15 - Diabetes Flashcards
(57 cards)
What are some sx of diabetes?
- Polyuria (frequent urination), polydipsia (excessive thirst), polyphagia (increased appetite)
- Elevated fasting blood sugar
- Ketosis
- Weight loss
What are the levels to diagnose impaired fasting glucose?
Fasting plasma glucose = 6.1-6.9 mmol/L
What are the levels to diagnose impaired glucose tolerance?
- Fasting plasma glucose over 7.0 mmol/L
- Plasma glucose 2h after 75-g glucose load = 7.8-11 mmol/L
What are the levels to diagnose diabetes mellitus?
- Fasting plasma glucose 7 mmol/L or greater
- Plasma glucose 2h after 75-g glucose load = 11.1 mmol/L or greater
What is the normal fasting plasma glucose?
4.4-6.1 mmol/L
How is insulin secreted from a beta cell of the pancreas?
- Glucose enters cell, driving metabolism and the production of ATP which binds to and closes the potassium channel
- Cell becomes depolarized => opening of calcium channel, and when calcium enters it interacts w/ insulin to cause insulin release
When will a beta cell not interact w/ insulin?
When the cell is hyperpolarized b/c calcium channel won’t open
How does glucose enter a beta cell?
Through the GLUT2 channel (passive channel)
What is the main function of the GLUT1 and 2 channels?
Equilibrate intracellular and extracellular glucose
Where are GLUT4 channels found? What is its function?
- Function = increase uptake of glucose
- Skeletal, cardiac and smooth muscle
- Mucosa
- Adipose tissue
- Leukocytes
- Pituitary
What is the main effect of insulin?
Inhibits glycogenolysis
Describe the defects in glucose levels in diabetes
- Increased extracellular glucose
- Decreased intracellular glucose (in tissues w/ insulin-sensitive glucose transporters)
- Increased intracellular glucose (in tissues w/ non-insulin sensitive transporters)
What does the liver do when there is decreased glucose production?
- Decrease glycogenolysis
- Gluconeogenesis isn’t affected or barely decreased
- Decrease fat oxidation
- Increase glucose oxidation
What does the liver do when there is increased glucose uptake?
- Increase glycolysis
- Increase glycogen synthesis
What are the causes of hyperglycemia in type 2 diabetes?
- Insulin resistance*
- Increased glucose production
- Impaired insulin secretion, and/or
- Insufficient glucose disposal
What does decreased glucose uptake lead to?
- Hyperglycemia
- Glucosuria
- Osmotic diuresis
- Ultimately leads to electrolyte depletion => dehydration acidosis => coma (RARE)
What does increased protein catabolism lead to?
- Increased nitrogen and amino acid loss in urine
- Ultimately leads to electrolyte depletion => dehydration acidosis => coma (RARE)
What does increased lipolysis lead to?
- Increased FFA, cholesterol, and ketone bodies
- Ultimately leads to electrolyte depletion => dehydration acidosis => coma (RARE)
What are some complications of diabetes?
- Macrovascular (blood vessels) –> heart disease, stroke, hypertension
- Microvascular (eye damage)
- Nephropathy -> renal failure
- Neuropathy -> nerve damage
What is the difference between preproinsulin, proinsulin, and insulin?
- Preproinsulin has signal sequence & chain C
- Proinsulin only has chain C
- Insulin has neither
Which formulations of insulin are rapid-acting?
Lispro and aspart
Insulin lispro closely resembles insulin response to ____
A meal
What is the function of regular novolin R?
Delays absorption into the bloodstream
What is the benefit to long acting basal insulins?
Less nocturnal hypoglycemia
