Diabetes Management Flashcards
Diabetes Mellitus
Glucose Homeostasis: insulin promotes uptake of glucose by cells
- reduces blood glucose
Glucagon promotes conversion of glycogen stores to glucose
- increases blood glucose
Stimulation of insulin release
- Glucose enters cell through GLUT transporter
- Glucose metabolized, increases ATP
- ATP inhibits Katp channel
- This leads to calcium entry through calcium channels
- Calcium entry leads to exocytosis of insulin
Diabetes Mellitus key feature
Sustained elevations in blood glucose
High blood glucose leads to these complications (5)
Circulatory disorder Neuropathy Nephropathy Retinopathy Cardiovascular disease
The two types of diabetes and how they are different
Type 1: insulin deficiency (reduced secretion)
Type 2: Insulin resistance and (then) reduced secretion
Type 1 characteristics
Low insulin
- due to destruction of pancreatic beta cells
- likely autoimmune
- also genetic component
- typically earlier onset but not always
Type 2 characteristics
Often associated with/or worsened by obesity
Typically later onset but that is changing
About 90% of DM cases are type 2
Treatment overview for type 1 and 2 diabetes
Type 1: manage with insulin
Type 2: lifestyle changes - diet, exercise, etc.
Manage initially with oral hypoglycaemic
May need to add insulin later as beta cells fail
Monitoring of glucose (acute)
- self-monitoring of blood glucose (glucometer)
- target fasting blood glucose (4-7 mmol/L)
- Post-prandial (2 hours): 5-10 mmol/L
Monitoring of glucose (chronic)
Hemoglobin A1c
- glycated hemoglobin
- Glucose attached to Hb in blood
- Considered a more stable measure of Glycemic control over time
Insulin
- a 51 amino acid protein
- consists of two peptide chains (A & B) joined by 2 disulphide bridges
Actions of Insulin
Promotes entry of glucose into the cells
- Insulin binds to tyrosine kinase receptor
- Prompts a cascade of intracellular signalling events (protein synthesis and glycogen synthesis)
- Prompts translocation of GLUT-4 transporters to cell membrane
Actions of insulin in the liver
- decreases glucose synthesis (Gbuconeogensis)
- increases conversion of glucose to glycogen (storage)
Actions of insulin in muscle
- Increase in glucose to glycogen
- increase in protein synthesis.
Actions of Insulin in Fat
- Increases in Lipogenesis
- decrease in Lipolysis
Insulins route of administration
Injected: Subcutaneous
- intravenous in emergencies
- absorption depends on site of injection: more rapid in abdomen, slower in thigh or buttocks and exercise, heat tend to increase absorption
Rapid acting insulins
Regular insulin: onset is 1/2 hour, peak around 2 hours, duration 8 hours
Aspart insulin: onset is 1/4 hour, peak in 1-1.5 hours, duration 4 hours
Intermediate/long acting insulins
NPH: onset 1-2 hours, peak 6-12, duration 18
- Neutral Protamine Hagedorn
Glargine insulin: onset 3-4 hours, duration 20-24 hours
SIde effects of Insulin
Hypoglycemia: symptoms include sweating, tachycardia, confusion
- can progress to coma/death
Treatment: SUGAR
Other side effects of Insulin
Weight gain
Immune reactions
Lipodystrophy
- atrophy of subcutaneous fat at injection site
Insulin secretagogues two classes
Sulfonylureas
Meglitinides
Sulfonylureas example
Glyburide
Sulfonylureas mechanism
- act on pancreatic beta cells
- bind to the sulfonylurea receptor-1 (SUR-1) and stimulate insulin release while inhibiting Katp channel
Risk of Sulfonylureas
Stimulates insulin regardless of blood glucose levels
Risk of hypoglycemia
Side effects of Sulfonylureas
Weight gain Rash (hypersensitivity to sulpha) Gastrointestinal Concern over cardiovascular effects: - receptors in the cardiovascular system