Endocrinology Flashcards
How would you diagnose Diabetes Mellitus?
Random glucose >11.1 or Fasting glucose > 7
HbA1c >48
Which diabetes drugs can cause hypoglycaemia?
Insulin
Sulphonylureas e.g. gliclazide (esp if alongside metformin)
Glinides
Causes of Diabetes
Type 1 = autoimmune destruction of beta cells = reduced insulin secretion
Type 2 = insulin resistance
Steroid use
Chronic pancreatitis
Cystic fibrosis
Haemachromatosis
Acromegaly
Cushing’s
Glucagonoma
Diabetes & DVLA
Group 1 drivers on insulin can still drive if….
1) Hypoglycaemic awareness
2) <1 hypo episode requiring assistance in last year
3) No visual impairment
True or False:
Group 2 (e.g. HGV) drivers do NOT need to inform DLVA if on oral anti-diabetic agents
FALSE
Group 2 drivers must stop driving HGVs and tell the DVLA if they are diabetic and taking insulin AND/OR oral anti-diabetic agents
They do not need to inform the DVLA if their diabetes is diet controlled
Grave’s Disease
70% of all hyperthryoidism
Autoimmune disorder
- antibodies to TSH receptor
Features of hyperthyroidism
- Tachycardic/AF
- Dry skin
- Tremor
PLUS
- Thyroid eye disease
- Lid lag
Thyroid Eye Disease
NO SPECS
N - nil
O - Only signs, no symptoms e.g. eye lid retraction
S - Swelling of periorbital soft tissue e.g. eyelid swelling
P - Proptosis
E - Extra-ocular muscle involvement (ophthalmoplegia)
C - Corneal involvement
S - Sight loss (suggests compression of CN II)
URGENT referral to ophthalmology if any loss of visual acuity/colour vision
How would you manage a patient with Grave’s Disease?
CONSERVATIVE
- Eye care
- STOP smoking! (v. important)
MEDICAL
- Carbimazole titration or carbimazole + levo (“Block and replace”)
—— risk of agranulocytosis
- Beta blockers (can help with symptom control)
- Radioiodine
—- Contraindicated in thryoid eye disease
SURGICAL
- Thyroidectomy (risk of parathyroid damage)
Toxic Multinodular Goitre (TMG)
2nd most common cause of hyperthyroidism
Features of hyperthyroidism PLUS
- Goitre (can be painful/painless)
NO thyroid eye disease present!
Negative for thyroid autoantibodies
How would you investigate a patient in whom you suspect hyperthyroidism?
ECG
Bloods
- FBC, baseline renal function
- TFTs
- Thyroid autoantibodies
USS thyroid +/- CT neck or thorax (if suspicious of extension into mediastinum ?compression issues)
Thyroid Scintigraphy
- Diffuse uptake = Grave’s
- Focal/patchy uptake = TMG/thyroid adenoma
How would you manage a patient with Toxic Multinodular Goitre?
Indications for Rx =
- Cosmetic
- Compression/obstructive issues e.g. horner’s syndrome secondary to goitre
- Marked intra-thoracic extension
Management
- Radio-iodine
- Surgical resection of goitre
Antithryoid drugs not particularly helpful as thyrotoxicosis recures once Rx stops
Hypothyroidism
Most common endocrine condition
(approx 5-10% of UK)
CAUSES
- Hashimoto’s thyroiditis
- Iodine deficiency
- Iatrogenic (thyroidectomy/iodine)
- Post illness (De Quervain’s thyroiditis)
- Post partum thyroiditis
- Drugs e.g. amiodarone & lithium
Features of hypothyroidism
- Dry skin
- ?goitre
- ?macroglossia (secondary to myxoedema)
- NO eye disease
- Pleural effusions/ascites (RARE!)
Hashimoto’s Thyroiditis
Autoimmune condition
Thyroid peroxidase antibodies
F > M
Associated with:
- Coeliac disease
- T1DM
- Vitiligo
- ADDISON’S!!
How would you investigate a patient in whom you suspect hypothyroidism?
Bloods
- FBC, renal function
- TFTs
- Thyroid peroxidase antibodies
USS neck ?goitre
How would you manage a patient with hypothyroidism?
Levothyroxine
- 50-100mcg OD (starting dose)
- 25-50mcg OD if elderly or history of IHD
Check TFTs every 8-12 weeks after a dose change
True or false
In pregnant women with hypothyroidism, you should reduce their usual levothyroxine dose
FALSE
Increase their levothyroxine dose by 25-50% (esp in 1st 12 weeks)
Risks of levothyroxine
Hyperthyroidism
AF
Worsening of IHD/angina
Lowers bone mineral density –> OP
What is a Myxoedema Coma?
Severe hypothyroidism
Endocrinological emergency!
Usually precipitated by infection/MI/surgery
Features
- Bradycardic
- Hypotensive
- Hypothermic
- Hyponatraemia
- Confused
Rx = IV liothyronine and IV hydrocortisone (in case of concurrent Addison’s)
What is Acromegaly?
Condition of increased production and secretion of Growth Hormone
CAUSES
- Pituitary macroadenoma
- Pituitary hyperplasia
- Carcinoid tumour (ectopic GH release)
5% associated with MEN-1
What symptoms may a patient with Acromegaly notice?
Increase hand/foot size - ?noticed a change in shoe size
Weight gain
Changes in vision (bitemporal hemanopia)
Headaches
Sweating
Drowsiness/somnolence (?OSA)
Proximal muscle weakness
Arthralgia
Change in bowel habit
What are the 4 signs of active disease in Acromegaly?
1) Sweating
2) Skin tags
3) HTN
4) Peripheral oedema
Associations/Complications of Acromegaly
Diabetes
HTN
LVF –> CCF (60% of deaths are due to CVD)
Cardiomyopathy
Arrhythmias
Carpal Tunnel Syndrome
OSA
Increased risk of IHD and stroke
Increased risk of colorectal cancer
How would you investigate a patient in whom you suspect Acromegaly?
Bedside
- BP
- BM
- Urine dip
- ECG
Bloods
- FBC, baseline renal function
- Calcium profile (MEN1 is also associated with hyperparathyroidism)
- Oral Glucose Tolerance Test (OGTT)
—- If fails to suppress GH to <2 = diagnostic
- IGF-1 (monitoring)
Imaging
- MRI pituitary
- Echocardiogram (CVD risk)
Special
- Visual fields and perimetry
How would you manage a patient with Acromegaly?
Surgery is first line!
- Usually transphenoidal surgery
Radiotherapy can be used as an adjunct or sole Rx in those who are unfit for surgery
MEDICAL
- Pegvisomont = GH antagonist (subcut)
- Bromocriptine = dopamine agonist (only works in <20%)
-Ocreotide = somatostatin analogue (negative feedback)
CVD risk factor management
?CPAP if OSA
?Surgery if CTS
FOLLOW UP
- Annual follow up with GH/IGF1 levels, visual fields and CVD assessment
- Low threshold for colonoscopy
What are the MEN syndromes?
Multiple Endocrine Neoplasia syndromes
Autosomal dominant
Associated with NF1, vHL and peutz jeger’s
Outline the components of MEN1
3Ps
Primary hyperparathyroidism
Pancreatic tumours e.g. insulinoma
Pituitary tumours e.g. prolactinoma, macroadenoma
Outline the components of MEN2a
2 Ps, 1M
Primary hyperparathyroidism
Phaeochromocytoma
Medullary thyroid cancer
Outline the components of MEN2b
1P, 2 Ms
Phaeochromocytoma
Medullary thyroid cancer
Marfanoid habitus
Causes of Hypoadrenalism?
DISORDERS OF THE ADRENAL GLANDS
Addison’s disease (autoimmune)
Congenital adrenal hyperplasia (= excess ACTH and androgens, but low cortisol/mineralocorticoids)
Infiltration of adrenal glands
- Metastases
- Haemochromatosis
- Sarcoidosis
- TB
- Amyloidosis
Damage to adrenal glands
- Adrenal haemorrhage
- Adrenalectomy
DISORDERS OF THE PITUITARY
- Hypopituitarism (low ACTH levels)
What is Addison’s disease?
Autoimmune condition of the adrenal glands = reduced adrenal cortex hormones
Associated with other AI disorders e.g.
- T1DM
- Thyroid disease
- Coeliac disease
- Pernicious anaemia
Outline features of Addison’s disease
GLUCOCORTICOID LOSS
- Weight loss
- Anorexia
- Malaise/fatigue
- Postural hypotension
- CIBH/vomiting
MINERALOCORTICOID LOSS
- Hypotension
- Hyponatraemia
- Hyperkalaemia
ACTH EXCESS (due to feedback loop)
- Pigmentation of sun exposed/pressure areas and mucosa = BRONZE skin
- Amenorrhoea
- Body hair loss
How would you investigate a patient in whom you suspect Addison’s disease or hypoadrenalism?
Bedside
- L+S BP
- BM
- Urine dip
Bloods
- FBC, U&Es
- Glucose, HbA1c
- TFTs
- Morning cortisol
- Short synacthen test (does cortisol level rise appropriately with synthetic ACTH?)
Imaging
- ?CT adrenals
- ?CXR (?TB)
- ?MRI pituitary
How would you manage a patient in whom you suspect has Addison’s disease?
Education regarding steroids, sick day rules and Addisonian crises
Hydrocortisone +/- fludrocortisone
Monitor HbA1c
Outline Autoimmune Polyglandular Syndrome 1
Chronic mucocutaneous candidiasis
(immunodeficiency)
Hypoparathyroidism
Addison’s disease
Outline Autoimmune Polyglandular Syndrome 2
Addison’s disease
T1DM
Hypo OR hyperthyroidism
What is Nelson’s Syndrome? What clinical features may you see on examination?
Occurs following bilateral adrenalectomy (e.g. for Cushing’s disease)
Reduced cortisol = loss of negative feedback loop back to anterior pituitary = +++ ACTH production and secretion
= Pituitary adenoma
= Activates melanocytes = hyperpigmentation
SIGNS
- Abdominal rooftop incision
- Bronze skin
What is Cushing’s Syndrome?
= any condition which causes increased cortisol production (hypercortisolism)
EXOGENOUS CUSHING’S
- Steroid use (most common cause)
ENDOGENOUS CUSHING’S
ACTH DEPENDENT
- Pituitary adenoma = increase ACTH production and then cortisol = Cushing’s DISEASE!
- Ectopic ACTH e.g. SCLC
ENDOGENOUS CUSHING’S
ACTH INDEPENDENT
- Adrenal adenoma = increased cortisol
PSEUDOCUSHING’S
- Alcoholism
- Severe depression
What is Cushing’s Disease?
Pituitary adenoma resulting in increased ACTH production –> hypercortisolism
Features of Cushing’s Syndrome
Weight gain
Adipose tissue deposition on abdomen and back of neck
Abdominal striae
Typical cushing facies (“moon”)
Thin skin
Easy bruising
Mood disturbance
Fluid retention
HTN
Gynaecomastia
Amenorrhoea, hirsutism
Acne
Hyperglycaemia –> Diabetes
Osteoporosis
CVD risk
Cataracts
How would you investigate someone in whom you suspect Cushing’s syndrome?
Bedside
- BP
- BM
- Urine dip
- ECG
Bloods
- FBC
- Renal function (can cause hypokalaemic metabolic acidosis)
- Overnight dexamethasone suppression test (give dex at 00:00 then test cortisol level in morning)
— If ODST is positive = ACTH levels and High Dose Dex Suppression Test (identifies pituitary vs adrenal/ectopic cause)
Imaging
- CT adrenals or MRI pituitary
- ?HRCT if suspect ectopic ACTH
How would you manage a patient with Cushing’s syndrome?
Depends on underlying cause e.g. if on steroids, consider whether able to reduce/stop (risk vs benefits)
Metyrapone (cortisol inhibitor) whilst awaiting results
If PITUITARY cause = surgery/radiotherapy
If ADRENAL cause = adrenalectomy
Management of CVD RFs e.g. antihypertensives
Clinical Features of Hypopituitarism
ANTERIOR PITUITARY
Growth hormone
- Lethargy
- FTT/growth failure
FSH/LH
- Reduced libido
- Hair loss
- Amenorrhoea
- Infertility
TSH
- Features of hypothyroidism
ACTH
- Lethargy
- Postural hypotension
- Hypoadrenalism
POSTERIOR PITUITARY
ADH
- Diabetes insipidus = polyuria & thirst
Causes of Hypopituitarism
Large compressive pituitary tumour
Removal of a pituitary macroadenoma
Pituitary haemorrhage/infarct
Severe head injury
Cranial radiotherapy
Sarcoidosis
Haemochromatosis
How would you investigate a patient in whom you suspect Hypopituitarism?
Bedside = L+S BP, urine dip
Bloods
- Baseline FBC, U&Es
- Pituitary Screen =
– GH / LH & FSH / TFTs / ACTH
- Synacthen test
Imaging
- MRI pituitary
How would you manage a patient with hypopituitarism?
Treat underlying cause if possible e.g. surgery if large compressive tumour
Low GH = daily subcut GH
Low FSH/LH = intramuscular testosterone or COCP
- Refer to fertility specialists
Low TFTs = levothyroxine
Low ACTH = hydrocortisone (prevent addisonian crises)
