Endocrinology conditions

Question 1

Whilst type 1 diabetes mellitus is due to relative insulin deficiency, type 2 DM is due to relative insulin….

Answer 1

…resistance

Question 2

What percentage of those with DM have type 2?

Answer 2

90%

Question 3

Does type 1 or type 2 DM have a higher twin concordance?

Answer 3

Type 2 (80%)
Type 1 (30%)

Question 4

What test results indicate diabetes?

Answer 4

Venous blood glucose either >7mmol/L fasting or >11mmol/L random.
Oral glucose tolerance test - HbA1c >48mmol/L

Question 5

What treatments are given in DM?

Answer 5

Control CV risk with ACE-i, statin and low dose aspirin
Type 1: Insulin will always be required
Type 2: 3 main drugs - biguanide (metformin), sulfonylureas, thiazolidendiones. May eventually need insulin. Bariatric surgery can be curative.

Question 6

What causes hypothyroidism?

Answer 6

Iodine deficiency (presents with goitre)
Hashimoto’s thyroiditis (autoimmune)
Primary atrophic hypothyroidism (common, no goitre)
Iatrogenic
Drugs (amiodarone, lithium, carbimazole)
Subacute thyroiditis
Secondary hypothyroidism (caused by hypopituitarism, very rare)

Question 7

Symptoms of hypothyroidism?

Answer 7

Fatigue, low mood, cold intolerance, weight gain, constipation, menorrhagia, hoarse voice, reduced memory/cognition, dry skin, loss of outer third of eyebrow, thin hair
SIGNS: pre-tibial myxoedema, bradycardia, delayed tendon reflex relaxation, goitre

Question 8

What will TFTs show in primary hypothyroidism and primary hyperthyroidism?

Answer 8

Hypo-: High TSH, low T3 and T4

Hyper-: Low TSh, high T3 and T4

Question 9

What causes hyperthyroidism?

Answer 9

Graves’ disease (most common, autoimmune)
Toxic multinodular goitre (nodules secrete T3+4, seen in elderly and iodine deficient areas)
Toxic thyroid adenoma
Ectopic thyroid tissue
Iodine excess from food contamination/contrast media/drugs
Secondary hyperthyroidism (TSH secreting pituitary adenoma
Gestational thyrotoxicosis (TSH, T3 and T4 all high)

Question 10

Symptoms of hyperthyroidism?

Answer 10

Diarrhoea, weight loss, increased apetite, over-activity, sweating, heat intolerance, palpitations, tremor, irritability, labile emotions, oligomenorrhoea
SIGNS: palmar erythema, sweaty palms, fine tremor, tachycardia/AF, brisk reflexes, goitre, proximal myopathy, gynaecomastia, lid lag
Graves: exomphthalmous, ophthalmoplegia, pretibial myxoedema, thyroid acropachy, thyroid bruits

Question 11

How is hyperthyroidism managed?

Answer 11

Anti-thyroid medication (carbimazole)
Radio-iodine (most become hypothyroid)
Surgery - thyroidectomy

Question 12

Frequency of goitres that may be a sign of thyroid cancer?

Answer 12

1 in 20

Question 13

What is Cushing’s syndrome?

Answer 13

Clinical state produced by chronic glucorticoid excess and loss of normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis and loss of circadian rhythm of cortisol secretion

Question 14

What are the ACTH-dependent causes of Cushing’s syndrome?

Answer 14

Cushing’s disease (anterior pituitary adenoma secretes excess ACTH)
Ectopic ACTH production (small cell lung cancer and carcinoid tumours)
Ectopic CRH production (some thyroid and prostate cancer)

Question 15

What are the ACTH-independent causes of Cushing’s syndrome?

Answer 15

Iatrogenic (most common, prolonged glucocorticoid administration)
Adrenal adenoma/carcinoma
Adrenal nodular hyperplasia
Carney complex

Question 16

Symptoms of Cushing’s syndrome?

Answer 16

Weight gain, mood change, proximal weakness, gonadal dysfunciton, acne, recurrent Achilles tendon rupture.
Some get skin pigmentation
SIGNS: central obesity, plethoric, moon face, buffalo neck hump, supraclavicular fat distribution, skin and muscle atrophy, bruises, purple abdominal striae, osteoporosis, high BP, high glucose, infection prone, poor healing

Question 17

What are the 1st line tests for suspected Cushing’s syndrome?

Answer 17

Overnight dexamethasone suppression test

24hr urinary free cortisol

Question 18

What 3 actions does parathyroid hormone produce?

Answer 18

1. Increased osteoclast activity releasing Ca++ and Phosphate from bones
2. Increased Ca++ and decreased Phos reabsorption in kidney
3. Active 1,25 dihydroxy-vitamin D3 production

Question 19

Symptoms of hyperparathyroidism?

Answer 19

STONES: renal stones, polyuria, polydipsia
BONES: osteoporosis, osteomalacia, arthritis
MOANS: lethargy, fatigue, weakness, depression, memory loss, psychosis, ataxia, delirium
GROANS: Constipation, indigestion, N+V, peptic ulcers, acute pancreatitis

Question 20

What is Addison’s disease?

Answer 20

Adrenal insufficiency
Primary - destruction of glands (80% due to autoimmunity)
Secondary - iatrogenic, commonly due to long term steroid use which suppresses pituitary-adrenal axis

Question 21

Symptoms of Addison’s disease?

Answer 21

Lean, tired, tanned and tearful, weakness, anorexia, dizzy, faints, flu-like myalgia, depression, psychosis, low self-esteem.

Question 22

How is Addison’s disease managed?

Answer 22

Replace steroids. Daily hydrocortisone PO (glucocorticoid), fludrocortisone (mineralocorticoid)