Diabetes Mellitus

Question 1

Cause of type 1?

Answer 1

HLA associated polygenic autoimmune condition.
Beta cells which produce insulin in the Islets of Langerhans in the pancreas, are destroyed.
Severe insulin deficiency leads to hyperglycaemia.

Question 2

Symptoms of T1?

Answer 2

Childhood onset.

Weight loss, polydipsia, polyuria, can present as DKA.

Question 3

Causes of type 2?

Answer 3

Relative insulin deficiency due to build up of adipose tissue and insulin insensitivity.
Increasing age, obesity, ethnicity, family history, hypertension.
Identical twin risk >50%. Non identical siblings 25%.

Question 4

Symptoms of T2?

Answer 4

Polyuria, polydipsia, retinopathy, skin infections, often picked up on routine testing.

Question 5

What tests are available?

Answer 5

BM/one off blood glucose.
HbA1C- measure of glycosylated Hb. Represents average blood glucose over last 2-3 months.
Glucose tolerance test- take fasting levels, then drink 75mg glucose drink, take again 2 hours later.

For T1: urine dip for glucose and ketones. Fasting and random blood glucose. C-peptide levels are low. Don’t use HbA1c. Test for specific autoantibodies.

Question 6

What might the tests show?

Answer 6

Normal blood glucose should be 3.5-8mmol/L.
HbA1c should be < 6.5%/48mmol/L. >6.5% is indicative.
If patient is symptomatic, diagnosis can be made off:
Fasting blood glucose > 7
Random blood glucose > 11.1.
If asymptomatic then same criteria but on 2 occasions.

Question 7

Type 1 treatment

Answer 7

Monitor BM > 4 times a day, before bed and meals. More often if extra stress on body e.g. illness. BM should be 5-7 after waking and 4-7 before meals.

Multiple daily infection basal/bolus regime.
Twice daily insulin detemir.
Rapid acting insulin analogues before meals.

Question 8

Type 2 treatment

Answer 8

Lifestyle changes- weight loss, exercise, healthy eating.
Oral medication, metformin is 1st line.
HbA1c target is 48 if following lifestyle advice +/- metformin. Changes to target of 53 if on a 2nd drug.

Add in 2nd drug if HbA1c rises to 58. Triple therapy if necessary.

Question 9

When wouldn’t you use HbA1c as a measure of blood glucose?

Answer 9

Haemoglobinopathies, haemolytic anaemia, gestational diabetes, children, HIV, CKD, on corticosteroids.