Endocrinology Flashcards
Difference between proptosis and exophthalmos?
Exophthalmos is forward protrusion of eyeball related to Graves
Proptosis - forward protrusion related to any cause:
Malignancy
Inflammation
Traumatic
Signs of Cushing’s syndrome?
ACTH/cortisol
Moon face Buffalo hump Supraclavicular fat pads Central obesity Wasted limbs
Signs of hyperandrogenism
Hirsutism
Temporal balding
Acne
What are the micro and macro problems of diabetes?
Micro:
Retinopathy
Nephropathy
Neuropathy
Macro:
Stroke
Renovascular disease
Limb ischaemia
What are the three ways diabetes may be diagnosed?
- Symptoms + 1 BM
- 2 BMs
- HbA1c ≥48 (6.5%)
BM: fasting ≥7 or random > 11
What signs indicate thyrotoxicosis?
Hair loss
Bulging eyes (proptosis/exophthalmus)
Onycholysis- nail separation from nail bed
Pretibial myxoedema
What measurements suggest impaired fasting glucose?
Fasting glucose of 6.1-7mmol/L
Impaired glucose tolerance is defined as?
Fasting plasma glucose
What HbA1c indicates prediabetes?
42-47mmol
6-6.4%
What is the target blood glucose if on metformin?
6.5%
48mmol
How is Atorvastin dosed differently depending on whether someone has a QRISK above 10% or has existing IHD?
Primary prevention (QRISK)- 20mg Secondary prevention (IHD)- 80mg
What values after 2 hours indicate impaired glucose tolerance on an OGTT?
7.8-11mmol/L
Which drugs can cause diabetes mellitus?
Steroids
Anti-HIV drugs
Thiazides
Atypical antipsychotics
What features define metabolic syndrome?
Central obesity (BMI>30) with 2 of:
BP >130/85
Triglycerides >1.6
HDL 5.6 or diabetes
Functions of PTH?
In the kidney:
Increases Calcium reabsorption
Lowers Phosphate reabsorption
Vit D synthesis
Osteoclast activity
Vit D functions?
Acts mostly on the guts:
Calcium and phosphate reabsorption
Increases osteoclast activity
How does tertiary hyperparathyroidism arise in CKD?
Failure of the kidney to activate vit D reduces Ca2+ absorption from the gut, chronic overproduction of hyperparathyroidism leads to it’s autonomous activation (tertiary hyperparathyroidism)
Patient has high PTH, but low Ca and high PO4 and short fourth and fifth metcarpals.
What’s the syndrome?
Pseudo-hypoparathyroidism
Target organs don’t react to PTH (due to genetic insensitivity) so kidney’s don’t absorb more calcium, low Ca drives PTH secretion
In what circumstances does post-prandial hypoglycaemia typically occur?
IHX:
After bariatric surgery
In type 2 diabetics
IHx: prolonged Oral Glucose Tolerance Test
Which endocrine tumour syndrome is insulinoma associated with?
Men1
Parathyroid tumours, pancreatic endocrine tumours, pituitary prolactinoma
IHx for suspected insulinoma?
Screening: Prolonged fast leads to high insulin (unusual) and low glucose
Suppression test: IV insulin and measure C-peptide (in normal people C peptide is suppressed by exogenous insulin)
If you suspect hyperthyroidism is due to abuse of levothyroxine, what IHx can be used to confirm?
Low Serum thyroglobulin
- may be used to monitor carcinoma also
Which illnesses warrant screening for thyroid dysfunction?
Those with: AF, hyperlipidaemia DM, or type 1 DM in 1st trimester of pregnancy, or Addison's (yearly screen) DHx: amiodarone or lithium PMH: Down's, Turner's disease
IHx that is useful for detecting retrosternal goitre or ectopic thyroid tissue?
Isotope scan with 123-iodine or 99-technetium
What type of Ig antibodies occur in Grave’s disease?
IgG- TSH receptor antibodies
How do you test to differentiate a toxic multinodular goitre from a toxic adenoma in thyroid disease?
USS: cystic vs solid
+ fine needle aspiration in a multinodular goitre
Isotope scan: cold nodules (more likely to be malignant), hot nodules (more likely to be adenoma producing thyroid hormone)
If a goitre is painful what does that make it likely to be?
Subacute de Quervain’s thyroiditis
Thyrotocosis Rx?
Propranolol
Carbimazole (titrated to TFTs) or carbimazole + levothyroxine
For 12-18 months
Carbimazole SE: agranulocytosis
Main RF for eye involvement in Grave’s disease?
Smoking
Occurs in 25%-50% of those with Grave’s disease
Rx for eye disease in Graves?
Mild- symptomatic (artificial tears, sunglasses etc)
Severe- methylprednisolone if opthalmoplegia or gross oedema
Why do those with hashimoto’s get a goitre?
Lymphocytic and plasma cell infiltration of the thyroid, with autoantibodies against it
60 year old woman has high TSH and normal T3 and T4
Management?
Subclinical hypothyroidism:
Repeat in 2-4 months to check it’s persistent
Rx if symptomatic, TSH >10, thyroid autoantibodies, previous Graves
Or Rx trial for 6 months if TSH 4-10
Which types of cancer may produce ectopic PTH?
Lung
Breast
Kidney
Risk reducing Rx for patients with MEN-2 and test to determine if someone is applicable?
Test for ret-oncogene before age 3
Do a thyroidectomy (as 100% get medullary thyroid cancer- of the parafollicular C cells making calcitonin)
What are the 3 types of thyroid cancer?
70% papillary thyroid cancer (fingerlike)
15% follicular thyroid cancer
10% medullary thyroid cancer (parafollicular C cells- calcitonin)
3 causes of primary hyperaldosteronism?
And Rx?
- Conn’s (solitary adenoma)- laparoscopic adrenalectomy + spironolactone 4 weeks pre-op
- Adrenocortical hyperplasia. Rx: aldosterone R antagonist (spironolactone or eplerenone)
- Rarely glucocorticoid-remediable aldosteronism, where ACTH controls aldosterone expression. Rx: dexamethasone
Causes of secondary aldosteronism?
Due to high renin from reduced kidney perfusion:
Renal artery stenosis
Accelerated hypertension
Diuretics
CCF or hepatic failure
Features of Bartter’s syndrome:
Leaky sodium and chloride channel in the Loop of Henle means children become hypovolaemic, hypokalaemic and alkalotic (without much K+ to swap for Na+ they rely on H+ instead)
Rx: ACEi, K+ supplements, NSAIDs (reduces renal perfusion pressure)
What type of cell forms phaeochromocytomas?
Sympathetic cells (chromaffin cells), often in the adrenal medulla
IHx for suspected phaeochromocytoma?
Plasma and 3x24 hour urines for:
Free metadrenaline + normetadrenaline
If borderline: clonidine supression test
Localising: MIBG chromaffin-seeking isotope
Rx pre-op for phaeochromocytoma?
A blocker (phenoxybenzamine) then b-blocker if tachycardic/heart disease
Surgical removal
A 30 year old woman with hypertension, low K+ that has been resistant to antihypertensives has her renin:angiotensin checked. Angiotensin is raised. What further tests are warranted?
- CT/MRI of adrenals
- Adrenal vein sampling
If no nodules, consider adrenal hyperplasia or glucocorticoid-remediable aldosteronism
Drug causes of gynaecomastia?
Digoxin Isoniazid Spironolactone Cimetidine Oestrogen
CIs to phosphodiesterase 5? (Sildenafil)
CVS: unstable angina, concurrent nitrate use
MI 3 months ago, stroke 6 months ago
High BP, arrhythmia
Retina degeneration, renal or liver failure
Low FSH + LH, lack of smell and colour blind = which syndrome?
Kallman’s Syndrome:
Isolated lack of GnRH from the hypothalamus = secondary hypogonadism
NB lack of smell and colour blindness do not necessarily occur