Module 1 - Diabetes Mellitus Flashcards
Incidence
rate of new cases
on the rise
conveys risk of contracting disease
Prevalence
proportion of actual cases
conveys how widespread disease is
Diabetes Insipidus versus Mellitus
Insipid is a disorder of ADH
Mellitus is a disorder of blood glucose regulation
Exocrine
releases through a duct
Endocrine
Secretion right into the blood stream
Is the pancrease endo or exocrine
Both
Pancreas
Large diffuse abdominal organ functioning as both an endocrine and exocrine gland
made up of acini and islets of langerhans (the two major tissue types)
Acini
Exocrine tissue of the pancreas that secretes into ducts
Releases digestive enzymes like amylase, protease, and lipase as well as sodium bicarbonate
Islets of Langerhans
Endocrine tissue of the pancreas that secretes right into blood - key role in blood glucose levels
takes up 1-2% volume of the pancreas
Has alpha delta and beta cells releasing hormones that regulate glucose levels
Exocrine Pancreatic Function
Acini release digestive enzymes and sodium bicarbonate
Contents are released into the pancreatic duct
Exocrine function here plays an essential role in digestion and absorption of food in the smal;l intestine
Endocrine Pancreatic Function
Involves synthesis and release of hormones produced by specialized cells in the Islets of Langerhans
Key role in blood glucose levels
Different Cells in the Islets of Langerhans
Alpha
Beta
Delta
What do Beta cells and Amylin release?
Insulin
What do alpha cells release
glucagon
What do delta cells release
Somatostatin
Diabetes is not strictly involved with …
Insulin
Other hormones that keep glucose levels high
Catecholamines (EP qand NEP)
Growth Hormones
Glucocorticoids (Cortisol
Insulin, Glucagon, and Somatostatin are what to one another? What do they work to do?
They are counter regulatory hormones and work to keep glucose levels lower/regulate glucose
What counteracts glucagon?
Insulin
Where are the Islets of Langerhans located?
Around the blood vessels surrounding the pancreas
The only hormone known to lower blood glucose ?
Insulin
What cell releases Insulin and what is Insulins action
Beta
Decrease blood glucose by allowing it to enter cells (changes cell membrane makeup to allow cell opening for glucose thus lowering blood glc levels)
What cell releases Glucagon and what is Glucagons action?
Alpha
Increased release of glucose from the liver into the blood to increase blood glc levels. Causes the release of stored glycogen specifically to turn into glucose for use
What cell releases Somatostatin and what is Somatostatins action?
Delta
Extends the use of absorbed nutrients for tissues by blocking increases in glc levels after we eat to allow a slower rise and better control over the glucose levels
Decreases GI activity after ingestion –> extends time over which food is absorbed –> inhibits insulin and glucagon –> extends use of absorbed nutrients by tissues
How much of ingested glucose is used for metabolism?
1/3
How much glucose undergoes Glycogenesis after eating?
2/3
What happens to blood glucose after a meal?
Glucose levels rise –> insulin secreted in response from beta cells
2/3 of glucose stored as glycogen in the liver (Glycogenesis) while 1/3 is used for metabolism
Saturation of tissues with glycogen –> glucose converted to fatty acids –> stored as triglycerides in gat (Lipogenesis)
What happens to blood glucose between meals?
Liver releases glucose to maintain blood glucose within normal limits via Glycogenolysis and potentially gluconeogenesis
Glycogenesis
Glucose converted to glycogen and stored in the liver
Lipogenesis
Excess glycogen in the tissues leads to glucose being converted to 3 fatty acids and adipose cells and then being stored as triglyceride in fat cells
Glycogenolysis
glycogen is broken down to release glucose into the blood
Gluconeogenesis
synthesis of glucose from amino acids, glycerol, and lactic acid
What can be used interchangeably with glucose for energy everywhere but cardiac and skeletal muscles, kidneys, brain, and the liver?
Fatty Acids
Fatty acids cannot normally be used for energy in the brain as it requires steady glucose amount, the only exception is ..
During starvation situations ketone bodies can be used
What occurs if blood sugar is low?
glucagon released by pancreas –> glycogen breakdown is promoted to glucose in the blood
What occurs when blood sugar is high?
- Insulin is released by the pancreas to promote glycogen synthesis in the liver
- stimulates glucose uptake in tissue cells
- Over Saturation with glycogen leads to storage as triglycerides in fat cells
What is the action of Insulin on Glucose
Increase glucose transport into skeletal and adipose tissue
Increase glycogen synthesis
Decrease gluconeogenesis
What is the action of Insulin on Fats
Increase glucose transport into fat cells
Increase Fatty acid transport into adipose cells
Increase triglyceride synthesis within fat cells
Inhibit adipose cell lipase (breaking down triglycerides)
Activates lipoprotein lipase in capillary walls
What is the action of Insulin on Proteins
Increase active transport of amino acids into cells
Increases protein synthesis (anabolism) by increasing transcription mRNA and accelerating protein synthesis by rRNA
Decreases protein breakdown by enhancing use of glucose and fatty acids as fuel (prevents muscle wasting - catabolic)
Normal insulin release only occurs in normal conditions when..
Blood glucose levels are high
Atheroscleorosis
Body fats deposited on lining of blood vessels
HDL
High Density Lipoproteins
The good cholesterol
takes fats on blood cells back to the liver for use
Insulin has a beneficial effect on this process
Want levels greater than 45 and 55 in women and men respectively
LDL
Low density lipoproteins
Lousy bad cholesterol
Levels between 60-80
smaller than HDL so we want more HDL and less LDL as HDL is more effective at moving fats away and preventing atherosclerosis buildup
How does Diabetes mellitus impact cholesterol?
It increases cholesterol levels while increasing LDL and greatly decreasing HDL leading to increased triglycerides and fat/plaque buildup
DM –> Not enough insulin –> no activation –> atherosclerotic buildup as a result –> risk for stroke, heart attack, etc –> elevated LDL, cholesterol and triglycerides with lower HDL
Anabolic Activity
Promotes synthesis
Catabolic Activity
Promotes break down
Why do children with diabetes often lose weight rapidly despite eating a lot and being hungry?
Not enough insulin means protein begins to catabolize and muscle wasting occurs
Proteins are needed for AA production and use in metabolic function
Major activity of Insulin on tissues?
Decrease blood glucose by allowing it to enter cells
Major action of insulin in regards to anabolic action?
Promote synthesis of proteins, carbs, lipids, nucleic acids in liver, muscle and adipose tissue
major action of insulin on the liver
Stimulates the synthesis of glycogen and increases uptake as well as fatty acid synthesis
Inhibits glycogenolysis, gluconeogenesis, and ketogenesis
major action of insulin on muscle
increase uptake of glucose and amino acids
increase glycogen and protein synthesis
inhibit protein catabolism
Major action of insulin on adipose
increase glucose uptake and fat synthesis (Lipogenesis)
decreased fat breakdown (by inhibiting adipose cell lipase)
Major action of insulin on Potassium (K+)
increase potassium uptake by cells (GIK)
Major action of insulin on lipids
metabolism of plasma lipids and lipoproteins WNL ranges
___% of insulin is used or degraded and why
50% - so insulin is released in phases since its half life is 15 minutes
What follows glucose when insulin allow transport into cells?
K+ (potassium) which makes K levels decrease too in the blood
A cell does not need insulin if…
they have special glucose carriers: the brain cells, RBC, endothelial lining cells, glomerular lining cells
GIK Mechanism
Glucose-Insulin-Potassium Mechanism allowing potassium uptake in cells at the same time as insulin allow glucose in
Why may we give glucose and insulin to someone with lower serum potassium levels?
It can instigate intake of potassium to raise levels
it is not a long term effect but it can save lives
Why are too high or too low K levels bad?
Can cause arrhythmia of the heart
Normal function of insulin
increased uptake of blood glucose into cells
decrease blood glucose levels
Excess insulin leads to …
Hypoglycemia
Deficit Insulin leads to..
Hyperglycemia
What can hypoglycemia cause?
Decreased blood glucose:
hunger tremors sweating weakness malaise irritability mental changes coma --> death
What can hyperglycemia cause?
Increased blood glucose:
Polydipsia Polyphagia Polyuria Dehydration Fatigue Mental Changes coma --> death
What are the 3 P’s of Hyperglycemia that define it?
Polydipsia
Polyphagia
Polyuria
Polydipsia
Intense Thirst (to dilute sugars)
Polyphagia
Intense Hunger
Polyuria
increased urinary output (leads to dehydration)
Why is it better to give insulin rather than more food?
because the cells are starving because lack of insulin means they cannot get the glucose in so they need a way in rather than more glucose
How does a blood sugar of 30 differ from one of 400?
normal range is 60-100
30 can be deadly while 400 is less dangerous and more just uncomfortable
What is more dangerous, hypoglycemia or hyperglycemia?
Hypoglycemia
Always assume what if you do not know blood sugar levels?
Assume they have hypoglycemia since it is more dangerous and BE SAFE AND GIVE SUGAR
Glucagon
Secreted by pancreas alpha cells
action opposite of insulin
diabetics may need a glucagon pen in case of emergency
Insulin acts on all body cells, but glucagon…
primarily acts in the liver
How does glucagon travel?
via portal vein to the liver where it exerts its main effects
Function of Glucagon
Stimulate glycogenolysis and gluconeogenesis
Increase lipolysis and output of ketones by the liver
Enhance uptake of amino acids by the liver (can be used for anabolic process or gluconeogenesis)
*It will help form new glucose when glucose is depleted
What occurs to glucagon when blood glucose is high
secretion is inhibited (when low it increases)
How is glucagon related to diabetic ketoacidosis
Increases lipolysis which makes ketone waste products
Action of Glucagon on Glucose
promotes breakdown of glycogen into glucose phosphate
increases gluconeogenesis
Action of Glucagon on Fats
enhances lipolysis in adipose tissue –> liberates glycerol for use in gluconeogenesis
activates adipose cell lipase
enhances lipolysis in adipose tissue –> liberates fatty acids (so they can be used for energy - ketones produced as a waste product!)
Action of Glucagon on Proteins
increases breakdown of proteins into amino acids for use in gluconeogenesis
New glucose, through the help of glucagon, comes from what
Glucagon action on amino acids, fatty acids, and glycerols together
Catecholamines
produced by adrenal medulla
EP and NEP
an important homeostatic mechanism during periods of hypoglycemia as its purpose is to conserve glucose
Function of Catecholamines
maintain blood glucose levels during stress:
mobilize glycogen stores
decreases movement of glucose into body cells (keeps it high in the blood)
inhibits insulin release from beta cells
mobilizes fatty acids from adipose tissues (prevent storage of glucose and keep levels high)
The main purpose of catecholamines is to..
conserve glucose!
Main catecholamines
NEP and EP
where are catecholamines produced?
adrenal medulla
How does hypoglycemia relate to catecholamines?
It activates the bodies stress response - leading to autonomic symptoms like palpitations, shakiness, nervousness, sweating, pallor, irritability, etc
The catecholamines then allow glucose levels to be conserved and maintain glucose levels/raise them
Why is it hard to potentially manage diabetes during a hypoglycemic attack
Symptoms of neuroglycopenia can lead to hypoglycemia of the brain impairing ability to think making it hard to manage (alongside other symptoms like weakness and lethargy)
Growth Hormone’s Function relating to glucose levels
increase protein synthesis in ALL cells of the body (anabolic)
mobilize fatty acids from adipose tissue (to use for fuel)
antagonize the effects of insulin
decrease cellular uptake and use of glucose –> increase blood glucose by 50-100% –> stimulate further insulin secretion
Normally it helps with growth but has an antagonistic effect on insulin
How do the GH levels compare between adults and children
They are the same levels!
What inhibits GH
Insulin and increased levels of blood glucose (so there is not a prolonged effect of elevated GH)
When do GH levels increase
When fasting (and hypoglycemia)
Exercise: running, cycling, etc
Stress: anesthesia, fever, trauma
What does prolonged GH excess cause?
increased glc levels despite increased insulin release –> leads to insulin resistance in peripheral tissue –> this inhibits glc uptake by muscle and adipose tissue and contributes to diabetes
Acromegaly
chronic hypersecretion of GH in adulthood
causes symptoms of glucose intolerance, insulin resistance, and diabetes
Gigantism
GH hypersecretion / excess in childhood
What releases GH
anterior pituitary
Pathway for increased GH?
Hypothalamus –> GHRH –> Anterior Pituitary –> Increased GH
Pathway for decreased GH?
Hypothalamus –> Somatostatin –> Anterior Pituitary –> Decreased GH
Somatostatin is released by …
many places like the hypothalamus, pancreas, and GI tract
it is counterregulatory to GH
Glucocorticoid Hormones
Main: Cortisol (Hydrocortisone)
Synthesized in Adrenal Cortex
Regulates metabolism of glucose
95% of glucocorticoid activity comes from …
cortisol
Functions of Glucocorticoids in relation to diabetes/blood glucose
Regulate metabolism of glucose (critical to survival during periods of fasting and starvation)
Stimulate gluconeogenesis by the liver (increased production (6-10x)
When do glucocorticoid levels increase
During stress: infection, pain, trauma, surgery, prolonged strenuous exercise, acute anxiety
During hypoglycemia: a potent stimulus for secretion of glucocorticoids
Why does chronic stress relate to diabetes
lots of cortisol is released which increases and conserves glucose levels
stress in the hospital can lead to a need for insulin
Ghrelin
Made by GI cells / in the stomach
helps control hunger (no release = no feelings of hunger)
Gastrin
made by stomach/GI cells
important to acid secretion and satiation
Cholecystokinin
released by duodenum
gall bladder contraction
GI motility
pancreatic exocrine secretion functions
Secretin
released by duodenum
related to pancreatic exocrine secretion
GIP
released by duodenum
related to Incretin activity
Motilin
released by duodenum
related to GI motility
Pancreatic Polypeptide
released by pancreas
related to gastric motility and satiation
Oxyntomodulin
released by large intestine
relates to satiation and acid secretion
PYY 3-36
released by large intestine
relates to satiation
GLP-1
glucagon like peptide 1
released in the distal small bowel
works with GIP
incretin hormone released from your gut that signals beta cells to increase insulin secretion and decrease the alpha cells release of glucagon
this one also slows down the rate at which food empties from the stomach and acts on the brain to increase satiety (and suppress glucagon)
GIP
Glucose dependent insulinotropic polypeptide
released in jejunum
incretin hormone released from the gut that signals beta cells to increase insulin secretion and decrease the alpha cells release of glucagon
GLP-1 and GIP mimic the action of ____-
somatostatin
increase the amount of insulin made and act as messengers between the digestive tract and the pancreas
Amylin
similar to somatostatin
released along with insulin from beta cells
has a similar effect as GLP-1 (decrease glucagon levels to decrease liver glucose production; slow rate at which food empties from the stomach; increase satiety by acting on the brain)
Pramlintide
medication that encourages amylin release
Diabetes
disorder of carb, protein, and fat metabolism
mult. etiologic factors
involves absolute or relative insulin insufficiency and/or insulin resistance
glucose cannot be carried into fat and muscle cells –> cell starvation –> fat and protein breakdown
Examples of Etiologic Reasons for Diabetes
genetics
viruses
cancer
obesity
sometimes it cannot be ID’ed
Why is Diabetes referred to as the “Running through of sugar”?
Because the amount of glucose overwhelms the glomerulus and spills into the urine
Absolute Insulin Deficiency
Type 1 Diabetes
Cannot make any endogenous insulin with your beta cells
You end up needing exogenous insulin
Relative Insulin deficiency
not making enough insulin
it is either destroyed early, broken, etc
Insulin Resistance
cells do not use insulin correctly and beta cells may need to make more and more until failing
lack of ability to keep up with production can occur with endogenous insulin, but resistance can occur with exogenous OR endogenous
What problems can insulin resistance lead to?
Diabetes
Heart Problems
What are some insulin issue types that can lead to diabetes
Absolute deficiency (type 1)
no insulin being made (type 1)
relative deficiency
impaired release by pancreatic beta cells
inadequate or defective insulin receptors
production of inactive insulin
insulin being destroyed begore it carries out its action
Types of Cells that do not need insulin for glucose to get into them?
Nerve cells
RBCs
Cells lining the glomerulus
endothelial cells
What can the brain use as emergency energy in severe starvation situations
Ketones from fat breakdown
Cause of death rank for Diabetes in the USA`
7th
risk for death is twice of that for non-diabetics of the same age
The leading cause of end stage renal disease (ERSD) in the US is..
Diabetes
Risk for heart disease and stroke is 2-4 times more for ___ than non
Diabetics
Diabetic Comorbidities for children and adolescents with Type 1 DM
Nephropathy
Hypertension
Dyslipidemia
Celiac Disease
Hypothyroidism
Important HP2020 Diabetes Take aways
Prevalence has increased in the last decade but leveled off
targets have been met
2/3 of diabetics are diagnosed
A1C greater than 9% in 20% of adults
half of diabetic objectives seen little or no change in the last decade
Type 1 Diabetes
Absolute insulin deficiency (cannot make insulin)
Etiology: autoimmune or idiopathic - but strongly autoimmune since attacks on beta cells and langerhans islets occur (occurs in children often)
Treatment: Insulin (only treatment)
Type 1.5 Diabetes
Latent autoimmune disease occurring in adults
Treatment: Oral medicines at first but will need insulin within 5 years
Type 2 Diabetes
Due to: Insulin insensitivity, insulin secreting deficiency, inappropriate gluconeogenesis (either insulin is formed wrong, receptors do not work, or glucose cannot be made right)
Etiology: obesity or genetics
Treatment: Diet, exercise, hypoglycemics, transporter stimulators (first two especially for pre diabetics)
In what form of diabetes is genetics more important?
Type 2
What maybe the etiology and treatment for other specific types of diabetes
Etiology: Malnutrition, Corticosteroid use, secondary to pancreatic cancer, pancreatitis, steroid use, etc
Treatment is based on case
GDM
Gestational Diabetes
etiology: increased metabolic demands of the fetus
Treatment: Diet, metformin, insulin; usually resolves post delivery
If GDM occurs in 2-3 pregnancies in a row what is likely to happen?
It may convert to type 2 diabetes (or potentially type 1)
If someone is diabetic then gets pregnant…
it is NOT GDM, its either 1 or 2
Former names for Type 1 Diabetes
Juvenile Onset (adults could get it, its just less common)
Insulin Dependent (not good name since type II could use insulin too)
IDDM
Type I (people dont know roman numerals)
Former names for type 1.5 Diabetes
Latent Autoimmune Diabetes in Adults (LADA) - Still used