Endocrine Flashcards
Addisons
Def, cause, sx, ix, mx
arises due to the insufficient production of glucocorticoids and mineralocorticoids from the adrenal cortex. It is primary as the cause lies within the adrenal glands themselves
Cause:
- auto-immune destruction
- surgical removal of adrenal glands
- trauma
- TB
- haemorrhage
- infarction
Sx:
- hypotension
- fatigue
- GI sx
- syncope
- skin pigmentation as ACTH stimulates MSH production
Ix:
- first line is U+E (low sodium and potassium) and serum cortisol (low)
- ABG of acutely unwell would show metabolic acidosis
- high ACTH and renin
- low aldosterone
- test for adrenal auto-antibodies
- CXR
- CT
Mx:
- adrenal insufficiency= education on sick day rules, doubling steroid dose in any intercurrent illness, hydrocortisone and fludrocortisone
- addisonian crisis= fluid resus, IV steroids, glucose
Cushing’s syndrome
Def, cause, sx, ix, mx
characterised by excess glucocorticoids
Cause:
- ACTH-dependent disease: This is caused by excessive production of ACTH, most often due to a pituitary tumour (Cushing’s disease) or ectopic ACTH-producing tumours (e.g. lung carcinoids, thymic carcinoids, and others).
- ACTH-independent: This arises from primary adrenal diseases, such as adrenal adenomas or adrenal carcinomas, which produce excess cortisol independently of ACTH stimulation. Exogenous steroids can also cause ACTH-independent Cushing’s.
Sx:
- proximal myopathy
- striae and easy bruising
- osteoporosis
- diabetes mellitus
- obesity
- HTN
- hypokalaemia
- hirsutism in women
- muscle wasting at extremities
- thin fragile skin
- erectile dysfunctional in men
Ix:
- 24 hour urinary free cortisol test
- low dose Dexamethasone suppression test (not suppressed by low dose is positive result)
- ACTH levels
Mx:
- Metyrapone, an inhibitor of cortisol synthesis; Ketoconazole, an adrenolytic agent; Mifepristone, a glucocorticoid receptor antagonist; and Pasireotide, a somatostatin analog
- resection of pituitary tumour if that’s the cause
Diabetes in pregnancy
Def, rf, sx, ix, mx
glucose intolerance with fasting blood glucose levels equal to or above 5.6 mmol/L or 2-hour plasma glucose levels equal to or above 7.8 mmol/L on a 75g Oral Glucose Tolerance Test (OGTT)
Rf:
- Middle Eastern, south Asian, Afro-Caribbean
- delivery of babies >4.5kg
- history of stillbirth
- BMI >30
- fhx diabetes
Sx:
- polyuria
- thirst
- fatigue
Ix:
- 75g OGTT main ix
- HbA1c
- urinalysis
Mx:
- diet and exercise
- insulin if fasting glucose >7
Diabetes insipidus
Def, types, cause, sx, ix, mx
characterised by either an inadequate production (AVP-D) or an insufficient renal response (AVP-R) to arginine vasopressin (AVP), also called antidiuretic hormone (ADH).
Cause:
AVP deficiency:
- head trauma
- sarcoidosis
- meningitis
- sickle cell disease
AVP resistance:
- lithium
- metabolic disturbance
- chronic renal disease
Sx:
- Large volumes of dilute urine (>3 litres in 24 hours and a urine osmolality of <300 mOsm/kg)
- Nocturia
- Excessive thirst
Ix:
- U+E showing raised Na
- blood glucose to rule out mellitus
- urine dip
- urine osmolality (raised (>295 mOsm/kg) with inappropriately dilute urine (urine osmolality < 300 mOsm/kg))
- water deprivation test (In AVP-D, urine osmolality increases with ADH administration. In AVP-R, urine osmolality remains low/unchanged despite ADH administration)
Mx:
- AVP-D= desmopressin and Na monitoring
- AVP-R= correct metabolic abnormalities, high dose desmopressin, thiazide diuretic
Diabetes mellitus type 1
Def, sx, ix, mx
autoimmune condition characterized by the destruction of the insulin-producing beta cells within the pancreas, leading to insulin deficiency
Sx:
- polyuria
- poly dips is
- weight loss
Ix:
- symptomatic then 1 of the following: 1) Random blood glucose ≥ 11.1mmol/l or Fasting plasma glucose ≥ 7mmol/l 2) 2-hour glucose tolerance ≥ 11.1mmol/l 3)HbA1C ≥ 48mmol/mol (6.5%)
- asymptomatic then 2 of the following: 1) Autoantibody testing: Identification of specific antibodies (e.g. anti-GAD, ICA, IAA) contributes to confirming the autoimmune nature of T1DM. 2) C-peptide levels: Evaluation of C-peptide production helps assess endogenous insulin secretion. 3) Urine ketone testing: Presence of ketones may suggest concurrent DKA.
Mx:
- insulin
- glycaemic control
- lifestyle changes
- glucose monitoring
Diabetes mellitus type 2
Def, sx, ix, mx
chronic metabolic condition characterized by inadequate insulin production from pancreatic beta cells, resulting in insulin resistance. This leads to an elevation in blood glucose levels, causing hyperglycaemia.
Sx:
- polyuria
- poly dips is
- weight loss
- blurry vision
- fatigue
Ix:
- 1 of the following if symptomatic or 2 if asymptomatic: 1) Random blood glucose ≥ 11.1mmol/l 2) Fasting plasma glucose ≥ 7mmol/l 3) 2-hour glucose tolerance ≥ 11.1mmol/l 4) HbA1C ≥ 48mmol/mol (6.5%)
Mx:
- lifestyle changes
- metformin
- if on monotherapy HbA1c >58mmol/mol consider dual therapy with metformin, pioglitazone, a DPP‑4 inhibitor or a sulphonylurea (such as gliclizide)
- insulin therapy with isophane
Diabetic ketoacidosis
Def, triggers, sx, ix, mx
Occurs due to insulin deficiency leading to hyperglycaemia. Characterised by the triad of:
- Hyperglycemia (blood glucose >11 mmol/L)
- Ketosis (blood ketones >3 mmol/L or urinary ketones ++ or higher)
- Acidosis (pH <7.3 or bicarbonate <15 mmol/L)
Triggers:
- infection
- dehydration
- missed insulin
- steroids or diuretics
- surgery
- stroke or MI
- alcohol or drugs
- pancreatitis
Severe DKA if 1 of the following:
- Blood ketones > 6mmol/L
- Bicarbonate < 5mmol/L
- Blood pH < 7
- Anion gap above 16
- Hypokalaemia on admission
- GCS less than 12
- Oxygen saturations < 92% in air
- Systolic BP < 90mmHg
- Brady or tachycardia (heart rate < 60 or > 100bpm)
Sx:
- nausea and vomiting
- abdo pain
- polyuria
- poly dips is
- weakness
- dry mucous membranes
- hypotension
- tachycardia
- confusion
- kussmauls breathing to compensate
- fruit smelling breath
Ix:
- glucose
- ketones
- urine dip
- ECG
- blood gas showing metabolic acidosis
- CXR for septic screen
Mx:
- A to E
- IV fluid with saline
- insulin infusion
- LMW heparin
Diabetic neuropathy
Cause, types, ix, mx
Primary cause is chronic hyperglycaemia
Types:
- distal symmetrical sensory neuropathy (most common)= sensory loss in a glove and stocking distribution
- small fibre predominant neuropathy= pain and temp deficiency in glove and stocking distribution
- diabetic amyotrophy= severe pain around thighs and hips with proximal weakness
- mononeuritis multiplex= neuropathies involving two or more distinct peripheral nerves
- autonomic neuropathy= postural hypotension, gastroparesis, constipation, urinary retention, arrhythmias, and erectile dysfunction
Ix:
- neuro exam
- nerve conduction study
- bloods
Mx:
- control glucose
- gabapenti or pregabalin
Hyperlipidemia
Cause, sx, ix, mx
Causes of hypercholesterolaemia without hypertriglyceridaemia:
- Familial hypercholesterolaemia
- Nephrotic syndrome
- Hypothyroidism
- Cholestatic liver disease e.g. primary biliary cirrhosis
- Cushing’s syndrome
- Anorexia nervosa
- Medications e.g. ciclosporin
Causes of hypertriglyceridaemia +/- hypercholesterolaemia:
- Diabetes
- Pregnancy
- End-stage renal disease
- HIV
- Alcohol excess
- Metabolic syndrome
- Monoclonal gammopathy
- Medications e.g. steroids, isotretinoin, antiretrovirals
- Familial combined hyperlipidaemia
Sx:
- often asymptomatic
- tendon xanthoma
- xanthelasma
- corneal arcus
Ix:
- urine dip (CKD)
- blood glucose (diabetes)
- ECG (ischaemic changes)
- pregnancy test (no statins for breastfeeding)
- lipid profile
- genetic testing
Mx:
- lifestyle changes
- primary prevention= 20 mg atorvastatin (can go to 80 mg)
- secondary prevention= 80 mg atorvastatin
- exetimibe as second line
Hyperosmolar hyperglycaemic state
Def, rf, sx, ix, mx
Marked hyperglycaemia (30 mmol/L or more) without significant ketosis (<3 mmol/L) or acidosis (pH>7.3, bicarbonate >15 mmol/L) AND Osmolality 320 mosmol/kg or more: 2Na+ + glucose + urea
Rf:
- T2DM
- age
- infection
- meds that affect glucose metabolism
Sx:
- dehydration
- polydipsia and polyuria
- confusion
- seizures
- hypotension and tachycardia
Ix:
- blood glucose
- serum osmolality
- electrolytes
- urinalysis for ketones (absent)
Mx:
- fluid resus with 0.9% NaCl
Hyperparathyroidism
Types, sx, ix, mx
Types:
- Primary Hyperparathyroidism (PHPT): Commonly caused by a parathyroid gland adenoma, hyperplasia of all four glands, or parathyroid carcinoma.
- Secondary Hyperparathyroidism (SHPT): Typically due to vitamin D deficiency, loss of extracellular calcium, calcium malabsorption, abnormal parathyroid hormone activity, or inadequate calcium intake.
- Tertiary Hyperparathyroidism (THPT): Occurs after prolonged secondary hyperparathyroidism due to conditions like chronic kidney disease.
Sx:
- moans (painful bones)
- stones (renal)
- groans (GI sx)
- psychiatric moans (memory loss, psychosis)
Mx:
- Primary Hyperparathyroidism (PHPT): Definitive management is parathyroidectomy.
- Secondary Hyperparathyroidism (SHPT): Address underlying causes; vitamin D supplementation and phosphate binders may be needed.
- Tertiary Hyperparathyroidism (THPT): Managed with medication like Cinacalcet, a calcimimetic that mimics the action of calcium on tissues, or via total or subtotal parathyroidectomy.
Hyperthermia
Def, cause, sx, ix, mx
abnormally high core body temperature (over 38 degrees Celsius)
Causes:
- heatstroke
- sepsis
- hyperthyroidism
- phaeochromocytoma
- adrenal crisis
- cocaine
- status epilepticus
- CNS disorders eg. Stroke or encephalitis
Sx:
- thirst
- fatigue
- dizziness
- headache
- sweating
- tachycardia
- hypotension
- tachypnoea
- oliguria
- seizures
Ix:
- ECG showing sinus tachycardia
- urinalysis
- ABG showing respiratory alkalosis due to tachypnoea, a metabolic acidosis due to a raised lactate or a respiratory acidosis in obtunded patients
- U+E showing AKI from dehydration
- CXR
Mx:
- A to E
- catheter to measure urine output
- cooling measures
- avoid antipyretics
Hypoglycaemia
Def, cause, sx, ix, mx
typically defined as less than 3.5 mmol/L
Causes:
- Drugs: Insulin, Sulphonylureas, GLP-1 analogues, DPP-4 inhibitors, Beta-blockers
- Alcohol
- Acute liver failure
- Sepsis
- Adrenal insufficiency
- Insulinoma
- Glycogen storage disease
Sx:
Adrenergic sx (Blood glucose concentrations <3.3 mmol/L):
- trembling
- sweating
- palpitations
- hunger
- headache
Neuroglycogenic sx (Blood glucose concentrations below <2.8 mmol/L):
- double vision
- concentration difficulty
- slurred speech
- confusion
- coma
Mx:
- mild= A to E, 15-20g fast acting carbohydrates
- severe= 200ml 10% dextrose IV, 1mg glucagon IM
Hypoparathyroidism
Def, rf, sx, ix, mx
Hypoparathyroidism is a medical condition characterized by abnormally low levels of parathyroid hormone (PTH), leading to disturbances in calcium and phosphorus metabolism. It can be primary (due to parathyroid gland dysfunction) or secondary (resulting from other medical conditions or treatments).
Rf:
- neck surgery or radiation involving the parathyroid glands
- autoimmune polyendocrine syndrome
- genes
Sx:
- muscle cramps
- parasthesias
- tetany
- seizures
- anxiety and depression
- cataracts
- dental enamel hypoplasia and tooth discoloration
Ix:
- low serum calcium
- high phosphate
- low PTH
- ECG may show prolonged QT
Mx:
- calcium and vitamin D supplements
- Parathyroid gland autotransplantation or glandular tissue implantation in refractory cases
Hypothyroidism
Cause, sx, ix, mx
Cause:
- hashimotos thyroiditis
- atrophic thyroiditis
- Autoimmune polyendocrine syndromes
- surgical removal
- radiation
- thyroid aphasia
- pendred syndrome
- sarcoidosis
- haemachromatosis
Sx:
- dry thick skin
- brittle hair
- Queen Anne’s sign (loss of outer 1/3 eyebrow)
- cold intolerance
- macroglossia
- puffy face
- goitre
- bradycardia and cardiomegaly
- carpal tunnel syndrome
- cerebellar ataxia
- peripheral neuropathy
- joint pain
- menorrhagia
Ix:
- first line is TFTs showing low t3-4 and raised TSH
- anti-TPO, anti-thyroglobulin and anti-TSH testing
- imaging and biopsy
- iodine levels
Mx:
- first line is levothyroxine
Obesity
Def, sx, ix, mx
BMI >30
Sx:
- high weight
- central obesity
- joint pain
- fatigue
- SOB
- sleep apnoea
Ix:
- BMI
- hip to waist ratio
- BP
- fasting blood glucose
- lipid profile
- LFT
Mx:
- diet and exercise
- orlistat (lipase inhibitor)
- liraglutide (GLP-1 receptor agonist)
- bariatric surgery (BMI >35)
Pituitary tumours
Def, sx, ix, mx
Pituitary adenomas are the most common type of pituitary tumors, typically benign and non-secretory in nature. Prolactinomas are the most common hormone-secreting tumors originating in the pituitary gland. They can be categorized as microadenomas (less than 10mm) or macroadenomas (greater than 10mm).
Sx:
Adenoma:
- headache
- visual field defects
Prolactinoma:
- women= oligomenorrhea or amenorrhea, galactorrhea (breast milk production outside of pregnancy or breastfeeding), infertility, and vaginal dryness
- men= erectile dysfunctional and reduced facial hair growth
- both= headaches and visual field defects
Ix:
- brain MRI
- visual field tests
- serum prolactin
Mx:
- Trans-sphenoidal surgery is the primary treatment for pituitary adenomas
- radiotherapy
- cabergoline (dopamine agonist) to reduce serum prolactin
Thyroid eye disease
Def, cause, sx, mx
is a complication of Grave’s disease, which is an autoimmune hyperthyroidism. An inflammatory process results in swelling of the extraocular muscles and orbital fat, which leads to multiple ocular complications
Sx:
- ocular pain
- dry red eyes
- bulging eyes
- proptosis
- chemosis
- exposure keratopathy
Mx:
- steroids
- in sight threatening urgent surgical orbital decompression followed by IV corticosteroids
- artificial tears and ointments
Peripheral vascular disease
Causes, sx, ix, mx
Causes:
• Smoking
• Diabetes mellitus
• Hypertension
• Hyperlipidaemia, characterised by high total cholesterol and low high-density lipoprotein (HDL) cholesterol levels
• Physical inactivity
• Obesity.
Sx:
Symptoms
• Impaired ability to walk
• Pain in the buttocks and thighs, relieved at rest
Signs
• Pale, cold leg
• Hair loss
• Presence of ulcers
• Poorly healing wounds
• Weak or absent peripheral pulses
Ix:
PAD investigations start with a complete cardiovascular risk assessment, which includes measurements of blood pressure, full blood count, blood glucose, lipids, and an electrocardiogram (ECG).
Specific investigations include the Ankle-Brachial Pressure Index (ABPI). This straightforward, first-line investigation for PAD is conducted by using a Doppler probe to measure the systolic brachial blood pressures of the arms and comparing them with the ankle blood pressures.
The ABPl is computed as follows:
Ankle pressure (on side of interest)/Brachial pressure (on side of interest)
Interpretation of ABPI:
• 1.2: suggests abnormal thickening of vascular walls (typically in diabetes)
• 0.9 - 1.2: Normal
• 0.8 - 0.9: Mild disease
• 0.5 - 0.8: Moderate disease
• <0.5: Severe disease
Imaging investigations may include:
• Duplex arterial ultrasound: beneficial for individuals who might be suitable for revascularisation.
• MR arteriogram: utilised for those who are candidates for revascularisation.
• CT arteriogram: employed in those unsuitable for MR.
• Digital subtraction angiography: typically performed at the time of intervention or for monitoring disease.
Mx:
Cardiovascular risk management:
• Antiplatelet therapy with clopidogrel 75mg once daily (Aspirin is an alternative if clopidogrel is not tolerated or contraindicated).
• Lipid-lowering therapy with atorvastatin 80mg once nightly.
• Optimising glycaemic control in diabetic patients.
• Appropriate management of high blood pressure.
Pain management:
• Naftidrofuryl oxalate, a vasodilator, can alleviate pain in PAD. It should only be prescribed if supervised exercise is ineffective and the patient does not want to be referred for angioplasty or bypass surgery.
Surgical options include:
• Endovascular methods, recommended for small discrete stenosis.
• Surgical bypass, suitable for larger, more extensive stenosis.
• Amputation may be required in cases of critical limb ischaemia unsuitable for other interventions, intractable pain, an unresolving ulcer, or severe loss of function
Osteomalacia
Def, cause, sx, ix, mx
refers to a metabolic bone disease that features osteopenia and disordered bone calcification, resulting in an excess of osteoid, or unmineralized, mainly collagenous, tissue. This process occurs after the closure of the epiphyses, distinguishing it from rickets, a similar disorder occurring before epiphyseal closure.
The primary cause of osteomalacia is vitamin D deficiency, which can arise from:
• Inadequate dietary intake of vitamin D
• Insufficient sunlight exposure
• Malabsorption disorders such as celiac disease or inflammatory bowel disease
• The presence of melanin in darker skin types, which lowers the skin’s ability to produce vitamin D from sunlight
• Increased demand, such as during pregnancy or breastfeeding
Sx:
• Pain in the lower back, hips, and pelvis
• Pseudofractures, or Looser’s zones, which are areas of incomplete stress fractures
• Bone tenderness
• Muscle weakness
Ix:
• Blood tests to check for low levels of vitamin D, calcium, and phosphate, and to assess kidney function
• Bone biopsy, considered the gold standard for diagnosis
• Imaging studies such as X-rays to identify pseudofractures or other bone abnormalities. DEXA scan shows low bone mineral density
Mx:
- colecalciferol
Osteoporosis
Def, sx, ix, mx
Osteoporosis is a systemic skeletal disease characterized by reduced bone mass and altered microarchitecture of the bone tissue, leading to increased bone fragility and a consequent increase in fracture risk. It is typically defined by a DEXA scan T-score of -2.5 or lower.
Sx:
• Back pain, caused by a fractured or collapsed vertebra
• Loss of height over time
• A stooped posture
• A bone fracture that occurs much more easily than expected
Ix:
• DEXA scan (Gold standard) with a T-score of -2.5 or lower indicating osteoporosis
• X-rays for suspected fractures
• MRI of the spine to assess vertebral fractures
• Blood tests to exclude metabolic bone diseases and assess vitamin D, calcium, and hormone levels
- FRAX Score
The FRAX (Fracture Risk Assessment Tool) score is used to estimate the 10-year probability of a major osteoporotic fracture. Interpretation of FRAX scores:
• Normal: 10-year probability <10%
• Osteopenia (low bone density): 10-year probability 10-20%
• Osteoporosis: 10-year probability >20%
Mx:
- first line is bisphosphonates eg. Alendronate, risendronate and zolendronic acid
- if bisphosphonates not suitable then denosumab and others can be used
Hypertension
Def, classification, ix, mx
24 hour ambulatory bp > 135/85
Classification:
• Stage 1: Clinic => 140/90mmHg; ABPM => 135/85mmHg
• Stage 2: Clinic => 160/100mmHg; ABPM =>150/95mmHg
• Stage 3: Clinic systolic BP (SBP) => 180 or diastolic BP (DBP) =>120mmHg
Ix:
- 1st line is ABPM or home blood pressure monitoring
Mx:
- lifestyle changes
- start meds if high risk stage 1 or any stage 2
Hypothermia
Def, cause, sx, ix, mx
a core body temperature below 35°C
Classification:
- Primary hypothermia is environmental, occurring for example after immersion in cold water or prolonged exposure to cold weather conditions
- Secondary hypothermia occurs secondary to an insult or illness such as infection, alcohol excess, hypothyroidism or major trauma
- Mild - 32 to 35°C
- Moderate - 28 to 32°C
- Severe - 20 to 28°C
- Profound - < 20°C
Sx:
- shivering
- hunger
- dizziness
- chills
- tachycardia
- tachypnoea
- cool peripheries
- hypotension
- reduced consciousness
Ix:
- urine toxicology if suspected drug intoxication
- ABG may show an initial respiratory alkalosis, followed by respiratory acidosis as hypothermia worsens
- ECG may show prolonged PR, QRS and QT, Osborn (J waves), bradyarrhytmias
- bloods
- CXR for aspiration pneumonia or pulmonary oedema
- CT if elderly and long lie from fall
Mx:
- A to E
- rewarming
- fluid resus
- severe hypothermia may require cavity lovage using warm fluids and axtracorporeal blood rewarming
Hypercalcaemia of malignancy
Def, classification, cause, sx, ix, mx
Elevated adjusted calcium levels (>2.6mmol/L) due to a known or suspected cancer
Classification:
- Mild hypercalcaemia is defined as a calcium level of 2.6-3.0mmol/l with minimal symptoms.
- Moderate hypercalcaemia may be symptomatic with a calcium level of 3.0-3.5mmol/l.
- Severe hypercalcaemia is defined as calcium levels greater than 3.5mmol/l and/or the presence of severe symptoms.
Causes:
- Tumour secretion of parathyroid hormone-related peptide (PTHrP), associated with squamous cell lung cancer, renal, ovarian, breast and endometrial cell cancers.
- Bone metastases promoting osteolysis and calcium release, associated with breast cancer and multiple myeloma.
- Autonomous vitamin D production by lymphoma cells
Sx:
- Bone pain & fractures
- Altered mental status, confusion & lethargy
- Mood disturbance
- Nausea & vomiting
- Constipation
- Renal colic
- Polyuria, polydipsia & dehydration
- Shortened QT interval
- Hypertension
Ix:
- ECG showing short QT interval
- calcium, vit V and PTH levels
- bone profile
Mx:
- rehydration as first priority with IV saline
- review meds and stop any that raise ca if possible
- IV bisphosphonates or denosumab if confirmed malignancy
- corticosteroids if vitamin D-mediated hypercalcaemia of malignancy
