Type 1 Diabetes Flashcards
What is the ideal blood glucose level?
4.4-6.1
Where is insulin produced?
By the beta cells in the Islets of Langerhans in the pancreas
Which hormone has the opposite effects to insulin and where is it made?
Glucagon
- produced by the alpha cells in the Islets of Langerhans
What is ketogenesis?
When there is insufficient glucose supply + glycogen stores are exhausted –> liver turns fatty acids into ketones to use as fuel
What is the difference between the aetiology of type 1 and type 2 DM?
Type 1 –> pancreas doesn’t produce insulin
Type 2 –> reduced insulin sensitivity
What are the symptoms of diabetes?
Polydipsia + polyuria Weight loss (type 1) Visual blurring from lens swelling Genital thrush Muscle cramps Lethargy
T1DM often presents acutely e.g. in DKA
What are the risk factors for T1DM?
Family history
HLA-DR3 + DR4
Other autoimmune conditions
How is diabetes diagnosed?
If symptomatic, any of of:
- fasting glucose >/= 7
- random glucose >/= 11.1
- OGTT >/= 11.1
- HbA1c >/= 48 (6.5%)
If asymptomatic:
- repeat fasting glucose/OGTT/HbA1c on another day to confirm
How is an OGTT carried out?
Patient fasts overnight
Measure glucose before and 2 hours after a glucose drink in the morning
Following a diagnosis of diabetes mellitus, how do you know it’s type 1?
Largely clinical, supportive features:
- ketosis
- weight loss
- age < 50
- BMI < 25
- personal or family autoimmune history
If typical clinical features are absent, can check:
- GAD65 Ab (islet cell antibody)
- C-peptide (reduced in T1DM)
Which other investigations should be done in a patient with newly diagnosed T1DM?
Urine albumin
HbA1c - re-check every 3-6 months
U&Es
Test for other AI disease: coeliac, TFTs
What are the main components of managing T1DM?
Patient education essential –> DAFNE (dose adjustment for normal eating)
Lifelong SC insulin
Monitoring carbohydrate intake
Monitoring blood glucose
Monitoring for and managing complications
When should newly diagnosed T1DM be started on insulin?
Same day –> referral to hospital diabetes team
How often should blood glucose be checked?
At least 4 times a day
–> before each meal + before bed
Where should insulin be injected, why?
Vary injection site across outer thigh + abdomen
- repeated injection into same site –> lipodystrophy
What are the different types of insulin?
Rapid acting Short acting Intermediate acting Long acting Biphasic
What is the onset and duration of rapid acting insulin? Give examples
Onset 5 mins
Take just before/after meal
Peaks 1-2 hours, lasts 4 hours
Lispro (Humalog)
Aspart (NovoRapid)
What is the onset and duration of short acting insulin? Give examples
Onset 30 mins
Take 20 mins before meal
Peaks 3 hours, lasts 8 hours
Humulin S
Actrapid
What is the onset and duration of intermediate acting insulin? Give examples
2 hour onset, peaks at 8 hours, lasts 12-16 hours
Isophane
Insulatard
Humulin I
What is the onset and duration of long acting insulin? Give examples
1-2 hour onset, then constant up to 24 hours
Glargine (Lantus)
Levemir (Detemir)
What is biphasic insulin? Give examples
Combination intermediate + rapid/short acting insulin
Novomix30 –> 30% rapid acting
Humalog50 –> 50% rapid acting
How can the approximate total daily dose of insulin (TDDI) be calculate for children and adults?
Children –> 0.5 units/kg/day
Adults –> 0.3-0.5 units/kg/day
What are the different regimens for insulin?
Once daily regimen
Twice daily regimen
Basal-bolus insulin regimen
Continuous SC insulin infusion
When is once daily regimen used? What is involved?
Type 2 diabetes
Long or intermediate insulin at bedtime
