Diabetes Mellitus

Question 1

What are the risk factors for the development of Type 1 diabetes? Outline the pathophysiology

Answer 1

• Genetic predisposition
• Autoimmune beta islet cell destruction leading to an absolute insulin deficiency

Question 2

What is the typical presentation of a patient with Type 1 diabetes?

Answer 2

• Polydipsia
• Polyuria
• Weight loss
• Ketosis

Question 3

How is diabetes mellitus diagnosed? How are Type 1 and Type 2 distinguished?

Answer 3

• Diagnosis: any of the following
  
  • Symptoms and RBG of > 11.1 mmol/L OR
    
    • FBG of > 7.0 mmol/L
  • HbA1c > 6.5%
  • 2hr value > 11.1 mmol/L in the OGTT
• Distinction
  
  • Predominantly history/symptom/RF based
  • Antibody testing (may be positive in T1D)
  • C-peptide testing (likely to be higher in T2D)

Question 4

What are the long term complications of hyperglycaemia?

Answer 4

• Retinopathy
• Neuropathy
• Nephropathy
• Diabetic foot syndrome
• Atherosclerosis

Question 5

Describe the two main dosing regimes used in type 1 diabetes

Answer 5

• Biphasic
  
  • Long and short acting insulin administered twice daily
  • Peaks cover mealtimes
• QDS regime
  
  • Long acting insulin administered once daily
  • Short acting insulin administered before mealtimes
  • More flexible around mealtimes/exercise

Question 6

Describe the main management principles used in the treatment of type 2 diabetes

Answer 6

• Decrease CV risk factors
  
  • Smokin cessation, ACEIs, diuretics, statins, antiplatelet therapy, lifestyle changes
• Oral anti-hyperglycaemics
  
  • Metformin (biguanide increasing insulin sensitivity and promoting weight loss) (?AND)
  • Gliclazide (sulfonylurea) (?AND)
  • Basal insulin dose (long-acting) (?AND)
  • Gliptins, GLP-1 agonists, a-glucosidase inhbitors, SGLT1-inhibitors

Question 7

Describe the mode of action of metformin. What are the important side-effects?

Answer 7

Increases insulin sensitivity

Lactic acidosis (especially in elderly and renal failure)

Question 8

Describe the mode of action of sulfonylureas. What are the important side-effects?

Answer 8

Increase in beta-islet cell insulin output

Hypos, weight gain

Question 9

Describe the mode of action of SGLT-2 inhibitors. What are the important side-effects?

Answer 9

Prevents renal reabsorption of glucose, promotes glycosuria

Can mask DKA (intracellular glucose may be low even with low blood sugars)