Endocrinology Flashcards
Cheat sheet for these diseases?
Diabetes =
Thyroid disorders =
Cushing’s =
Acromegaly =
Conn’s syndrome =
Addison’s =
Diabetes = too much blood glucose / not enough insulin
Thyroid disorders = too much or too little thyroid hormone
Cushing’s = too much cortisol
Acromegaly = too much growth hormone
Conn’s syndrome = too much aldosterone
Addison’s = too little cortisol and too little aldosterone
Cheat sheet for these diseases?
Diabetes insipidus =
SiADH =
Hyperkalaemia =
Hypercalcaemia =
Parathyroid disorder =
Diabetes insipidus = not enough ADH
SiADH = too much ADH
Hyperkalaemia = too much potassium
Hypercalcaemia = too much calcium
Parathyroid disorder = too much or too little parathormone
Describe the pituitary gland?
Lies just inferior to the optic chiasm
Connected to the hypothalamus via pituitary stalk
Formed of separate anterior and posterior parts
Describe the anterior pituitary?
- Recieves blood from portal venous circulation of hypothalamus
- Contains 5 types of hormone producing cell which together produce 6 hormones
- Hormone production is stimulated by the hypothalamus
Describe the CRH axis?
Hypothalamus > CRH > Ant. pituitary > ACTH > Adrenal cortex > glucocorticoids (cortisol)
Describe the GRH axis?
Hypothalamus > GRH > Ant. Pituitary > LH/FSH > gonads > various effects inc production of testosterone and oestrogen
Describe the GHRH axis?
Hypothalamus > GHRH > Ant. Pituitary > GH > Liver > IGF-1
Describe the TRH axis?
Hypothalamus > TRH > Ant. Pituitary > TSH > thyroid > T3 and T4
Describe the dopamine axis?
Hypothalamus > Dopamine > Ant. Pituitary > DECREASED prolactin
Describe the posterior pituitary?
Hormones are produced in the hypothalamus and stored in the posterior pituitary for release
The only two hormones are:
- Oxytocin
- ADH (vasopressin)
Symptoms of hyperthyroidism?
Symptoms:
Diarrhoea
Weight loss
Sweats
Heat intolerance
Palpitations
Tremor
Anxiety
Menstrual disturbance
Signs of hyperthyroidism?
Tachycardia Thin hair Lid lag Onycholysis Lid retraction Exophthalmos
Investigation of hyperthyroidism?
Thyroid function tests
Primary = low TSH, high T3/T4
Secondary = high TSH, high T3/T4
Thyroid autoantibodies
Radioactive iodine isotope uptake scan
Treatment for hyperthyroidism?
Beta blockers for rapid symptom control
Carbimazole = antithyroid drug
Radioiodine therapy
Thyroidectomy
Pathology and aetiology of Graves disease?
aetiology: Associated with other autoimmune diseases
pathology: Increased levels of TSH Receptor Stimulating Antibody (TRAb) - causes excess TH secretion from the thyroid
What is Graves’ Ophthalmology?
- Extraocular muscle swelling
- Eye discomfort
- lacrimation
- Diplopia
What is the investigation and treatment for Graves’ disease
Same as normal hyperthyroidism but with emphasis on TRAb (Ix)
Aetiology of hypothyroidism?
Hashimoto’s thyroiditis
Iodine deficiency
Previous radioiodine therapy
Over-treatment of hyperthyroidism
Symptoms of hypothyroidism
Fatigue Cold intolerance Weight gain Constipation Myalgia Constipation Menorrhagia
Signs of hypothyroidism?
Bradycardic
Bradycardia Reflexes relax slowly Ataxia Dry thin hair/skin Yawning Cold Hands Ascites Round puffy face Defeated demeanor Immobile Congestive HF
What is is acromegaly?
Increased production of growth hormone occurring in adults after fusion of epiphyseal plates
What is gigantism?
Increased production of growth hormones occurring in children
Aetiology of acromegaly?
Mainly a pituitary adenenoma
Very slow insidious onset over many years
Signs of acromegaly?
Massive growth of hands and feet Big tongue and widely spaced feet Darkening skin Obstructive sleep apnoea Deep voice
What is acroparaesthesia?
pins and needles
What are the symptoms of acromegaly?
Acroparaesthesia Sweating Headache Arthralgia Decreased libido
Investigation of acromegaly?
Not a random gH test because GH is a pulsatile protein and levels may vary throughout the day
ORAL GLUCOSE TOLERANCE TEST
- normally a rise in blood glucose will suppress GH levels
- Give glucose then test GH, if still high this is diagnostic for acromegaly
MRI the pituitary fossa for adenomas
Treatment for acromegaly?
Transphenoidal surgery to remove the adenoma
GH antagonist e.g. pegvisomant
Define: hyperaldosteronism
Excess production of aldosterone independent of the RAAS system
Aldosterone works in the kidney to cause potassium loss, excess causes hypokalaemia and sodium and water retention
2/3 - conns syndrome
1/2 - bilateral adrenocortical hyperplasia
Symptoms of hyperaldosteronism?
Symptoms of hyperaldosteronism = symptoms of hypokalaemia
- constipation
- weakness and cramps
- paraesthesia
- polyuria and polydipsia
Also causes hypertension due to increased bv
Investigation of hyperaldosteronism?
U&E
- decreased renin
- increased aldosterone
ECG flat T, long PR, long QT, U waves
Adrenal CT
Treatment of hyperaldosteronism?
Conn’s: laproscopic adrenalectomy
Spirolactone - aldosterone anatagonist
Describe the action of PTH?
Increased bone resorption by osteoclasts
Increased intestinal calcium absorption
Activates 1,25 dihydroxyVD in kidney
Increased calcium reabsorption and phosphate excretion in the kidney
Aeitology of hyperparathyroidism?
80% solitary adenoma
20% = parathyroid hyperplasia
rare = parathyroid cancer
Symptoms of hyperparathyrodism?
Symptoms of hyperparathyroidism = symptoms of hypercalcaemia
Bones stones groans moans
Investigation of hyperparathyroidism?
Bloods:
Primary: ↑PTH, ↑Ca, ↓Phosph
Secondary: ↑PTH, ↓Ca, ↑Phosph
Tertiary: ↑everything (progression of secondary)
Increased 24hr urinary calcium excretion DEXA bone scan for osteoporosis
Treatment of hyperparathyroidism?
Fluids, surgically treat underlying cause, bisphosphates
Aetiology, S+S and Tx of hypoparathyroidism?
Aeitology: autoimmune destruction of PT, congenital, surgical removal (secondary) Mg/VD deficiency
S+S = hypocalcaemia = SPASM
Tx = Ca supplement, calcitriol, synthetic PTH
Pseudohypoparathyroidism
Decreased response to PTH
Bloodwork shows low Ca, high PTH
Treat as normal hypoparathyroid
The initial treatment for someone having a thyrotoxic storm is:
a )IV 0.9% saline
b) Propanolol
c) Salbutamol
d) Carbimazole
e) Omeprazole
B) propanolol
Which autoantibody will be present in Graves’ disease?
a) Thyroid Peroxidase (TPO)
b) TSH Receptor Stimulating Antibody (TRAb)
c) Graves Related Thyroid Antibody (GRTA)
d) Eutonic Auto Thyroid-Fascicle Automatic Renal Thyroid (EAT-FART)
e) T3 Mimicking antibody (TMA)
b) TSH Receptor Stimulating Antibody (TRAb)
Describe hypokalemia?
[K+] <3.5 mmol/L
Which causes…
- Low K+ in the serum (ECF) causes a water concentration gradient out of the cell (ICF)
- Increased leakage from the ICF causing hyperpolarisation of the myocyte membrane
Investigation of hypokaelemia?
ECG!
U got no Pot and you got no T but a long PR and and long QT
U waves
No T waves
Long PR
long QT
Treatment of hypokalemia?
Not enough potassium - give some
Mild = oral K+ Severe = IV K+
Hyperkalemia investigation?
ECG
Tall tented ECG
Small P
Wide QRS
Treatment of hyperkalemia?
non urgent - polystyrene sulphonate resin - binds the K+ in the gut decreasing uptake
urgent - calcium gluconate - decreases VF risk in the heart
Insulin - drives K+ into the cells
Things that cause
HYPOkalemia
HYPERkalemia
HYPOkalemia - fasting, anorexia
HYPERkalemia - excessive consumption at a fast rate: IV fluids
Hyperokalemia on muscles?
Smooth- constipation
Skeletal - weakness/cramps
Cardiac - arrhythmias and palpitations
Hyperkalemia on muscles?
Smooth - cramping
Skeletal - weakness/flaccid paralysis due to overcontraction of muscles becoming totally drained of energy
Cardiac - arrhythmias and arrest
Potassium excretion issues?
HYPO (high secretion) = high aldosterone
HYPER (low secretion) = low aldosterone, adrenal insufficiency
AKI decreased filtration rate so more K+ os maintained in the blood
Describe hypokalemia internal balance issues?
insulin = excess
pH = alkalosis
B2 receptor = B2 agonists
Describe hyperkalemia internal balance issues?
insulin = deficiency pH = acidosis B2 = beta blocker
Where is calcium stored?
99% of calcium is stored in bone calcium as calcium phosphate
What is calcium balance controlled by?
Parathyroid: PTH
Thyroid: Calcitonin
What causes hypocalcaemia?
HAVOC
hypoparathyroidism acute pancreatitis vit D deficiency osteomalacia chronic kidney disease
Symptoms and signs of hypocalcaemia?
SPASM
spasms peripheral paraethesia anxious seizures muscle tone increase
Investigation and treatment of hypocalcaemia?
ECG= long QT interval
Tx:
mild - adcal
severe - calcium gluconate
Aetiology of hypercalcaemia?
90% is due to primary hyperparathyroidism
Symptoms of hypercalcaemia?
bones stones groans moans
painful bones
kidney stones
abdominal groans
psychiatric moans
Investigation of hypercalcaemia?
- Find cause - corrected calcium levels and PTH
2. Identify damage - U&E renal damage, Xray
What would the correct calcium and PTH levels show if hypercalcaemia was being caused by hyperparathyroidism?
Corrected calcium - mild increase
PTH - high
What would the corrected calcium and PTH levels show if hypercalcaemia was being caused by cancer?
Correct calcium - severe increase
PTH - low
How do you calculate corrected calcium levels?
Corrected calcium = total serum calcium +0.02 * (40 – serum albumin)
What is Cushing’s syndrome?
Excess cortisol + loss of hypothalamic pituitary axis feedback + loss of circadian rhythm
What is Cushing’s disease?
Excess cortisol + loss of hypothalamic pituitary axis feedback + loss of circadian rhythm + CAUSED BY PITUITARY ADENOMA
What as some ACTH independent causes of excess cortisol?
Oral steroids = iatrogenic !!
Adrenal adenomas
What are some ACTH dependent causes of excess cortisol?
Cushing’s disease - bilateral adrenal hyperplasia due to ACTH hypersecretion by pituitary adenoma
Ectopic Cushing’s Syndrome- due to paraneoplastic syndrome e.g. small cell lung cancer prpducing ACTH
Signs of Cushing’s?
CUSHING
Cataracts Ulcers Striae HTN Infections Necrosis Glucosuria
Aesthetic symptoms of Cushing’s?
Truncal obesity Moon face Buffalo hump Acne Hirsutism (excess hair) Wt gain
Investigations for Cushing’s?
NOT a random plasma cortisol rest as levels change with stress, time of day, etc
DEXAMETHASONE SUPRESSION TEST - usually supresses cortisol level, failure to suppress over 24hr period is diagnostic of Cushing’s
Check 24hr urinary free cortisol - if normal Cushing’s unlikely
Describe the treatment of Cushing’s?
If iatrogenic - stop steroids
Cushing’s disease - transphenoidal removal of pituitary adenoma
Adrenal adenoma - adrenalectomy, radiotherapy
Ectopic ACTH - surgery to remove tumour if location known
Epidemiology and aetiology of type 2 diabetes?
Epi = old, obese, asian, male
Aeti = insulin resistance, B cell dysfunction
Risk factors of type 2 diabetes?
Lack of excercise
High calorie intake
Fx or PHM of T2DM
Presentation of T2DM?
Asymptomatic
How is T2DM diagnosed?
WHO criteria:
Symptomatic
+
1 abnormal glucose result
(fasting / random)
OR
Asymptomatic
+
2 separate abnormal glucose result (fasting / random / 2hpostprandial)
OR
Abnormal HbA1c
What is HBA1c
HBA1c is glycated Hb that is covalently bound to glucose
Treatment of T2DM?
Prediabetic = lifestyle
Diabetic = lifestyle, then:
1st line - meformin
2nd = duel therapy eg. metformin + DPP4 inhibitor
3rd - triple therapy e.g. metformin + DPP4 + SU
4th - insulin / metformin / SU / GLP 1 mimetic
What diabetic emergencies present with T2DM?
Hypoglycaemia
Hyperglycaemic hyperosmolar state
Epidemiology and aetiology of T1DM?
Epi = young
Aeti = Autoimmune b cell destruction
Risk factors of T1DM?
Fx or PMH of autoimmune disease
Presentation of T1DM?
Weight lost
Polyuria
Polydipsia
Treatment of T1DM?
Insulin
What diabetic emergencies present with T1DM?
Hypoglycaemia
Diabetic Ketoacidosis
Complications of T1DM and T2DM?
Microvascular: diabetic neuropathy(leg), diabetic retinopathy(eye) diabetic nephropathy (kidney)
Macrovascular: Stroke, MI
Describe the pharmacology of biguanides?
Drug class: Biguanide
Example: Metformin
Mechanism: Reduces gluconeogenesis in liver
Side effects: GI disturbances, weight loss, can cause lactic acidosis (rare)
Describe the pharmacology of sulfonylureas?
Drug class: Sulfonylurea
Example: Gliclazide
Mechanism: Stimulates B cells to secrete insulin
Side effects: hypoglycaemia, weight gain (appetite stimulation)
Describe the pharmacology of DP4 inhibitors?
Drug class: DPP4 inhibitors
Example: sitagliptin
Mechanism: Inhibits DPP4, so increased incretins (GLP-1 and GIP), increasing insulin
Side effects: do not weight gain/loss
What is an incretin?
A group of hormones released after eating and augment the secretion of insulin
e.g. GLP-1 and GIP
Describe the pharmacology of glitazones?
Drug class: Glitazone
Example: Pioglitazone
Mechanism: Enhance the uptake of fatty acids and glucose
Side effects: fluid retention and fat gain - weight gained
Describe the weight changes for the following drugs:
Metformin
Gliclazide
Sitagliptin
Pioglitazone
Metformin = lost
Gliclazide = gain
Sitagliptin = no change
PioGlitazone (glitazones) - gain
G is for gain
S is for same
M is for mini
What is Addisons disease?
Primary Adrenal Insufficiency
Impairment of adrenal gland, low cortisol and aldosterone
Opposite of Cushing’s
What is the commonest cause of primary adrenal insufficiency in the world?
TB
What is the commonest cause of primary adrenal insufficiency in the UK?
Addison’s disease
Describe the signs and symptoms of Addison’s?
Look= Lean and tanned
Mood = Depressed and tearful
GI: abdominal pain
Investigation for addision’s?
Short ACTH stimulation test: give ACTH (synacthen) then measure cortisol levels - in Addisons cortisol remains low
Test from 21-hydrolyase (+Ve in 80%)
Bloods will show Na+ low and K+ high due to low aldosterone
Treatment of Addisons?
Hydrocortisone to replace cortisol
Fludrocortisone to replace aldosterone
Emergencies with Addisons?
Addisonian crisis:
Patients present with shock
Treat with fluid and hydrocortisone
Diabetic ketoacidosis:
How?
Aetiology?
How - insufficient insulin
Aetiology - More ketones due to less glucose available, more ketones produced
Signs and symptoms of diabetic ketoacidosis?
- Fruity breath
- Vomiting and abdominal pain
- Signs of dehydration
- Kussmaul breathing
Diagnosis of DKA?
Acideamia (blood pH)
Hyperglycaemia
Ketonaemia/ketoniuria
Management of DKA?
Fluid
Insulin
Hypoglycaemia:
How?
Aetiology?
How - Too much insulin / oral hypoglycaemic agents
Aetiology - Insufficient glucose to brain
Signs and symptoms of hypoglycaemia?
Odd behaviour
Sweating
Raised pulses
Seizures q
Diagnosis of hypoglycaemia?
Blood glucose level
Treatment of hypoglycaemia?
Glucose
Glucagon
Hyperglycaemic Hyperosmolar State:
How?
Aetiology?
Insufficient oral hypoglycaemic agents
Aetiology - no ketogenesis, just hyperglycaemia
Signs and symptoms of hyperglycaemic HS?
Signs of dehydration
Diagnosis of hyperglycaemic HS?
Blood glucose level
Treatment of hyperglycaemic HS?
LMWH prohpylaxis
Fluid
Insulin if severe
What is diabetes insipidus?
Too little ADH from the posterior pituitary gland (cranial DI)
Kidney not responding to ADH (nephrogenic DI)
Causes of diabetes insipidus?
Cranial DI: Head trauma, pituitary tumour
Nephrogenic: drugs e.g. lithium
Signs and symptoms of DI?
Water deprivation test
- Restrict fluid
- Measure urine osmolarity (+ve for DI if urine osmolarity is low)
- Desmopressin (ADH analogues) to differentiate cranial or nephrogenic
Treatment of diabetes insipidus?
Cranial: desmopressin
Nephrogenic: bendroflumethiazide, NSAIDs
What is SIADH?
Syndrome of inappropriate ADH secretion
Too much ADH
Causes of SIADH?
Malignancy
Drugs
CNS disorder
S&S of SIADH?
Confusion
Anorexia
Nausea
Concentrated urine
Diagnosis of SIADH?
Measure urine and plasma osmolarity
Treatment of SIADH?
Treat the underlying cause
Restrict fluid
Vasopressin receptor antagonists
Actions of PTH?
- Increased bone resorption by osteoclasts
- Increased intestinal calcium resorption
- Activates 1.25dihydroxyVD in kidney
- Increased calcium reabsorption and phosphate excretion in the kidney
What might the thyroid function tests show in SECONDARY hyperthyroidism
a) Low TSH, High T3/T4
b) High TSH, High T3/T4
c) Normal TSH, High T3/T4
d) High TSH, Low T3/t4
e) High TSH, Normal T3/T4
b)High TSH, High T3/T4
In secondary hyperthyroidism, something is triggering high levels of TSH, which in turn causes high T3/T4
What might the thyroid function tests show in PRIMARY hyperthyroidism
a) Low TSH, High T3/T4
b) High TSH, High T3/T4
c) Normal TSH, High T3/T4
d) High TSH, Low T3/t4
e) High TSH, Normal T3/T4
a)Low TSH, High T3/T4
What is the best blood test for acromegaly?
a) Random plasma growth hormone test
b) IGF-1 conversion test
c) Glucose tolerance test
d) Serum GHRH tolerance test
e) Random plasma glucose
c)Glucose tolerance test
You cannot do a random GH test because GH is pulsatile
Best blood test is to check if glucose is suppressing GH levels as it should do
Spironolactone is a…
a) Loop diuretic
b) Potassium – losing diuretic
c) Renin agonist
d) Aldosterone antagonist
e) Calcium channel blocker
d)Aldosterone antagonist
Spironolactone is a potassium SPARING diuretic, but its main action is as an aldosterone antagonist
Give 4 causes of hypocalcaemia?
H- hypoparathyroidism A- Acute pancreatitis V- Vitamin D Deficiency O- Osteomalacia C- Chronic Kidney Disease
In acidosis, how would the blood potassium level be?
Hyperkalemia
What does a high Plasma ACTH but negative response to methotrexate suppression test indicate about the cause of a patients Cushing’s?
High ACTH so dependant and negative response to dexamethasone suppression test so paraneoplastic e.g. small cell lung cancer
Which of the following ECG findings is indicative of Hypokalemia?
Tented T, short QT
Long QT, U waves
Tented T, no P
Long QT
Long QT
Lara Williams, a 16yr old female, presents to A&E with her mother after feeling vey weak and experiencing some palpitations. Her mother is concerned that her daughter is very skinny, you check her BMI and it is 16.What is the most likely cause of her condition?
Hypokalaemia
Hyperkalaemia
Hypocalcaemia
Hypercalcemia
Hypokalemia
Anorexic - BMI
Jim Bob a 73 year old gentleman presents to his GP for some routine tests following a recent diagnosis of tertiary hyperparathyroidism. All the results get mixed up in the pile which one is Jims?
A) Calcium high, Phosphate high, ALP high
B) Calcium low, phosphate low, ALP low
C)Calcium low, Phosphate high, ALP high
D) Calcium low, phosphate low, ALP high
B) Calcium low, phosphate low, ALP low
Jim Bob a 73 year old gentleman presents to his GP for some routine tests following a recent diagnosis of secondary hyperparathyroidism. All the results get mixed up in the pile which one is Jims?
A) Calcium high, Phosphate high, ALP high
B) Calcium low, phosphate low, ALP low
C)Calcium low, Phosphate high, ALP high
D) Calcium low, phosphate low, ALP high
A) Calcium high, Phosphate high, ALP high
Jim Bob a 73 year old gentleman presents to his GP for some routine tests following a recent diagnosis of primary hyperparathyroidism. All the results get mixed up in the pile which one is Jims?
A) Calcium high, Phosphate high, ALP high
B) Calcium low, phosphate low, ALP low
C)Calcium low, Phosphate high, ALP high
D) Calcium low, phosphate low, ALP high
D) Calcium low, phosphate low, ALP high
A 29yo man presents with 4-week history of polyuria and extreme thirst. The urine is very dilute. The patient does not have any weight loss and maintains a good diet. No findings are found on urine dipstick. The most appropriate invevstigation is:
Serum osmolality Fasting plasma glucose Urinary electrolytes MRI head Water deprivation test
Water deprivation test
A 50yo Asian man is referred to the diabetes clinic after presenting with polyuria and polydipsia. His BMI = 30, BP = 137/88, Fasting plasma glucose = 7.7mmol/L (high). The most appropriate first-line treatment is:
Dietary advice and exercise Sulphonylurea Exenatide Thiazolidinediones Metformin
Dietary advice and exercise
Metformin = first line drug but not first line treatment
A 6yo girl presents to accident and emergency with severe abdominal pain, nausea and vomiting. Patient has a sweet (fruity) odour from her breath and is breathing fast (tachypnoeic). The most likely diagnosis is:
Diabetic ketoacidosis Hyperglycaemia hyperosmolar state Gastroenteritis (Infection of intestine) Pancreatitis Addisonian crisis
Diabetic ketoacidosis
A 57yo woman presents with dull grey-brown patches in her mouth and the palms of her hand which she has noticed in the last week. She has also noticed she gets very dizzy when rising from a seated position and is continually afraid of fainting. The most likely diagnosis is:
SIADH Hyperthyroidism Hypothyroidsim Addison’s disease Diabetes insipidus
Addison’s disease
PIGMENTATION
