Obesity 2 Flashcards
Blood glucose curve after a meal is ingested
What is the fasting blood glucose?
4.5-5 mmol/l
What are the process that increase and decrease after CHO-containing meal is ingested
↑GI absorption
↓Glycogenolysis
↑Glycolysis
↓Gluconeogenesis
Insulin release
What are the processes that occur 2 after a meal is ingested
Decay slope-> High Insulin : ↑Tissue uptake ↑Glycogenesis
Causes blood glucose levels to drop
When is glucgon start to be released after ingesting a meal?
2.5 h
What is the steady phase of the blood glucose curce
4h after a meal
↓Insulin:Glucagon
↑ Glycogenolysis
↑Gluconeogenesis
Between which values do we regulate our blood glucose
we regulate our glucose in the blood between 4.5-7.8 mmol.l
What are the glucose blood level processes controlled by?
insulin to glucagon ratio
What initially increases as a response to a meal?
- Insulin
- Glucose
- Lactate
- Pyruvate
lactate and pyruvate are glycolysis intermediates
- Triglycerides
- Alanine
- BCAA
- Total Amino Acids
- I:G
What initially decreases in the blood as a response to a meal
- Glucagon
- Free Fatty Acids
TG are released by lipolysis durign a fast to make energy
insulin inhibits lipolysis
as FA are attached to glycerol, thus we see an decrease in both
- Ketoacids
- Glycerol- insulin inhibits lipolysis-> decrease in free fatty acids and glycerol
- Urea Nitrogen- inhibitory effect of insulin on protein breakdown
protein breakdown levels are the highest during fasting
Glucose, lactate, pyruvate response to a meal
TG, Free FA and ketone bodies response to a meal
Glycerol, Alanine and BCAA response to a meal
Total amino acids and urean nitrogen response to a meal
Does ingestion of fat lead to an insulin release?
no
Do CHOs only result in inuslin release?
CHO do have the highest effect on insulin release, some AA however also result in insulin release
How doe blood glucose levels in circulation differ in an individual with insulin resistance from a normal patient
in people with insulin resistance blood glucose response will be higher and will remain high for a longer period of time
What is reactive hypoglycemia
Also known as postprandial hypoglycemia, drops in blood sugar are usually recurrent and occur within four hours after eating
associated wiht insulin resistance, and results from overproduction of insuln
When do blood glucose levels normally start to drop after a meal?
1 hour after a meal
What is insulin resistance associated with?
With high BMIs
What dictates energy storage
ratio of insulin:glucagon
How much energy does brain need?
The brain needs ≈500 kcal of water-soluble fuels (usually glucose) per day.
Describe the events of the first 24h of fast
first 24h of fasting in someone who expends 2000kcal/day:
- TG will be released from fat stores-> FA + glycerol will be released
- FA will be taken up by muscle and liver
- Glycerol will be used by the liver to be converted to glucose. FA will be used for energy by liver by b-oxidation
- Protein will be released from muscles-> liver will do gluconeogenesis-> makes glucose
- Muscle provides amino acids and also provides alanine which will be used as a precursor for glucose
- lactate-pyruvate is being released from tissues that use glycolysis (RBC, skin, renal medulla) will be released from the use of glucose. It will then be reconverted to glucose via cori cycle
What are the methods of glucose production in short -term fast
- Liver converst substrates from lactate, pyruvae, alanine cycles are converted to glucose
- Glycerol form FA release from adipose tissue is converted to glucose in the liver
- Glygcogenic AA from muscles
What are glucogenic precursors?
glycerol, amino acids, lactate-pyruvate, alanine, glycogen in the liver
What is the production of ketones determined by?
by the amount of FA in the circulation > the rate of supply of FA to the liver triggers ketoacedosis
this is mainly regulated by insulin and glucagon at early fast state
What are the effects of low insulin levels in a short-term fast?
- insulin being low, allows lipolysis to occur at a high rate (insulin normally inhibits lipolysis);
- low insulin will also allow protein breakdown to occur (insulin inhibits protein breakdown)
- glycogenolysis is stimulated by low insulin and high glucagon as well as stimulating gluconeogeneis from AA and glycerol
WHat are the outputs of ketones prodcued by the liver
breath, urine and energy supply for the brain
is lipolysis rate ever increasing?
No, after reachign a certain poitn, it will occur only at a certian rate
When will ketones be excreted in urine
when ketone concentration will reach a certain level in the circulation