Treatment of Diabetes Mellitus Flashcards
What can type 1 diabetes be due to?
- Genetic predisposition
- Viral infections (Coxsackie B)
How many Beta cells are usually destroyed before type 1 diabetes is presented?
> 80 - 90 %
- 2/3s of patients present with life-threatening diabetic ketoacidosis
What is the clinical course of type 1 diabetes characterised by?
Rapid onset of osmotic symptoms
- Including:
- Polyuria
- Polydipsia
- Weight loss
- Fatigue along with hyperglycaemia
What is metabolic syndrome?
Combination of diabetes, hypertension and obesity
What is the prediabetic stage in type 2 diabetes?
- Plasma insulin increases (compensatory hyperinsulinemia)
- Insulin sensitivity decreases
- Plasma glucose is raised
- Beta cells progressively fail - leading to diabetes with decreased plasma insulin and hyperglycaemia
What are the different levels of fasting plasma glucose in non-diabetics vs prediabetics vs diabetics?
- Normal < 6.1 mmol/L
- Prediabetes 6.1 - 6.9 mmol/L
- Diabetes > 7.0 mmol/L
How is bood glucose monitored?
Self-monitoring of blood glucose (SMBG) - samples capillary blood after a finger prick
- 4 times a day (before each meal and at bedtime)
Random glucose measurement above what number indicates diabetes?
11.1 mM (7mM if fasting)
What measurement gives a measurement of blood glucose over a long time frame (~120 days, RBC lifetime)?
HbA1c
What HbA1c levels indicate diabetes?
Above 7%
What should fasting blood glucose levels not be above?
7.8 mM (2 hours after a meal)
At what level of blood glucose would glucose be detected in the urine?
> 10 mM (will overload the renal capacity)
At what level of blood glucose would glucose be detected in the urine?
> 10 mM (will overload the renal capacity)
How is Insulin made?
Recombinant DNA technology (used to be from pigs, cows)
- Can be modified (with proteins, salts, fatty acids) to alter duration activity or increase absorption rate
How is insulin administered?
- Subcutaneously routinely
- IV in emergencies (only soluble forms)
What are examples of rapid-acting soluble insulins?
- Insulin lispro
- Insulin aspart
- Insulin glulisine
How do rapid-acting soluble insulins work? (e.g insulin lispro)
- Prevent dimer formation
- Contain amino acid substitutions that block the formation of insulin dimers allows for more active monomers to be used rapidly
- Increase bioavailability of active monomers - rapid omset (10-20 mins) and short duration (2-5 hours)
What is isophane insulin? (neutral protamine hagedoen; NPH)
- Intermediate-acting insulin
- Complexes with protamines as well as zinc
- Forms precipitate suspensions which slowly dissolve
What is insulin glargine?
A longer acting designer insulin which has decreased solubility at neutral pH - forms aggregates that slowly dissolves - prolonging activity
What is insulin detemir?
A long-acting designer insulin with a fatty acid
- Myrestic acid bound to insulin Beta chain
- This confers albumin binding, slowly dissociates prolonging activity
What is insulin degludec?
Long-acting designer insulin with a fatty acid - this results in multi-hexamer formation at injection site with slow release, 42 hours duration
What proportion of Type 2 diabetics use insulin?
1/3rd (and for some mothers with gestational diabetes)
What are basal forms of insulin?
- Activity lasts ~ 24 hours, peakless
- Insulin detemir and glargine
- Provides background amount of insulin (can be used in conjunction with a bolus which is given througout the day)
What are the advantages and disadvantages of fixed insulin doses?
- FIxed dose can help simplify understanding of blood glucose results but does not offer the flexibility of how much carbohydrates a patient may choose to consume at each meal