Endocrinology Flashcards
HbA1c 86 mmol/mol (10.0%). What is the average glucose?
Average glucose = (HbA1c, % x 2) - 4.5 Average glucose = 15.5
45F, Lethargy, Na 129, K 5.1, Total T4 66 (RR 70-140). Next Ix?
Short synacthen test Addison’s: Fatigue, Low Na, High K May be associated with hypothyroidism Hypothyroidism would not cause high K
Abdo pain, vomiting, Hypotensive, Hypoglycaemia, PMHx Hypothyroidism. Tx?
Dx: Addison’s Tx: Hydrocortisone Addison’s is associated with Hypothyroidism
Causes of hypokalaemia with hypertension (4)
Causes of hypokalaemia with normal BP (5)
Hypokalaemia with hypertension
- Cushing’s syndrome
- Conn’s syndrome (primary hyperaldosteronism)
- Liddle’s syndrome
- 11-beta hydroxylase deficiency
Hypokalaemia without hypertension
- Diuretics
- GI loss (e.g. Diarrhoea, vomiting)
- renal tubular acidosis (type 1 and 2)
- Bartter’s syndrome
- Gitelman syndrome
Heavy periods + Polycythaemia. Dx?
Uterine fibroids
Osmolality formula
Estimated osmolality = 2 (Na + K) + Urea + Glucose
Ix for GH deficiency
Insulin
Hypoglycaemia is a potent stimulus for GH release
Ix for Acromegaly
Initial Ix?
Definitive Ix?
Serum IGF-1: ↑ [initial Ix]
OGTT [confirm diagnosis]
- If Normal: Glucose load –> ↓ GH levels
- If Acromegaly: Glucose load –> Paradoxical ↑ GH levels
Tx for Acromegaly
(1st line) Trans-sphenoidal surgery
(2) Somatostatin analogue (Octreotide)
(2) Dopamine agonist (Cabergoline, Bromocriptine)
(3) GH receptor antagonist (Pegvisomant)
Causes of hyperprolactinaemia
Pregnancy
Prolactinoma
Pituitary adenoma (stalk compression)
Acromegaly (high GH has prolactin like effects)
Primary hypothyroidism (high TRH)
Dopamine receptor antagonists
Tx for prolactinoma
(1) Dopamine agonist (Cabergoline, Bromocriptine)
(2) Trans-sphenoidal surgery
Raised serum osmolality, Low urine osmolality
Diagnosis?
Ix?
Treatment?
Diabetes insipidus
Ix: Fluid deprivation + DDAVP test
If cranial DI –> Desmopressin
If nephrogenic DI –> Thiazide diuretic (Bendoflumethiazide)
Low plasma osmolality, Raised urine osmolality
Diagnosis? Treatment?
SIADH
Treat underlying cause
Fluid restriction
+/- Lithium +/- Demeclocycline +/- Tolvaptan
Known pituitary tumour
Acute onset headache
N&V
Xanthochromia
Diagnosis? Tx?
Pituitary apoplexy (haemorrhage of pitutiary tumour)
Tx:
(1) IV Hydrocortisone (given first)
(2) Levothyroxine
+ Surgical intervention
Tx of acute thyroid storm
- High-dose anti-thyroid drug (Carbimazole, Propylthiouracil, Methimazole)
- + Corticosteroids
- β-blockers (IV Propanolol)
- Iodine (Lugol solution)
Hashimoto’s thyroiditis
Associated with
Hashimoto’s thyroiditis
Associated with
- Other autoimmune diseases
- MALT Lymphoma
Pendred’s syndrome
Clinical features? Cause?
Pendred’s syndrome
Autosomal recessive –> defect in organification of iodine
- Progressive hearing loss
- Hypothyroidism
- Goitre
- MRI: one ond a half turns of cochlea
Middle-aged woman
Hypothyroidism
“woody” goitre
Diagnosis?
Riedel’s thyroiditis = thyroid is replaced by fibrotic tissue
Adrenal zones
Ix for Cushin’s syndrome
Low dose dexamethasone suppression test:
diagnostic [GOLD STANDARD] [1st line]
Tx for Cushing’s syndrome
Medical
- Metyrapone (S/E: Hyperaldosteronism, Hirsuitism)
- Ketoconazole (S/E: Hepatotoxic)
Surgical
- If Cushing’s disease –> Pituitary surgery (Transsphenoidal hypophysectomy)
- If Ectopic ACTH production –> removal of tumour
- If Adrenal adenoma –> Unilateral (or Bilateral) adrenalectomy
Hypertension + Hypokalaemia
Diagnosis? Ix? Tx?
Hyperaldosteronism
- Bilateral adrenocortical hyperplasia (2/3) –> most common
- Conn’s syndrome (1/3) = aldosterone-producing adenoma
Ix: Plasma Aldosterone : Renin ratio
Tx:
- Short term –> MR antagonists (Spironolactone / Epleronone)
- Long term –> Laparoscopic adrenalectomy (both NOT both!)
Ix for Phaeochromocytoma
24 hour urinary metanephrines: raised
Hyponatraemia + Hyperkalaemia
Diagnosis? Ix?
Addison’s disease
SynACTHen test
Congenital adrenal hyperplasia
Types / Presentations
21-hydroxylase deficiency (most common)
- Ambiguous genitalia
- Virilisation of females
- Complete –> Addisonian crisis (Hypotension)
- Partial –> Precocious puberty
11-hydroxylase deficiency
- Conn’s syndrome (Hypertension + Hypokalaemia)
- Ambiguous genitalia
- Precocious puberty
17-hydroxylase deficiency
- Conn’s syndrome (Hypertension + Hypokalaemia)
- Failure to enter puberty
MALE Hypogonadism
Klinefelter’s syndrome vs Kallmann’s syndrome
Klinefelter’s syndrome (XXY) –> primary hypogonadism
Kallmann’s syndrome (failure of GnRH neurones) –> secondary hypogonadism
Causes of FEMALE hypogondism
Pregnancy [most common]
Primary hypogonadism
- Turner’s syndrome (45 XO)
- Premature ovarian insufficiency
Secondary hypogonadism
-
Hypopituitarism
- Sheehan syndrome
- Low BMI
- Kallmann syndrome
- Hyperprolactinaemia
Tx for PCOS
Hirsuitism/Acne
Subfertility
PCOS
Hirsuitism/Acne –> COCP
Subfertility –> Clomifene or Metformin
Hypocalcaemia
Low Ca, High PTH
Abnormal 4th metacarpal
Diagnosis? Definition
Pseudohypoparathyroidism = PTH resistance
Osteitis fibrosa cystica
Features
Associated with
Osteitis fibrosa cystica = replacement of bone with fibrosis (–> brown tumours)
Associated with Primary hyperparathyroidism
Skull X ray shows
Pepper pot skull
Rugger jersey spine
Diagnosis?
Primary hyperparathyroidism
Cause of Tx of primary hyperparathyroidism
Parathyroid adenoma (most commonly) –> Primary HyperPTH
(1) Parathyroidectomy
(2) Medical –> Cinacalcet
Treat hypercalcaemia
Hungry bone syndrome
Associated with?
Definition? Ix?
Primary hyperparathyroidism
Due to sudden drop in previously high levels of PTH
Previously, ↑ PTH stimulates osteoclasts to resorb bone –> ↑ Ca
Sudden ↓ PTH (due to short half life)
–> ↓ osteoclast activity and ↑↑osteoblast activity
–> bones rapidly re-mineralise –> ↓ Ca, ↓ PO4
Ix: ↓ Ca2+, PTH, ↓↓ PO4
Tx of Osteoporosis + S/E
- (1) Bisphosphonates (Alendronate, Risedronate)
- S/E: Oesophagitis, Osteonecrosis of jaw, Atypical fractures
- + Calcium
- + Vitamin D
- (2) Strontium ranelate
- MOA: dual action bone agent
- –> promotes osteoblasts and inhibits osteoclasts
- S/E: multiple! (VTE)
- MOA: dual action bone agent
- (2) SERMs (Tamoxifen)
- S/E: DVT/PE
- (2) Denosumab
- RANKL inhibitor
- S/E: Hypocalcaemia
- (3) Teriparatide (recombinant PTH)
If post-menopausal –> HRT
Fracture
Marble bone on X ray
Ca , PO4 , ALP
Diagnosis? Cause?
Osteopetrosis = Marble bone disease
Autosomal recessive
Defect in osteoclast function –> unable to resorb bone –> dense + brittle bones
Bone pain
Sensorineural deafness
Fracture
Age > 50 years old
ALP: ↑↑↑
Ca2+, PO4, PTH: normal
Diagnosis? Tx? Complications?
Paget’s disease of bone
(1) Bisphosphonates
Complications: Osteosarcoma (1%)
Latent autoimmune diabetes in adults (LADA)
Features?
Epidemiology?
LADA
Anti-islet cell +ve
Very slow progression of autoimmune cell failure
Young + obese
Maturity onset Diabetes of the Young (MODY)
Features? Cause? Tx?
MODY
T2DM in patients < 25 years old
Autosomal dominant (HNF-1-a mutation)
Tx: Gliclazide (very sensitive to sulfonylureas)
Definition of Diabetes
Definition of DKA
Diabetic
Shiny, yellow/red skin
Not painful
Diagnosis?
Necrobiosis lipoidica diabeticorum
Sulphonylurea
Example
MOA
S/E
Sulphonylurea
Example: Gliclazide + Glibenclamide
MOA: increase insulin secretion
S/E: Hypoglycaemia, Weight gain, SIADH
a-glucosidase inhibitor
Example
MOA
S/E
a-glucosidase inhibitor
e.g. Acarbose
MOA: delays absorption of carbohydrates
S/E: Flatus
Thiazolidinediones
Example
MOA
S/E
C/I
Thiazolidinediones
e.g. Pioglitazone
MOA: Acts on PPAR-y receptor on adiopcytes –> peripheral insulin sensitiser
S/E: Fluid retention, Weight gain, Bladder cancer
C/I: Heart failure, Bladder cancer
SGLT2 inhibitor
Example
MOA
S/E
SGLT2 inhibitor
Examples: Empagliflozin | Dapagafloxin | Canagliflozin
MOA: inhibits Na-glucose co-transporter in early DCT –> inc renal glucose excretion
S/E: Weight loss, UTIs, Euglycaemic DKA
GLP-1 agonists
Example
MOA
S/E
GLP-1 agonists
e.g. Liraglutide S/C, Exenatide S/C
MOA: GLP-1 agonist –> increase insulin
S/E: Weight loss, GI side effects
DPP4 inhibitors (Gliptins)
Example
MOA
S/E
DPP4 inhibitors (Gliptins)
e.g. Linagliptin
MOA: DPP4 inhibitor –> inhibit breakdown of endogenous GLP-1
S/E: Weight loss
Diabetic medications which cause hypoglycaemia
- Insulin
- Sulphonylurea (Gliclazide)
Diabetic medications which cause weight gain
Diabetic medications which cause weight loss
Weight gain (SIT)
- Sulphonylurea (Gliclazide)
- Insulin
- Thiazolidinedione (Pioglitazone)
Weight loss (renal excretion of glucose + GLP)
- SGLT2 inhibitors (Empagliflozin)
- GLP-1 agonists (Liraglutide, Exenatide)
- DPP4 inhibitors (Linagliptin)
Diabetic medications step wise
Gestational diabetes
Targets
Tx
Diabetic retinopathy - stages
Diabetic retinopathy
Screening Ix
Ideal Ix
Screening Ix –> Fundoscopy
Ideal Ix –> Fluorescein angiography
Diabetic neuropathy + neuropathic pain
Tx?
Duloxetine or Amitriptyline or Pregabalin or Gabapentin
Diabetic
Bloating
Vomiting
Erratic blood glucose control
Cause?
Diabetic neuropathy (Gastroparesis)
Tx: Metoclopramide
Diarrhoea
Flushing
Wheeze
Telagniectasia
Diagnosis? Ix? Tx?
Carcinoid syndrome
24hr urine collection of 5-hydroxyindoleacetic acid: ↑
Serum Chromogranin A/B: ↑
Tx: Surgical resection +/- Octreotide
Schmidt’s syndrome
Definition
APS-2 (= Schmidt’s syndrome)
Need 2/3 features below:
- Addison’s disease
- Autoimmune thyroid disease
- T1DM
MEN syndromes
Causes of hypertriglyceridaemia
Causes of hyperholesterolaemia
How to uptitrate statins
Repeat Lipid profile @ 3 months
If non-HDL cholesterol ↓ < 40% –> ↑ Atorvastatin to 80mg ON
