Endo & Metabolic Flashcards
What is classed as a prolonged QTc? How should you treat it in the context of hypocalcaemia?
> 450 in males and >460 in females
Treat with IV calcium gluconate
Name 4 factors which can give falsely low HbA1c results?
Haemodialysis, sickle cell, G6PD deficiency and Hereditary spherocytosis
Describe Klinefelter’s syndrome?
47 XXY
They will be tall, have small testes and gynaecomastia with little secondary sexual characteristics. These patients are infertile
Will have raised gonadotrophins but low testosterone
What is the single most useful test in diagnosing the cause of hypocalcaemia?
PTH levels
What should you give to anyone with HTN and T2DM?
ACEi or ARB
How do you treat hyperthyroidism in pregnancy?
Propylthiouracil in the 1st trimester then switch to Carbimazole once in the 2nd trimester
What should you start a patient with T2DM on if they have a QRISK3 >10%, HF or CVD (e.g. angina)?
An SGLT2 inhibitor, this is for organ protection
Describe primary hyperparathyroidism?
Most commonly caused by a solitary parathyroid adenoma
Raised PTH and Calcium with low Phosphate
Management = surgery
Describe secondary hyperparathyroidism?
Caused by parathyroid gland hyperplasia due to low Calcium (usually secondary to CKD or vitamin D deficiency)
Raised PTH and Phosphate (if kidney disease), low or normal calcium and low Vitamin D
Management = fix underlying cause
Describe tertiary hyperparathyroidism?
Occurs due to uncontrolled parathyroid hyperplasia after correction of the underlying renal disorder.
VERY raised PTH, normal or high Calcium and normal or low Phosphate
Management = surgical correction
True or false, over replacement of thyroxine can cause osteoporosis?
True
What can lead to a falsely high HbA1c?
Splenectomy, iron deficiency anaemia, B12/folate deficiency and chronic alcoholism
What are the sick day rules in DM?
If on insulin take as normal but check blood sugars more frequently
What is the initial investigation in Cushing’s syndrome?
Low dose (overnight) dexamethasone suppression test. If Cushing’s morning cortisol spike will not be suppressed
You have confirmed Cushing’s syndrome with a low dose dexamethasone suppression test. What should you do next?
Perform a high dose dexamethasone suppression test to establish the cause.
If suppressed ACTH and cortisol = pituitary cause aka Cushing’s disease
If suppressed ACTH but not cortisol = adrenal cause
Neither is suppressed = ectopic ACTH
When is a Short Synacthen test used?
To diagnose Addison’s disease. It will distinguish Addison’s from secondary and tertiary adrenal insufficiency (Synacthen is synthetic ACTH)
Which metabolic abnormality may be seen in Cushing’s syndrome?
Hypokalaemic metabolic alkalosis. This is most pronounced if there is ectopic ACTH e.g. in small cell lung cancer
Describe Primary Adrenal Insufficiency?
Addison’s disease
Occurs due to autoimmune destruction of the adrenal glands or secondary to metastatic malignancy
Low Cortisol and low Aldosterone, raised ACTH
Mx = hydrocortisone and fludrocortisone
Describe Secondary Adrenal Insufficiency?
Inadequate ACTH secretion from the pituitary glands. Can occur secondary to Sheehan’s syndrome in women who have recently gave birth.
Low Cortisol and low ACTH
Describe Tertiary Adrenal Insufficiency?
Inadequate CRH release from the hypothalamus due to long term steroids use being stopped suddenly
Low Cortisol and low ACTH
What symptoms are seen in adrenal insufficiency?
Tired, Tanned, Tearful and Thin
Abdominal pain, muscle cramps, hypotension.
Hyponatraemia and hyperkalaemia if Priamary.
Sx and Mx of an Addisonian Crisis?
Reduced consciousness, low glucose, low BP, low Na+ and high K+
Give IV hydrocortisone and fluid resus
Sx of Hyperaldosteroneism?
HTN (most common cause of secondary HTN), low K+, high Na+ and low H+ (alkalosis)
Describe Primary Hyperaldosteronism?
Most commonly caused by an adrenal adenoma, known as Conn’s syndrome
High Aldosterone, low Renin
Mx = Eplerenone or Spironolactone, surgical removal of adenoma
Describe Secondary Hyperaldosteronism?
Most commonly caused by renal artery stenosis
High Aldosterone, high Renin
Mx = Eplerenone or Spironolactone, renal artery angiography
What should you always test in treatment resistant HTN?
Renin:Aldosterone Ratio to look for hyperaldosteronism
What is an important complication of fluid resus in DKA?
Cerebral oedema, especially in children
How should you correct hyponatraemia?
Slowly! Otherwise there is a risk of cerebral oedema and Osmotic Demyelination Syndrome (aka Central Pontine Myelinosis) - this causes a locked in syndrome
How can we manage the symptoms of Grave’s disease whilst we await definitive treatment?
Propranolol
Mx of DKA?
Start fixed rate insulin infusion. Continue long acting but stop short acting insulins
Which condition are anti-TSH receptor antibodies seen in?
Grave’s disease
What condition are anti thyroid peroxidase (TPO) antibodies seen in?
Hashimoto’s
What is the 1st line Mx of Hypercalcaemia?
IV fluids
Describe Hyperosmolar Hyperglycaemic State?
Seen in those with T2DM secondary to illness, dementia or sedative drugs
Sx = Slow onset dehydration, polyuria/polydipsia, nausea and vomiting, reduced consciousness and hyper viscosity
Ix and Mx of Hyperosmolar Hyperglycaemic State?
Ix = low BP, high glucose, no hyperketonaemia, no acidosis
Mx = IV fluids and VTE prophylaxis. Do not give insulin
What are features which separate Grave’s from other causes of hyperthyroidism?
Exophthalmos, ophthalmoplegia, pretibial myxoedema, thyroid acropachy (digital clubbing, soft tissue swelling of hands/feet, new periosteal bone formation)
How frequently should insulin dependant diabetics check blood glucose whilst driving?
Every 2 hours
You are initiating diabetes treatment for a type 2 diabetic. You want to give Metformin and an SGLT2 inhibitor for organ protection. How should you proceed?
Start metformin. Once tolerability is confirmed add the SGLT2 inhibitor
You are initiating diabetes treatment for a type 2 diabetic. You want to give Metformin and an SGLT2 inhibitor for organ protection. The patient states they can’t tolerate Metformin, how should you proceed?
Treat with SGLT2 monotherapy
How do SGLT2 inhibitors and sulfonylureas affect weight?
SGLT2 inhibitors cause weight loss
Sulfonylureas cause weight gain
What is the most common thyroid cancer? What is the prognosis?
Papillary cancer. It spreads early to the lymph nodes but shows a good prognosis
Name 4 drugs known to cause Galactorrhoea?
Metoclopramide, Domperidone, Haloperidol and Chlorpromazine
Mx of Diabetic peripheral neruopathy?
Amitriptyline (avoid in those with BPH due to risk of urinary retention), Duloxetine (avoid if eGFR <30), Gabapentin and Pregabalin
How can we Mx galactorrhoea?
Bromocriptine
What is Pseudo-Cushing’s?
It can mimic Cushing’s disease. It occurs secondary to alcohol excess or severe depression. Insulin stress test will differentiate it from true Cushing’s
How many units is 1ml insulin?
1000 units
Ix of secondary hypothyroidism?
Low TSH and low T4
Ix = MRI pituitary gland
What are the top 2 causes of Cushing’s syndrome?
Most common = exogenous steroids
2nd most common = pituitary adenoma
How do you diagnose asymptomatic patients with T2DM?
They must have a fasting plasma glucose >=7mmol/l OR a random plasma glucose (OGTT) >=11.1mmol/l OR HbA1c >=48 on 2 separate occasions
When should you set up an infusion of 10% dextrose alongside the saline infusion in DKA?
When BM <14
What can happen if you correct high sodium too quickly?
Cerebral oedema
How can Pioglitazone affect weight?
It can cause weight gain
Describe sick euthyroid syndrome?
A normal TSH but low T3/T4 in elderly patients who are unwell
Which type of anti-diabetic drugs cause weight loss?
GLP-1 inhibitors (-tides), DPP4 inhibitors (-gliptins) and SGLT2 inhibitors (-flozins)
What may be the cause of a bitemporal inferior quadrantopia?
Craniopharyngioma
What may be the cause of a bitemporal superior quadrantopia?
Pituitary tumour
What should every person on insulin always be given?
A glucagon kit for emergenices
How does prolactinoma present?
Headaches, loss of libido and visual field defects
In women amenorrhoea, in men erectile dysfunction and gynaecomastia
Mx of prolactinoma?
1st line = dopamine agonists such as cabergoline
2nd line = trans sphenoidal surgery
What are some important side effects of pioglitazone? How do they work?
It can cause fluid retention (so is contraindicated in HF), can cause liver issues (so LFTs must be monitored) and can cause bladder CA.
They work by reducing peripheral insulin resistance
What should you do if you find increased urinary cortisol but decreased plasma ACTH?
CT of the adrenal glands to look for ?adrenal adenoma
How does orlistat work?
It decreases gastric and pancreatic lipase secretion so decreases the digestion of fat leading to weight loss
Which metabolic abnormality can thiazide like diuretics cause?
Hypercalcaemia
Sx of Sub-acute (De Quervian’s) thyroiditis?
Hyperthyroidism following a viral illness.
Sx: Phase 1 (3-6 weeks) = hyperthyroidism, painful goitre and increased ESR
Phase 2 (1-3 weeks) = euthyroid
Phase 3 (weeks-months) = hypothyroid
Phase 4 = normalisation
Ix and Mx of Sub Acute (De Quervian’s) thyroiditis?
Ix = Globally reduced uptake of iodine 131
Mx = Aspirin/NSAIDs for pain. Steroids if severe or if hypothyroidism develops
What is pre-diabetes?
HbA1c of 42-47
Fasting plasma glucose 6.1-6.9
What is the target HbA1c in DM?
Aim for HbA1c <48 unless there is a risk of hypos/initial diabetic therapy has failed and the current HbA1c is >58, then aim for 53
Describe sub clinical hypothyroidism? How do you manage it?
Raised TSH but normal T3/T4
Mx = If TSH >10 on 2 separate occasions 3 months apart offer levothyroxine
If TSH 5.4-10 on 2 separate occasions 3 months apart AND there are Sx present AND under 65 offer 6/12 trial of levothyroxine
Otherwise watch and wait approach
How does hyperkalaemia show on an ECG?
Tall tented T waves, 1st degree heart block, flattened/absent p waves and ST depression and prolonged QRS
When do you start a second diabetes drug?
When metformin has been titrated to the maximum dose (2g) and HbA1c is >58
What are the main contributors to diabetic foot?
Loss of sensation in the foot and peripheral artery disease
How does RBC lifespan affect HbA1c reading?
Premature RBC death = falsely low HbA1c
Increased RBC lifespan = falsely high HbA1c
Describe Maturity Onset Diabetes of the Young (MODY)?
AD - associated with HNF-1 alpha mutation
T2DM occurs in those <25
Ketosis is not present at diagnosis
Mx = sulfonylureas
Acromegaly is often caused by a pituitary tumour, what are some complications?
HTN, DM, Cardiomyopathy and colorectal CA
What do iodine studies show in Grave’s disease?
Diffuse homogenous increased uptake of radioactive iodine
How can small cell lung cancers lead to coma?
They secrete ADH which causes SIADH which leads to hyponatraemia. This can cause cerebral oedema leading to coma
What should you suspect in hyperthyroidism with tender goitre and a raised ESR?
Sub Acute (De Quervain’s) thyroiditis.
Graves is NOT painful
What would expect to happen after 24 hours of DKA treatment? What do you do if it hasn’t happened yet?
Resolving blood markers - Ketonemia <0.6 and Acidosis >7.3
If this has not happened review with senior endocrinologist
What are the 2nd choice T2DM drugs when HbA1c is >58 on metformin
DDP-4 inhibitor, Pioglitazone, Sulfonylurea or SGLT-2 inhibitor
1st line Mx of pituitary tumour causing acromegaly?
Trans-sphenoidal surgery
Ix of Acromegaly?
Initial screening = Insulin like Growth Factor 1 (is raised)
Then OGTT whilst measuring GH (glucose will not suppress GH in acromegaly)
MRI Pituitary gland
Should you continue metformin when starting insulin for T2DM?
Yes!
What should you do if triple drug therapy has failed to control T2DM?
Switch one of the drugs to a GLP-1 mimetic (-tides)
A patient is taking levothyroxine. They have a raised TSH but normal T4. What does this indicate?
Poor compliance with the drug
What are the causes of hypovolaemic hyponatraemia? How do you treat?
Diuretics, Addisonian crisis, diuretic stage of renal failure, N+V (dehydration)
Mx = isotonic saline
What are the causes of euvolaemic hyponatraemia? How do you treat?
SAIDH
Mx = fluid restriction
What are the causes of hypervolaemic hyponatraemia? How do you treat?
HF, liver failure and nephrotic syndrome
Mx = fluid restriction
How can magnesium affect calcium?
Low magnesium can cause low calcium. It can also cause those with low calcium to be resistant to treatment
What drug class is Silagliptin?
DPP-4 inhibitor
Describe a Myxoedemic coma?
Occurs due to uncontrolled hypothyroidism.
Sx = Sx of hypothyroidism may have pre-ceded. Non-pitting oedema, hypothermia, hypotension, bradycardia, hypoventilation and coma
Mx = IV thyroxine and hydrocortisone
How do SGLT-2 inhibitors caused UTIs?
They lead to glycosuria which increases the risk of UTI
What should you do if a patient complains of GI SEs of metformin?
Switch to a modified release version
How does Kallmann syndrome affect the hormones?
X-linked recessive
Abnormally normal or low LH and FSH
Low testosterone
ANOSMIA!!
How does Klinefelter syndrome affect the hormones?
47 XXY
High LH and FSH, Low testosterone
A patient has a HbA1c of <58 after commencing Metformin but is considered high risk of CVD (QRISK >10%, has CVD or has CHF). Should you start an SGLT-2 inhibitor?
YES
Which DM drug is always contraindicated in HF? What drug class is it?
Pioglitazone
It is a thiazolidinedione
What is seen in Ix of De Quervian’s tyroiditis?
Raised T4, Raised ESR, globally reduced uptake of iodine-131.
Goitre is painful
What is classed as impaired glucose tolerance?
OGTT (at 2 hours) 7.9-11.1
FPG <7.0
What is classed as impaired fasting glucose?
FPG 6.1-7.0
True or false, spironolactone can cause gynaecomastia?
TRUE
How much fluid should patients with T1DM aim to drink per day when ill?
3L per day
What should you do with any diabetic patient who has foot problems other than simple calluses?
Follow them up regularly in local diabetic foot centre
When should you measure BMs in T1DM? What should the BM targets be?
At least 4 times a day (before each meal and before bed)
Targets are 5-7 on waking and 4-7 before other meals
When should you always give levothyroxine in subclinical hypothyroidism?
If TSH is >10 on 2 separate occasions at least 3 months apart
You have low PTH but hypercalcaemia secondary to malignancy. What has caused this?
PTHrP released by squamous cell carcinoma
What is the HbA1c target in T2DM?
48 unless there is drug associated hypoglycaemia then 53
What type of foods is it good to increase in the diet if patients want to diet control their DM?
High fibre foods
How do non-functioning pituitary adenomas present?
Hypopituitarism and mass effect
What should you do with all patients presenting with incidental pituitary adenomas (even if no symptoms)?
Clinical and lab evaluations for hormone hypersecretion and hypopituitarism to determine if it is functional or non-functional
When must patients with DM surrender their driving lisence?
If they have >= 2 hypoglycaemic episodes requiring assistance in 12 months
What are BP targets in DM?
The same as normal BP targets (<140/90 clinic, <135/85 ABPM)
True or false, medullary thyroid cancers can be associated with pheochromocytoma?
True, it is part of MEN2 and is inherited in an AD fashion
What should you consider the cause of thyrotoxicosis (high TSH and T4) and a hot solitary nodule on scintigraphy?
Toxic adenoma
When should you take hydrocortisone for addison’s?
Morning and night with the majority of the dose to be given in the morning
DKA is associated with hyperkalaemia. Once you start insulin therapy they may become hypokalaemic, how do you treat?
If K+ is <5.5 give 40mmol/L potassium mixed into a fluid bag
What metabolic abnormality is seen in renal tubular acidosis?
Hyperchloremic metabolic acidosis with a normal anion gap
What are the types or renal tubular acidosis?
Type 1 = distal = low potassium, causes nephrocalcinosis and renal stones
Type 2 = proximal = low potassium, causes osteomalacia
Type 3 = mixed = low potassium, is very rare
Type 4 = secondary to low aldosterone, causes high potassium
What is seen in alcoholic ketosis?
Raised ketones in the presence of low or normal glucose
How do you treat acute, severe, symptomatic hypernatraemia?
Na+ <120
Give hypertonic saline (3% NaCl)
True or false, raised ALP can be seen in normal pregnancy
True
Which types of adrenal insufficiency is hyperpigmentation seen in?
Primary as this is the one associated with increased ACTH
What type of DI is caused by lithium?
Nephrogenic
What is classed as low urine osmolality in DI?
<300
