Diabetes Flashcards
What is diabetes mellitus?
Diabetes mellitus describes a metabolic disorder of multiple aetiology characterised by chronic hyperglycaemia with disturbances of carbohydrate, fat, and protein metabolism, resulting from defects in insulin secretion, insulin action, or both
What processes occur when an individual has low blood glucose?
- Glucagon released by alpha cells of pancreas
- Liver releases glucose levels
How can glycaemia be assessed?
- Blood glucose level (BGL): immediate
- Oral glucose tolerance test (OGTT): Glycaemic response over two hours to an oral glucose load
- HbA1c: gold standard for assessing BGL control over the preceding 2-3 months
When is HbA1c usually used and when is it not?
Usually used to monitor the effectiveness of glycaemic therapy, rather than for acute diagnosis
How is plasma glucose tested?
- Overnight fasting
- Two hour plasma glucose in oral glucose tolerance test
What factors can affect plasma glucose during the day?
- Dietary intake and composition
- Exercise
- Illness
What are the current diagnostic criteria for disorders of glycaemia and diabetes mellitus?
- HbA1c > 6.5%
- Fasting blood glucose >126mg/dL (7.0 mmol/L)
- 2hr plasma glucose >200mg/dL (11.1 mmol/L) during an OGTT
- With symptoms, a random PG >200mg/dL (11.1 mmol/L)
How is diabetes mellitus diagnosed?
- Fasting venous plasma glucose (FPG)
- 2hr plasma glucose in OGTT
What does IFG stand for?
Impaired fasting glucose
What does IGT stand for?
Impaired glucose tolerance
What is the diagnostic criteria for impaired fasting glucose?
Plasma glucose concentration 5.6 - 6.9 mmol/L after fasting
What is the diagnostic criteria for impaired glucose tolerance?
Plasma glucose concentration 7.8 - 11.0 mmol/L after two hours
What is 1 mmol/L in mg/dL?
18mg/dL
What is pre-diabetes?
Patients with either or both impaired fasting glucose or impaired glucose tolerance, but not in the diabetic range.
What percentage of Australians have pre-diabetes?
About 16%
What are you at greater risk of with pre-diabetes?
Macrovascular disease
What percentage of the Australian population have some form of disorder glycaemia?
25%
What are the four WHO classifications of diabetes?
- Type 1 diabetes mellitus
- Type 2 diabetes mellitus
- Gestational diabetes
- Other specific types
What does Type 1 diabetes mellitus involve?
- Destruction of pancreatic islets
- Absolute deficiency of insulin
What treatment options are used for T1DM?
- Insulin: lowers BGL
- Exercise: reduce CV risk
What does Type 2 diabetes mellitus involve?
- Resistant to the action of insulin
- Fasting hyperglycaemia
What is the goal of treatment for T2DM?
To reduce HbA1c, hence limit/reduce diabetic complications
What treatment methods are used for T2DM?
- Exercise
- Diet: low GI
- Oral hypoglycaemics (+/- insulin)
What percentage of pregnant women are affected by gestational diabetes? What percentage are then at greater risk of T2DM?
6-9%.
30-50% greater risk of developing T2DM
What are the risk factors of gestational diabetes?
- Glycosuria
- Age >30 years
- Obesity
- Family history
- Past history of gestational diabetes or impaired glucose tolerance
- High risk group (ATSI, Polynesian, Middle Eastern, Indian, Asian)
At what time is screening for gestational diabetes recommended?
26-28 weeks
How is gestational diabetes diagnosed?
Oral glucose tolerance test: 100g glucose drink after fast.
1 hr > 10 mmol/L
2 hr > 8.6 mmol/L
3 hr >7.8 mmol/L
Positive test if 2 or more of above readings are recorded
Management of gestational diabetes
Exercise is recommended