Endocrinology (Week 9) Flashcards
What fasting glucose level is indicative of diabetes?
> /=7 mmol/L
What random plasma glucose level is indicative of diabetes?
> /= 11mmol/L
What is the significance of testing C-peptide in diabetes diagnosis?
Secreted in equimolar concentration to insulin (shows level secreted in blood/urine)
What is the significance of HbA1c in diabetes diagnosis?
Shows blood sugar levels over the last 6-8 weeks
Name three causes of pancreatic diabetes
- Pancreatectomy
- Pancreatitis
- Cystic Fibrosis
Why do patients with pancreatic diabetes have a greater risk of hypoglycaemia than T1DM?
Due to loss of alpha cells and hence glucagon
What does LADA stand for?
Latent autoimmune diabetes of the adult
What is the average HbA1c target for diabetics?
HbA1c <53mmol/L
What is the mechanism of action of Metformin?
Reduced hepatic glucose production and increased muscle uptake and peripheral sensitivity
What is the mechanism of action of Sulfonylureas?
Close K+ channels in beta cells to release insulin
What is the mechanism of action of DDP-4 inhibitors?
Enhance effect of endogenous incretin to increase insulin release and decrease glucagon secretion
What is the mechanism of action of Flozins?
Inhibit SGLT-2 transported in PCT to decrease renal glucose absorption
What is the mechanism of action of Glitazones?
Increase fat, muscle and liver sensitivity to endo and exo insulin
What is the major side effect of Metformin?
Diarrhoea
During pituitary pathology, which cells are lost first and which cells tend to preserved until late disease?
1st to be lost: somatotrophs (hence growth hormone)
Last to be lost: Thyrotrophs
Bruit and thyroid eye disease are indicative of which condition?
Grave’s disease
Name 2 treatments for hyperthyroidism
- Beta blockers for symptom relief e.g. sweating
2. Carbimazole to block thyroid hormone production
Name a drug which actively causes hyper- and hypothyroidism
Amiodarone
In thyroid eye disease, what is lid lag?
If the sclera is seen above the iris
What is exophthalmos?
If the sclera is seen below the iris, indicates changes in pupil
What does proptosis indicate?
Changes behind the pupil
Which layer of the adrenal cortex produces aldosterone?
Zona glomerulosa
Which layer of the adrenal cortex produces cortisol?
Zona fasciculata
Which layer of the adrenal cortex produces androgens?
Zona reticularis
What cells produce catecholamines and where are they found?
Chromograffin cells in the adrenal medulla
Name three tests used to diagnose Cushing’s syndrome
- 24hr free urinary cortisol
- Urine cortisol:creatinine ratio
- Dexamethasone suppression test
What is Addison’s disease?
Primary adrenal insufficiency
What test is commonly used in Addison’s disease diagnosis?
Short synacthen test
What is congenital adrenal hyperplasia?
AR disorder with deficiency of 21 alpha-hydroxylase so cortisol cannot be produced
How is late onset CAH diagnosed?
Short synacthen test with 17-OH progesterone (cortisol precursor)
What is the best screening tool in primary aldosteronism?
Aldosterone-renin-ratio
What is a paraganglioma?
Catecholamine producing tumour outside the adrenal glands in neural crest cells anywhere in the sympathetic chain
Name the three components of Whipple’s triad
- Hypoglycaemia symptoms
- Low plasma glucose
- Symptoms resolve after plasma glucose raised
In multiple endocrine neoplasia type 1, what three areas are predisposed to tumours?
Pancreas
Pituitary (anterior)
Parathyroids
Name 4 symptoms of carcinoid syndrome
- Flushing
- Diarrhoea
- Asthma
- Right heart valvular lesions
What is hirsutism?
Male pattern hair growth due to increased androgens and increased skin sensitivity to them
Name the three chemicals implicated in PCOS
- Gonadotrophins
- Androgens
- Insulin
In hypogonadotrophic hypogonadism, where is the problem?
Hypothalamus or anterior pituitary
In primary gonadal failure, where is the problem?
Testes
Give three signs of hypogonadism in children
Slow growth
Small testes
Lack of 2nd sexual characteristics
Give three signs of hypogonadism in adults
Low libido
Depression
ED
On an orchidometer, what testes volume indicates late puberty?
12-15ml
What syndrome is described as isolated gonadotrophin deficiency when GnRH cells don’t migrate to the hypothalamus?
Kallmann’s syndrome
In Kallmann’s syndrome, which sense is often absent?
Smell
What sex chromosome karyotype is seen in Klinefelter’s syndrome?
XXY
How does androgen binding protein assist in sperm development?
It ‘locks’ testosterone in the testes to encourage sperm maturation
What is bimanual synkinesia?
R and L hands execute same movements despite only one being intentionally moved
