Endocrinology Flashcards
Low calcium and phosphate with high ALP in Asian female presenting with bone pain and muscle weakness
Osteomalacia (normal bony tissue but decreased mineral content ) treat with calcium with vit d
Causes of hypercalcaemia
Primary hyperparathyroidism and malignancy amount for 90%
Sarcoidosis (and tb)
Vitamin d intoxication
Acromegaly
Thiazides, calcium containing antacids, PPI
Dehydration
Paget’s disease Vs osteomalacia bloods
Both have raised ALP, bone pain… Osteomalacia may have reduced calcium and phosphate.
Multiple endocrine neoplasia 1
3 Ps
Parathyroid (95%)
Pituitary (70%)
Pancreas (50%) insulinoma, gastrinoma (causing Zollinger-Ellison syndrome: epigastric pain and diarrhoea)
.. hypercalcaemia
Multiple endocrine neoplasia 2a
2 Ps
Parathyroid
Pheaochromocytoma
Medullary thyroid cancer (hypocal)
Multiple endocrine neoplasia 2b
Pheaochromocytoma
Medullary thyroid cancer (hypocal)
Marfinoid body
Neuromas
Absence of hyperparathyroidism
Rate of insulin infusion in DKA
0.1 unit/kg/hour… Start dextrose when glucose under 15
Reversible features of haemochromatosis
Cardiomyopathy and skin tanning
Genetics of haemochromatosis
Autosomal recessive, mutations in HFE gene in chromosome 6
What hormone from pituitary is under continuous inhibition?
Prolactin (by dopamine from hypothalamus)
When do you commence statins for primary prevention hyperlipidemia
If 10yr risk above 10%
Or t1dm who are >40yr, diagnosis longer than 10yr or established nephropathy or other risk factors
Or eGFR<60
Then start atorvastatin 20mg. Increase to up to 80 if HDL not fallen by more than 40%
Secondary prevention with statin
Any IHD, CVD, PAD then start atorvastatin 80mg
Most common cause of primary hyperaldosteronism
70% caused by bilateral idiopathic adrenal hyperplasia
Second is adrenal adenoma - Conn’s
Acromegaly complications
Carpal tunnel, sleep apnoea, hypertension, diabetes (>10%), cardiomyopathy, and colorectal cancer
Diagnosis of acromegaly
IGF-1 then OGTT
in normal patients GH is suppressed <2 with hyperglycaemia. In acromegaly there’s no suppression
Management of acromegaly
Trans sphenoidal surgery for most
Somatostatin analogues eg octreotide.
Cause of hypercalcaemia in squamous cell lung cancer
Parathyroid hormone related peptide release is the cause of 80% of hypercalcaemia in malignancy
Also in Ovarian etc
causes of hypomag
- Diuretics like furosemide
- PPI
- TPN
- diarrhoea
- alcohol
- metabolic disorders: Gitleman’s and Bartter’s
Causes of hypomag
Diuretics like furosemide, TPN, diarrhoea, alcohol, PPI
Modifiable risk factor for development of thyroid eye disease
Smoking is the most important modifiable risk factor for the development of thyroid eye disease
features of Zollinger Ellison syndrome
Gastrinoma… epigastric pain and diarrhoea. 30% have MEN type 1 (so would also have hyperparathyroidism)
features of haemochromatosis
lethargy, arthralgia, chrondrocalcinosis, diabetes… cardiomyopathy, bronze skin
features of Wilson’s
behavioural and psychiatric problems are often the first manifestations, basal ganglia degeneration, speech…
Liver cirrhosis,
blue nails
Kayser-Fleischer rings
renal tubular acidosis (esp. Fanconi syndrome)
Anti thyroid peroxidase antibody is found in…
90% hashimoto (hypothy)
75% Graves (hyperthy) also TSH antibodies
T2DM with diabetic neuropathy and a background of BPH .. drug treatment for nephropathy
Would be amitriptyline but because of risk of retention then pregabalin
Treatment for myxoedema coma
Hydrocortisone and levo
Osteoblasts Vs osteoclasts
OsteoBlasts Build Bone
OsteoClasts Create Calcium
Treating T1DM for dka, 24 hr later she starts to get confused irritable and slurring. Why?
Cerebral oedema
usually occurs 4-12 hours following commencement of treatment but can be present at any time.
Test to confirm Cushing’s
Overnight low dose dexamethasone suppression test…
Or 24 urinary cortisol
Management for prolactinoma
Medical treatment of hyperprolactinemia is based upon use of dopamine agonists
bromocriptine, lisuride, quinagolide andcabergoline
Common endo condition in Turner’s syndrome
Hypothyroidism and raised FSH (gonadotropins)
Diagnosis of acromegaly
iGF 1 levels
then OGTT with serial GH measurements to confirm
Contraindications of radioiodine therapy
Pregnancy (incl 4-6months after radioio treatment)
Age <16yr
Thyroid eye disease may get worse so relative contraindication
Precipitating factors of thyroid storm
Surgery (thyroid / non thyroid)
Trauma
Infection
Acute ioidine intake (eg CT contrast)
features and progression of De Quervain’s subacute Thyroiditis
Usually post viral and self-limiting
3-6/52 Painful goitre, hyperthy, raised ESR, globally reduced iodine uptake
1-3/52 euthyroid
Weeks/months hypothy (can give steroids if severe)
Then usually returs back to normal
chance of subclinical hypothyroidism progressing to Hypothyroidism
2-5% / year
Higher if you’re a man or have thyroid autoantibodies
Management of subclinical hypothyroidism
T4 normal, and if TSH 4-10 then
- If <65 and ?symptoms then trial treatment, stop if it doesn’t help
- Watch and wait if asymp / old
If TSH >10
- Treat everyone under 70
- watch and wait above
management of hypothyr in preg
Thyroxine is safe in preg / breast feeding
Some people need increased dose so monitor TSH in each trim and 6-8/52 post partum
which thyroid cancer is lnked to MEN2
MEdullary (only 5% of all thyroid Cancer, cancer of parafollicular C cells from neural crest…Secretes calcitonin)
management of hyperparathyroidism
total parathyroidectomy is definitive
Conservative an option if calcium less than 0.25 above upper limit and over 50yr with no end organ damage
Calcimimetics like cinacalcet can be used if surgery not an option
Thyroid related cause of galactorrhoea?
primary hypothyroidism because thyrotropin releasing hormone stimulates prolactin release
(NOTE hypERthyroidism causes gynaecomastia)
What is Wolfram’s syndrome
DIDMOAD - association between diabetes insip, diab mellitis, optic atrophy and deafness
management of pre-existing diabetic who gets pregnant
stop all antidiabetic meds except metformin, add insulin
weight loss
Start folic acid 5mg until 12 weeks
Start Aspirin 75mg from 12weeks until birth
anomaly scan at 20wks including 4chamber view of heart
What adrenal autoantibody may be demonstrated in Addison’s disease?
anti-21-hydroxylase
note: 21-hydroxylase deficiency is the cause of 90% of congenital adrenal insuff
What cells are pheochromocytomas derived from
Chromaffin cells in adrenal medulla or extra adrenal in 10%
What is the rate of familial, bilateral, malignant, and extra adrenal cases respectively in pheochromocytomas
10%
most common site of phaeochromocytoma outside of adrenal
extra adrenal in 10%
most common is Organ of Zuckerkandl, adjacent to bifurcation of aorta
zones of adrenal gland
GFR M - ACDC zona Glomerulosa - (mostly) Aldosterone zona Fasciulata - (mostly) Cortisol zona Reticularis - (androgens, mostly) DHEA zona Medulla - Catecholamines
List investigtions for Acromegaly
1) IGF-1
2) if elevated or unequivocal then OGTT
3) positive diagnosis if GH not suppressed by hyperglycaemia
4) MRI or CT
5) Colonoscopy to screen for colorectal Ca
6) Visual fields
Side effect of Octreotide
Biliary stasis -> gallstones
where is grehlin produced
P/D1 cells lining fundus of stomach and epsilon cells of pancreas - stimulates hunger
where is leptin produced
adipose tissue - acts on arcuate nucleus of hypothal to decrease apetite
Autoimmune polyendocrinopathy syndrome 1 and 2
2 is much more common. It is addison’s + either t2dm or autoimm thyroid - HLA DR3/DR3
type 1 is auto recessive and has two of addison’s, mucocutaneous candidiasis or primary hypoparathyroidism
diagnosis for 18yr old with recurrent balanitis and raised fasting glucose. Two family members with t1dm
MODY
blood results of premature ovarian failure
Low Oestradiol but high LH and FSH (due to feedback mechanisms)
Investigation for possible insulinoma
Supervised fasting
If CBG goes below 4 then measure C-peptide
features of psuedohypoparathyroidism
auto dom inherited insensitivity to PTH
Low calcium high pth high phosphate
Short stature, obesity round face short 4th and 5th metacarpals cog impairment
Middle aged woman presents with tiredness, weight gain and a hard fixed painless neck lump. Diagnosis?
Riedel’s Thyroditis
mostly euthyroid, 30% hypothy
bloods of Kleinfelters vs kallmans
both are tall with low testosterone…
but kallmans has inappropriately low LH FSH (and anosmia).
Klein has raised LH FSH
diabetic patient commenced on degludec liraglutide combination therapy… what is it?
Long acting insulin and GLP-1 agonist respectively
so can cause hypos
management of thyroid storm
- Propylthiouracil
- Potassium (Lugol’s) iodide
- Propranol
- Prednisolone
what advice should you give to a T2DM on Metformin during Ramadan
During Ramadan, one-third of the normal metformin dose should be taken before sunrise and two-thirds should be taken after sunset
What medication can interfer with testing for Conn’s
Ramipril due to its interference with the renin-angiotensin-aldosterone system
Results of Dexa suppression test in Cushing’s disease
Low dose - cortisol isn’t suppressed
High dose - cortisol is suppressed
Raised ACTH
Low dose dexa - cortisol isn’t suppressed
High dose - cortisol is suppressed
Raised ACTH
What would the MRI pituitary show?
Cushing’s disease - adenoma
HOWEVER adenoma in Cushing’s disease is often too small to be picked up on CT or MRI imaging, so negative scan does not exclude it
In hypocalcaemia, which is the more sensitive sign?
Trousseau’s sign is more sensitive than Chvotsek’s
carpal spasm with BP tight over brachial vs tapping over parotid muscles
What biochemical abnormalities are likely seen in Cushing’s syndrome
Hypokalaemic metabolic alkalosis…
This is due to increased mineralocorticoid action… Causing increased exchange of potassium and H+ for sodium and water
Genetic defect in the majority of MODY cases
HNF-1 alpha gene defect in MODY 3
60% of cases
What is dipsogenic diabetes insipidus?
Defect in thirst mechanism due to damage of hypothalamus
Role of ghrelin and leptin
Obesity hormones:
- Leptin Lowers appetite
- Ghrelin Gains appetite….grrrr I’m hungry
Most common cause of hypothyroidism in developed world
Hashimoto’s
10 X most common in women
Anti TPO and anti Thyroglobulin antibodies
Associated with other autoimmune and also development of MALT lymphoma
What hyperlipidemia results from hypothyroidism?
Predominantly hypercholesterolemia rather than hypertriglyceridaemia
Same with nephrotic syndrome and cholestasis
Patient presents with bilateral deafness and mild hypothyroidism
Pendred’s syndrome
Auto recessive, Ch7
One and a half turns in cochlea (rather than 2.5!)
Management of thyrotoxicosis in pregnancy
Propylthiouracil in first trimester (monitor LFTs)
Then switch to carbimazole (because could cause congenital abnormalities)
Don’t use block and replace or radioiodine
Cause of thyroid disease w amiodarone
High iodine content counterintuitively causes hypo (autoreg inhibition of thyroxine formation) Wolff-Chaikoff effect
Type 1:
High iodine causing thyroid synthesis - goitre, stop amiodarone start carbimazole
Type 2:
Destructive thyroiditis -no goitre, corticosteroids and stop amiodarone
Most common autoantibodies in Graves’
TSH receptor stimulating antibodies
Hungry bone syndrome
Uncommon occurrence, post parathyroidectomy where you get hypocalcaemia due the rapid change in hormone levels
Contraindications to radioiodine therapy
Pregnancy and 6 months following
Can worsen eye disease
Diagnosis of phaeochromocytoma
24h urinary metanephrines
(97% sens)
Better than catecholamines
Management of phaeochromocytoma
Surgery is definitive after medical stabilisation
With alpha- blocker (phenoxybenzamine) and beta blocker
21-hydroxylase Def causes what condition…
Congenital adrenal hyperplasia….
… Low cortisol, High androgens - so hypertension and virilusation in females, precocious puberty in males
Which is more common cause of primary hyperaldosteronism - adrenal adenoma or adrenal hyperplasia
Bilateral idiopathic adrenal hyperplasia is the most common cause of primary hyperaldosteronism
Pitaglitazone SE
Peripheral oedema
Worsened with using insulin too
Metabolic acidosis or alkalosis for Addison’s?
Acidosis Addison’s
Alkalosis Cushing’s and Conn’s
Started new anti diabetic drug. Gets excessive flatulence
Acarbose ( inhibitor of intestinal alpha glucosidases)
MODY Vs LADA
MODY has family history
LADA has autoimmune history
LH and FSH with Klinefelter and kallman
Klinefelter’s - LH and FSH raised
Kallman’s - LH and FSH low-normal
Which antihypertensive should be started in phaeochromocytoma
PHaeochromocytoma - give PHenoxybenzamine
pretibial myxoedema
Thyrotoxicosis
Elderly patient with urge incontinence
mirabegron beta-3 agonist
Oxybutynin Contra if urinary retention and can come confusion
Hypertension management in diabetic
ACE i regardless of age
Bloods of osteomalacia
Raised ALP, Low calcium low phosphate..
low vitamin D (in 100% of patients, by definition)
So might have raised PTH (but in secondary hyperPTH you would have high phosphate… And this is almost always due to CKD)
Management nephrogenic diabetes insipidus
thiazides, low salt/protein diet
