Endocrinology Flashcards

1
Q

What are the 6 hormones secreted by the anterior pituitary?

A
LH/ FSH
TSH
PRL
GH
ACTH
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2
Q

What are the 2 hormones released by the posterior pituitary?

A

ADH

Oxytocin

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3
Q

Thyroid mainly produces T4 but T3 is far more active

A

The vast majority of T3/4 is bound to proteins such as thyroid binding globulin (TBG) - remember that only unbound stuff is metabolically active

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4
Q

What is sick euthyroid?

A

Derangement of TFT due to systemic illness - classically everything will be low - TSH, T3 and T4

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5
Q

Other than those with thyroid disease, who needs TFTs measured regularly?

A

Patients with AF
Type 1 DM
Those with hyperlipidaemia
Drugs e.g. lithium and amiodarone (6 monthly)
Other conditions e.g. Downs, Addison’s etc (yearly)

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6
Q

What are the triad of features specifically associated with Graves’ disease?

A

Eye disease = exophthalmos, lid lag and opthalmoplegia
Pretibial myxoedema
Thyroid acropachy = clubbing, painful finger and toe swelling

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7
Q

What is the commonest cause of hyperthyroidism?

A

Graves’ disease
IgG autoantibodies bind and activate thyrotropin receptors causing smooth muscle proliferation and excess hormone secretion

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8
Q

Presentation of toxic adenoma of they thyroid

A

Hyperthyroidism
Adenoma will be ‘hot’ on radio-isotope scan
Treat with radio-iodine

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9
Q

Diagnosis in patient with high T4, painful goitre, high CRP and fever

A

Sub-acute de-quervains thyroiditis
There will be low uptake on scan
Treat with NSAID - it is self limiting

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10
Q

Propranolol and carbimazole are mainstay of treatment for hyperthyroidism - what is the important side effect?

A

Carbimazole can cause agranulocytosis (low neutrophils)- seek medical help if fever/ unwell

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11
Q

Radioiodine treatment for hyperthyroidism often causes hypothyroid

A

Thyroidectomy risks hypothyroidism and damage to the recurrent laryngeal nerve

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12
Q

What is the differential diagnosis of a goitre?

A

Diffuse = physiological, grave’s, hashimotos and sub-acute de Quervains thyroiditis

Modular = toxic adenoma, carcinoma, multi-modular goitre

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13
Q

What is the differential for hypothyroidism?

A
Primary atrophic hypothyroidism
Hashimoto’s thyroiditis
Iodine deficiency
Post-thyroidectomy/ radioiodine
Pituitary disease
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14
Q

Healthy/ young person with hypothyroid = start with 50micrograms/ day thyroxine

A

For an old, frail person, start with 25 micro grams per day

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15
Q

Amiodarone can cause significant impairment of thyroid function - check levels every 6 months

A

Also risk of pulmonary fibrosis so need to do an CXR before treatment

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16
Q

Why is untreated hypothyroidism a risk factor for cardiovascular disease?

A

Low thyroxine levels cause lipid levels to rise = clear link with heart disease

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17
Q

Both hyperparathyroidism and familial hypocalciuric hypercalcaemia cause mild hypercalcaemia. Other then FH how else do you differentiate?

A
Hyperparathyroidism = high urinary calcium
FHH = Low urinary calcium
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18
Q

Define the diagnostic criteria for DM

A

1) Symptoms of hyperglycaemia e.g. polyuria, recurrent infection, blurred vision + raised glucose (fasting >7mmol/L, random >11.1 mmol/L
2) No symptoms but raised glucose measured on 2 occasions. Fasting >7mmol/l, random >11.1 mmol/L or OGTT 2 hr value >11.1

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19
Q

Define criteria for impaired glucose tolerance

A

Fasting glucose <7mmol/L but OGTT 2 hours >7.8 but less than 11.1

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20
Q

Which oral hypoglycaemic is suitable in pregnancy?

A

Metformin
(discontinue all others)

Remember to do a fasting glucose 6 weeks post partum to see if GDM has disappeared

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21
Q

What is LADA

A

Latent autoimmune diabetes in adults

Late onset type 1 with gradual progression to insulin dependence

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22
Q

What are the components of the metabolic syndrome?

A

Central obesity
Hypertension
Hyperglycaemia
Dyslipidaemia

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23
Q

Diabetes and DVLA?

A

Inform but ok to drive

The only exception is if hypoglycaemic spells with no warning

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24
Q

Novorapid/ Humalog

A

Ultra-fast acting insulin, inject at start of meal

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25
Novomix
30% short acting insulin e.g. Novorapid | 70% long acting insulin e.g. Lantau
26
Insulin rules if unwell
1) illness often increases insulin requirement - even if you dont feel like eating 2) Maintain calorie intake e.g. drink milk, fruit juice etc 3) Check blood glucose regularly (>4-6 times per day) 4) Look for ketones 5) Speak to DM specialist nurse if concerned 6) Admit if vomiting, ketones, dehydrated etc v
27
Side effects of metformin
1) GI disturbance 2) Lactic acidosis - stop if EGFR <36 3) Weight loss
28
Side effects of sulpholyureas e.g. gliclazide and glibenclamide
Hypoglycaemia | Weight gain
29
Glitazones e.g. pioglitazone
1) Diabetic drugs which increase sensitivity to insulin 2) Hypoglycaemia (less than SU) 3) Increased risk of fractures (CI in osteoporosis) 4) Increased risk of bladder cancer - avoid in current, previous or unexplained haematuria 4) Can cause fluid retention (CI in CCF) 5) Can raise LFT - monitor 2 monthly for 1 year)
30
Dapagliflozin
An SGLT2 inhibitor which prevents the reabsorption of glucose in the proximal convuluted tubule and therefore increases urninary excretion SE = weight loss, UTI etc
31
Sitagliptin
A DPP4 inhibitor —> inhibits the enzyme which breaks down incretins Incretin stimulate the production of insulin —> better glycaemic control They also reduce appetite —> weight loss
32
HbA1c target
Roughly 48 Or 6.5% For older people/ with hypoglycaemia the target can be up to 53
33
Metformin is the 1st line diabetes drug. If HbA1c is still high what is the second line?
Add in another agent e.g. Metformin + SU Metformin + Pioglitazone Metformin + Gliptin (DPP4 inhibitor) For interest 3rd line = metformin, gliptin and SU
34
What is the target BP for patients with type 2 DM?
140/ 80
35
Other than diabetic drugs, what other drugs should be used in T2DM
1) Statin - for all. 2) Fibrate - if high triglycerides and low HDL 3) ACEI/ ARB if evidence of renal disease e.g. microalbuminaemia 4) Aspirin - if previous stroke/ MI
36
Eye disease associated with diabetes
1) Diabetic retinopathy (background, pre-proliferative and proliferative) 2) Diabetic maculopathy 3) Cataracts 4) Rubeosis iris = new vessel formation on iris
37
How do you test sensation in a diabetic foot exam?
Using a 10g monofilament with just enough force to bend it Touch big and middle toe and over the 3 ‘knuckles’ Proprioceptive testing with tuning fork 128Hz (big)
38
Describe a diabetic ulcer
Typically painless, ‘punched out’ lesion in an area of thick callus Risk of abscess formation, cellulitis or osteomyelitis
39
Treatment for diabetic neuropathy
1) Paracetemol 2) amitryptilline 3) gabapentin 4) Others including capsaicin cream, baclofen etc
40
Mononeuritis multiplex has several causes. Name them
``` WARDS PLC Wagner’s Amyloid/ AIDS RA DM Polyateritis nodosum Leprosy Cancer ```
41
What is the definition of hypoglycaemia?
Plasma glucose <3mmol/L | Symptoms =sweating, anxiety, hunger, confusion, drowsiness
42
In a non-diabetic you must EXPLAIN the cause of hypoglycaemia
``` EX= exogenous drugs e.g. insulin, alcohol P = pituitary insufficiency L =Liver failure A = Addison’s disease I = Insulinoma (often seen in MEN 1) N = Non- pancreatic neoplasm ```
43
Diagnosis of insulinoma
1) Suspect if Whipple’s triad (symptoms associated with exercise/ fasting, hypoglycaemia with symptoms and relieved by glucose) 2) Prove via suppression - give IV insulin and measure C-peptide (normally this will he suppressed by insulin) 3) Treat with excision
44
30% of pituitary adenoma secrete no hormone
35% secrete PRL only 20% secrete GH only 10% secrete ACTH only 10% are mixed
45
Most likely diagnosis in a patient with sudden onset headache, meningism and reduced GCS in a patient with known pituitary adenoma
Pituitary apoplexy - rapid pituitary enlargement due to bleed into tumour Treatment will include steroids, fluid balance and surgery
46
A child presents with growth failure and is found to have an intracranial tumour. Most likely diagnosis?
Craniopharyngioma - a tumour originating from Rathke’s pouch - between pituitary and 3rd ventricle Commonest childhood intracranial tumour Surgery +/- radiotherapy
47
Most pituitary surgery is trans-shpeniodal. What does this mean?
Up nose, through sphenoid bone and sphenoid sinus
48
Differential of high prolactin
1) Physiological e.g. pregnancy 2) Drugs e.g. dopamine antagonists such as metoclopramide/ haloperidol 3) Pituitary disease e.g. microadenoma, stalk disease etc
49
1st line for prolactinoma
Bromocriptine or cabergoline Use bromocriptine if fertility is goal (cabergoline has not been shown to be safe in pregnancy) Surgery if pressure effect e.g. visual disturbance, not controlled quickly by dopamine antagonists
50
What are the complications associated with acromegaly?
1) Impaired glucose tolerance/ DM 2) Vascualr problems e.g. HT, LVH, arrhythmias 3) Colon cancer —> offered colonoscopy
51
In acromegaly, GH stimulates bone and soft tissue growth by increasing secretion of IGF-1
Normally, GH secretion is inhibited by glucose If high basal GH/ IGF-1 then do OGTT - if GH fails to suppress then acromegaly is diagnosed Also useful to look at old photos, do an MRI and check visual fields
52
Management of acromegaly
1) Surgery 2) Somoatostain analogue e.g. octreotide (SE flactulence, loose stools etc) if surgery is not fully effective 3) Follow up - visual field, vascular assessment, colonoscopy etc
53
What is DIDMOAD?
``` A rare autosomal recessive syndrome characterised by: DI DM Optic atrophy Deafness ```
54
How to differentiate between cranial and nephrogenic DI?
``` Cranial = urine osmolality increases to >600 after desmopressin injection Nephrogenic = no increase in urine osmolality after desmopressin injection ```
55
The GAD antibody (glutamic acid decarboxylase) is used for determining the type of diabetes where there is diagnostic doubt?
It is positive in type 1 and LADA (latent autoimmune diabetes of adulthood) Type 1 also has anti-islet cell antibodies
56
What are the major complications of DKA?
- hypoglycaemia - hypo/Hyperkalaemia - cerebral oedema - pulmonary oedema
57
How would a patient with HONK present?
Hyperosmolar non-ketotic coma - T2DM (or not diagnosed) - polyuria, polydipsia - reduced conscious level - thrombosis - high Na - very high glucose and osmolality
58
SAIL is a nice mnemonic for remembering causes of hypoglycaemia. What does it stand for?
``` S = sulfonyureas A = alcohol/ Addison’s I = insulin, infection, insulinoma L = liver failure ``` Patients are sweaty with a tremor and possible confusion Plasma glucose >2.5
59
How is ketoconazole used in endocrinology?
It is used to manage endogenous Cushing’s e.g. from a tumour or adrenal cancer which has spread Metyrapone is an alternative
60
How does a high dose dexamethasone suppression test help in Cushing’s?
Used to differentiate between pituitary and ectopic ACTH ``` Pituitary = will eventually by suppressed Ectopic = never suppressed ```
61
Nelson’s syndrome is a rare side effect of bilateral adrenalectomy for Cushing’s. What are the features?
- increased pituitary size | - increased skin pigmentation
62
List some of the physiological effects of acromegaly?
- increased insulin resistance - growth of some tissues e.g. bone and muscles - release of IGF-1 from some tissues e.g. liver and bone
63
Differential for acromegaly?
- Pituitary adenoma - Hypothalamic tumour - Ectopic GH AlWAYS remember that there is an increased risk of acromegaly
64
Medical treatment for acromegaly?
Dopamine agonist e.g. carbergoline | Somatostatin analogue e.g. octreotide
65
What is a sestamibi scan?
A type of nuclear medicine scan used to localise a parathyroid adenoma
66
What is the main ECG abnormality of hypercalcaemia?
Shortened QT interval
67
Secondary hyper-parathyroidism = High PTH in response to chronically low Ca
Tertiary = excess PTH as a result of longstanding secondary hyperPTH
68
What is Trosseau’s sign?
Inflation of BP cuff above systolic —> ulnar and median ischaemia —> carpal spasm
69
21- a hydroxylase is the commonest type of CAH. It presents with salt wasting or female virilization —> depending on severity. What are the other types?
11b hydroxylase —> presents with female virilization 17 a hydroxylase —> presents with male under virilization
70
Importance of lithium in endocrinology?
- Can affect TFT - need to monitor closely | - can cause nephrogenic DI
71
Clinically how can you differentiate between cranial and nephrogenic DI?
1) Cranial = urine osmolality will increase when given desmopressin 2) Nephrogenic = no improvement with desmopressin as kidneys do not respond
72
What is the treatment for nephrogenic DI?
Weirdly the answer is thiazide diuretics
73
What are the features of SIADH?
LOW blood sodium LOW blood osmolality HIGH urinary sodium HIGH urine osmolality
74
List some causes of SIADH?
- Stroke - haemorrhage - trauma - drugs e.g. anti-epileptic - small cell lung cancer - lung and brain infection
75
What is the major risk of correcting very low sodium levels too quickly?
Central pontine myelinosis | presents with progressive spastic quadripartite, pseudobulbar palsy and emotional lability
76
How do you calculate serum osmolality?
2 (Na + K) + urea + glucose
77
Bus drivers/ lorry drivers are group 2 vehicles and therefore must be seizure free for 10 years before they can return to work
Bus drivers/ lorry drivers are group 2 vehicles and therefore must be seizure free for 10 years before they can return to work
78
Give examples of conditions which show high, low and nodular uptake on thryoid radioactive iodine scan?
``` High = graves (anti TSH and anti- thyroid peroxidase) Low = thyroiditis Nodular = multi-nodular goitre or tumour ```
79
What is corticobasilar degeneration?
A type of Parkinson plus syndrome where patients develop an ‘alien limb’ syndrome e.g. feel like arm has a mind of its own
80
Anti-coagulant secondary prevention after a stroke?
1st line = clopidogrel (life long) 2nd line = aspirin + dipyramidole if clopidogrel not tolerated Remember aspirin 300mg daily is given for the 1st 2 weeks post-stroke
81
Always consider GMB in a patient with ascending pattern of neuropathy
Remember that loss of reflexes in the lower limbs is typical
82
Bitemporal hemianopia with lower quadrant defect due to inferior chiasmal compresssion —> usually a pituitary tumour
Bitemporal hemianopia with upper quadrant defect is due to superior chiasmal compression e.g. craniopharyngioma
83
Always remember that increased PTH action —> high Ca and low phosphate
High Ca and low phosphate
84
Which significant side effect are gliptins associated with?
Gliptins are DPP4 inhibitors Potentially increase risk of pancreatitis