Endocrinology Flashcards
Define Adrenal Insufficiency
Destruction of adrenal cortex with reduced adrenal output
Can be Primary (Addison’s) or Secondary
Causes of Adrenal Insufficiency
AI most common in developed countries
TB most common in rest of world
Primary: Addisons, Adrenectomy, Trauma, Infection, Haemorrhage, infarction, neoplasm
Secondary: Congenital, Trauma, CAH
Other: Suppression of axis, AIDS patients, Critically ill
Symptoms of adrenal insufficiency
Hypotension Hypovolaemic shock Fever Vomiting Fatigue Weakness Anorexia
Signs of adrenal insuffciency
Hyperpigmentation
Hypotension
Postural hypotension
What things would make you consider addisons?
Hypothyroidism / Women on thyroxine
Unexplained hypotension in T1DM
Presence of other AI conditions
Low Na+ and Low K+
Investigations for Adrenal insufficiency
Electrolytes (Low Na+, Raised K+) FBC ( Anaemia, mild eosinophilia, WBC) Glucose (Low) LFTs (Raised) ACTH (Raised in Primary, low/normal in secondary)
Management for Adrenal insufficiency
Medical emergency bracelet
Steroids (Hydrocortisone + Fludrocortisone in prmiary disease)
Double dose of hydrocortisone for surgery, infections
Manage acute Adrenal insufficiency
ICU
High dose Hydrocortisone Paternally
IV Fluid
Complications of Adrenal insufficiency
Adrenal crisis
Osteoporosis
Reduced QOL
Prognosis of Adrenal insuffciency
If untreated = fatal
Lifelong treatment but normal life
What is Acromegaly?
Growth hormone stimulates production of IGF-1. This is produced in liver and many other tissues.
What causes Acromegaly?
Usually caused by a pituitary tumour (1:3 microadenoma to macroadenoma)
Rarely, ectopic GH from non-endocrine tumours e.g. Lung cancer, cancer of the pancreas
Insidious onset and slow progression
Several familial causes (MEN1, Mccube-albright’s syndrome or familial isolated pituitary adenoma)
What are the risk factors for acromegaly?
GPR101 over-expression MEN1 Isolated familial acromegaly McCune-albright's syndrome Carney's complex
What are the signs and symptoms of Acromegaly?
Coarsening of facial features Soft-tissue and skin changes Carpal tunnel syndrome Joint pain and dysfunction Snoring (macroglossia) Alterations in sexual functioning History or family history of inherited syndromes Fatigue Hypertension, arrhythmias Organomegaly Increased appetite, polyuria/polydipsia Headaches Visual field defects Signs and symptoms of hypopituitarism Cranal nerve palsies (ophthalmoplegia)
What investigations are done for Acromegaly?
Serum IGF-1 (elevated) Oral glucose tolerance test (GH value >1 microgram/L) Random serum GH Pituitary MRI or CT scan (Adenoma) Plasma cortisol (May be low) TSH and free T4 (abnormal) Estradiol or testosterone Visual field testing
How do you manage Acromegaly?
Somatostatin analogues (Octreotice) Dopamine agonists (Bromocriptine, cabergoline and quiagolide) Pegyisomant (PEG)
How do you manage Acromegaly in pregnancy?
Medical therapy withheld during pregnancy
Short-acting octreotide used as needed when attempting to conceive
Patients with macroadenomas monitored for headaches and visual symptoms
Cabergoline safe to the foetus
What are complications of acromegaly?
Cardiac complications Sleep apnoea Osteoarticular complications Impaired glucose tolerance and diabetes Pre-cancerous polyps Carpal tunnel syndrome Hypopituitarism
What is Carcinoid syndrome?
Constellation of symptoms caused by systemic release of humoral factors from carcinoid tumours (tumour of neuroendocrine cells)
What causes carcinoid syndrome?
Slow-growing neuroendocrine tumours
Mostly derived from serotonin-producing enterochromaffin cells (Neural crest origin)
Common sites: Appendic, ileum, Rectum
Produce secretory products: Serotonin, Histamin, Tachykinins, kallikrein and prostaglandins
75-80% with it have small bowel carcinoids
What is important to know about Carcinoid syndrome in the bowel?
Hormones released into the portal circulation will be metabolised by the liver so symptoms dont appear untill there are hepatic metastases
What are the Risk factors for carcinoid syndrome?
None
What are the Symptoms of Carcinoid syndrome?
Paroxysmal flushing Diarrhoea Crampy abdominal pain Wheeze Sweating Palpitations
What are the signs of carcinoid syndrome?
Telangiectsia
Congestive cardiac failure (Due to tricuspid incompetence/pulmonary stenosis from serotnonin induced fibrosis)
Right-sided murmurs
Nodular hepatomegaly
Carcinoid crisis (When mediators flood out - often during surgery) [Profound flushing, Bronchospasm, Tachycardia, Fluctuating blood pressure]
What are the investigations for Carcinoid syndrome?
24hr urine collection (Check 5-HIAA levels)
Blood (Plasma chromogranin A and B, Octreoscan, fasting gut hormones)
CT/MRI scan (Localise tumour)
Radioisotope scan (Radiolabelled somatostatin analogue (octreotide) localises the tumour)
Investigations for MEN-1
Echo and BNP investigates carcinoid heart disease
What is Cushing’s syndrome?
Clinical manifestation of pathological hypercortisolism from any cause.
What is caused by Cushing’s syndrome?
Exogenous corticosteroid exposure is most common cause of cushing’s syndrome
Majority caused by ACTH-secreting pituitary adenomas
10-15% of pituitary tumours secrete ACTH
New gene ubiquitin-specific protease 8, mutated in Cushing’s disease
Adrenal overproduction of cortisol in 30-40% of carcinomas, resulting in ACTH-independent cushing syndrome
What are the Risk Factors for Cushing’s syndrome?
Exogenous corticosteroid use Female 20-45 Pituitary adenoma Adrenal adenoma Adrenal carcinoma Neuroendocrin tumours Thoracic or bronchogenic carcinoma
What are the signs and symptoms of Cushing’s syndrome?
Truncal obesity Buffalo hump Supraclavicular fat pads Weight gain Facial fullness Moon facies Facial plethora Proximal muscle wasting and weakness Diabetes or impaired glucose tolerance Skin atrophy Purple striae Easy bruising Hirsutism Acne Pigmentation Oedema
What are the investigations for Cushing’s syndrome?
Pregnancy test (Negative)
Serum Glucose (Raised)
Late-night salivary cortisol (Raised)
1mg overnight dexamethasone suppression test (morning cortisol >50)
24-hour urinary free cortisol (>50)
48-hour 2mg dexamethasone suppression test
How do you manage Cushing’s syndrome?
Tumour resection (Trans-sphenoidal microsurgery or Bilateral adrenelectomy) Medications for those who are unfit for surgery or with an unknown tumours
What medications are used for Cushing’s syndrome?
Drugs (Metyrapone, Ketoconaxole and mitotane)
Pituitary radiotherapy
What are the complications of Cushing’s syndrome?
Adrenal insufficiency secondary to adrenal suppression
CVS Disease
HTN
DIabetes mellitus
OSteoporisus
Nephrolithiasis
Nelson’s syndrome
Treatment- related central hypothyroidism/GH deficiencies
Treatment related adrenal insufficiency/hypogonadism/DI
What is Cushing’s disease?
Cushing’s syndrome caused by a pituitary adenoma specifically
What is Diabetes Insipidus?
Diabetes insipidus is caused by hyposecretion of, or insensitivity to the effects of ADH aka AVP.
Its failure to act causes an inability to concentrate urine in the distal renal tubule, leading to passage of a lot of urine
Passes >3 litres of urine in 24hrs with low osmolality (<300mOsml/kg)
What are the 2 major forms of Diabetes insipidus?
Cranial
Nephrogenic
What is Cranial DI?
Decreased ADH secretion, reducing the ability to concentrate urine and so causes polyuria and polydipsia
What is Nephrogenic DI?
Decreased ability to concentrate urine because of resistance to ADH in the Kidney
What are the 2 other forms of DI?
Gestational
Primary polydipsia
What is Gestational DI?
Degaradtion of Vasopressin by a placental vasopressinase. associated with increased complications of pregnancy
What is primary polydispia?
AKA Dipsogenic DI - caused by a primary defect in osmoregulation of thirst. Reported in TB meningitis, MS and Neurosarcoidosis
What causes cranial DI?
Acquired
- Idiopathic
- Tumours
- Intracranial surgery
- Head injury
- Granulomata (sarcoidosis, TB, Wegner’s granulomatosis)
- Infections (Encephalitis, Meningitis, cerebral abscess)
- Vascular disorders (Haemorrhage/thrombosis, aneurysms, SCD, sheehan’s syndrome)
- Post Radiotherapy
Inherited
- Autosomal recessive (Wolfram’s syndrome)
- AD mutations of vasopressin gene
What causes Nephrogenic DI?
Acquired - Idiopathic - Hypokalaemia - Hypercalcaemia - CKD - Other metabolic derangements - Drugs (Ofloxacin, orlistat, lithium) - Renal tubular acidosis - Pregnancy - Post obstructive uropathy Congenital/genetic nephrogenic DI - X linked mutations in V2 ADH-receptor gene - Autosomal recessive defect in aquaporin 2 (AQP2) gene - water channel in distal renal tubule - Sporadic nephrogenic DI with general learing disability and intracerebral calcificaiton (very rare)
What are the risk factors for Diabetes insipidus?
Pituitary surgery Craniopharyngioma Pituitary stalk lesions Traumatic brain injury Congenital pituitary abnormalities Medication AI disease Family history/genetic mutations Pregnancy Subarachnoid haemorrhage Renal sarcoidosis/amyloidosis Hypercalcaemia or hypokalaemia Release of obstructive uropathy Previous CNS infection
What are the symptoms of Diabetes insipidus?
Polyuria Nocturia Polydipsia In children: Enuresis (bed wetting), Sleep disturbance Sensorineural deafness and visual failure Visual field defects Motor deficits Skin lesions
What are the signs of Diabetes Insipidus?
Urine output >3L/day
Fluid intake < fluid output, signs of dehydration (tachycardia, reduced tissue trigor, postural hypotension)
Signs related to teh cause
What are the investigations for Diabetes Insipidus?
Plasma glucose
U&Es
Urine specific gravity
Simultaneous plasma and urine osmolality
MRI of pituitary, hypothalamus and surrounding tissues, including the pineal gland
Fluid deprivation test with response to desmopressin!
What results are seen in the fluid deprivation test?
Normally:
- Increased plasma osmolality
- Increased ADH secretion
- Increased water reabsorption
- Increase in urine osmolality (Urine >600 mosmol/kg)
In psychogenic polydipsia:
- Urine osmolality is slightly lower than a normal person
In Diabetes insipidus:
- Lack of ADH means that urine cannot be concentrated
- Urine osmolality is LOW (<400 mosmol/kg)
Cranial - urine osmolality rises >50% following administration of desmopressin; Nephrogenic has a rise of <45% after desmopressin
What is the management of Diabetes insipidus?
Treat Cause!
Cranial DI - MRI to find cause, give desmopressin, if mild: chlorpropamide/carbamezapine to potentiate residual effects of any residual vasopressin
Nephrogenic diabetes insipidus - Sodium and/or protein restriction helps with polyuria, thiazide diuretics e.g. bendroflumethiazide
What are the complications of DI?
Desmopressin worsens MI in susceptible patients, may be a need for nitrates/other anginal methods
Need careful management of fluid balance and therapy following surgery
Patients with genetic causes of Nephrogenic DI are prone to bladder dysfunction and hydroureter/hydronephrosis
Hypernatraemic dehydration
Thrombosis
Bladder and Renal dysfunction
Iatrogenic hyponatraemia
What is Diabetes Mellitus?
Lack of effective endogenous insulin
Leading to serious microvascular (Retinopathy, Neuropathy and Nephropathy) or Macrovascular (stroke, renovascular disease, limb ischaemia, heart disease) problems
What is Type 1 diabetes mellitus?
Immune destruction of the pancreas Insulin dependent diabetes Usually young Diabetic ketoacidosis Quite high glucose
What is Type 2 diabetes mellitus?
Resistance to action of insulin Non-insulin dependent diabetes Maturity onset diabetes (30-70 years old) Often overweight Very high glucose
What is the cause of T1DM?
Destruction of pancreatic beta cells
AI process
Associated with other AI conditions
90% carry HLA DR3 +/- DR4
Latent autoimmune diabetes of adults is a form of T1DM with slower progression to insulin dependence
T1DM prone to ketoacidosis have sufficient insulin to suppress ketone body
Auto antigens: GAD, Insulin, Insulinoma-associated protein 2, Cation efflux zinc transporter
What are the risk factors for T1DM
Geographical region
Genetic predisposition
Infectious agents
Dietary factors
What are the symptoms of T1DM?
Polyuria Nocturia Tiredness Weight loss DKA symptoms ( Caused by: Surgery, UTI, MI, pancreatitis, chemo, psychotics, wrong dose) - Drowsiness - Confusion - Kussmaul breathing - Ketotic breath
What are the signs of T1DM?
Diabetic retinopathy
Neuropathy
Monitor BP
Associated with AI conditions: Vitiligo, Addison’s disease, AI thyroid disease
What are the investigations for Diabetes mellitus?
Urinalysis > Random glucose (>7.1) > Fasting glucose (>11.1) > OGTT > HbA1c U&Es - Nephropathy and hyperkalaemia Lipid profile Urine A:CR - detect microalbuminaemia Urine - glycosuria, ketonuria, MSU
What investigations are done for Ketoacidosis?
Capillary blood glucose > Urine dipstick > ABG (metabolic acidosis)> Plasma osmolality
FBC (leucocytosis)
Fasting C-peptide (Low)
AI markers (Positive)
What is the management of T1DM?
Patient education
- Short acting insulin 3x daily or long acting insulin once daily
Insulin pumps
Monitor: Capillary blood glucose, HbA1c every 3-6 months.
Screen and manage complications
How do you manage DKA?
If Systolic BP <90 give 500ml saline 50U soluble insulin Continue untill: Ketones <0.3 Venous pH >7.30 Venous bicarbonate >18 Potassium replacement Thromboprophylaxis Broad spectrum ABx
What are the complications of T1DM?
Diabetic Ketoacidosis Hypoglycaemia Retinopathy Diabetic kidney disease Peripheral or autonomic neuropathy Cardiovascular disease
What are the macrovascular complications of T1DM?
Retinopathy
Neuropathy
Nephropathy
What are the complications of T1DM treatment?
Weight gain Fat hypertrophy at insulin injection sites Hypoglycemia - Personality changes - Fits - Confusion - Coma - Pallor
What is T2DM?
Increased peripheral resistance to insulin action, impaired insulin secretion and increased hepatic glucose output. Associated with Obesity, lack of exercise, calorie and alcohol excess
What causes T2DM?
Genetic predisposition characterised by insulin resistance Causes: Obesity Genetics Pancreatic disease Endocrine disease Drugs Circulating autoantibodies
What are the Risk factors for T2DM?
Metabolic syndrome Obesity Asian ethnicity TB drugs SSRIs Pregnancy Acromegaly Renal failure Cystic fibrosis PCOS Werner's syndrome
What are the symptoms of T2DM?
May be incidental
Polyuria
Polydipsia
Tiredness
Present with hyperosmolar hyperglycaemic state
Infections
Assess cardiovascular RFs (HTN, Hyperlipidaemia, Smoking)
What are the signs of T2DM?
Calculate BMI Waist circumference Blood pressure Diabetic foot (Dry skin, reduced SC tissue, Ulcerations, Gangrene, Charcot's arthropathy, Weak foot pulses) Skin changes - Necrobiosis lipoidica diabeticorum - Granuloma annulare - Diabetic dermopathy
What are the investigations for T2DM?
Urinalysis > Random glucose > Fasting glucose > OGTT > HbA1c
Diagnosed with: Plasma glucose (>7.1), Plasma glucose (>11.1)
Monitor: HbA1c, U&Es, Lipid profile, eGFR,Urine A:CR
Ankle-brachial index (= 0.9)
What is the management of T2DM?
Glycaemic control
Initial:
- Lifestyle advice (smoking cessation, diet, exercise)
- Metformin [a Biguanide] increases insulin sensitivity
HbA1c >53 add sulphonylurea [gliclazide]
HbA1c >57 at 6 months consider: Insulin, Glitazone, sulphonylurea, GLP analogues and DPP4 inhibitors, A-glucosidase inhibitors)
Screen for complications, pregnancy, hyperosmolar hyperglycaemic state
What are the complications of T2DM?
Diabetic kidney disease Impaired vision Lower extremity amputation Cardiovascular disease Congestive heart failure Stroke Infection Peridontal disease Treatment-related hypoglycaemia Depression Obstructive sleep apnoea Diabetic ketoacidosis Non-ketotic hyperosmolar state Autonomic or peripheral neuropathy
What is Diabetic Ketoacidosis?
Medical emergency with a significant morbidity and mortality
Characterised by hyperglycaemia, acidosis and ketonaemia
What are the precipitating conditions?
Infection
Discontinuation of insulin
Inadequate insulin
CVS disease
Drug treatments (Steroids, thiazide-like diuretics or SGLT2 inhibitors)
Menstruation
Physiological stress (pregnancy, trauma and/or stress)
What is Graves’ disease?
AI thyroid condition associated with hyperthyroidism. Associated orbitopathy occurs in 25% of cases and is usually mild
What causes Graves’ disease?
AI condition, caused by TSH receptor antibodies
80% genetic, 20% environmental
What are the Risk Factors for Graves’ disease?
Family history of AI thyroid disease Female sex Tobacco use High iodine uptake Lithium therapy Biological agent and cytokine therapies Radiation Radioiodinetherapy for benign nodular goitres Stress
What are the signs and symptoms of Graves’ disease?
Heat intolerance Sweating Palmar erythema Weight loss Palpitations Tremor Tachycardia (may be AF) Urticaria/pruritis Diffuse goitre Orbitopathy Lid lag Pretibial myxoedema Proptosis Onycholysis (detachment of nail from nail bed)
What are the investigations for Graves’ disease?
TSH (suppressed/low)
Serum free or total T4 (Raised)
Serum free or total T3 (elevated)
Total T3/T4 or fT4/fT3 (high compared to thyroiditis)
What is Hyperparathyroidism?
An endocrine disorder in which autonomous overproduction of PTH results in derangement of calcium metabolism. In approximately 80% of cases, over-producton of PTH is due to a single parathyroid adenoma, and less commonly, multi-gland involvement may occur
What are the types of hyperparathyroidism?
Primary
Secondary
Tertiary
What is Primary Hyperparathyroidism?
Parathyroid adenoma most common and familial forms are well defined May be due to external radiation - lithium therapy Familial causes (MEN1/2a), HPT-JT or familal isolated hyperparathyroidism
What are the risk factors for primary hyperparathyroidism?
Female sex Age >50-60 years Family history MEN (1,2a or 4) Current or history of lithium treatment HPT-JT History of head and neck irradiation
What are the signs and symptoms for Primary hyperparathyroidism?
History of Osteoporosis/Osteopenia Family history Nephrolithiasis Bone pain Poor sleep Fatigue Anxiety Depression Memory loss Myalgia Paraesthesia Muscle cramp Constipation Overt neuromuscular dysfunction Abdominal pain
What are the investigations for primary hyperparathyroidism?
Serum Calcium (raised)
Serum intact PTH with immunoradiometric or immunochemical assay
Serum ALP
Serum phosphorous
24 hour urinary calcium
Tc99m sestamibi scanning and ultrasonography
MRI neck
What is the management of primary hyperparathyroidism?
Mild, asymptomatic disease: - Elevated calcium - 1/3 will have features of HPT -Avoid dehydration -Avoid thiazide diuretics Surgical treatment: parathyroid surgery to remove abnormal glands Surgical treatment Medical treatment
What are the guidelines for surgical treatment?
Age under 50 Creatinine clearance <60 Nephrolithiasis DXA of less than -2.5 Vertebral fracture
What is the medical treatment for primary hyperparathyroidism?
HRT and Raloxifene in post menopausal women
Cincalcet reduces serum Calcium and PTH levels and raises serum phosphorous
What are the complications for primary hyperparathyroidism?
Neck haematoma following surgery Recurrent and superior laryngeal nerve injury Hypocalcaemia post-surgery Pneumothorax post-surgery Osteoporosis Bone fractures Nephrolithiasis
What is Secondary hyperparathyroidism?
Most commonly in CKD
Parathyroid glands become hyperplastic after long-term stimulation on response to chronic hypocalcaemia
Seen in all patients with dialysis-dependent CKD
Occur in any condition with chronic hypocalcaemia
What are the risk factors for secondary hyperparathyroidism?
Ageing Chronic renal failure Absence of dairy and fish Malabsorption Hepatic dysfunction Genetic disorder Obesity Medication use
What are the signs and symptoms of secondary hyperparathyroidism?
Features of chronic renal failure
Features of underlying malabsorption syndrome
Muscle cramps and bone pain
Perioral tingling or paraesthesia in fingers or toes
Chvostek’s/trousseau’s sign
Bowed legs or knocked knees
Fractures
What investigations are done for Secondary hyperparathyroidism?
Serum Calcium (Decreased)
Serum Intact PTH (Raised)
Serum creatinine (Raised)
Serum Urea Nitrogen (Raised)
What is the management of secondary hyperparathyroidism?
Mostly medical - treat underlying conditions
In CKD (calcium supplementation, correct Vit. D analogues, calchimimetics [cincalet])
Parathyroidectomy
What are the complications of secondary hyperparathyroidism?
Osteodystrophy
Osteoporosis
Uraemia
Calchiphylaxis
What causes tertiary hyperparathyroidism?
Occurs after prolonged secondary glands become autonomous, producing excessive PTH even after cause of hypocalcaemia is corrected
How does tertiary hyperparathyroidism present?
Symptoms and signs are due to hypercalcaemia so can be similar to primary hyperparathyroidism
What investigations are done for tertiary hyperparathyroidism?
Serum Calcium (Raised) Serum PTH (Raised) Serum phosphate (Raised)