Endo 7.5 Flashcards
What is type 3c diabetes?
2ry to pancreatic disease e.g. inflammation
When to consider bariatric surgery for people with severe obesity?
- BMI >40 OR
- BMI >35 with other significant disease that could be improved by weight loss
AND: - all non-surg measures have failed to achieve/maintain adequate beneficial weight loss at least 6m
- intensive specialist Rx
- gen fit for anaesthesia & surgery
- they commit to need for long-term follow-up
When to consider bariatric surgery as a 1st line?
BMI > 50 & sugical intervention appropriate
- consider orlistat before if waiting time is long
What are the types of bariatric surgery?
1rily restrictive: laparoscopic adjustable gastric banding (LAGB) or sleeve gastrectomy
- LAGB less weight loss than the others but fewer complications, so usually 1st line if vmi 30-39
1rily malabsorptive: classic biliopancreatic diversion (BPD) but with duodenal switch - usually reserved for v obese
mixed: Roux-en-Y gastric bypass surgery
Causes of thyrotoxicosis?
Graves (50-60%) toxic nodular goitre acute phase of subacute de Quervain's thyroiditis acute phase of post-partum thyroiditis acute phase of Hashimoto's thyroiditis amiodarone Rx
How do thiazolidinediones work?
PPAR-gamma agonists
- reduce peripheral insulin resistance
- intracellular nuclear receptor - it’s natural ligands are free fatty acids & thought to control adipocyte differentiation & function
Adverse effects of thiazolidinediones ?
C/I?
increased risk of what?
- weight gain
- liver impairment - monitor LFTs
- fluid retention - therefore C/I in heart failure
- increased risk of fractures
- increased risk bladder cancer with pioglitazone
Causes of Cushing’s syndrome?
ACTH-dependent:
Cushing’s disease
ectopic ACTH
ACTH-independent: steroids commonest adrenal adenoma adrenal carcinoma - rare Carney complex: syndrome inc cardiac myxoma micronodula adrenal dysplasia - v. rare
Pseudo-Cushing’s
- mimics often etoh XS or severe depression
- causes false +ive dexamethasone suppression/24h urinary free cortisol
- insulin stress test can be used to differentiate
Causes of 1ry hyperaldosteronism - what is the commonest?
70% BL idiopathic adrenal hyperplasia
adrenal adenoma (Conn’s)
adrenal carcinoma - extremely rare
Features of 1ry hyperaldosteronism?
HTN
hypokalaemia (muscle weakness etc)
alkalosis
1st line Ix in suspected 1ry hyperaldosteronism?
plasma aldosterone:renin ratio
- high aldosterone
- low renin
How to differentiate between UL & BL sources of aldosterone XS?
high-resolution CT abdomen
adrenal vein sampling
Management of 1ry hyperaldosteronism?
adrenal adenoma -> surgery
BL adrenocortical hyperplasia -> AA e.g. spironolactone
1ry site of absorption of iron & calcium?
duodenum
1st line antihypertensive in PHaeochromocytoma?
PHenoxybenzamine
= non-selective alpha blocker
Associations of a phaeochromocytoma?
MEN type II
neurofibromatosis
von-Hippel-Lindau syndrome
Features of phaeochromocytoma?
episodic HTN headaches palpitations sweating anxiety
Most sensitive test for phaeochromocytoma?
24h urinary metanephrine collection
Rx of phaeochromocytoma?
- alpha-blocker phenoxybenzamine
- then beta-blocker propranolol
- surgery when stable
Features of metabolic syndrome?
- inc waist circumference/central obesity
- raised triglycerides
- reduced HDL cholesterol
- HTN
- impaired fasting glucose/T2DM
- microalbuminuria
- raised uric acid levels
- nafld
- pcos
Test to confirm / screen for Cushing’s syndrome?
OVERNIGHT dexamethasone suppression test (LOW dose) = most sensitive = DIAGNOSTIC
24h urinary free cortisol - screen
1st line localisation test for Cushing’s syndrome?
9am & midnight plasma ACTH & cortisol levels
- if ACTH suppressed then a non-ACTH dependent cause is likely e.g. adrenal adenoma
What does high-dose dexamethasone suppression test confirm?
If it suppresses cortisol, then it confirms a pituitary source of Cushing’s (it can’t suppress adrenal/ectopic cortisol)
What does CRH stimulation test show in Cushing’s syndrome?
It it shows a rise in cortisol then confirms a pituitary source
If no change in cortisol, it is ectopic/adrenal
How differentiate ectopic ACTH & pituitary ACTH?
Petrosal sinus vein sampling
Which gland secretes prolactin?
What is the 1ry prolactin releasing Inhibitory factor?
Anterior pituitary
Dopamine so DA agonists can be used to control galactorrhoea
Features of XS prolactin?
M: impotence, galactorrhoea, loss of libido
F: amenorrhoea, galactorrhoea
Drugs causing raised prolactin?
metoclopramide, domperidone
phenothiazines
haloperidol
v rarely: SSRIs, opioids
Causes of raised Prolactin?
Pregnancy Prolactinoma Pcos Primary hypothyroid (TRH stimulates prolactin release) Phys: stress, exercise, sleep Oestrogens Acromegaly (1/3)
Definite Ix for suspected Addison’s disease?
short synACTHen test
- measure plasma cortisol
- can also check adrenal autoAb e.g. anti-21-hydroxylase
9am cortisol in Addison’s?
<100 abnormal think Addisons
100-500 borderline - do synacthen test
>500 normal, Addisons v unlikely
Electrolyte abnormalities in Addison’s?
hyponatraemia
hyperkalaemia
HYPOGLYCAEMI
metabolic Acidosis
Side-effects of mineralocorticoids?
HTN
fluid retention
Side-effects of glucocorticoids?
MSK: osteoporosis, proximal myopathy, AVN femoral head
immunosuppression: inc infections risk, TB reactivation
endocrine: impaired glucose, increased appetitie/weight gain, hirsutism, hyperlipidaemia, Cushing’s syndrome
GI: peptic ulcers, acute pancreatitis
psych: insomnia, mania, depression, psychosis
ophthalmic: glaucoma, cataract
intracranial HTN
growth suppression in children
MoA of Mirabegron?
Beta-3 agonist used for urge incontinence if others have failed or C/I
Urge incontinence Rx
- minimum 6wks bladder retraining
- 1st line antimuscarinic as a bladder stabiliser; oxybutynin IR (avoid in frail older women), tolterodine IR or darifenacin OD
- If above fail, mirabegron (beta3 agonist)
Stress incontinence Rx?
pelvic floor muscle training: Min 3months of 8 contractions 3x/day
surgery: retropubic mid-urethral tape procedures
MEN type 1
- features?
- gene?
- most common presentation?
Parathyroid 95% (hyperplasia) Pituitary 70% Pancreas 50% e.g. insulinoma, gastrinoma (rec peptic ulcers) - MEN1 gene - hypercalcaemia
MEN type IIa
- features?
- gene?
Medullary thyroid ca 70%
Parathyroid 60%
Phaeochromocytoma
- RET oncogene
MEN type IIb
- features?
- gene?
Medullary thyroid cancer Phaeochromocytoma Marfinoid body habitus Neuromas - RET oncogene
Causes of 1ry hyperPTH?
solitary adenoma 80%
hyperplasia 15%
multiple adenoma 4%
carcinoma 1%
Features of 1ry hyperPTH?
polydipsia, polyuria peptic ulcer, constipation, pancreatitis bone pain/fracture renal stones depression hypertension
Xray showing pepper pot skull - Dx?
hyperparathyroidism
Ix in 1ry hyperPTH?
- low phosphate, high Ca
- PTH raised or normal
- technetium-MIBI subtraction scan
Rx for 1ry hyperPTH?
- definitive = total parathyroidectomy
- cons Rx ok if Ca++ < 0.25 above ULN + pt>50yrs + no evidence of end-organ damage
- calcimimetics e.g. Cinacalcet can be used if surgery unsuitable
Indications for considering parathyroidectomy in 1ry hyperparathyroidism?
- age < 50
- adj Ca2+ 0.25+ above ULN
- eGFR<60
- renal stones/nephrocalcinosis
- osteoporosis/osteoporotic fracture
- Sx disease
Pt with HTN + low K + metabolic alkalosis - what is the Dx? best Ix?
1ry hyperaldosteronism
renin:aldosterone
What is an insulinoma?
= most common pancreatic endocrine tumour; is a neuroendocrine tumour mainly derived from islets of Langerhans
- 10% malignant, 10% multiple (1/2 of which have MEN-1)
Dx of insulinoma?
Rx?
- supervised, prolonged fasting upto72h
- can do insulin & C-peptide levels DURING attack
- CT pancreas but doesn’t always show up
- surgery
- Diazoxide & Somatostatin if pts not candidates
Features of insulinoma?
- hypo usually ***early in AM or just before meals
- rapid weight gain
- high insulin, raised proinsulin:insulin ratio
- high C-peptide
high renin & high aldosterone think ?
BL renal artery stenosis
MoA of Acarbose?
commonest side effect?
- inhibitor of intestinal alpha-glucosidases -> decreased absorption of starch & sucrose
- therefore increased carb load delivered to colon where bacteria digest complex carbs -> GI side-effects e.f. flatulence & diarrhoea
- XS flatulence
What is measured in an insulin stress test?
When is it used?
What would happen normally?
What are the contraindications?
- IV insulin -> measure GH & cortisol
- Ix hypopituitarism
- GH & cortisol should rise with normal function
- C/Is = epilepsy, IHD, adrenal insufficiency
Which drugs can cause false negative renin:aldosterone ratio results in 1ry hyperaldosteronism?
ACE-I
ARBs
direct renin inhib e.g. aliskiren
AAs
What is acromegaly?
XS growth hormone
95% pituitary adenoma
minority ectopic GHRH or GH production by tumours e.g. pancreatic
Features of acromegaly?
- coarse facies, spade hands, inc shoe size
- large tongue, prognathism, interdental spaces
- XS sweating (gland hypertrophy), oily sin
- features of pituitary tumour e.g. hypopituitarism, headaches, bitemporal hemianopia
- 1/3 raised prolactin -> galactorrhea
- 6% MEN-I
Complications of acromegaly?
- HTN
- diabetes >10%
- CARDIOmyopathy
- BOWEL ca (initial colonoscopy age 40, then surveillance)
Definitive test for acromegaly?
Screening/monitoring?
OGTT with serial GH measurements
- IGF-1 may be used as a screening test, & sometimes for monitoring
- MRI pituitary may show a tumour
OGTT in acromegaly?
- in acromegaly, there is no GH suppression (may also show impaired glucose tolerance)
- normally, GH is suppressed < 2 with hyperglycaemia
Acromegaly Rx:
what is 1st line Rx?
what may be used in older pts or following failed medsurg Rx?
1st line: trans-sphenoidal surgery
if everything fails external irradiation sometimes used
Medical Rx options in acromegaly?
SOMATOSTATIN analogue e.g. OCTREOTIDE (50-70% efficacy) 1st line
- can be used as an adjunct to surgery
Dopamine agonist e.g. BROMOCRIPTINE - 1st effective med Rx, effective in only a minority
GH receptor antagonist that prevents dimerisation of the GH receptor e.g. PEGVISOMANT OD SC
- v effective, reduces IGF-1 levels in 90% to normal
- surgery still needed if mass effect because doesn’t reduce tumour volume
Features of Addison’s disease?
- lethargy, weakness, anorexia, N&V, weight loss, ‘salt craving’
- hyperpigmentation (esp palmar creases), vitiligo, loss of pubic hair in women, hyPOtension
- crisis: collapse, shoch, pyrexia
Causes of Hypoadrenalism/Addison’s?
80% autoimmune destruction of adrenal glands
1ry: TB, mets, meningococcal septicaemia, HIV, antiphospholipid syndrome
2ry: pituitary disorders
Causes of Addisonian crisis?
- sepsis/surgery causing an acute exacerbation of an chronic insufficiency
- adrenal haemorrhage e.g. fulminant meningococcaemia Waterhouse-Friderichsen syndrome
- steroid withdrawal
Rx of Addisonian crisis?
- 100mg IM/IV hydrocortisone
- 1L fluid over 30-60mins
- cont hydrocortisone 6hrly if pt stable
- oral replacement can start after 24h and be reduced to maintenance over 3-4days
- hydrocortisone has weak mineralocorticoid action
Causes of 1ry amenorrhoea?
- Turner’s syndrome
- Testicular feminisation
- CAH
- congenital malformations of genital tract
Causes of 2ry amenorrhoea i.e. when menses has previously occurred but has not stopped for 6+months?
(after excluding pregnancy)
- hypothalamic amenorrhoea e.g. stress, XS exercise
- PCOS
- hyperPRL
- premature ovarian failure
- thyrotoxicosis(/hypothyroid)
- Sheehan’s syndrome
- Asherman’s syndrome
Initial Ix in amenorrhoea?
- exclude pregnancy
- TFTs, prolactin
- oestradiol, androgen levels
- gonadotrophins (if low often hypothalamic cause, if high then suggests ovarian problem)
What is androgen insensitivity syndrome?
What are the features ?
How do you Dx?
Rx?
- X-linked recessive condition due to end-organ resistance to testosterone causing genotypical males to have a female phenotype (46XY)
- testicular feminisation syndrome = complete andogen insensitivity
- ‘1ry amenorrhoea’
- undescended testes causing groin swellings
- breast development may occur (testosterone converted to estradiol)
Dx = buccal smear or chromosomal analysis (46XY)
Rx =
- counselling (raise as female)
- oestrogen therapy
- BL orchidectomy (undescended testes increases risk of testicular cancer)
How is hyperaldosteronism, caused by cortisol activating the mineralocorticoid nuclear receptor, prevented?
cortisol -> inactive cortisone
by 11-hydroxysteroid dehydrogenase type 2 at the renal parenchyma
What is apparent mineralocorticoid XS?
often inherited
autosomal recessive
mutation in 11-hydroxysteroid dehydrogenase type 2 (which normally converts cortisol to inactive cortisone)
rarely, XS liquorice can inhibit this enzyme -> xs cortisol -> AME
What is autoimmune polyendocrinopathy/polyglandular syndrome: APS?
What can occur in both types?
What is type 1 (v rare)?
What is type 2?
- Where addison’s disease/autoimmune hypoadrenalism is associated with other endocrine deficiencies (10%)
- Vitiligo in both
APS type 1 aka MEDAC = multiple endocrine deficiency autoimmune candidiasis
- V. rare a. recessive
- mutation of AIRE1 gene on chr 21
- Need 2/3 of:
1. Addison’s disease
2. 1ry hypoPTH
3. chronic mucocutaneous candidiasis (typically 1st feature as young child)
APS type 2 - much more common - polygenic inheritance linked to HLA DR3/DR4 Addison's disease \+ T1DM OR \+ autoimmune thyroid disease
What is Bartter’s syndrome?
‘think lots of furosemide’
What are the features?
- usually inherited cause of severe HYPOKALAEMIA due to defective chloride absorption at the Na/K/2Cl- cotransporter (NKCC2) in ascending loop of Henle
- failure to thrive in childhood (presentation)
- polyuria, polydipsia
- hypokalaemia
- weakness
- NORMOtension (unlike conns/cushings/liddles)
What are the 3 enzyme deficiencies that can cause congenital adrenal hyperplasia, and what are their features?
21-hydroxylase deficiency:
- virilisation of female genitalia
- precocious puberty in males
- !60-70% pts have a salt-losing crisis at 1-3weeks of age
11-beta hydroxylase deficiency:
- virilisation of female genitalia
- precocious puberty in males
- hyPOkalaemia, HTN
17-hydroxylase deficiency:
- Non-virilising in females
- inter-sex in boys
- HTN
Which steroids have the highest glucocorticoid activity with minimal mineralocorticoid?
Dexamethasone
Betmethasone
Which steroid has very high mineralocorticoid activity with minimal glucocorticoid?
Fludrocortisone
Which steroid is predominantly glucocorticoid, with low mineralocorticoid activity?
Prednisolone
Which steroid has high mineralocorticoid activity, with some glucocorticoid activity?
Hydrocortisone
What is a dynamic pituitary function test for?
What is given?
What is measured at intervals?
What would be normal?
Used to assess pts with suspected 1ry pituitary dysfunction
- > Given insulin, TRH & LHRH
- > Measure glucose, cortisol, GH, TSH, LH, FSH +/- PRL
Normally GH rises > 20 Cortisol rises > 550 TSH rises > 2 from baseline LH & FSH double
Disorder of sex development:
46XX or 47XXY
both ovarian & testicular tissue present
v rare
True hermaphroditism
Disorder of sex development:
46XX
ovaries present but male/ambiguous external genitalia (virilised)
may be 2ry to CAH
Female pseudohermaphroditism
Disorder of sex development:
46XY
testes present but external genitalia are female/ambiguous
may be 2ry to androgen insensitivity syndrome
Male pseudohermaphroditism
Disorder of sex development: 46XY ambiguous genitalia in newborn period hypospadias common virilisation in puberty autosomal recessive results in inability of males to convert testosterone -> DHT
5-alpha-reductase deficiency
Disorder of sex development:
46XY
genotypical male has a female phenotype
rudimentary vagina & testes present but no uterus
elevated testosterone, oestrogen & LH
X-linked recessive
Androgen insensitivity syndrome
RFs for endometrial cancer?
- nulliparity, early menarche, late menopause
- unopposed oestrogen (adding a progestogen reduces risk, eliminates it if prog given continuously)
- Tamoxifen (ER+ breast ca)
- obesity, DM, PCOS
Ix for endometrial cancer?
1st line TVUS: normal endometrial thickness <4mm has a high NPV
if thick will probably have hysteroscopy with endometrial biopsy
Rx of endometrial cancer?
Localised -> TAH with BSO
If high-risk, may have post-op RT
Progestogen Rx sometimes used in frail elderly not suitable for surgery
What is Gitelman’s syndrome?
What are the features?
Defect in thiazide-sensitive Na/Cl transporter in the dct
Low K & Mg
Low Ca2+ in urine
NORMOtension
Metabolic ALKAlosis
Causes of gynaecomastia inc drugs?
Usually caused by increased oestrogen:androgen
- phys: puberty
- liver disease
- syndromes with androgen deficiency: Kallman’s, Klinefelter’s
- testicular failure e.g. mumps
- testicular ca e.g. seminoma secreting hCG
- ectopic tumour secretion
- hyperthyroidism
- haemodialysis
Drugs:
- spironolactone commonest
- digoxin
- cimetidine
- cannabis
- finasteride
- gonadorelin analogues e.g. goserelin, buserelin
- oestrogens, anabolic steoirds
What is HRT composed of?
Small dose of oestrogen
(WITH progestogen in women with a uterus) to help alleviate menopausal vasomotor Sx
Side effects of HRT?
Potential complications/increased risks?
- nausea
- breast tenderness
- fluid retention & weight gain
- increased risk of VTE, stoke, & IHD (10yrs after menopause)
- increased risk of breast & endometrial ca
Adding a progestogen increases risk of breast cancer & VTE further, but reduces risk of endometrial cancer
Causes of hypercalcaemia?
- 1ry hyperPTH
- Malignancy: bone mets, myeloma, PTHrP, any ca
- in malignancy, 80% due to PTHrP, remaining due to osteolysis, some due to calcitriol-mediated high Ca & ectopic PTH secretion
Others:
- dehydration
- drugs: thiazides, vitamin d toxicity, calcium-containing antacids
- endocrine: acromegaly, thyrotoxicosis, addison’s disease
- granulomas: sarcoid, TB
- milk-alkali syndrome
- can occur with prolonged immobilisation in Paget’s bone disease
What is 1ry hypoPTH?
Cause?
Rx?
- decrease in PTH secretion leading to low Ca, high phosphate
- e.g. 2ry to thyroid surgery
- Rx with Alfacalcidol
Sx of hypoPTH?
usually 2ry to hypocalcaemia
tetany - muscle twitch, cramp, spasm
perioral paraesthesia
Trousseau: carpal spasm if brachial artery occluded by maintaining BP cuff above systolic
Chvostek: tapping parotids causes facial muscle twitch
ecg - prolonged QT interval
chronic - depression, cataracts
What is pseudohypoPTH? type I? type II? features? how to Dx?
- target cells are insensitive to PTH, due to mutation in a G protein, leading to high PTH, low Ca, high phosphate
I: complete receptor defect
II: cell receptor intact
- low IQ
- short stature
- short 4th & 5th metacarpals
- obesity, round face
- Dx: PTH infusion -> measure urinary cAMP & phosphate levels
(hypoPTH will cause increase in cAMP & phosphate) - In pseudohypoPTH type I, neither increase; in type II cAMP rises
What is pseudopseudohypoPTH?
similar phenotype to pseudohypoPTH but normal biochemistry
What is Kallmann’s syndrome?
Failure of GnRH-secreting neurons to migrate to the hypothalamus
X-linked recessive
Cause of delayed puberty 2ry to hypogonadotrophic hypogonadism
Features of Kallmann’s syndrome?
- ‘delayed puberty’
- hypogonadism, cryptorchidism (undesc testes)
- anosmia
- low sex hormone levels
- LH & FSH inappropriately low/normal
- pts typically of normal/above average height
- sometimes cleft lip/palate & visual/hearing defects
What is Klinefelter’s syndrome?
Dx?
Features?
Karyotype 47XXY
Dx by chromosomal analysis
- often taller than average
- lack of 2ry sexual characteristics
- small, firm testes
- infertile
- gynaecomastia - inc incidence of breast ca
- elevated gonadotrophin levels
What is Liddle’s syndrome?
Rx?
- rare a dominant condition causing HTN & hypokalaemic alkalosis
- thought to be caused by disordered sodium channels in distal tubules -> inc reabsorption of sodium
Rx with amiloride/triamterene