Corrections - Endocrinology 2 Flashcards
What are the 3 main actions of PTH?
1) increases the activity and number of osteoclasts in bone, causing increased reabsorption of calcium from bone
2) stimulates calcium reabsorption in the kidneys
3) stimulates the kidneys to convert vitamin D3 into calcitriol (active form of vitamin D)
What are the causes of Cushing’s syndrome (4)?
1) Cushing’s disease (pituitary tumour secreting ACTH)
2) Tumour from somewhere else secreting ectopic ACTH e.g. SCLC
3) Exogenous steroid
4) Adrenal adenoma: secreting excess cortisol
What are the two initial investigation options when suspecting a phaeochromocytoma?
1) 24 hour urine catecholamines
2) Plasma free catecholamines
What is the action of aldosterone? (3)
1) Stimulates Na+ reabsorption from distal tubule
2) Stimulates K+ secretion from distal tubule
3) Increased H+ secretion from collecting ducts
What are the causes of secondary hyperparathyroidism? (2)
1) CKD
2) Insufficient vitamin D
What is the normal blood glucose concentration? (1)
4.4-6.1 mmol/L
What antibodies result in Graves’ disease?
TSH receptor antibodies
What is the action of angiotensin-converting enzyme? (1)
Where does this happen? (1)
Converts angiotensin I to angiotensin II
In the lungs
What medications may be used to replace the missing hormones in adrenal insufficiency? (2)
1) hydrocortisone (glucocorticoid to replace cortisol)
2) fludrocortisone (mineralocorticoid to replace aldosterone)
What are the initial medical treatments for diabetic ketoacidosis? (3)
1) Fluid therapy –> 0.9% saline
2) With added potassium
3) Fixed rate insulin infusion
What are the causes of thyroiditis? (4)
1) Hashimoto’s thyroiditis
2) Post-partum thyroiditis
3) Drug-induced thyroiditis
4) De Quervain’s thyroiditis
What medications are particularly known to cause hypothyroidism? (2)
1) Amiodarone
2) Lithium
What TSH and T4 results would you expect in secondary hypothyroidism? (2)
1) Low TSH
2) Low T4
What class of medication may be used to treat severe hyponatraemia caused by SIADH?
Vasopressin receptor antagonists (e.g. tolvaptan)
What medical treatments are available for controlling the symptoms of a phaeochromocytoma before surgery? (2)
1) Alpha blockers (e.g. phenyoxybenzame or doxazocin)
2) Beta blockers (only when established on alpha blockers)
Role of alpha blockers & beta blockers in a pheochromocytoma?
Initial treatment with alpha blockers –> to control BP.
Once established on alpha blockers, add beta blockers –> to control HR.
1st line alpha blocker in a pheochromocytoma?
Phenoxybenzamine
At what threshold are ACE inhibitors started to treat chronic kidney disease in type 2 diabetics? (1)
Albumin to creatinine ratio (ACR) above 3mg/mmol
What dynamic function test is used to test for adrenal insufficiency? (1)
Short synacthen test
What is the mechanism of action of sitagliptin and alogliptin? (1)
DPP-4 inhibitors
What term describes a discoloured, waxy, oedematous appearance to the skin on the anterior aspect of the leg in patients with Graves’ disease?
Pretibial myxoedema
What term describes hand swelling and finger clubbing caused by Graves’ disease?
Thyroid acropachy
Where is adrenaline normally produced?
Chromaffin cells in the medulla in the adrenal gland.
What medication may be used to treat diabetes insipidus caused by a hormone deficiency?
Desmopressin
What is the action of angiotensin II? (3)
1) Vasoconstriction of blood vessels
2) Stimulates release of aldosterone from adrenal glands
3) Contributes to cardiac remodelling by promoting hypertrophy of heart muscle
What is the HbA1c target for type 2 diabetics that require more than one anti-diabetic drug?
53 mmol/mol
What is the first-line anti-thyroid drug for primary hyperthyroidism?
Carbimazole
What are 2 major side effects of carbimazole?
1) acute pancreatitis
2) agranulocytosis
What is the classic triad of symptoms of hyperglycaemia seen in type 1 diabetes?
1) polyuria
2) polydipsia
3) weight loss
What is the major risk of rapidly correcting longstanding severe hyponatraemia?
Osmotic demyelination syndrome (AKA central pontine myelinolysis).
What test is used 1st line to test for acromegaly?
Serum IGF-1 levels
What dynamic function test is used to test for diabetes insipidus?
Water deprivation test
What gastrointestinal disorder are all patients with a new diagnosis of type 1 diabetes screened for?
Coeliac disease
What is the second-line anti-thyroid drug for primary hyperthyroidism?
Prophylthiouracil
What is the major risk associated with prophylthiouracil?
Severe liver reactions
What are the options for treating severe hypoglycaemia where the patient has reduced consciousness? (2)
1) IV dextrose
2) IM glucagon
What three criteria need to be met for a diagnosis of diabetic ketoacidosis? (3)
1) Hyperglycaemia (>11 mmol/L)
2) Ketosis (e.g. blood ketones >3 mmol/L)
3) Acidosis (pH <7.3)
What is the most common cause of acromegaly?
Pituitary adenoma
What HbA1c range indicates type 2 diabetes? (1)
48 mmol/mol or above
What are the top causes of SIADH? (3)
1) Drugs e.g. SSRIs, MDMA
2) Post-operative
3) SCLC
What is postop hyponatraemia caused by?>
Surgical stress, which causes SIADH.
What causes bronze hyperpigmentation in Addison’s disease?
Excessive ACTH (in response to low cortisol & aldosterone) stimulates the melanocytes to produce melanin.
What is involved in a basal-bolus regime for type 1 diabetes? (2)
Background long-acting insulin injected once a day.
Short acting insulin injected 30 mins before consuming carbs.
What genetic disorders are associated with the development of phaeochromocytomas? (3)
1) MEN2
2) Neurofibromatosis type 1
3) Von Hippel Lindau
What are the causes of primary hyperthyroidism? (4)
1) Grave’s disease
2) Thyroiditis
3) Solitary toxic thyroid nodule
4) Toxic multinodular goitre
What is the 1st line insulin regime in children with T1DM?
Twice daily mixed preparation of insulin
What is a myxoedemic coma?
A potentially fatal complication of undiagnosed hypothyroidisim or poor adherence to levothyroxine therapy.
How is a myxoedemic coma treated?
With IV thyroxine (for low levels of thyroid hormone) and hydrocortisone (to manage the potential possibility of adrenal insufficiency).
What are 2 key complications of subclinical hyperthyroidism?
1) osteoporosis
2) AF
Which class of diabetes drug is associated with an increased risk of bladder cancer?
Thiazolidinediones (particularly pioglitazone)
What is fasting glucose & random glucose values for diagnosis of T2DM?
Fasting: ≥7.0 mmol/l
Random: ≥11.1 mmol/l (or after 75g OGTT)
What is fasting glucose & random glucose values for diagnosis of impaired fasting & impaired glucose tolerance?
Fasting: ≥6.1 but <7 mmol/l
Tolerance: >7.8 but ≤11.1 mmol/l
What does TFTs show in sick euthyroid?
Low T3/T4 and normal TSH with acute illness
Why is HbA1c not recommended in the diagnosis of diabetes?
As it may not accurately reflect a recent rapid rise in serum glucose
What is the max dose of metformin in diabetes?
1g BD
Which diabetes drug is contraindicated in active foot disease such as skin ulceration?
SGLT-2 inhibitors - due to possible increased risk of toe amputation
What is an important blood test to perform in unwell patients on carbimazole?
FBC - risk of agranulocytosis
Diabetic foot disease occurs 2ary to which 2 main factors?
1) Neuropathy
2) PAD
What are the 2 key features of 1ary hyperaldosteronism?
1) HTN
2) Hypokalaemia e.g. muscle weakness
How can a splenectomy affect HbA1c levels?
Can give a falsely high HbA1c level due to increased lifespan of RBCs.
How long is carbimazole indicated for in Grave’s disease?
12-18 months
Carbimazole induces remission of Graves’ disease and therefore is only needed for a period of 12-18 months usually.
How should levothyroxine dose be adjusted in pregnancy?
Increased by up to 50% as early as 4-6 weeks of pregnancy
Management of a patient with Addison’s who is vomiting?
Take IM hydrocortisone until vomiting stops
How can HIV lead to adrenal insufficiency?
Adrenal insufficiency affects approx. 10% of patients with HIV, commonly due to CMV-related necrotising adrenalitis.
HIV increases susceptibility to CMV infection, and thus risk of CMV-associated adrenal failure.
Mx –> steroid replacement.
How is a thyroid storm treated? (3)
1) Beta blockers
2) Propylthiouracil
3) Hydrocortisone
What is a thyroid storm?
A rare but life-threatening complication of thyrotoxicosis.
It is typically seen in patients with established thyrotoxicosis and is rarely seen as the presenting feature.
What should be used to assess for diabetic neuropathy in the feet?
A 10g monofilament
