Type 1 Diabetes

Question 1

what are GAD antibodies characteristic of?

Answer 1

type 1 diabetes

Question 2

rare presentation of T1DM?

Answer 2

headaches
muscle spasms
anxiety

Question 3

how can T1DM be found incidentally?

Answer 3

GAD antibodies can appear on lumbar puncture

Question 4

when in gestational diabetes diagnosed?

Answer 4

2nd or 3rd trimester of pregnancy

Question 5

types of monogenic diabetes syndromes?

Answer 5

MODY

neonatal diabetes

Question 6

type 1 vs type 2?

Answer 6

1 = absolute insulin deficiency
2 = relative insulin deficiency

Question 7

what mediates type 1?

Answer 7

T cells

Question 8

what other diseases is type 1 associated with?

Answer 8

other autoimmune diseases - thyroid, coeliac, addisons, pernicious anaemia, vitiligo

Question 9

epidemiology of type 1?

Answer 9

genetic susceptibility
environmental trigger
prolonged prodrome (months to years)
80-90% loss of beta cell function before marked hyperglycaemia

Question 10

what is LADA?

Answer 10

latent autoimmune diabetes of adulthood
middle aged diagnosis so misdiagnosed as type 2
non-obese and slower onset
HLA positive (GAD)
low C peptide
no family history
mild IR
80% of those who are GAD positive are insulin dependant within 6 years

Question 11

what is polyglandular endocrinopathy?

Answer 11

diseases associated with type 1

- ………

Question 12

histology of type 1 and type 2 ?

Answer 12

type 1 = lymphocyte infiltration

type 2 = amyloid deposition

Question 13

major islet antibodies?

Answer 13

IA-2
IA-2beta
GAD
Zn-T8
- all intracellular

Question 14

how specific are islet autoantibodies?

Answer 14

present in 70-80% of new type 1 diagnoses

depends on age, gender, ethnicity and quality of assay

Question 15

how can islet antibodies predict disease?

Answer 15

1 positive = 20-25% chance
2 present = 50-60% chance
3 present = 70% chance of developing T1DM within 5 years

Question 16

most important autoantibody?

Answer 16

GAD
75-84%
………..

Question 17

is there any genetic component to T1DM?

Answer 17

yes

increased risk if family member affected

Question 18

genetic association with T1DM?

Answer 18

chromosome 6 HLA DR3, ………………

Question 19

environmental effect on T1DM?

Answer 19

incidence higher in winter than summer

Question 20

pathogenesis of T1DM?

Answer 20

beta cell mass decreases over time
immune dysregulation (event?) at early age decreases beta cell mass
environmental triggers and regulators and age cause mass to decrease further over time until diabetes presents when beta cells reach a certain low enough level
larger immune dysregulation event = earlier onset as beta cell mass has less to lose before reaching the point

Question 21

main regulator of glucose homeostasis?

Answer 21

insulin and glucagon

interaction/balance of the two (especially in the liver) controls blood glucose levels

Question 22

insulin functions?

Answer 22

increases glucose uptake (skeletal muscle)
decreases gluconeogenesis
decreases lipolysis (fat accumulation)

Question 23

glucagon functions?

Answer 23

stimulates gluconeogenesis and lipolysis

Question 24

features of insuin deficiency?

Answer 24

“accelerated starvation”
reduces glucose uptake in muscle so muscle wasting due to protein breakdown/catalysis
increases lipolysis so weight loss

Question 25

counterregulatory effects of beta cell loss in T1DM?

Answer 25

alpha cells become less responsive

= alpha cell disregulation

Question 26

how does T1DM present?

Answer 26

weight loss
fatigue
frequent urination (osmotic diuresis)
thirst

Question 27

features of DKA?

Answer 27

vomiting
abdominal pain
altered consciousness
acidotic breathing
pH <7.3
dehydrated
urine ketones +ve
can lead to coma or death if untreated

Question 28

which type is a family history more common in?

Answer 28

type 2

Question 29

when does type 1 most commonly present?

Answer 29

pre school
peri-adolescence
small peak in 30s
60% <30 yrs

Question 30

specific type 1 diagnosis?

Answer 30

history and presentation can be enough

autoantibodies more specific

Question 31

how are insulin levels divided in normal people?

Answer 31

background insulin accounts for 50% - fairly constant level

meal time insulin accounts for 50% - varies with eating

Question 32

problems with external insulin delivery?

Answer 32

given subcutaneously so need twice as much to get round circulation and into portal system where it would be produced normally
means everyone on insulin is hyperinsulinaemic
effects of high insulin as anabolic - hypertrophy, weight gain etc

Question 33

what can day to day glucose variability in type 1 diabetics even when controlling condition with same insulin delivery every day?

Answer 33

failure to mix insulin adequately
accuracy of device
dynamics of delivery
leak from injection site
external factors - exercise, temperature
tissue - accidental injection into muscle, lipohypertrophy, blood supply
carbohydrate delivery - meal consituents, gsatroparesis

Question 34

2 main types of insulin therapy?

Answer 34

meal time - lispro, aspart

long acting - glargine, detemir

Question 35

function of insulin pump?

Answer 35

continuously regulates insulin by delivering specific insulin amounts?
best at maintaining basal levels

Question 36

closed loop insulin?

Answer 36

sensor to sense glucose/insulin? levels and pump to deliver correct amount of insulin

Question 37

what is DAFNE?

Answer 37

educational programme

dose adjusting for normal eating

Question 38

risks of long term hyperglycaemia?

Answer 38

micro and macro vascular complications

• retinopathy
• nephropathy
• neuropathy
• MI/stroke

Question 39

what is HbA1c?

Answer 39

glycated haemoglobin

glucose sticks to haemoglobin A1 so the more

Question 40

how can glucose be monitored?

Answer 40

…

Question 41

home blood glucose monitoring?

Answer 41

effective but not frequently used as inconvenient in daily life
need to measure pre and psost prandial

Question 42

flash glucose monitoring?

Answer 42

abbot free style libre

can quickly measure glucose via device on arm at any time

Question 43

smart insulin?

Answer 43

once a day self regulating insulin injection
causes glucose responsivity
not widely used?