IGF-1 produced at the growth plate and liver
What are the causes of Cushing’s in children?
How common is it (2)?
NTK
Rare in children
- Usually iatrogenic and induced by corticosteroid therapy
- Non-iatrogenic Cushing syndrome is very unusual and may be caused by pituitary or adrenal pathology
What are the pathological causes of extreme short stature (2)?
- Idiopathic short stature - no diagnostic explanation
- Abnormalities in gene short stature homeobox (SHOX) located on the X chromosome
- Absence of one SHOX gene in Turner syndrome causes short stature
What are features of Russell-Silver syndrome (5)?
IUGR combined with some of the following:
- Dismorphic features - Triangular shaped face with a small jaw and a pointed chin that tends to lessen slightly with age. The mouth tends to curve down
- Hypoglycaemia
- Excessive sweating as a baby
- Continued poor growth with no “catch up” into the normal centile lines on growth chart
- A striking lack of subcutaneous fat