Endocrinology

Question 1

What is type 1 diabetes?

Answer 1

When the pancreas stops being able to produce insulin - autoimmune destruction of beta cells leading to insulin deficiency

Question 2

Causes of T1DM?

Answer 2

May be genetic component - HLA 6 predisposition

Viruses - Coxsackie B virus and enterovirus.

Question 3

What is glucagon?

Answer 3

A hormone that increases blood sugar levels. It is produced by the alpha cells in the Islets of Langerhans in the pancreas.

It is a catabolic hormone (a breakdown hormone). It is released in response to low blood sugar levels and stress.

Question 4

What is glycogen?

Answer 4

The stored form of glucose in muscle and liver cells

Question 5

What is glycogenolysis?

Answer 5

The breakdown of glycogen into glucose in the liver

Question 6

What is gluconeogenesis?

Answer 6

Conversion of proteins and fats into glucose in the liver

Question 7

What is ketogenesis?

Answer 7

When there is insufficient supply of glucose, and glycogens stores are exhausted, such as in prolonged fasting.

The liver takes fatty acids and converts them to ketones.

Ketones are water soluble fatty acids that can be used as fuel. They can cross the blood brain barrier and be used by the brain.

Question 8

Sx of T1DM

Answer 8

Polyuria
Polydipsia
Wgt loss
Ketoacidosis (fruity breath smell)
Excessive tiredness
Polyphagia

Question 9

Ix for T1DM

Answer 9

Normal glucose levels - 11.1 plasma glucose

Patient has DM if:

Fasting glucose - >5.5 - 7 plasma glucose

HbA1c - 6.5% / 48 mmol/mol

Question 10

Tx of T1DM

Answer 10

1. Basal bolus regime - a combination of a background, long acting insulin given once a day, and a short acting insulin injected 30 minutes before the intake of carbohydrates (i.e. at meals).
2. Insulin pump - small devices that continuously infuse insulin at different rates to control blood sugar levels. The pump pushes insulin through a small plastic tube (cannula) that is inserted under the skin. The cannula is replaced every 2 – 3 days.

Question 11

DKA Sx

Answer 11

Diabetes Sx + confusion, vomiting, dehydration

Question 12

DKA Tx

Answer 12

If px alert - insulin injection
If px confused - Fluid replacement with IV 0.9% sodium chloride + insulin

Question 13

Hypoglycaemia acute Tx

Answer 13

IV dextrose and intramuscular glucagon.

Question 14

Macrovascular complications of DM

Answer 14

Coronary artery disease

Peripheral ischaemia causes poor healing, ulcers and “diabetic foot”
Stroke

Hypertension

Question 15

Microvascular complications of DM

Answer 15

Peripheral neuropathy

Retinopathy

Nephropathy

Question 16

What is the pathophysiology of T2DM?

Answer 16

Insulin resistance, where the body’s cells become less responsive to the effects of insulin. This resistance results in impaired glucose uptake by cells.

Question 17

T2DM RF

Answer 17

Genetics
Obesity
Physical inactivity
Age
Race/ethnicity

Question 18

Tx of T2DM

Answer 18

1st line → Metformin

If Hba1c is >58 then add:
2nd line → DPP4i or SGLT2-i or sulfonylurea or pioglitazone (based on individual factors and drug tolerance)

If not effective then add:
3rd line → insulin (triple therapy)

Question 19

What is the mechanism of action of sulfonylureas?
Plus give an example.

Answer 19

Stimulate the pancreas to release more insulin by binding to specific receptors on pancreatic beta cells.

Example - gliclazide

Question 20

What is the mechanism of action of DPP-4 Inhibitors?
Plus give an example.

Answer 20

DPP-4 is an enzyme that breaks down incretins, hormones that stimulate insulin release and reduce glucagon secretion.

DPP-4 inhibitors block the action of DPP-4, increasing the levels of incretins.

Example - sitagliptin

Question 21

What is the mechanism of action of SGLT-2 Inhibitors?
Plus give an example.

Answer 21

SGLT-2 is a protein responsible for reabsorbing glucose in the kidneys, allowing it to be excreted in the urine.
SGLT-2 inhibitors block the action of SGLT-2, leading to increased urinary glucose excretion.

Example - dapagliflozin

Question 22

Define thyrotoxicosis aka thyroid storm

Answer 22

Abnormal and excessive quantity of thyroid hormones in the body.

Question 23

Describe step by step release of TSH into blood?

Answer 23

Hypothalamus detects low T3 and T4 levels in blood = releases TRH (thyrotropin-releasing hormone) = stimulates anterior pituitary gland = release of TSH into blood = acts on thyroid gland = inc. release of T3 and T4 into blood

Question 24

What is Graves disease?

Answer 24

Autoimmune condition where TSH receptor antibodies cause primary hyperthyroidism. TSH antibodies are abnormal antibodies that mimic TSH and stimulates TSH receptors on thyroid to release T3 and T4.

Question 25

Causes of hyperthyroidism

Answer 25

G - Graves’ disease MC
I - Inflammation (thyroiditis)
S - Solitary toxic thyroid nodule
T - Toxic multinodular goitre

Question 26

Hyperthyroidism Sx

Answer 26

Anxiety and irritability
Sweating and heat intolerance
Tachycardia
Weight loss
Fatigue
Insomnia
Diarrhoea
Sexual dysfunction

Question 27

Sx specific to Graves’ disease

Answer 27

Diffuse goitre (without nodules)

Exophthalmos

Pretibial myxoedema - skin condition caused by deposits of glycosaminoglycans under the skin on the anterior aspect of the leg

Thyroid acropachy - hand swelling and finger clubbing

Question 28

Ix for hyperthyroidism

Answer 28

Bloods:
TSH level (primary = low, secondary = high)
Free T4 and T3 (high)
TSH receptor antibodies (+ve)

Question 29

Hyperthyroidism Tx

Answer 29

1st line: Carbimazole
if high dose - levothyroxine can be added

2nd line: Propylthiouracil

Radioactive iodine - drinking a single dose of radioactive iodine. The thyroid gland takes this up, and the emitted radiation destroys a proportion of the thyroid cells.
requires long-term levothyroxine

Question 30

Side effects of taking carbimazole and propythiouracil?

Answer 30

Carbimazole: acute pancreatitis

Both: Agranulocytosis, with a dangerously low white blood cell counts. Agranulocytosis makes patients vulnerable to severe infections. A sore throat is a key presenting feature of agranulocytosis.

Question 31

Pre-cautions of radioactive iodine use

Answer 31

Women must not be pregnant or breastfeeding and must not get pregnant within 6 months of treatment

Men must not father children within 4 months of treatment

Limit contact with people after the dose, particularly children and pregnant women

Question 32

Sx of thyrotoxicosis

Answer 32

Presentation of hyperthyroidism with fever, tachycardia and delirium.

Question 33

Tx of thyrotoxicosis

Answer 33

Propylthiouracil - preferred tx

Question 34

Describe Hashimoto’s thyroiditis

Answer 34

Autoimmune condition causing inflammation of the thyroid gland. It is associated with anti-thyroid peroxidase (anti-TPO) antibodies and anti-thyroglobulin (anti-Tg) antibodies.

Question 35

Causes of hypothyroidism?

Answer 35

Hashimoto’s thyroiditis MC
Iodine deficiency *
Lithium
Pituitary adenomas

Question 36

Sx for hypothyroidism + specific sx in Hashimoto’s?

Answer 36

Weight gain
Fatigue
Dry skin
Coarse hair and hair loss
Fluid retention (including oedema, pleural effusions and ascites)
Heavy or irregular periods
Constipation

Hashimoto’s - initially cause a goitre, after which there is atrophy (wasting) of the thyroid gland.

Question 37

Ix of hypothyroidism?

Answer 37

Bloods:
TSH level (primary = high, secondary = low)
Free T4 and T3 (low)

Question 38

Tx of hypothyroidism

Answer 38

Oral levothyroxine (T4)