Clinical aspects of Diabetes Mellitus and Complications

Question 1

How is DM diagnosed ?

Answer 1

 Glycated Haemoglobin≥48mmol/mol

 Fasting blood glucose≥7.0mmol/L (on two occasions)

 2hr blood glucose≥11.1mmol/L following OGTT

 Random blood glucose≥11.1mmol/L in presence of symptoms

Question 2

Identify other types of diabetes besides type I and II.

Answer 2

• Genetic (Maturity onset diabetes of the young)
• Pancreatic disease
• Endocrine disease
• Drugs

 Gestational diabetes (occurs in pregnancy)

Question 3

Identify the main autoantibodies present in type I DM.

Answer 3

• antibodies against islet cell
• antibodies against Insulin
• GAD (GAD65) autoantibody
• antibodies against tyrosine phosphatases

Question 4

Describe the genetics of type I DM.

Answer 4

Strong HLA associations
• linkage to the DQA and DQB genes
• influenced by the DRB genes.

Question 5

Describe the ideal diet for a diabetic patient.

Answer 5

• Protein 15%
• Carbohydrate 50%
  (mainly starches, less simple carbs)
• Fat 35%
• Fibre (to slow down gut transit, so glucose peak slower)

Question 6

Identify the main components of education for type I DM patients.

Answer 6

• Diet
• Hypoglycaemia (what will happen if sugars drops too much when start on insulin)
• Sick day rules (how to respond to intercurrent illness)
• Monitoring (blood and urine)
• Driving
• Alcohol
• Smoking
• Insulin card
• Pregnancy/ Contraception (may change this if DM)
• Complications (acute and chronic)

Question 7

How is DM type 1 monitored ?

Answer 7

• Glucose meter

- FreeStyle Libre (reads interstitial glucose)

Question 8

What is Diasent (in the context of DM type I) ?

Answer 8

Software which allows practitioner to see patterns of blood glucose over time (e.g. last two weeks, last two months etc.)

Question 9

What is the significance of Glycated Hb ?

Answer 9

Glycated Haemoglobin (HbA1c) is a marker for average blood sugar over past two to three months

Question 10

How many time is insulin given per day ?

Answer 10

Usually, once or twice daily intermediate acting insulin (e.g. Isophane or mixture using short acting and long acting)

Multiple injections/basal bolus (background basal insulin once a day, and everytime patient eats, depending on amount of carbs in the meal, give amount of insulin to match that)

Question 11

Describe clinical features and their timeline in type 2 diabetes.

Answer 11

 Thirst, polyuria
 Malaise, fatigue
 Infections e.g. Candidiasis
 Blurred vision
 Complications

MORE CHRONIC, INSIDIOUS PRESENTATION

Question 12

Describe CT findings of type II DM.

Answer 12

More visceral fat present (metabolically active)

Question 13

Identify complications of DM.

Answer 13

ACUTE

• DKA (type 1)
• Hypoglycaemia
• Other emergencies (HyperOsmolar Non-Ketotic coma, Metformin associated Lactic Acidosis)

CHRONIC

• Glycation
• Microvascular (eyes, kidneys, nerves, small vessels)
• Macrovascular (heart, brain, feet)

Question 14

What are the main biochemistry changes occurring in DKA ?

Answer 14

Bicarbonate is low

Glucose is high

Question 15

How does DKA result in impaired excretion of H+ and jketone bodies ?

Answer 15

Insulin deficiency results in:

1) HyperG
Glycosuria
Osmotic diuresis

2) Ketosis
Acidosis
Gastroparesis

1) and 2) lead to:
- V depletion
- Renal hypoperfusion

Which leads to:
-Impaired excretion of H+ and ketone bodies

Question 16

How much water is lost in DKA ?

Answer 16

5 to 10 L

Question 17

Identify symptoms of Hypoglycaemia.

Answer 17

ADRENERGIC

• tachycardia
• palpitations
• sweating
• tremor
• hunger

NEUROGLYCOPAENIC (due to lack of glucose to brain)

• dizziness
• confusion
• sleepiness
• coma
• seizure

Question 18

What is the formal definition of hypoglycaemia ?

Answer 18

Blood glucose <=2.2mmoll-1

Question 19

What are the main causes of hypoglycaemia ?

Answer 19

• Too much insulin
• Too little good
• Unusual exercise

Question 20

What are the mains stages of hypoglycaemia ? Describe the signs and symptoms which occur at each.

Answer 20

1) Below Blood Glucose 4 mmoll-1:
- Autonomic Reaction

2) Below Blood Glucose 3 mmoll-1: Neuroglycopaenia
- Impaired cognitive function
- EEG changes
- Visual dysfunction

3) Below Blood Glucose 2: Biochemical Hypoglycaemia (Behavioral changes)
- Reduced conscious level
- Coma
- Death
- EEG generalised slowing

Question 21

Describe the mechanisms in palace to counter falls in blood glucose.

Answer 21

Falls in blood Glucose
⬇
Vagal stimulation ➔ PSNS ➔ Glucagon Release
⬇
Adrenal Medulla Stimulation ➔ SNS ➔ Adrenaline Release
⬆
Neuroglycopaenia

Both Glucagon release and Adrenaline release result in Glycogen release by liver

Question 22

Describe treatment for hypoglycaemia.

Answer 22

IV 50% Dextrose

Question 23

What are the main features of Hyperosmolar Non-Ketotic coma (HONK) (AKA Hyperosmolar hyperglcemic state) ?

Answer 23

• Elderly patients
• Often undiagnosed
• Associated with intercurrent stress (e.g. may be caused by MI, chest infection)

Question 24

Why does Metformin Associated Lactic Acidosis (MALA) occur ?

Answer 24

“Often associated with pre-existing renal impairment”

Question 25

Describe the chronic complication of glycation.

Answer 25

Increased cross linking and browning of protein, can lead to CT abnormalities (e.g. cannot do prayer sign)

Question 26

Identify the main stages of nephropathy as a chronic complication of DM.

Answer 26

- Hyperfiltration - Normal - Microalbuminuria - Overt Nephropathy - Chronic Renal Failure

Question 27

How is nephropathy (as a chronic complication of DM) managed ?

Answer 27

BP - Aggressive treatment ACEI/AIIRA - Aim is 130/80 or lower Hyperlipidaemia - Statin Good glycaemic control Diet

Question 28

Describe screening for nephropathies.

Answer 28

- Albustix (test for protein) - Microalbuminuria - Creatinine (annual creatinine blood check)

Question 29

What are the main features of microangiopathy as a chronic complication of diabetes ?

Answer 29

- Lumen decreases in size | - Can get ischemic neuropathy, and diabetic foot

Question 30

What are the main steps in foot examination (in the context of diabetes) ?

Answer 30

General appearance “Architecture” Pulses Sensation - Neurosthesiometer (vibration measuring tool) - Monofilament Education (tell patient to look after their feet)

Question 31

Identify the main stages of diabetic retinopathy.

Answer 31

Pre-proliferative to proliferative to advanced eye disease Maculopathy can result from Diabetic Retinopathy (

Question 32

Describe screening for diabetic retinopathy.

Answer 32

Annual if no previous DR More frequent as necessary Using ophthalmoscope, or retinal camera

Question 33

Describe the main features of macrovascular disease as a chronic complication of diabetes.

Answer 33

Atherosclerosis affects heart, brain, large vessels to feet causing foot disease