Beetus 2 Flashcards
What is DM?
chronic disorder caused by either deficient insulin or defective insulin action
DM is characterized by (hypo/hyper)glycemia
Hyperglycemia
DM is the leading cause of:
- ESRD
- blindness
- non-traumatic amputation of LE
What are the 3 main roles of insulin?
- helps muscle, fat, and liver cells absorb glucose from the blood
- stimulates the liver and (to a lesser extent) muscle tissue store excess glucose in the form of glycogen
- lowers blood glucose by reducing glucose production in the liver
Type 1 DM and insulin
Little or no insulin produced
Type II DM
Defective insulin and/or impaired cell receptor binding of insulin
How does activity impact glucose uptake by muscle?
- increased membrane permeability to glucose
- during mod to heavy exercise
How does carbohydrate consumption impact insulin/muscle
insulin can increase rate of glucose transport into resting muscle cell by 15x
How does the brain use glucose?
- brain has GLUT1 transporters to allow glucose uptake
- NOT directly insulin dependent
What is critical blood glucose level for normal brain function?
Over 20-50 mg/dl
What happens below blood glucose of 20-50?
hypoglycemic shock with
- fainting
- seizures
- potentially coma
What brain-related effects happen with hyperglycemia that are similar to hypoglycemia?
- progressive loss of consciousness
- leads to coma
3 major insulin effects that lead to fat storage in adipose tissue
- Increased utilization of glucose will decrease utilization of fat, functioning as a fat sparer
- Promotion of fatty acid synthesis
- Increased uptake of glucose by fat cells and conversion to fatty acids
What does insulin deficiency promote?
- increased plasma cholesterol
- increased phospholipid synthesis from fatty acids in the liver
- ketoacidosis
High lipid concentration, especially cholesterol, promotes the development of:
Atherosclerosis in people with deficient insulin action
When insulin isn’t available, what is used for metabolism?
Fat
Byproduct of ketone bodies produces:
- decreased pH
- results in ketoacidosis
s/s of DKA
- strong, fruity breath odor
- drowsiness, confusion, difficulty waking up
- blurred vision
- hot, dry, flushed skin
- thirst and excessive urination
Lack of insulin: how does this affect protein metabolism?
- can lead to protein wasting
- results in weakness and diminished organ function
Insulin does what for protein metabolism?
Increases protein synthesis and storage
Insulin is secreted by beta cells in response to
High blood sugar
After a meal, what happens to blood glucose and insulin?
- BG increases
- insulin increases
In response to insulin increase, what do cells do?
- take in glucose from the blood for nutrition
- blood glucose and insulin levels go back to resting range
What happens when blood glucose decreases between meals and during exercise?
- glucagon is activated to cause the liver to release stored glucose
- in order to maintain homeostasis
What factors and conditions increase insulin secretion?
- insulin resistance
- obesity
How does insulin resistance increase insulin secretion
- cell receptors damaged
- glucose can’t be absorbed from blood
- insulin increased to overcome resistance
How does obesity increase insulin secretion?
Belly fat hormones
- metabolic syndrome causing insulin resistance
- increased BP
- Increased lipids
- increased cardio disease
Normal fasting BG range (without DM)
70-99 mg/dL
BG concentration: fasting with diabetes
80-130 mg/dL
BG: 2 hours after meals
Normal without diabetes
Less than 140 mg/dL
BG: 2 hours after meals
Someone with diabetes
Less than 180 mg/dL
How does the liver act for blood glucose?
Acts as a buffer system
How might a pt with liver disease have issues related to blood glucose?
Pts with severe liver disease have problems maintaining narrow range of BG concentrations
This is the primary controller in feedback control systems for maintaining normal blood glucose
Insulin
Normal blood glucose restoration following meals
- increased glucose
- insulin secretion to drive glucose into cells
- restores normal BG
Decrease in BG leads to decrease in
Insulin
What are the critical reasons blood glucose should not rise too high?
- Glucose can exert large amt of osmotic pressure in extracellular fluid
- Excessively high level of BG causes “spill” of glucose into urine
- Glucose in urine can deplete body of fluid and electrolytes
- Longer term increase in BG may damage many tissues, especially cardiovascular
