Diabetes Mellitus

Question 1

Types of Diabetes Mellitus

Answer 1

1. Type 1
2. Type 2
3. MODY - maturity onset diabetes of the young
4. Pancreatic diabetes - pancreatitis, surgery, cancer
5. Endocrine diabetes - acromegaly, Cushing’s
6. Malnutrition related diabetes

Question 2

Define Diabetes Mellitus

Answer 2

A disease in which the body is unable to produce/respond to insulin normally, resulting in abnormal carbohydrate metabolism and increased blood glucose

Question 3

Type 1 pathology

Answer 3

Autoimmune disease in which beta cells are destroyed resulting in cessation of insulin production. Glucose can’t be transported into cells -> high blood glucose

Question 4

Type 2 pathology

Answer 4

Peripheral insulin resistance -> more insulin produced to have same effect (beta cell hyperplasia), normoglycaemia -> amylin secretion by beta cells -> beta cell hypoplasia and hypotrophy -> decreased insulin production -> high blood glucose

Question 5

RF T2DM (10)

Answer 5

1. > 40yrs
2. Men
3. South Asian, Black-Caribbean, Black-African (>25y)
4. Obesity
5. Hypercholesterolaemia
6. Sedentary lifestyle
7. Family history
8. HTN
9. Smoking & alcohol
10. PCOS (polycystic ovary syndrome)

Question 6

Diagnosis of T2DM

Answer 6

1. Symptoms and 1 abnormal blood glucose test (fasting>7mmol/L, random >11.1mmol/L)
2. 2 abnormal blood glucose tests (as above, oral glucose tolerance test 2h >11.1mmol/L)
3. Abnormal HbA1c

Question 7

HbA1c level ranges

Answer 7

Normal <42mmol/mol
Pre-diabetic 42-47mmol/mol
Diabetic >48mmol/mol

Question 8

When to avoid HbA1c

Answer 8

1. Pregnancy
2. Type 1
3. Children
4. Haemoglobinopathies

Question 9

Symptoms of hyperglycaemia

Answer 9

1. Polydipsia
2. Polyphagia
3. Glycosuria
4. Polyuria

Question 10

Explain symptoms of hyperglycaemia

Answer 10

High blood glucose damages nephrons, causing glycosuria. High osmolarity of filtrate draws in water - polyuria. Dehydration from polyuria causes polydipsia. Cells starved of glucose causes hunger and weight loss due to lipo and proteolysis.

Question 11

Diagnosis of T1DM

Answer 11

1. Fasting glucose (8h w/o food) >7mmol/L
2. Random glucose >11.1mmol/L
3. Hyperglycaemic symptoms with 1 or more of
   
   • Ketoacidosis
   • Rapid weight loss
   • Onset <5y/o
   • BMI<25
   • FHx of autoimmune disease

Question 12

RF T1DM (2)

Answer 12

1. HLA-DR3, HLA-DR4 gene (FHx autoimmune disease)

2. PMH of autoimmune disease

Question 13

T1DM treatment

Answer 13

Insulin

Question 14

T2DM management

Answer 14

1. Lifestyle and diet modification (low sat fat, sugar, high starch-carb)
2. Monotherapy - metformin
3. Dual therapy (if HbA1c >58mmol/mol)
   
   • Metformin + DDP4 inhibitor
   • Metformin + pioglitazone
   • Metformin + sulphonylurea (SU)
   • Metformin + SGLT-2i
4. Triple therapy (if HbA1c >58mmol/mol)
   
   • Metformin + DDP4 inhibitor + SU
   • Metformin + pioglitazone + SU
   • Metformin + SU/pioglitazone + SGLT-2i
   • Insulin based therapy

Question 15

Metformin

Answer 15

Biguanide. Increases insulin sensitivity and helps with weight
SE: nausea, diarrhoea (try modified release), abdominal pain
Avoid if eGFR <36mL/min - risk of lactic acidosis

Question 16

DPP4-inhibitors

Answer 16

E.g Sitagliptin

Block DDP4 action - enzyme that destroys incretin

Question 17

Pioglitazone

Answer 17

Increases insulin sensitivity
SE: hypoglycaemia, fractures, fluid retention, increase LFT
CI: CCF, osteoporosis, increasing weight/oedema

Question 18

Sulphonyurea

Answer 18

Increase insulin secretion

SE: hypoglycaemia

Question 19

SGLT-2i

Answer 19

Selective sodium-glucose co-transporter 2 inhibitor.

Blocks reabsorption of glucose in the kidneys and promotes secretion of excess glucose in urine

Question 20

Annual diabetic review (9)

Answer 20

1. HbA1C test
2. BP
3. BMI
4. Plasma lipids
5. Visual acuity and retina state
6. Urine test for proteinuria, microalbuminuria
7. Renal function blood test - creatinine
8. Check condition of feet, pulses, neurology
9. Review of CV RF

Question 21

Define hypoglycaemia

Answer 21

Plasma glucose <3mmol/L

Question 22

Causes of hypoglycaemia (diabetic) (4)

Answer 22

• Insulin or SU treatment
• Increased activity
• Missed meal
• Accidental/non-accidental overdose

Question 23

Symptoms of hypoglycaemia

Answer 23

Autonomic: sweating, anxiety, hunger, tremor, palpitations, dizziness, tachycardia
Neuroglycopenic: confusion, drowsiness, visual trouble, seizures, coma

Question 24

Complications of diabetes (8)

Answer 24

1. Vascular disease
2. Nephropathy
3. Diabetic retinopathy
4. Cataracts - senile or snowflake
5. Rubeosis iridis (new vessels on iris - lead to glaucoma)
6. Metabolic complications
7. Diabetic feet
8. Neuropathy

Question 25

Treatment of hypoglycaemia (3)

Answer 25

1. 15-20g quick-acting carbohydrate snack and recheck blood glucose after 10-15mins 2. If conscious but uncooperative, squirt glucose gel in gums and teeth 3. Glucose IVI or glucagon 1mg/IVI

Question 26

3 key features of Diabetic Ketoacidosis (DKA)

Answer 26

1. Hyperglycaemia 2. Raised plasma ketones 3. Metabolic acidosis

Question 27

Pathogenesis of DKA

Answer 27

1. Insufficient insulin -> unrestrained gluconeogenesis in the liver 2. Dehydration due to osmotic diuresis in the kidneys as a result of hyperglycaemia 3, Peripheral lipolysis -> lots of FFAs in the blood -> converted into ketones in the liver -> metabolic acidosis

Question 28

Clinical features of DKA (7)

Answer 28

1. Dehydration (reduced tissue turgor pressure -> skin takes longer to snap back into place) 2. Vomiting and abdominal pain (electrolyte disturbance) 3. Sunken eyes and dry tongue 4. Low BP 5. Kussmaul's breathing (deep and rapid - respiratory compensation) 6. Fruity breath (ketones) 7. Low body temp

Question 29

DKA investigations

Answer 29

1. Blood glucose >11mmol/L 2. Ketonaemia - finger prick sample measuring b-hydroxybutyrate 3. Acidaemia - pH < 7.35 4. Urine dipstick - glycosuria and ketouria 5. U&E - creatinine and urea high, serum potassium high (low insulin allows to shift out cells), low total body potassium (osmotic diuresis)

Question 30

Management of DKA

Answer 30

1. Fluid replacement - NaCl 0.9% 2. IV glucose - 6 units/hour 3. Electrolytes

Question 31

Symptoms of diabetic neuropathy (8)

Answer 31

1. Numbness or reduced ability to feel temp/pain in fingers and toes, glove and stocking distribution 2. Tingling/burning sensation 3. Sharp pains or cramps 4. Hypersensitivity 5. Muscle weakness 6. Hyporeflexia - particularly in ankle 7. Loss of balance and coordination 8. Foot issues - ulcers, infection, amputation

Question 32

Symptoms of diabetic retinopathy (6)

Answer 32

1. Spots or floaters in vision 2. Blurred vision 3. Fluctuating vision 4. Impaired colour vision 5. Dark or empty areas in vision 6. Vision loss

Question 33

Investigations for diabetic retinopathy

Answer 33

Fundoscopy - cotton wool spots and flare haemorrhages

Question 34

Pathophysiology of diabetic nephropathy (3)

Answer 34

1. Glomerular disease 2. Ischaemic renal lesions 3. Ascending UTIs