Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Phase 3 > Week 15 > Flashcards

Week 15 Flashcards

1
Q

What is the definition of diabetes?

A

a metabolic disorder of multiple aetiology characterised by chronic hyperglycaemia with disturbances of carbohydrate, protein and fat metabolism resulting from defects in insulin secretion, insulin action or both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the WHO criteria for the diagnosis of diabetes

A

fasting plasma glucose >7mmol/L
random plasma glucose of >11.1
one abnormal value diagnostic if symptomatic
2 abnormal values diagnostic if asymptomatic
HbA1c 6.5% or 48mmol/mol
diabetes should not be diagnosed on the basis of glycosuria or a BM stick
OGTT only required if IFG of GDM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the main presentations of diabetes?

A 
glyocosuria
glucose shifts
ketone production
depletion of energy stores
complications (T2DM)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe glycosuria

A

tired, weak, weight loss, difficulty concentrating, polyuria, polydipsia, dry mucous membranes, reduced skin turgor, postural hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe glucose shift

A

swollen ocular lenses leading to blurred vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe effects of ketones production

A 
nausea
vomiting
abdominal pain
heavy/rapid breathing
acetone breath
drowsiness
coma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe depletion of energy stores

A

weakness
polyphagia
weight loss
growth retardation in young

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give overview of T1DM

A 
age <20
lean
symptoms weeks
northern european 
HLA DR3/DR4
autoimmune
ketonuria
insulin deficiecny / ketoacidosis/ dependent on insulin for survival
peptide C inappropriate /negative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give overview of T2DM

A 
>30
overweight
months / years
asian, african, polynesian and american indian
no HLA links
no ketones
partial insulin deficiency, hypoerosmolar state
C peptide positive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe islet autoantibodies

A

markers of autoimmune process associated with T1Dm

glutamic acid decarboxylase and insulinoma associated antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe C-peptide

A

secreted in equimolar concentrations to insulin
marker of endogenous insulin secretion
most usuful 3-5 years from onset
can be measured in blood or urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the pathogenesis of type 1 diabetes

A

chronic progressive metabolic disorder characterised by hyperglycaemia and the absence of insulin secretion
type 1 diabetes results from autoimmune destruction of the the insulin producing beta cells in the islets of langerhans
occurs in genetically susceptible subjects and is probably triggered by one or more environmental agents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some of the potential triggers of T1DM?

A 
viral infections
immunisations
diet
higher socio-economic status
obesity
vitamin D deficiency
perinatal factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the pathogenesis of Type 2 DM

A

chronic progressive metabolic disorder characterised by hyperglycaemia, insulin resistance and relative impairment of insulin deficiency
common with a prevalence that rises markedly with increases levels of obesity
most likely arises through a complex interaction among many genes and environmental factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does MODY stand for?

A

maturity onset diabetes of the young

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe MODY

A

caused by a change in a single gene. Autosomal dominant
often <25 years
runs in families in each generation
managed by diet, OHAs, insulin (not always)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe gestational diabetes

A

carbohydrate intolerance with onset, or diagnosis during pregnancy
risk factors include high BMI, previous macrosomic baby or gestational diabetes, family history or ethnic prevalence of diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe screening and diagnosis of gestational diabetes

A

all women with risk factors should have an OGTT at 24-28 weeks.
fasting venous plasma glucose >5.1
one hour - >10
2 hours >8.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the causes of secondary diabetes?

A

genetic defects of beta cell fucntion
genetic defects in insulin action
disease of exocrine pancreas- pancreatitis/ carcinoma/CF/haemochromatosis
endocrinopathies - acromegaly/cushing’s , phaeo
immunosuppressive agents - glucocorticoids, tacrolimus, ciclosporin
anti-psychotics - cloazpine/onlazipine
genetic syndromes associated with DM - Down’s syndrome, friedreich’s ataxia. turners, myotonic dystrophy, kleinfelter’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the layers of the adrenal cortex?

A

glomerulosa
fasiculata
reticularis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the zone glomerulosa produce?

A

aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does the zone fasiculata produce?

A

cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the zone reticularis produce?

A

androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What sort of cells are found in the adrenal medulla and what do they produce?

A

chromograffin cells

catecholamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the regulation of the renin-angiotensin system

A

renin major regulator of aldosterone production
activated in response to decreased blood pressure
leads to production of angiotensin II which causes vasoconstriction and aldosterone production, both of which raise blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe the action of aldosterone

A

binds to mineralocorticoid receptor and causes increased absorption of sodium (and water) and increased potassium secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the regulation of cortisol / androgen production

A

illness, stress time of day - release of corticotropin releasing hormone
anterior pituitary releases adrenocorticotropic hormones which causes the adrenal cortex to produce cortisol (and androgens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When is a secondary cause of hypertension more likely?

A

young
resistant / severe hypertension
clinical suspicion - hypokalaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What tests are used to investigated aldosteronism?

A

aldosterone (high)
renin (low)
aldosterone, renin ration (high)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the causes of primary aldosteronism?

A

adenoma

bilateral hyperplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe the confirmation of aldosterone excess

A

stop beta blockers and MR antagonists
Saline suppression test - 2L saline over 4 hours
4h aldosterone >270 highly suspicious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the management of primary aldosteronism

A 
Surgical 
unlilateral laparoscopic adrenalectomy
(only if adenoma)
cure hypokalaemia
cures hypertension in 30-70% of cases
medical 
use MR antagonists (spironalactone or eplerenone)
or amiloride (blocks Na reabsorption by kidney)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are common signs and symptoms of cushings syndrome?

A 
weight gain
hirsutism
psychiatric
proximal myopathy 
obesity - trunk/generalised
plethora 
moon face
hypertension
brusing 
striae
buffalo humo
poor wound healing
avascular necrosis of femoral head
osteoporosis
insulin resistance
increased appetite
infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Describe screening for cushing’s syndrome

A

urinary free cortisol (X3 cortisol:creatinine ration or 24 hour urine collection cortisol)
dexamethasone suppression test (plasma cortisol should be undetectable in normal circumstances )
late night salivary cortisol - should be very low or undetectable normally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the causes of ACTH dependent cushings?

A 
pituitary adenoma (Cushing's disease)
ectopic ACTH (cancer)
ectopic CRH (rare)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are causes of ACTH independent cushings?

A

adrenal adenoma
adrenal carcinoma
nodular hyperplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Describe the tests used to localise the cause of cortisol excess

A

plasma ACTH
high dose dexamethasone suppression test
CRH test
imaging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Describe high dose dexamethasone suppression test

A

if pituitary, cortisol will suppress to <50%

no response to ectopic ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Describe CRH test

A

exaggerated response in pituitary disease

no response to ectopic ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Describe imaging in Cushing’s disease

A

adrenal CT or MRI
pituitary MRI (only detects 50% of ACTH producing pituitary tumours)
optimal imaging for ectopic tumours unclear (CT/PET/MRI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Describe congenital adrenal hyperplasia

A 
autosomal recessive disorder
range of genetic disorders relating to defects in steroidogenic genes
most common CYP21 (21 alpha hydroxylase)
females - ambiguous genitalia 
boys -adrenal crisis, early virilisation

treated with mineralocorticoid and glucocorticoid replacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Describe phaeochromocytoma

A

usually in adrenal medulla
paraganglioma - extra-adrenal neural crest cells

symptoms /signs
hypertension
episodes of headache, palpitations, pallor and sweating
also tremor, anxiety, nausea, vomiting, chest or abdominal pain
crises last 15 minutes
often well in between

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Describe the diagnosis of pheochromocytoma

A 
24 hour urinary catecholamines (atleast twice)
imaging - CT abdomen 
MIGB scan (chromatin seeking analogue)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What genetic conditions are associated with pheochromocytoma?

A

MEN
VHL
SDHB and SDHD
neurofibromatosis

some are malignant and have poor prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Describe the pre-operative treatment of pheochromocytoma

A

alpha blockade initially
Then beta blocker if tachycardic
encourage salt intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Describe adrenal insufficiency

A

inadequate adrenocorticol function
primary - Addison’s, autoimmune destruction

clinical features
anorexia, weight loss
fatigue / lethargy
dizziness and low BP
abdominal pain, vomiting and diarrhoea 
skin pigmentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Describe the diagnosis of adrenal insufficiency

A

suspicious biochemistry (low sodium, high potassium, hypoglycaemia)

short synacthen test
ACTH levees
renin aldosterone levels
adrenal autoantibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Describe the short SYNACTHEN test

A

measure plasma cortisol before and 30 minutes after IV ACTH injection
normal:baseliin >250, post ACTH >480

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Describe ACTH levels in primary adrenal insufficiency

A

should be very high

causes skin pigementation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Describe the renin and aldosterone levels in primary adrenal insufficiency

A

very high renin

very low aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Describe the management of primary adrenal insufficiency

A

do not delay treatment to confirm diagnosis
hydrocortisone as cortisol replacement - if unwell give IV first
usually 15-30mg day in divided doses
try to mimic diurnal rhythm
fludrocortisone as aldosterone replacement - careful monitoring of BP and K
need education - sick day rules, cannot stop suddenly, must wear ID

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is non-diabetes related hypoglycaemia?

A

an uncommon cause of symptoms in adults, except in those with DM treated with glucose-lowering meds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the non DM plasma glucose level classified as hypoglycaemia?

A

<2.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the autonomic symptoms of hypoglycaemia?

A

sweating, palpitations, pallor, tremors, nausea, irritability, hunger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the neuroglycopenic symptoms?

A

inability to concentrate, confusion, drowsiness, personality change, slurred speech, incoordination, weakness, dizziness, vision impairment, headache, seizures, coma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is Whipple’s triad?

A

symptoms consistent with hypoglycaemia
low plasma glucose concentration
relief of those symptoms after the plasma glucose has raised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is important to ascertain in the history about hypoglycaemia

A

Does WHipples triad exist?
Ensure that there is definite evidence of a low glucose level (must be venous blood)
Do symptoms occur in the fasting or post-prandial state?
Take a full past medical history, family history and drug history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Describe the Investigations for hypoglycaemia

A 
Post prandial investigations - mixed meal test
72 hour fast 
glucose
insulin
C peptide
SU screen
Beta hydroxybutyrate low in insulinoma
Pro-insulin low with exogenous insulin
insulin antibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Describe the 72 hour fast in the investigation of hypoglycaemia

A

provoke the homeostatic reponse that keeps blood glucose concentrations from falling to concentrations that cause symptoms in the absence of food
Glucagon, adrenaline > GH/cortisol are the most important components
complete at plasma glucose at 2.5, 62 hours have elapsed or when plasma glucose is <3 if Whipple’s triad previously documented

young, lean, healthy women may have plasma glucose ranges of 2.2 or even lower after prolonged periods of fasting

60
Q

Describe localising studies in the investigation of hypoglycaemia

A

Radiology - CT, MRI, EUS

arterial calcium stimulation - distinguishes focal from diffuse disease

61
Q

What are causes of spontaneous hypoglycaemia?

A 
pancreatic - insulinoma, non insulin pancreatogenic hypoglycaemia
non islet cell tumour hypoglycaemia 
autoimmune 
reactive hypoglycaemia 
drug induced
dietary toxins
organ failure
endocrine disease
inborn errors of metabolism
sepsis
starvation
anorexia
total parenteral nutrition 
severe excessive exercise
62
Q

What drugs can cause hypoglycaemia?

A 
insulin
sulphonylureas
repaglinide
salicylates
quinine
hapoperidol
beta blockers
indomethacin
lithium
levofloxacin
heparin
trimethoprim
pentamidine
disopyramide
63
Q

How should an ill or medicated individual be investigated for hypoglycaemia?

A

drugs
critical illness
hormone deficiency - cortisol
non islet cell tumour

64
Q

how should a seemingly well individual be investigated for hypoglycaemia?

A

endogenous hypoerinsulinsim - insulinoma, functional islet cell disorders, insulin autoimmune hypoglycaemia
accidental, surreptitious, malicious hypoglycaemia

65
Q

Give examples of congenital abnormalities in mullerian development

A

isolated defect androgen insensitivity syndrome
5-alpha reductase deficiency
vanishing testes syndrome
defect in Sry gene

66
Q

Give examples of congenital defects or urogenital sinus development

A

agenesis of lower vagina

imperforate hymen

67
Q

What hormones increase and decrease hypothalamus secretion of GnRH?

A

leptin increases

ghrelin decreases

68
Q

What is important in the investigation of oligomenorrhoea?

A 
HCG
history - weight change, exercise, illness
galactorrhea
drugs - dopamine agonists 
hot flushes, vaginal dryness, libido
hirsutism

examination - BMI, acanthuses, hirsutism, acne
dental erosions

bloods - FSH, LH oestrogen, SHBG, testosterone, prolactin, TSH, fT4

69
Q

What is the differential diagnosis for oligomenrrohea and androgenisation of a female?

A

PCOS
congenital adrenal hyperplasia
Cushing’s
virilising tumours

70
Q

What additional tests can be carried out for investigation of oligomennorhea and androgenisation?

A

progesterone (early morning)
USS ovaries
overnight 1mg dexamethasone suppression (of features of Cushing’s)

71
Q

Describe PCOS

A

heterogeneous disorder of unclear aetiology

complex interaction of metabolic, hypothalamic, pituitary, ovarian an adrenal mechanisms

72
Q

What is the definition of PCOS?

A

clinical and / or biochemical signs of hyperandrogenism

oligo- and or anovulation

73
Q

Describe the pathophysiology of PCOS

A

increased insulin secretion to given glucose load
insulin stimulates ovarian thecae cells to produce androgens
insulin reduces hepatic SHBG
increase free testosterone
oligo-ovulation, hirsutism,

74
Q

What are the long term consequences of PCOS?

A

T2DM
dyslipidaemia
cardiovascular disease
endometrial hyperplasia

75
Q

What pharmacological treatment is available for PCOS?

A

ovarian androgen suppression - OCP. dianette
adrenal androgen suppression - glucocorticoid
androgen receptor antagonist - spironalactone
5 alpha reductase inhibition - finasteride / spironalactone
topical inhibitors - eflornithine

76
Q

Describe the secretion and regulation of growth hormone

A

growth hormone releasing hormone is released by the hypothalamus
growth hormone is released by the anterior pituitary by somatotrophs
it acts on multiple target organs

77
Q

What are all the names of ADH?

A

AVP
vasopressin
arginine vasopressin
argipressin

78
Q

Describe hypopituitarism

A

failure of (anterior) pituitary function
can affect single hormonal axis or all hormones
Leads to secondary gonadal / thyroid/ adrenal failure
need multiple hormone replacement

79
Q

What can cause hypopituitarism?

A 
tumours
radiotherapy
infarction / haemorrhage
 - associated headache / visual disturbance 
assoc pPH (sheehan's syndrome)
Infiltration (sarcoid)
trauma
lymphocytic hypophytis
80
Q

Describe anterior pituitary hormone replacement

A 
ACTH - hydrocortisone
TSH - thyroxine
FSH / LH - testosterone / oestrogen 
GH - growth hormone
PRL - no replacement
81
Q

What are causes of high prolactin?

A

prolactinomas
physiological - lactation / pregnancy
drugs - tricyclics / antiemetics / antipsychotics
Stalk effect - due to loss of inhibitory dopamine

82
Q

What are the main types of pituitary tumours?

A 
Non-functioning (majority)
functioning - prolactin
GH (acromegaly)
ACTH (cushing's disease)
TSH ( TSHoma)

others - craniopharyngioma, pituitary cancer, Rathke’s disease

83
Q

Describe non- functioning pituitary tumours

A

commonest
no hormonal release

but cause problems - visual field defects
headache
stops other pituitary hormones working
eye morvement problems

84
Q

Describe the investigation and treatment of non- functioning pituitary tumours

A

Investigation - imaging
visual field assessment
prolactin
other pituitary hormones

treatment -
surgery
RT
medical management is unhelpful

85
Q

Describe prolactinomas

A

pituitary tumours releasing prolactin

clinical features
galactorrhoea
headaches
mass effect 
visual field defect 
amenorrhoea / erectile dysfunction
86
Q

Describe the diagnosis of prolactinomas

A

serum prolactin usually >6000
MRI pituitary
Test remaining pituitary function - gonadal function and thyroid hormones most effected

87
Q

Describe the treatment of prolactinomas

A

medical - dopamine agonists
cabergoline / bromocriptine / quinagolide

surgery - VF compromise
failure of medical therapy

88
Q

Describe prolactinomas in pregancy

A

pituitary gland gets bigger in pregnancy
dopamine agonists contraindicated
(prolactin) unhelpful
Cant do serial MRI in pregnancy
monitor visual fields if macroprolactinoma

89
Q

Describe acromegaly

A

pituitary tumour secreting growth hormone
-post puberty - after birth plates fuse
pre puberty - gigantism

features - sweats and headaches 
alteration of facial features
increased hand and feet size
visual impairment 
cardiomyopathy
increased inter-dental space
90
Q

How is acromegaly diagnosed?

A

glucose tolerance test
Glucose should suppress GH

measure IFG-1
long half life
more useful than random GH

Then MRI

91
Q

Describe the treatment of acromegaly

A

first line - surgery - often tumour can’t be fully removed

drugs - somatostatin analogue
octretide, before and after surgery
dopamine agonist
GH receptor agonist

radiotherapy - residual tumour / ongoing symptoms

92
Q

Describe cushing’s disease

A

pituitary tumour releasing ACTH
one of the causes of cushing syndrome

weight gain, thin skin, easy bruising, increased BP, osteoporosis

diagnosis- dexamethasone suppression testing

93
Q

What is the treatment of cushing’s disease

A

surgery first line

if surgery fails / inappropriate
bilateral adrenalectomy
medical therapy - ketoconazole / metyrapone

radiotherapy

94
Q

Describe TSHoma

A

Pituitary tumour releasing TSH
rare
causing high TSH and high fT4

95
Q

Describe diabetes insipidus

A

ADH deficiency - central or cranial
clinical feutres
polydipsia
polyuria

differential - nephrogenic diabetes insipidis
psychogenic polypisia

96
Q

Describe central diabetes insipidus

A 
Deficiency of ADH
idiopathic
trauma
pituitary tumour
pituitary surgery 
pregnancy 
familial 
other
97
Q

Describe the diagnosis of diabetes insipidus

A

try to stimulate its release
water deprivation test
assess ability to concentrate urine with ADH

98
Q

Describe the treatment of diabetes insipidus

A

treat underlying cause

DDACP - spray, tablet or injection

99
Q

What are the functions of calcium?

A 
muscle contraction
bone growth and remodelling
second messenger signalling
stabilisation of membranes
enzyme co-factor
secretion of hormones
100
Q

What is ionised calcium regulated by?

A

parathyroid hormone and vitamin D

101
Q

Describe the parathyroid glands

A

usually 4
posterior aspect of thyroid gland
10% are ectopic
supplied by inferior thyroid artery

102
Q

What is the action of PTH in the kidneys?

A

reabsorption of calcium at distal tubule
internalises sodium-phosphate co-transporters at proximal tubule
inhibits Na+/H+ leading to bicarbonate wasting

103
Q

What are the actions of PTH on the bones?

A

increased number and activity of osteoclasts in continuous PTH exposure
intermittent exposure increases anabolic activity of osteoblasts

104
Q

Describe the actions of PTH in the gut

A

stimulates synthesis of active form of Vitamin D in kidney

thereby increases calcium absorption from the gut

105
Q

What do calcimimetic drugs do?

A

Target CaSR and inhibit PTH secretion

106
Q

What does calcium sensing receptor do in the kidney?

A

increases urinary calcium and magnesium excretion

increases sodium, potassium and chloride excretion

107
Q

What does calcium sensing receptor do in the thyroid?

A

expressed in C cells

stimulates calcitonin secretion

108
Q

Describe vitamine D

A

steroid hormone
acts to increase serum calcium levels
precursors synthesised in the skin
active form is 1,25 dihydroxycholecalciferol

109
Q

What are the actions of active vitamin D?

A

increases calcium and phosphate absorption from gut
bone mineralisation and mobilises calcium stores
immunomodulation
increases muscle strength
reduces insulin resistance
interacts with RAAS - role in prevention of CVD?

110
Q

What are the symptoms of hypercalcaemia?

A

muscle weakness, bone pain, osteoporosis
confusion, depression, fatigue, coma
shortening of GTc, bradycardia, hypertension
anorexia, nausea, constipation, pancreatitism
polyuria, nephrogenic DI, stones, nephrocalcinosis

111
Q

What are the PTH mediated causes of hypercalcaemia?

A

primary hyperparathyroidism
familial syndromes - MEN1 and MEN2
familial hypocalciuric hypercalcaemia

112
Q

What are the PTH independent causes of hypercalcaemia?

A 
malignancy
granulomatous disorders
vitamin D toxicity 
Drugs - thiazides, lithium, calcium supplements 
adrenal insufficiency
milk-alkali syndrome 
immobilisation
113
Q

What investigations can be carried out in hypercalcaemia?

A 
history an exam
chest x-ray
FBC/ESR
TFTs
myeloma screen
synacthen test
Vit D
114
Q

Describe malignancy and hypercalcaemia?

A

commonest cause of hypercalcaemia in hospitalised patients
solid organ tumours and haematological malignancies
causes hypercalcaemia through increased bone resorption and calcium release through 3 possible mechanisms

115
Q

What are the 3 ways in which malignancy can lead to hypercalcaemia?

A

osteolytic metastases and myeloma
Tumour secretion of PTHrP - squamous cell lung cancer, oesophageal cancer, renal cell carcinoma, breast cancer

3 - tumour production of 1,25 dihydroxycholecaciferol
by activated macrophages - occurs in lymphoma

116
Q

Describe vitamin D toxicity

A

increased bone resorption and gut absorption
ingestion of high does of calcitriol (Hyperparathyroid or renal disease)
resolves within 48 hours of stopping offending agent

117
Q

Describe endogenous production of active vitamin D

A

lymphoma, sarcoid, wegeners
extra-renal activation of cholecalciferol
usually responsive to steroid treatment

118
Q

Describe milk-alkali syndrome

A

hypercalcaemia, metabolic alkalosis, renal insufficiency

due to ingestion of calcium and antacids

119
Q

What are the general principles of managing hypercalcemia ?

A

stop offending / contributing medications
rehydration - saline - 3-4 litres over 24 hours is appropriate
loop diuretic?
bisphosphonates
steroids

120
Q

What end organ damage can be caused by primary hyperparathyroidism?

A

bone - osteoporosis, other radiological changes - bone cysts, subperiosteal resorption

kidneys - renal calculi, nephrocalcinosis, renal impairment

other - pancreatitis

121
Q

What are the investigations for primary hyperparathyroidism?

A

confirm diagnosis - drugs, UEs, PTH, urine calcium:creatine ratio
Vit D

end organ damage - DEXA, KUB/ renal US

other conditions - MEN1/2 if <40 or history of hyperparathyroidism in 1st degree relative

if surgery indication - localised abnormal gland

122
Q

Describe Brown tumours

A

result of excess osteoclast activity
collection of osteoclasts, poorly mineralised bone and fibrous tissue

“brown” appearance because of haemosiderin deposition

123
Q

What is the management of primary hyperparathyroidism?

A

parathyroidectomy - if causing problems
observation
medical treatment (only if not fit for surgery ) - bisphosphonates, cincacalcet - calcium sensing receptor antagonist - reduces serum (not urinary) calcium, doesn’t prevent end organ damage

124
Q

What are the complications of parathyroidectomy?

A

mechanical - vocal cord paresis
haematoma ceasing tracheal compression

metabolic - transient hypoglycaemia (suppression of remaining glands)
may require oral calcium / vitamin D supplementation

hungry bones - uncommon
occurs in patients who have significant bone disease pre-op or very elevated PTH
sudden withdrawal of PTH leads to imbalance between bone formation and resorption - marked net increase in uptake of calcium, phosphate and magnesium by bone
requires calcium and vitamin D supplementation

125
Q

Describe vitamin D deficiency

A 
poor sunlight exposure
malabsorption
gastrectomy 
enzyme inducing drugs (anti-convulsants)
renal disease
126
Q

Describe osteomalacia

A

classically associated with very low levels of vitamin S
failure to ossifiedy bones in adulthood as a result of vitamin D deficiency
hypo-mineralisation of trabecular and cortical bone
presents insidiously with bone pain, proximal myopathy, hypocalcaemia

low calcium, low phosphate, high alkaline phosphate, low vit D, elevated PTH

127
Q

What is the treatment of vitamin D deficiency?

A

cholecalciferol -restore body stores and correct metabolic disturbance

alfacalcidol (active form)
in renal impairment
hypoparathyroidism 
not measured by traditional lab vit D assay 
higher risk of hypercalcaemia
128
Q

Describe testosterone production

A 
produced by leydig cells
steroid hormone
circulates bound to SHGB and albumin
free testosterone is active
activated to more potent form in target tissues
129
Q

What are the effects of testosterone on growth?

A 
sex organs
skeletal muscle
epiphyseal plates
larynx growth
secondary characteristics
130
Q

What are other effects of testosterone ?

A 
erythropoiesis
behaviour 
muscle mass
mood
bone mass
libido 
body shape
erectile function
spermatogenesis
131
Q

What do sertoli cells do/?

A

form blood-testis barrier
remove damaged spermatocytes
secrete androgen binding protein

132
Q

What are the clinical features of hypogonadism in children and young adults?

A

slow growth in teens
no pubertal growth spurt
small testes and phallus
lack of secondary development

133
Q

What are the lineal features of hypogonadism in adults?

A 
depression / low mood
poor libido 
erectile problems 
poor muscle bulk / power 
poor energy 
sparse body / facial hair
gynaecomastia
gyroid weight gain
great head hair
short phallus
small testes, abnormal consistency
134
Q

Describe testing for gypogonadism

A

sex steroid deficiency?
testosterone - early morning, free testosterone, total , SHBG

LH and FSH

semen analysis

135
Q

What are some causes of hypogonadotrophic hypogonadism?

A 
pituitary tumour
pituitary surgery / Rx
head injury
genetic syndrome 
cerebellar ataxia
Kallman's syndrome - isolated LH and FSH deficiency
136
Q

Describe Kallman’s syndrome

A

Commonest form of isolated gonadotrophin deficiency
failure of cell migration of GnRH cells to hypothalamus from olfactory node
associated with aplasia / hypoplasia of olfactory lobes - anosmia/hyposmia
also may be associated with deafness, renal agenesis, cleft lip
may have micropenins / crytochidism

137
Q

Describe the genetics of Kallman’s syndrome

A

Familial with variable penetration

AD, AR and X-linked forms

138
Q

Describe Kallman’s syndrome in childhood

A

poor growth

undescended testes

139
Q

Describe Kallman’s syndrome in adolescence

A

poor growth
small testes
micropenis
delayed / absent puberty features

140
Q

Describe Kallman’s syndrome in adults

A

slow, but adequate growth
small testes
small phallus
hypogonadal features

141
Q

What are causes of primary gonadal disease?

A 
chromosome defects - Kleinfelters
seminiferous tubule failure
adult leydig cell failure 
crytochidsim 
complex genetic syndromes - Myotonic dystrophy
142
Q

Describe Klinefelter’s syndrome

A

commonest genetic cause of male hypogonadism
XXY
clinically manifests at puberty
high LH and FSH but seminiferous tubules regress and leydig cells do not function normally

143
Q

What are the clinical fescues of Klinefelter’s?

A

delated puberty
suboptimal genital development
reduced secondary sexual characteristics
azospermia
behavioural issues / learning difficulties
androgen replacement +psychological support + fertility counselling

144
Q

Describe hypogonadism treatment

A

androgen replacement therapy - oral, IM, topical

fertility treatment
hCH,
recombinant LH and FSH
GnRH pumps

145
Q

What are the side effects of androgen replacement therapy?

A 
mood issues
libido issues
increased haematocrit 
possible prostate effects
acne, sweating
gynaecomastia

Phase 3 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions