Endocrine Flashcards
Give a simple definition of type 1 diabetes
Autoimmune destruction of the pancreatic beta cells –> complete insulin deficiency
What type of hypersensitivity reaction is T1DM?
4
What are 3 risk factors for T1DM
Northern European
Other autoimmune diseases e.g. coeliac, rheumatoid arthritis
Gene mutations/ variants
Which specific genes may be different in T1DM and where are they found (what cell)
HLA DR3-DQ2
HLA DR4-DQ8
Found on Beta cells (they express HLA genes)
Epidemiology of T1DM (3 things)
Age usually 5-15
BMI < 25
10% of all diabetes
How does T1DM cause hyperglycaemia?
B cells attacked –> insulin deficiency –> gluconeogenesis, glycogenlysis, decreased cell uptake of glucose
How does T1DM cause hyperkalemia (in blood)?
Insulin stimulates Na+/K+ ATPase pumps, therefore lack of insulin means K+ can’t get in cells
How is T1DM diagnosed?
RPA > 11.1 mmol/l
FPG > 7 mol/l
HbA1C >48 mol/l or 6.5%
Signs/ symptoms of T1DM (3)
Polydipsia
Polyuria
Weight loss (can’t get glucose in cells)
Treatment of T1DM
SC fat insulin injection
Rapid acting insulin name
aspart
Short acting insulin name
regular insulin
Intermediate acting insulin name
NPH (Neutral protamine hagedorn)
Long acting insulin name
Glargine
What is DKA (simple)
Complication of diabetes (usually type 1) where lack of insulin = high ketone levels, acidosis and hyperglycaemia
Pathology of DKA (hyperglycaemia, acidosis and high ketone levels)
No insulin –> hyperglycaemia (but cells starved of glucose) –> lipolysis/ ketogenesis –> increase in ketones in blood –> acidosis (initially buffered by bicarbonate)
What might bring on DKA
Illness/ infection
Symptoms of DKA (4)
Diabetes symptoms
Nausea/ vomiting
Confusion/ drowsiness
Abdo pain (liver stretches)
Signs of DKA (4)
Kussmaul breathing (deep+fast to expel CO2)
Pear drop breath
Hypotension (hypovolaemic)
Tachycardia
Diagnosis of DKA
RPG > 11 mmol/l
Plasma ketones > 3 mmol/l
Blood pH < 7.35 or Bicarb < 15 mmol/l
Treatment of DKA
- ABC (emergency)
- Fluids (0.9% saline)
- IV regular insulin and K+
Why is K+ essential to treat DKA with
Insulin makes K+ enter cells therefore K+ will immediately enter cells when insulin administered, so K+ in the blood must be restored to prevent cardiac arrest
Complications of DKA (3)
Coma/ death
Cerebral oedema
Aspiration pneumonia
What is T2DM (simple)
Peripheral insulin resistance and may lead to insulin deficiency
Pathology of T2DM
Repeated insulin exposure –> insulin resistance –> more insulin required for response –> beta cells grow tired + stop working –> insulin deficiency
T2DM risk factors (6)
Age (30+)
Male
Obesity
Sedentary
African or South Asian
Genetics
Signs + symptoms of T2DM (7)
Fatigue
Polydipsia + polyuria
Glucosuria
Slower onset > 6 months
Central obesity
Slow healing + infections (bad circulation)
Blurred vision (once progressed)
Diagnoses of T2DM (4 ways) and diagnostic values
Fasting plasma glucose = after 8 hours
Oral glucose tolerance test = 75g glucose drink after fast then measure glucose level 2 hours later
What are the 5 steps to manage T2DM
- Lifestyle changes
- Metformin
- Double therapy
- Triple therapy
- Insulin
What class of drug is metformin
Biguanide
How does Metformin work (2)
- Decrease liver gluconeogenesis
- Increase cell sensitivity to insulin
Metformin side effects (2)
- GI disturbances
- lactic acidosis, as no gluconeogenesis. (can be serious)
What can metformin be used in combination with (4)
- DPP 4 inhibitors
- Sulfonylurea - cause Beta cells to make more insulin (glicazide)
- Pioglitazone - improve insulin sensitivity
- SGLT-2 inhibitors
What is hyperosmolar hyperglycaemic state (simple)
Hyperglycaemia without ketosis
What is the pathophysiology of HHS how does it cause hyperglycaemia and dehydration?
Low insulin –> hyperglycaemia
(Insulin not absent therefore ketogenesis does not occur)
Hyperglycaemia –> glucose sucks water out of blood –> dehydration
What may bring on HHS in those with diabetes?
Infection/illness
Signs/ symptoms of HHS (4)
- Diabetes symptoms
- Confusion
- Dehydration
- Lethargy
Investigations for HHS (4)
- RPG = high
- Urine dipstick = glycosuria
- Plasma osmolality > 320 mOsm/kg
- No ketones in urine
Treatment for HHS
- Fluid replacement (0.9% saline)
- Insulin - slow infusion; with K+
What is diabetes insipidus (simple)
A lack of ADH or a lack of response to ADH
What are the 2 types of DI
- Nephrogenic - collecting ducts don’t respond to ADH
- Cranial - impaired production/ secretion from hypothalamus/ post. pituitary
Where does ADH take effect and what channel does it effect?
- V2 receptor - increases expresion of AQ2 in collecting ducts of kidneys; increases reabsorption of Na+ in the collecting ducts.
- V1 receptor - causes vasoconstriction
Where is AQ1 found
Proximal convoluted tubules and descending limb of LoH
What is primary polydipsia
Some idiot drinking too much
What causes nephrogenic DI (4)
- Drugs (e.g. lithium for BPD)
- Renal disease
- Electrolyte imbalances (damage nephrons)
- Congential/ inherited/ mutation
What causes cranial DI (5)
- Idiopathic
- Brain tumours
- Head injury
- Congential/ mutation
- Infection (meningitis)
Signs/ symptoms of DI (4)
- polyuria/ polydipsia
- dehydration
- Postural hypotension
- Hypernatraemia (hypovolemic)
How much urine is suspicious of DI
3 litres in 24 hours
What is the diagnostic test for DI and describe it
Water deprivation test:
* no fluids 8 hours - measure urine osmolality
* give synth. ADH - measuere urine osmolality 8 hours later
What are the expected results of water deprevation test for cranial DI, nephrogenic DI and pimary polydipsia
What other investigations may be done for DI (3)
- Urine dip
- U&Es
- Cranial MRI (check for tumours…)
Compliactions of DI (2)
- Dehydration
- Electrolyte imbalance
Treatment for DI
Treat underlying cause
* rehydration for mild
* Cranial - desmopressin
* Nephrogenic - thiazide diuretic: bendroflumethiozide
How do thiazide diuretics work
Block Na-Cl co-transporters and blarrrrr blarrrrr blarrrrrrrrr
But nobody has a fucking clue
What is syndrome of inappropriate ADH (simple)
Large amounts of ADH cause excess fluid to be reabsorbed in collecting duct
Pathophysiology of SIADH - how does it cause excess reabsorption of water
Excess ADH is produced/ secreted–> increase expression of AQ2 in collecting duct –> increased reabsorption of water
Why does euvolaemic hyponatraemia occur in SIADH
Sodium is excreted from kidneys to compensate for the over reabsorption of water. As water follows sodium the correct fluid volume is maintained, however the body is low in sodium.
What causes SIADH (4)
- Infection
- Head injury
- Medications
- Tumours (secrete ADH)
Which tumours can secrete ADH (5)
- SCLC
- Prostate
- Thymus
- Pancreatic
- Lymphomas
Which medications cause SIADH (3)
- Thiazide diuretics
- NSAIDs
- SSRIs
What are the symptoms of SIADH (4), (signs in next card)
- N+V
- Headache
- Fatigue
- confusion
siezures + reduced consiousness more severe symptoms of hyponatraemia
What are the signs of SIADH (3)
- Raised jugular vein pressure
- Oedema
- Ascites
How is SIADH diagnosed
It is a diagnosis of exclusion
* U&E –> hyponatraemia and normal K
* Urine sodium + osmolality = high
Exclude other causes of hyponatraemia e.g. CKD, diuretic use…
How is SIADH managed (what medicine is used)
- Treat cause
- Fluid restriction
- Tolvaptan - ADH receptor antagonist; Furosemide - strong diuretic
What are some complications of SIADH (4)
- Cerebral oedema
- Siezures
- Coma
- Central pontine myelinolysis
How does SIADH cause central pontine demyelinolysis
Na+ low in blood –> solutes move out of brain to prevent cerebral oedema
Hyponatraemia treated too quickly
Blood Na+ rises quickly –> water moves out of brain quickly –> demyelination of neuones
What is Cushing’s syndrome (simple)
Chromic excess of cortisol
Where is cortisol released from
zona fasiculata of the adrenal gland
Describe the HPA axis
Hypothalamus releases corticotropin releasing hormone –> anterior pituitary releases adrenocorticotropin releasing hormone –> adrenal gland releases cortisol
This is regulated by negative feedback
Cortisol actions in body (5)
- Inhibits immune system
- Increases blood glucose
- Increases alertness
- Increases metabolism
- Inhibits bone formation
All more long term flight/ fight responces
Causes of cushing’s ACTH dependant (2)
- Cushings disease - pituitary adenoma releases ACTH –> adrenal hyperplasia
- Ectopic ACTH - from SCLC
Causes of Cushing’s ACTH independant (2)
- Adrenal adenoma - secretes cortisol
- Iatrogenic steroid use (corticosteroids)
iatrogenic = caused by medical procedure or treatment
What are the sign and symptoms of Cushing’s (5)
- Moon face (round)
- Central obesity
- Buffalo hump (fat on shoulders)
- Abdominal striae
- Osteoporosis
How is Cushing’s syndrome investigated
- Random plasma cortisol levels, if abnormal…
- Dexamethasone suppression test, if abnormal…
- Plasma ACTH
How is random plasma cortisol levels different in those with cushing’s
Does not follow typical diurnal pattern (high in morning, low at night)
And generally higher overall
What is dexamethasone
Binds to same receptors as cortisol (therefore inhibits ACTH)
Describe how the low dose dexamethasone supression test works
1 mg DM given @10pm –> cortisol measured @9am
Low cortisol = normal
High/ normal cortisol = cushing’s
Describe how the high dose dexamethasone supression test works
8mg DM given @10pm –> ACTH and cortisol measued @9am
Low cortisol = cushings disease (-ve feedback in high dose able to suppress pit adenoma)
High/ normal cortisol and low ACTH = adrenal adenoma
High/ normal cortisol and high ACTH = ectopic ACTH tumour
How is Cushing’s treated (2)
- Treat/ stop underlying cause (excise tumour/ stop meds)
- Remove adrenal glands and give steroidal treatment
What are some compliactions of cushing’s (3)
- Diabetes (cortisol increases blood glucose so cells can become resistant to insulin)
- Hypertension/ CVD
- Osteoporosis
What is adrenal insufficiency (simple)
Adrenal glands dont produce enough steroid hormones (cortisol and aldosterone)
What are the two types of adrenal insufficiency
- Primary AI (Addison’s disease) = adrenal cortex damaged
- Secondary AI = pituitary/ hypothalamic involvement (low ACTH/ CRH)
Pathophysiology of two types of adrenal insufficiency
Primary - adrenal gland damaged = low steroids –> hight ACTH to try to compensate
Secondary - low CRH/ACTH –> low steroidal hormones
What are some causes of Addison’s disease (2)
- Autoimmune destruction - 80% of cases in UK
- TB infection - damages adrenal gland
What antibody is often present in those with Addison’s
21-hydroxylase antibody
What causes secondary AI (5)
- Surgery
- Infection e.g. meningitis
- Radiotherapy
- Necrosis
- Iatrogenic - supression of HPA
What are some symptoms of AI (5)
- Fatigue/ weakness
- Weight loss
- Nausea
- Decreased libido
- Change in body hair
(Dermatological stuff in the signs card)
What are some signs of AI
- Dermatological - hyperpigmentation and vitiligo
- Hypoglycaemia
- Postural hypotension
What causes hyperpigmentation in AI and therefore which type is affected
ACTH stimulates melanocytes to produce melanin
Therefore occurs in primary AI as lots of ACTH produced to compensate for damaged adrenal gland
What is a severe presentation of AI known as and what are the symptoms/ signs (3)
Addisonian/adrenal crisis
* reduced consciousness
* hypotension
* low NA+, hypoglycaemia, high K+
How is adrenal insufficiency investigated (2)
1st line: U&Es –> low sodium, high potassium, hypoglycaemia
Gold: short syncathen test
21-hydroxylase autoABs test
How does the short syncathen test work
Syncathen (synthetic ACTH) is administered –> cortisol levels monitored @baseline, 30 min and 60min –> if cortisol doesn’t increase by much (doesn’t double) = Addisons
How can secondary AI be diagnosed
Cortrosyn (synthetic CRH) administered –> affect an ACTH monitored
How is AI treated (name sof meds)
- Hydrocortisone (glucocorticoid) - to replace cortisol
- Fludrocortisone (mineralcorticoid) - to replace aldosterone
What should you do to AI medication during illness/ trauma
Double the dose to mimic stress responce
What is phaeochromocytoma (simple)
Tumour of the chromaffin cells of the adrenal medulla that secrete catecholamines
What pattern is adrenaline usually secreted in (for people with phaeochromocytoma)
Secreted in bursts, so periods of worse symptoms followed by settled periods
Which hormones are catecholamines (3)
- Adrenaline
- Noradrenaline
- Dopamine
What condition are phaeochromocytoma associated with
Multiple endocrine neoplasia type 2 (MEN type 2)
What is the pattern of phaeochromocytoma tumours (4 things)
- 10% bilateral
- 10% outside adrenal glands
- 10% cancerous
- 25% familial
What are the symptoms of phaeochromocytoma (think adrenaline) (4)
- Headache
- Sweating
- Cardiac - palpitations, tachycardia
- Tremor
What are some signs of phaeochromocytoma (2)
- Hypertension (hypertensive retinopathy)
- Pallor (looking pale)
How are phaeochromocytoma investigated
- Plasma metanephrines/ normetanephrines
- 24 hour urine catecholamines
- CT - look for tumour
What are metanephrines and why are they measured
Metabolites of adrenaline
They have a longer half life so less prone to fluctuation
How is phaeochromocytoma treated
- Medication (alpha/ beta blockers)
- Adrenalectomy = definitive treatment
What medication is used to treat phaeochromocytoma
- Alpha blocker - blocks noradrenaline
- Beta blocker - blocks adrenaline (prevents reactive vasoconstriction)
What is an example of an alpha blocker used in phaeochromocytoma?
Phenoxybenzamine
What is an example of a beta blocker
Atenolol
How is a hypertensive crisis treated in pheochromocytoma?
Phentolamine (antihypertensive alpha blocker)
What defines a hypertensive crisis
120/180
What is primary hyperaldosteronism (simple)
Overproduction of aldosterone idependant of the RAAS system
What causes primary hyperaldosteronism (2)
- Adrenal adenoma (Conn’s syndrome)
- Bilateral adrenal hyperplasia
What is the pathophysiology of primary hyperaldosteronism (how are electrolytes affected)
More aldosterone produced –> high NA+ reabsorption, high H2O reabsorption, high K+ excretion
What are the signs/ symptoms of Conn’s (4)
- Hypertension
- Electrolyte disturbance - arrhythmias, cramps, mood changes…
- Fatigue
- Polyuria/dipsia - low K+ interferes with kidney function
How is primary hyperaldosteronism investigated
- Low plasma K+
- Aldosterone high, renin low blood test
How is primary hyperaldosteronism treated
- Adrenalectomy for adenomas
- Aldosterone antagonist for bilateral hyperplasia
What is an example of an aldosterone antagonist
Spironolactone
What is secondary hyperaldosteronism
High rennin –> high aldosterone
(Not ACTH because this is Cushing’s disease)
What usually causes secondary hyperaldosteronism
Disproportionatly low renal BP
(low renal BP)
What is hyperthyroidism (simple)
Excess thyroid hormones
What is the pathophysiology of hyperthyroidism (2 types)
- Primary - thyroid produces excess T3/4 independant of TSH
- Secondary - thyroid produces excess T3/4 due to overstimulation by TSH
Which thyroid hormone is active
T3 = triiodothyronine
What are the effects of T3 (4)
- Increase metabolism
- Activates SNS
- Increases bone resporption
- Increases cardiac output
Who is mainly affected by hyperthyroidism
Women, 20-40 yrs
What is the prevelance of Grave’s disease in the population
0.5%
What causes primary hyperthyroidism (4)
- Grave’s disease - TSH receptor autoantibodies mimic TSH and stimulate thyroid gland
- Toxic multinuclear goitre - nodules on thyroid produce thyroid hormone independant of feedback
- Thyroid cancer
- Thyroiditis e.g. De Quervains - first hyperthyroidism then hypo due to negative feedback then return to normal
What causes secondary hyperthyroidism (2)
- Pituitary adenoma
- Hypothalamic pathology
What are some risk factors for graves disease?(2)
- Family history (gene HLA-DR3)
- Other autoimmune conditions
These are only really for Graves disease
What are some symptoms of hyperthyroidism (4)
- Hot and sweaty
- Weight loss + hyperphagia (being hungary)
- Irritable/ anxious
- Diarrhoea
What are some signs of hyperthyroidism (general - 2)
- Tachycardia
- Muscle waisting
How is hyperthyroidism investigated
- T4 and TSH plasma levels
- TSH-R auto ABs
- US and UT thyroid/ pit
How would T4 and TSH be affected in hyperthyroidism, primary and secondary
- Primary = T4 high, TSH low
- Secondary = T4 high, TSH high
How is hyperthyroidism managed (4)
- Adrenergic receptor blockers - e.g. beta blockers, propranolol (non selective)
- Medicines to block thyroid uptake of iodine
- Radioactive iodine - kills thyroid cells, (patient must stay away from kids for few days)
- Surgery
Levothyroxine if patient becomes hypo
Adrenergic receptor blockers used to treat syptoms as T3 activates SNS
What are two medications used for hyperthyroidism
- Carbimazole = 1st line
- Propylthiouracil = 2nd line
What are some complications of hyperthyroidism (not gaves complications) (2)
- Thyroid storm = emergency - very high T3/4 levels; fever, high HR
- Osteoporosis
How is thyroid storm treated
Same way as hyperthyroidism + supportive treatment e.g. Carbimazole, beta blockers
What antibody class causes Grave’s disease
IgG
What is the pathophysiology of Graves
Auto ABs stimulate TSH-R and mimick TSH.
They also affect other body parts such as muscles behind the eyes causing inflammation.
What are the symptom unique to Grave’s (3)
- Goitre (swollen thyroid)
- Exophthalmos - bulging eyes
- Pretibial myxoedema - buildup of mucin under skin on anterior part of leg
What is hypothyroidism (simple)
Lack of thyroid hormones - T3/4
What are the two types of hypothyroidism
- Primary - thyroid pathology = less T3/4 independant of TSH
- Secondary - ant. pituitary/ hypothalamic pathology = too little TSH produced/ released sometimes called hypopituitarism
Who does hypothyroidism mainly affect (2 things)
- Over 40s
- Females (6:1)
What causes hypothyroidism (5)
- Hasimoto’s thyroiditis
- Iodine deficiency
- Drugs - hyperthyroid drugs, lithium
- Thyroidectomy
- Hypopituitarism - infection, tumour, radiation
What is the pathophysiology of Hashimoto’s thyroid
AutoABs (e.g. antithyroid peroxidase) attack thyroid gland –> swelling (goitre) –> then atrophy of thyroid
What are some risk factors of hypothyroidism
Other AI diseases
What are some symptoms of hypothyroidism (5)
- Weight gain
- Fatigue/ lethargy
- Constipation
- Cold intolerance
- Menorrhagia (heavy periods)
What are some signs of hypothyroidism (4)
- Bradycardia
- Delayed reflexes
- Goitre
- Oedema
How is hypothyroidism investigated and what would the results be
Thyroid function tests
* Primary = low T3/4, high TSH
* Secondary = low T3/4, low TSH
How is hypothyroidism treated
Adress underlying cause
then… levothyroxine
What is levothyroxine and what happens to it in body
T4 - metabolised to T3
What are some complications of hypothyroidism (3)
- Congestive cardiac failure
- Myxoedema coma (hypothermia, difficulty breathing, confusion)
- Pregnancy problems
What is hyperparathyroidism
Too high levels of PTH in the blood
What are the effects of PTH on Ca2+ (3 things)
- Increase reabsorption of Ca2+ in kidneys
- Increase reabsorption of bone (more osteoclast activity)
- Activate vitamin D3 in kidneys
What effects does Vitamin D3 have on Ca2+ (4 things)
- Ca2+ absorption in intestines
- Ca2+ reabsorption in kidneys
- Ca2+ resorption from bone
- Negative feedback on PTH
What effect does PTH have on phosphate
- Decreases reabsorption of phosphate in kidneys
Overall small decrease in phosphate serum levels
Why does a decrease in phosphate mean an increase in Ca2+
Phosphate forms salts with Ca2+, therefore a decrease in phosphate = more ionised calcium circulating
Which cells produce PTH
Chief cells in the parathyroid gland
What are the three types of hyperparathyroidism
- Primary = Excessive inapropriate production of PTH
- Secondary = hypocalcaemia –> high PTH to compensate
- Tertiary = autonomous production of PTH after resolution of hypocalcaemia due to hyperplasia
Main cause of primary hyperparathyroidism
Parathyroid adenoma
Causes of secondary hyperparathyroidism (2)
- CKD –> low reabsorption of Ca2+
- Low vit D intake –> decreased absorption of Ca2+ from intestines
Cause of tertiary hyperparathyroidism
Prolonged secondary –> hyperplasia of PT gland; unresponsive to -ve feedback
What are the signs/ symptoms of hyperparathyroidism (5)
- Renal stones
- Painful bones
- Abdominal groans - constipation, N+V
- Psychiatric moans - fatigue/ depression
- Polyuria/dipsia = going to toilet more - thrones
How is hyperparathyroidism investigated
- PTH/ Ca2+/ phosphate blood tests
- DEXA scan
What would PTH, Ca and phosphate be in primary, secondary and tertiary hyperparathyroidism
How is hyperparathyroidism managed
- Primary - parathyroidectomy; medication to slow bone loss
- Secondary - calcium correction
- Tertiary - medication to increase calcium sensitivity; parathyroidectomy
What medicine is used to slow bone loss in primary hyperparathyroidism
Bisphosphonates
What medicine is used to increase calcium sensitivity of the parathyroid gland in hyperparathyroidism
Cinacalcet
What is hypoparathyroidism
A lack of plasma PTH
What are the types of true hypoparathyroidism
- Primary - pt glands dont produce enough PTH for whatever reason
- Secondary - pt glands dont produce enough PTH due to hypercalcaemia
What causes primary hypercalcaemia (3)
- Surgery/ damage/ radiation
- Genetic malformations
- Auoimmune
What are the symptoms of hypoparathyroidism (4)
- Convulsions
- Arrhythmias
- Tetany
- Numbness
CATs go NUMB
What are the signs of hypoparathyroidism (2)
- Trosseau’s sign - flexion of wrist when BP cuff put on
- Chvostek’s sign - spasm of facial muscles when CN7 tapped over parotid gland
These signs are due to increased firing of nerves due to hypocalcaemia
How is hypocalcaemia diagnosed (2)
- PTH low, Ca2+ low, phosphate high
- ECG = long QT syndrome
How is hypocalcaemia treated
Treat underlying cause
Give Ad Cal D3 (calcium and vitamin D3 to increase Ca2+ absorption)
What is pseudohypoparathyroidism
Lack of responce to PTH at bones and kidneys and can’t activate calcidiol
What is acromegaly (simple)
Excessive release of GH –> overgrowth of systems
What stimulates GH release
Growth hormone releasing hormone
What else stimulates GH release
Ghrelin
What hormones inhibit growth hormone release (2)
- Somatostatin - major effect
- Dopamine - minor effect
What does GH stimulate the release of that also exerts affects throught the body
Insulin like growth factor-1
Where is ILGF-1 released from
Liver
What are the effects of GH and ILGF-1 (5)
- Increase muscle growth
- Increase bone density
- Increase protein synthesis
- Increase fat/ glycogen breakdown
- Inrcease cell reproduction
What causes acromegaly
- Pituitary adenoma
- Lung/ pancreatic GHRH or GH secreting tumour
What are the signs/ symptoms of acromegaly (5)
- Changes in body shape/ features
- Bitemporal hemianopia
- Arthritis - growth of joint tissues
- Sleep aponea
- Fatigue
What changes in body shape/ features occur in acromegaly
- Large hands/ feet
- Prominent forehead
- Mandibular protrusion
What does acromegaly in children cause
Gigantisism
How is acromegaly investigated
- ILGF-1 blood test = raised
- OGTT while measuring GH
Why is ILGF-1 measured instead of GH for acromegaly diagnosis
ILGF-1 doesn’t fluctuate like GH does throught the day
How is OGTT used to diagnose acromegaly
Glucose drink given –> GH monitored, should be surpressed by high glucose levels
How is acromegaly managed
- Transphenoidal resection surgery
- Medication to inhibit GH
What medication is used to treat acromegaly (3)
- Somatostatin analogue (ocreotide)
- Dopamine agonist (bromocriptine)
- GH receptor antagonists (pegvisomant)
What are some complications of acromegaly
- T2DM
- Sleep apnoea
- IHD
- Colorectal cancer
What is a prolactinoma
Pituitary adenoma that secretes excess prolactin
What are the two types of prolactinoma tumours
- micro - less than 10mm on mri
- macro more than 10mm on mri
What are the functions of prolactin (2)
- Stimulates lactation
- Breast development
What other pituitary hormones does prolactin inhibit
Inhibits GnRH from hypothalamus –> inhibits LH and FSH
What are the signs and symptoms of prolactinoma (5)
- Amenorrhea - no periods
- Galactorrhoea - milky discharge
- Gynaecomastia
- Infertility
- Bitemporal hemianopia
How is prolactinoma investigated
- Prolactin levels
- MRI
How is prolactinoma managed
- Transphenoidal surgery
- Medication
What inhibits the production of prolactin
Dopamine
What medication is used to treat prolactinoma
Dopamine agonists (bromocriptine) - inhibits prolactin, shrinks tumour
What are some complications of prolactinoma (3)
- Sight loss
- Infertility
- Raised ICP
What are the two most common and other causes of hypercalcaemia
- Hyperparathyroidism
- Bone malignancies
- Thiazide diuretics, hyperthyroidism, dehydration, high Ca2+ intake
What may happen to the ECG trace in those with hypercalcaemia
Short QT segment
What are the symptoms of hypercalcaemia (5)
- Psyciatric moans
- Abdominal groans
- Painful boans
- Kidney stones
- Toiletry thrones
What are the causes of hypocalcaemia
- CKD (decreases vit d activation) - but can also cause hyper
- Vit D3 deficiency
- Drugs: calcitonin, bisphosphonates (slow bone loss)
What is the affect of hypocalcaemia on ECG
Long QT segment
What are the symptoms of hypocalcaemia
- Convulsions
- Arhythmias
- Tetany
- Numbness
CATs go NUMB
Hyperkalaemia causes
- Impaired secretion - AKI, CKD, low aldosterone, drugs
- Increased intake
- Shift to extracellular - acidosis, low insulin, sever burns
Symptoms/ signs on hyperkalaemia
- Fatigue
- Arrhythmias
- Weakness
- Dyspnoea
How is hyperkalaemia investigated
- Bloods: U&Es
- ECG
What ECG findings would be present in hyperkalaemia (4)
- No P wave (Go)
- Long PR interval (Go Long)
- Tall T wave (Go Tall)
- Wide QRS complex (Go Wide)
How is hyperkalaemia managed (4)
- ABCs
- Calcium gluconate - protects myocardium
- Insulin + dextrose - moves K+ into cells, replaces glucose
- Beta agonist (moves K+ into cells)
Hypokalaemia causes
- Increased excretion - CKD, increased aldosterone, D+V, drugs
- Reduced intake
- Shift to intracellular - alkalosis (K+ moves into cells so H+ can move out), drugs e.g. insulin, B2 agonists
What are the signs/ symptoms of hypokalaemia
- Arrhythmias
- Fatigue/ weakness
- Hypotonia
- Hyporeflexia
How is hypokalaemia investigated
- Blood: U&Es
- ECG
How is ECG abnormal in hypokalaemia
- Prolonged PR
- ST depression
- Prominent U wave
- Inverted T wave
How is hypokalaemia managed
- IV potassium
- Treat underlying cause
How do beta-2 agonists affect K+
Increases activity of Na+/K+ ATPase pump therefore more K+ into cells
Na/k pump = 3 Na out; 2 K in