4.7 Diabetes Mellitus

Question 1

Which is more common: T1DM or T2DM?

Answer 1

T2DM (90% of cases)

Question 2

Describe T1DM pathophys

Answer 2

• Immune mediated reduction of the insulin secreting capacity of beta cells of the pancreas
• Blunted/absent insulin response

Question 3

Describe T2DM pathophys

Answer 3

• Body becomes resistant to normal levels of insulin
• Impaired release of insulin
• Blunted/absent insulin response

Question 4

What are the effects of “incretin” hormones? Where are they released from?

Answer 4

• Promote release of insulin
• Released from duodenum and small intestine

Question 5

What are the two incretin hormones? Which type of cells secrete them?

Answer 5

• Gastric inhibitory peptide (GIP): K cells (Dr K likes this one)
• Glucagon like peptide-1 (GLP-1): L cells (semaglutide is an L)

Question 6

Why might insulin be higher from oral glucose than IV glucose?

Answer 6

• Oral glucose goes through the stomach
• This stimulates incretin hormones; much bigger insulin response

Question 7

What is the final straw that causes frank diabetes?

Answer 7

• Failure of insulin secretion in response to increased resistance
• This leads to much higher blood glucose levels

Question 8

What is C-peptide? Is it high or low in T1DM vs T2DM?

Answer 8

• Byproduct released during insulin secretion
• Low in T1DM
• Normal/high in T2DM

Question 9

What’s the mech for how T1DM can cause diabetic ketoacidosis

Answer 9

• No insulin
• No suppression of Hormone-Sensitive Lipase
• More FFAs in blood
• Excess are converted into ketones; lowers pH; acidosis

Question 10

What are the two most common precipitating factors for diabetic ketoacidosis

Answer 10

• Infection
• Deliberate insulin manipulation

Question 11

Hyperosmolar hyperglycaemic syndrome (HHS) pathophys. Which type of diabetes is it associated with?

Answer 11

• Relative insulin deficiency
• Incr. gluconeogenesis
• Hyperglycaemia
• Diuresis
• Hyperosmolarity :(
• Primarily associated with type 2 diabetes

Question 12

Precipitating factors for HHS

Answer 12

• Infection
• Infarction

Question 13

What are the four tiers, in order, that the body uses to prevent hypoglycaemia as BGL lowers?

Answer 13

1. Insulin suppression
2. Glucagon + adrenaline
3. Growth hormone
4. Cortisol

Question 14

List four autonomic symptoms of hypoglycaemia

Answer 14

• Palpitations
• Shaking
• Sweating
• Hunger

Question 15

Basic treatment algo for hypoglycaemia

Answer 15

• If responsive/cooperative, give high-sugar foods like jelly beans
• If not, give IV glucose

Question 16

What are the two classifications of chronic diabetes complications?

Answer 16

• Microvascular
• Macrovascular

Question 17

What are the three categories of macrovascular complications of diabetes?

Answer 17

1. Heart
2. Brain
3. Extremities

Question 18

What are the three categories of microvascular complications of diabetes?

Answer 18

1. Retino
2. Nephro
3. Neuropathy

Question 19

How do you test for microvascular renal complications of diabetes?

Answer 19

• Urinalysis
• High albumin levels indicate protein leakage -> nephro referral

Question 20

What are the three types of diabetic foot ulcers, as classified according to their causes?

Answer 20

• Neuropathic
• Ischaemic
• Neuroischaemic

Question 21

What is the proposed link between DKA and pancreatitis?

Answer 21

• Elevated lipids
• Parenchymal inflammation
• Ischaemic damage of tissue

Question 22

Proposed link between DKA and DVT

Answer 22

• DKA causes hypercoagulability
• Incr. DVT risk

Question 23

Proposed link between DKA and resp. disturbance

Answer 23

• Acidosis
• Body tries to blow off CO2
• Kussmaul breathing

Question 24

Proposed link between DKA and rebound cerebral oedema

Answer 24

• High BGL sucks fluid from brain via osmosis
• When insulin is given, there’s a rebound rush of fluid into the brain