T1 DM Flashcards
Epidemiology of DM
- Prevalence
- Peak onset
- Sex
- Race
- Geographical
Prevalence is increasing [6.7% in 16/17]
- T1 only accounts for 10-15% of all diabetes [0.5% prevalence]
Peak onset at adolescence
- Can present from 6 months to 80 [basically any age]
Affects males and females equally
- Slightly more male in UK
White caucasian
- More prevalence in the northern poles
Genetic predisposition to T1 DM
Greater predisposition if father has it compared to mother
- As well as sibling
Twin= roughly 35%
HLA regions
- DR3-DQ2
- DR4- DQ8
Can be used to identify individuals at high risk and put interventions in place.
Also used to differentiate T1 and T2 DM [as measures of diagnosing is not very accurate currently]
Pathophysiology of T1 DM
- Not completely understood
Autoimmune
- Viral infection causes autoimmune attack
- Selective beta-cell damage
Antibodies against
- Insulin
- GAD [glutamate decarboxylase]
Other antibodies against
- Ia2
- Zn2+ transporter 8
More antibodies= increased change of developing T1 DM
Pathological progression of T1 DM
- Genetic predisposition
- HLA regions etc
Environmental trigger
- Insulitis
- Pre-diabetes
- Diabetes
Viral stress of T1 DM
Viral infection [e.g coxsackie]
Triggers autoimmune reaction that destroys beta cells
- ER stress
- Cytokines
Associations with T1 DM
Coeliac
Hypothyroidism
Graves’
Addison’s
Hypogonadism
Pernicious
Vertiligo
Symptoms
Lethargy
Polyuria/ polydipsia
Blurred vision [swelling of lens]
Infections
- Thrush
- Abscesses
Weight loss
Ketosis/ ketoacidosis
Death
Age affects presentation
- Immune attack more brisk in younger patients
Ketone bodies
Acetone
Acetoacetate
D-beta-hydroxybutyrate
Metabolised when insulin is deficient and glucose cannot be used.
C-peptide
Measurement of insulin production
- Made in 1:1 ratio to insulin
By product of insulin metabolism
Insulin treatment
Administered subcutaneously
- Can also be inhaled in US [fear of increased risk of cancer]
- Mucous membrane
Insulin pen
Mode of insulin administration
- Contains needle injected subcutaneous
Sites of injection
- Lower abdomen
- Bum
- Upper outer thighs
- Upper outer arms
Physiological insulin secretion
Increases just after each meal
Basal bolus insulin
Basal insulin
- Long acting background insulin
Then rapid acting insulin given just before a meal
- Bolus
Carbohydrate count
Allows insulin calculation according to how much carbohydrate is being consumed
Factors that affect the absorption of insulin
Factors that affect blood glucose
- Diet
- Injection site
- Temperature
- Exercise
- Illness
- Stress
- Alcohol
- Menstrual cycle
Subcutaneous insulin pump
Administers constant insulin supply throughout the day
- Gives basal insulin
- Allows flexibility
- Can still give bolus pumps
Pump only needs to be changed 2/3 days.
Transplantations
- Pancreas
- Islet
Pancreas
- Not commonly done
- Surgery is very invasive [3% mortality], immunosuppressants increase other diseases
- Also not enough pancreases available.
- Only given when already on immunosuppressant and having surgery [SPK, PAK]
Islet cell
- Fusing healthy islet cells into the liver
- Still requires immunosuppressants
- Does not always cure.
Glucose monitor
Prick finger
- Place blood on tester at least 4x daily
Glucose sensor [CGMS]
- Gives a constant trace throughout the day
Can also monitor ketone.
Freestyle libre CGMS
Does not require pricking finger
Gives constant glucose reading when directed
Monitoring HbA1c
Measuring glycated haemoglobin
But affected by shorter red cell life span.
