Diabetes and DKA

Question 1

Two hormones involved in regulating the passage of glucose into cells

Answer 1

Insulin (fed state - more glucose in blood)

Glucagon (starved state - more glucose in blood)

Question 2

Cells producing insulin and glucagon

Where are they found?

Answer 2

Islet of Langerhans cells in the pancreas

Alpha cells on periphery of islet - glucagon

Beta cells in centre of islet - insulin

Question 3

How does insulin cause glucose to pass into cells?

Answer 3

Binds with insulin receptor (tyrosine kinase receptor) on surface of target cell, which causes vesicles within cell to bind with cell surface and create glucose transport channels

Question 4

Difference between type I and type II DM

Answer 4

Type I - body can’t make enough insulin, type IV hypersensitivity results in destruction of beta cells

Type II - body’s cells don’t respond to insulin, and it is eventually produced less

Question 5

What chromosome is HLA found on?

Answer 5

Chromosome 6

Question 6

Symptoms of T1DM

Why do these happen?

Answer 6

Polyphagia - glucose can’t get into cells despite being present in high amounts in blood. Body breaks down fats and proteins instead for energy, resulting in weight loss = hunger

Glycosuria and Polyuria - kidneys unable to filter all glucose so some is excreted in urine. Glucose is osmotically active and so water follows = excessive urination

Polydipsia - dehydration from polyuria causes excessive thirst

Question 7

How is DKA brought about?

Answer 7

Body breaks down fats for energy, resulting in generation of ketone bodies (acetoacetic acid and beta-hydroxybutyric acid), which raises the acidity of the blood

(Kussmaul breathing to compensate - deep and laboured, lowers CO₂ in an attempt to reduce acidity)

Hyperkalaemia also occurs

Excess of ketone bodies (specifically acetone) causes breath to be sweet and fruity

Question 8

How is DKA treated?

Answer 8

Fluid replacement

Insulin

Replace electrolytes

Question 9

What is Hyperosmolar Hyperglycaemic State (HHS)?

What type of DM is it most commonly seen in?

Answer 9

Increased plasma osmolarity due to extreme dehydration and concentration of the blood. Excess glucose in blood causes water to move from cells into circulation (remember glucose is osmotically active!)

Results in increased urination and total body dehydration

Much more common in T2DM