Diabetes Flashcards
Explain the glucose metabolism. (Where glucose is produced and where glucose is used + hormones involved)
Produced in liver & kidneys -> with glucagon
Used in muscle and adipocytes + brain, retina, kidneys, erythrocytes, leukocytes -> with insulin
What are the processes involved with the regulation of blood glucose related to glucagon and insulin separately ?
Glucagon:
- glycogenolysis
- gluconeogenesis
Insulin:
- glycogenesis
- glycolysis
- glucose oxisation
Describe the glucose flow during the fasting and postprandial states.
Fasting:
Glucose is produced 90% from liver and 10% from kidneys. Goes to circulation. 64% brain, 18% muscle/fat, 10% kidneys, 8% liver
Postprandial:
100% of the glucose comes from the gut. 33% brain, 33% muscle/fat, 34% liver
Describe the difference between a healthy and diabetic person in terms of glucose, insulin and glucagon levels in the blood after a meal.
Healthy:
Glucose goes up. A lot of insulin is secreted to store the glucose. Low glucagon.
Diabetic:
Glucose is very high. Not so much insulin is secreted, which allows for glucose to remain high. Glucagon is very elevated, which increases the glucose levels.
What are the actions of insulin on glucose metabolism?
ANABOLIC:
- glucose transport
- glycolysis (energy)
- glycogenesis
ANTI-CATABOLIC:
- gluconeogenesis
- glycogenolysis
What are the actions of insulin on lipid metabolism?
ANABOLIC:
- lipogenesis (make TG and FFA)
- LPL activity
ANTI-CATABOLIC:
- lipolysis
- LPL
- ketogenesis
- FA oxidation
What are the actions of insulin on protein/electrolytes metabolism?
ANABOLIC:
- makes proteins (stimulates uptake of aa by muscles)
- promotes electrolyte balance (more K enters cells)
ANTI-CATABOLIC:
- protein catabolism
Describe the insulin production/release.
glucose enters beta cells through GLUT2. calcium also enters the cells. Insulin is then produced, and released through exocytosis.
Insulin is released along with C-peptide
What is first and second phase insulin?
FIRST PHASE insulin is the initial burst of insulin (5-10min after beta cells are exposed to rapid increase in glucose)
Decreased hepatic glucose production and lipolysis
SECOND PHASE is when insulin secretion rises more gradually and is directly related to the degree and duration of the stimulus
What are the main 4 symptoms of diabetes and what are the 3 tests that can be done?
Increased:
- thirst (polydipsia)
- hunger (polyphagia)
- urination (polyuria)
- weight loss (T1) or obesity (T2)
TESTS:
- OGTT
- Glucosuria
- Hyperglycemia
Describe the catabolic state of diabetes (what happens in the absence of insulin).
gluconeogenesis muscle/fat use ketones and FA glycolytic enzyme activity lowers hypoglycemia liver increases VLDL production adipose tissue release FFA hexokinase increases cardiac and skeletal muscles rely on ketone bodies
What is the importance of incretins? What are the 2 main incretins?
when glucose is given through IV, there is no release of insulin. When glucose is given orally, glucose stimulates the release of incretins, which stimulates the release of insulin
Glucose -> incretins -> insulin
Main: GLP-1 and GIP
What factors determine the plasma concentration of glucose?
carb composition of food rate of gastric emptying rate of glucose absorption concurrent state of glucose disposal acute illness emotional stress alcohol intake diurnal change in insulin sensitivity
What is the main clinical presentation of T1DM?
DKA
Complication of severe insulin deficiency leading to hyperglycemia, causing glucosuria, dehydration and ketogenesis to the eventual acidosis
What are the symptoms of T1DM?
- vomiting
- abdominal pain
- hyperventilation
- lethargy
- confusion
- dehydration
- severe fatigue
What are the 2 factors that affect b-cells in T2DM?
decreased mass AND function
What are the 5 pathogenic features of hyperglycemia?
- decreased incretin effect
- increased hepatic glucose production
- decreased glucose uptake (increased lipolysis)
- increased glucose reabsorption
- increased glucagon secretion
Who secretes the most insulin?
Obese, non-diabetic, insulin resistant
What are the 3 things that happen in insulin resistance (decreased…)?
Decreased:
- ability of insulin to suppress endogenous glucose production in the liver
- uptake of glucose in tissues with insulin-dependent glucose transporters (skeletal muscles)
- inhibition of lipolysis
What 4 people are insulin sensitive?
- children with T1DM
- lean ppl with T1DM
- conditioned athletes
- newly diagnosed with T1DM
What are the 4 factors used to diagnose diabetes?
FPG: >7mmol/L
A1C: >6.5%
2hPG: >11.1mmol/L
Random PG: >11.1mmol/L
What is the macronutrient distribution for a diabetic person?
CHO: 45-60%
Pro: 15-20%
Fat: 20-35%
What is covered in the basic carb counting?
- introduces the concept
- encourages inclusion of consistent amounts of CHO at meals and snacks
What is covered in the advanced carb counting (on inuslin)?
- teaches patients who use MDI or insulin pump how to match short acting insulin to CHO using ratios
- match the amount of insulin to take with the amount of carb you want to eat
- still need to control intake in order to prevent weight gain
Where are the hidden carbs?
- breading on meat/poultry
- meal components (ex: cornstarch)
- pasta sauce
- croutons in salads
- large amount of salad dressing
- ketchup
What are the 4 teaching resources in order of complexity?
- just the basics
- beyond the basics
- glance at meal planning
- meal planning quebec
What are the 5 LCS?
- sucralose
- saccharin
- aspartame
- rebaudioside A
- acesulfame-k
What are the 4 proposed mechanisms for the fact that LCS are associated with weight gain?
- sweet-taste receptor mediated changes in gut hormones
- impaired predictive relationship between sweet taste and calories
- altered nutrient absorption via changing the gut microbiota
- change in taste preferences and dietary preferences
What are the 4 types of appropriate snacking?
- bedtime snack should include protein
- have a snack if gap of 5-6h between meals
- ppl that have low BG at a certain time of the day should have a snack at that time
- snack if starting a new exercise program or exercise longer than usual
What is A1C?
A series of stable minor hbg components formed slowly nonenzymatically from hgb and glucose
The rate of formation if proportional to the concentration of glucose
It provides a glycemic history of the previous 2-3months
It can also predict the risks of complications