Endocrinology 1 Flashcards
What is acromegaly most commonly caused by?
Other causes:
Excess GH secondary to pituitary adenoma
ectopic GHRH or GH production by tumours e.g pancreatic
Features acromegaly (6)
Coarse facial appearance
Spade like hands
Increased shoe size
Large tongue
Prognathism (bulging of jaw)
Excessive sweating
Features of pituitary tumour (3)
Hypopituitarism
Headaches
Bitemporal hemianopia
Other features of acromegaly (2)
Hint 1. MEN 2. increased in 1/3 of cases
MEN 1
Raised prolactin in 1/3 of cases
Complications of acromegaly (4)
HTN
Diabetes
Cardiomyopathy
Colorectal ca
What is Addison’s disease?
Leads to a change in which two hormones?
autoimmune destruction of adrenal glands leading to hypoadrenalism.
Leads to a reduction in cortisol and aldosterone.
Features of Addison’s (8)
lethargy
anorexia
N&V
weight loss
hyperpigmentation (palmar creases) (only in Addison’s)
vitiligo
loss of pubic hair
hypotension
Electrolyte changes in Addison’s (4) (na k+ glucose gas)
Hyponatramia and hyperkalaemia
Hypoglycaemia
Metabolic acidosis
Addison’s crisis symptoms (3)
Collapse
Shock
Pyrexia
Primary causes of hypoadrenalism (6)
TB
Metastases
Adrenal haemorrhage
Meningococcal
HIV
Antiphospholipid syndrome
Secondary causes of hypoadrenalism (3)
Tumours
Irradiation
Exogenous glucocorticoid therapy
Addison’s Ix
Definite investigation:
ACTH stimulation test (short synACTHen test)
What is an ACTH stimulation test (short synACTHen test)?
Measure cortisol before and 30 minutes after giving synACTHen 250ug IM
Baseline cortisol measured, given synachthen and expect cortisol to double when measured at 30 minutes and 60minutes. If still low then Addison’s
Addison’s - what can you do if an ACTH stimulation test is not possible?
Measure 9am cortisol
Results for a 9am cortisol
> 500 - unlikely Addison’s
<100 - abnormal
100-500 = do a ACTH stimulation test
Explain the hypothalamic pituitary axis
Hypothalamus releases hormones than impact both anterior and posterior pituitary as follows
Hypothalamus –> Anterior pituitary
CRH –> stimulates ACTH production
TRH –> stimulates TSH production
TRH –> stimulates prolactin
GnRH –> stimulates FSH/ LH production
Somatostatin –> inhibits GH production
Dopamine –> inhibits prolactin production
Posterior pituitary
Oxytocin
ADH
ACTH –> adrenals –> cortisol on many tissues
TSH –> thyroid –> thyroxine
FSH/LH –> gonads –> androgen or oestrogen production
GH –> liver –> insulin growth factor release (IGF) on many tissues
Prolactin –> breast –> lactation
Oxytocin –> uterine muscle
ADH –> distal convoluting tubules –> water reabsorption
Addison’s Mx (2)
- Hydrocortisone (20-30mg/day) (double if sick) - majority given in the first half of the day in 2-3 divided doses.
- Fludrocortiose (stays the same when sick)
What is Bartter’s syndrome?
What is the effect on BP
Autosomal recessive disease causing severe hypokalaemia
(defective chloride absorption at the NaKCl cotransporter in the ascending loop of Henle)
Associated with normotension
Features of Bartter’s (5)
Age group
Presents in childhood
FTT
Polyuria and polydipsia
Hypokalaemia
Normotension
Weakness
Mx of thyrotoxicosis
Carbimazole high dose for 6 weeks until pt becomes euthyroid before being reduced
MOA carbimazole
blocks thyroid peroxidase from coupling and iodinating thus reducing thyroid hormone production
Most common cause of thyrotoxicosis
Grave’s
Other causes of thyrotoxicosis (5)
Graves
Toxic nodular goitre
Acute phase of subacte thyroiditis
Acute phase of post partum thyroiditis
Amiodarone
DVLA rules for diabetics on insulin/ other hypoglycaemic inducing drugs such as sulfonylureas
Group 2
(5)
- no severe hypoglycaemia event in last 12 months
- full hypoglycaemic awareness
- show adequate control by regular blood glucose monitoring (BD monitoring and at times relevant to driving) (for 3 months before applying)
- driver must understand risks of hypoglycaemia
- no other debarring complications of diabetes