15 - Type I diabetes mellitus Flashcards
Name a form of type I diabetes that presents late.
Latent Autoimmune Diabetes in Adults (LADA)
Can T2DM present in childhood?
yes, this is becoming more common with the increasing prevalence of childhood obesity
Diabetic ketoacidosis is more common in T _ DM, but can present in both type of diabetes
1
What is meant by monogenic diabetes? In what type of diabetes do they present?
State two monogenic causes of diabetes.
single gene mutation causes β-cell disfunction
present in both T1 and T2 DM
2 causes:
Mitochondrial Diabetes
Maturity Onset Diabetes of the Young (MODY)
What conditions and triggers are required for the onset of type 1 diabetes mellitus?
Environmental trigger in the presence of a genetic predisposition
-> leads to autoimmune attack of islet cells
Which type of diabetes has a bigger genetic component?
Type 2 Diabetes Mellitus
What can be measured in the blood to give an indication of insulin function?
C-peptide
Describe the pathogenesis of T1DM.
You get gradual autoimmune destruction of beta cells resulting in gradually reducing levels of insulin (and C-peptide)
One of the first signs will be the loss of first phase insulin
There will be eventual destruction of all beta cells
Describe the presentation/onset of T1DM.
rapid onset and patients present very unwell (especially in children)
Why is T1DM described as a ‘relapsing-remitting’ disease?
Over time the beta cell mass appears to reduce, then stabilise, then reduce again
There is a theory that this is due to the imbalance in effector T-cells and regulatory T-cells
What is the importance of the autoimmune basis of T1DM?
Increased prevalence of other autoimmune diseases (e.g. rheumatoid arthritis, thyroid disease)
What are the histological features of T1DM?
Lymphocyte infiltration of beta cells (which destroys the beta cells) (Tc cells)
On which chromosome is the HLA found?
Chromosome 6
Which alleles convey a risk of diabetes? Which of these alleles is associated with the most significant risk?
DR alleles
DR3 and DR4 = significant risk
What are diabetic markers used for?
can be measured but won’t change the course of treatment
can be used to help differentiate between type 1 and 2 diabetes
What are the two most significant markers of diabetes?
Islet Cell Antibodies (ICA)
Glutamic Acid Decarboxylase Antibodies (GADA)
State some symptoms of T1DM.
Polyuria Nocturia Polydipsia Blurring of vision Thrush (due to increased risk of infection) Weight loss Fatigue
What are the signs of T1DM?
Dehydration Cachexia Hyperventilation (kussmaul breathing) Smell of ketones (on breath) Glycosuria Ketonuria