Week 2 - Glucose Regulation Flashcards
define glucose regulation
- process of maintaining OPTIMAL blood glucose levels
what 3 main factors interact to maintain glucose regulation?
- caloric intake (ie. food)
- hormones
- glucose uptake (by the cells for energy)
list 3 examples of hormones that play a role in glucose regulation
- insulin
- cortisol
- glucagon
what is euglycemia? what is the value?
- normal conc of glucose in the blood
- 4-7 mmol/L
describe normal glucose homeostasis; what happens when we eat to maintain our BG
- we eat & carbs are broken down into simple sugars called glucose which is absorbed into the blood
- elevations in blood glucose stimulate pancreatic cells to secrete insulin
- insulin allows glucose to enter the cell –> BG goes back down
what are 2 ways glucose can be used after insulin release?
- for energy by cells (ATP)
2. stored in the liver and fat cells as glycogen
what is stored glucose called?
- glycogen
what is glucagon
- hormone released when BG is too low
what does the release of glucagon cause?
- stimulates the liver to breakdown glycogen to glucose (glycogenlysis) = increased BG
what is glycogenolysis
- process by which glycogen is converted to glucose
what is the function of insulin? when is it released?
- released when we have high BG
- responsible for the transport of glucose from the blood into the cells
what happens if aspects of glucose metabolism malfunction or stop working?
- get hyperglycemia or hypoglycemia
what value is considered hyperglycemia
at or above 11mmol/L
what are the 3 main biomechanical causes of hyperglycemia
- insufficient insulin production or secretion from the pancreas
- insulin resistance
- excess counter regulatory hormone secretion
what can cause insufficient insulin production/secretion?
- damage to the pancreatic beta cells
ex. autoimmune disfunction, from injury or cancer
what is insulin resistance? what does this cause?
- the body cells are not responding to insulin
= body cannot use glucose for energy
= BG continues to rise
what are counter regulatory hormones
- hormones that work opposite of insulin
- hormones that work to increase BG
what are examples of counter regulatory hormones?
- glucagon
- cortisol
- epi
- growth hormone
what value is considered hypoglycemia
- <4 mmol/L
what are 3 causes of hypoglycemia
- insufficient nutrient intake
- adverse rxn to meds
- too much exercise
what are 2 examples of adverse rxn to meds that can cause hypoglycemia
- exogenous insulin –> ex. too much insulin = too much uptake
- oral antihypoglycemics
how can too much exercise cause hypoglycemia including both during exercise & post exercise
- work of muscle contraction requires energy which is derived from glucose stored in muscle cells as glycogen
- as exercise continues, glycogen is deplted & we start to use glucose from the circulation & liver for energy = lowered BG
- during post exercise, our body tries to restore our glycogen levels by converting glucose from the circulation = lowers BG even more
why is insulin so important (2)
- insulin is the key that unlocks glucose’s potential in the tissues
- some cell need insulin to utilize the glucose as fuel ex. the brain which requires a constant stream of glucose
how does hyperglycemia related to inflammation
- hyperglycemia is a pro-inflammatory phase (=can cause inflammation)
what are the long term consequences of hyperglycemia (5)
- blood vessel damage (angiopathy, both macro & micro)
- neuropathy
- fluid & electrolyte imbalances (dehydration)
- acid-base disturbances (DKA)
- insulin resistance
why does peripheral neuropathy occur with hyperglycemia
- elevated blood glucose has a toxic effect on nerves
how does hyperglycemia cause fluid & electrolyte imbalances + dehydration?
- high blood glucose causes osmotic diuresis = fluid pulled intro intravascular space & is peed out
= dehydration & imbalances
what are the consequences of insulin resistance (6)
- atherogenesis
- plaque formation
- increase CA risk
- HTN
- NASH
- sleep apnea
what causes the consequences of insulin resistance?
- both hyperglycemia & insulin resistance are toxic & proinflammatory states
what are the longer term consequences of hypoglycemia (4)
- seizures
- loss of consciousness
- death
- hypoglycemia unawareness syndrome
why do many of the consequences of hypoglycemia effect the CNS system?
- bc the brain requires a constant stream of glucose
what is hypoglycemia unawareness syndrome
- results from a frequent hypoglycemic state
- results in desensitivity to hypoglycemia = does not get warning signs such as shaky, irritable, dizzy, etc.
what is a consequence of hypoglycemia unawareness syndrome?
- lack of warning signs = may miss cue to act on the hypoglycemic episode
how does adherence r/t glucose regulation?
- important for the regimen for blood glucose control
ex. insulin, self monitoring
what are the symptoms of hyperglycemia (6)
- dry mouth
- increased thirst
- weakness
- headache
- blurred vision
- frequent urination
what are the symptoms of hypoglycemia (6)
- sleepiness
- sweating
- pallor
- lack of coordination
- irritability
- hunger
