Type I DM

Question 1

How common is it?

Answer 1

10% of all diabetes.

- In UK 1 in 300 develop type 1 DM at some stage.

Question 2

Who does it affect?

Answer 2

• Usually adolescent onset but can occur at any age.

Question 3

What risk factors are there?

Answer 3

• Association with other autoimmune disorders (>90% carry HLA DR3 ± DR4).
• Family history
• Concordance only 30% in identical twins, indicating environmental influence.
• Geography – Incidence increases as you get further away from the equator.

Question 4

How does it present?

Answer 4

• Polydipsia, polyuria, lethargy, boils, pruritus vulvulae.

- Specific to type 1 – weight loss, dehydration, ketonuria, hyperventilation.

Question 5

Which other conditions may present similarly?

Answer 5

• Type II DM, monogenic DM, secondary hyperglycaemia, disorders of target tissues, other endocrine hypersecretion disorders, drugs, chronic pancreatitis, CF, prader-willi syndrome, non-diabetic glycosuria, renal glycosuria, peripheral neuropathy from alcohol abuse of B12 deficiency.

Question 6

Investigations?

Answer 6

Diagnosis

• Symptoms of hyperglycaemia AND raised venous glucose detected once – fasting >7mmol/L or random >11.1mmol/L OR
• Raised venous glucose on 2 separate occasions – fasting >7mmol/L, random >11.1mmol/L or oral glucose tolerance test (OGTT) – 2h value >11.1mmol/L
• HbA1c >48mmol/L but below doesn’t exclude DM. Avoid in pregnancy, children and type 1 DM.

Question 7

What treatments would you consider?

Answer 7

• Specific to type 1 – Insulin.
• General – structured education programme, offer lifestyle advice, start a statin, give foot care, advise informing DVLA and not to drive if hypoglycaemic spells. Capillary glucose analysis, exercise, diet (↓sat fats, ↓sugar, ↑starch carbs, moderate protein).