Lecture: How to Diagnose Diabetes Mellitus Flashcards
What fasting glucose is diabetes
> 7.0
What random or 2 hour post 75g glucose (OGTT)
> 11.1
What is the HbA1c for diabetes
> 6.5
When can HbA1c be under-estimated
Haemoglobinopathy
Anaemia
Reduced RBC turnover
Use blood glucose instead
What are the parameters of IFG and IGT
What are the types of diabetes
Type 1:
- Pancreatic beta cell destruction
- So you have an absolute insulin deficiency
- Either immune or non-immune
Type 2:
- Insulin secretory defect
+/- insulin resistance
Many other less common types
What are some other causes of diabetes?
Gestational
Genetic
Pancreatic destruction/insufficiency (surgery, pancreatitis, haemochromatosis)
Endocrinopathies (e.g. Cushings, phaemochromocytoma)
Drug/Chemical induced (esp glucocorticoids)
Infections: CMV
What are the 4 factors that usually make T2DM a likely diagnosis
- Middle to later age
- Overweight/obese
- Fam Hx
- No features of marked insulin deficiency (nil significant weight loss, nil ketosis)
If any of these are absent ensure there isn’t another cause of the diabetes
What is the classic presentation of T1DM
- Young usually (>6mo, <30)
- Lean (but not always)
- May have family history of T1DM but most don’t
- Short history of relatively sudden onset polyuria, polydipsia, weight loss ++ with ketosis
- Antibody positivity is common (GAD, IA2, ICA, ZnT8)
What are some other non type 2 diabetes
LADA (latent autoimmune diabetes in adults
- Masquerade as type 2 diabetes unless antibodies are detected because they’re older
Ketosis prone (type 2) diabetes
- mimics the type 1 presentation
Pancreatic diabetes
- Acute and chronic pancreatitis
MODY (Maturity Onset Diabetes of the Young)
- Commonly have milder hyperglycaemia and may not even need treatment
- Autosomal inheritance
Medication related
Other endocrinology
