T1DM

Question 1

define T1DM

Answer 1

loss of beta cells due to progressive AI destruction

Question 2

presentation

Answer 2

usually acute onset of severe symptoms e.g. weight loss, polyuria, thirst, etc.
DKA
pre-school and peri-puberty (but can be any age group)
non-obese (not necessarily)
insulin dependent
FH uncommon

Question 3

diagnosis

Answer 3

• antibodies GAD, IA-2 and ZnT8
• C-peptide is usually still present at diagnosis. for this to be positive it must be low, even undetectable. it becomes low by 3 years in children and 5 years in adults (CONFIRMATORY test)
• genetic risk score (high if 50th centile, 5th T2DM)
• ketones e.g. ketonuria/ketonemia

Question 4

how can C-peptide by investigated?

Answer 4

random or post meal C-peptide
fasted C-peptide
urine or plasma C-peptide 120 minutes after largest meal

Question 5

aims of management

Answer 5

avoid hyperglycaemia
avoid hypoglycaemia
reduce complications

Question 6

management

Answer 6

insulin
annual review of weight, BP, bloods (HbA1c, renal function and lipids), retina and feet
pancreas transplant either kidney-pancreas auto-transplant or islet auto-transplant
admit to hospital if persistent vomiting, diarrhoea, ketones, etc.

Question 7

describe the use of insulin

Answer 7

never omit
alcohol predisposes to hypo, so reduce insulin dose before drinking and don’t take insulin for alcohol
less insulin with meal if exercising
advanced carb counting with MDI (risk of lipohypertrophy) and SCII (insulin pump)
blood glucose monitoring every 4 hours
sick day rules

Question 8

different types of insulin used

Answer 8

prandial insulin (analogue or soluble)
basal insulin (isophane or analogue)
most T1DM are on an analogue basal insulin

Question 9

blood glucose target pre-meal

Answer 9

3.9-7.2mmol/L

Question 10

blood glucose target 1-2 hours post-meal

Answer 10

<10mml/L

Question 11

how many grams of carbohydrate is one unit of insulin?

Answer 11

10g of carb

Question 12

limitations to exogenous insulin

Answer 12

secreted into subcutaneous tissue so peak too slow to prevent post-meal hyperglycaemic spike
slow clearance

Question 13

hypoglycaemia management

Answer 13

dextrose