Diabetes Flashcards
Name and describe the two types of diabetes.
- Diabetes mellitus: Body doesn’t produce enough insulin or doesn’t properly respond to insulin
- Diabetes insipidus: Excessive thirst and excretion of large amounts of dulute urine. Results from malfunction of the vasopressin/antidiuretic hormone system
Describe the oral glucose tolerance test.
It determines the rate of glucose removal from the blood.
Patients fast, and then drink glucose. Blood glucose is measured before glucose consumption and at intervals thereafter.
What fasting blood glucose concentration suggests diabetes?
> 126 mg/dl (After 2 hours, >200)
Uncontrolled diabetes results in very high _______ concentration.
blood glucose
What are the two types of diabetes mellitus?
- Type I diabetes: Body produces little to no insulin
- Type II diabetes: Body becomes resistant to insulin
How does type I diabetes develop?
The body’s immune system destroys pancreatic beta cells, which produce insulin
Type I diabetes usually strikes which demographic?
Children and young adults
Which type of diabetes accounts for 90% of all cases?
Type II
How does type II diabetes develop?
It begins as insulin resistance. As the need for insulin rises, the pancreas gradually loses ability to produce it.
Type II diabetes is associated with what conditions?
Older age, obesity, family history of diabetes, and physical inactivity
Why do those with type I diabetes die without insulin?
Ketoacidosis
Those with type 2 diabetes can’t survive without insulin. True or false?
False. They can.
Where are glucose transporters stored?
Within the cell in membrane vesicles
What happens when insulin interacts with its receptor?
Vesicles move to the surface and fuse with the plasma membrane, bringing up the glucose transporters
When insulin levels drop, what happens to glucose transporters?
They’re removed from the plasma membrane via endocytosis, forming small vesicles.
These small vesicles fuse with a larger endosome, and patches of the endosome bud off to become small vesicles, ready to return to the surface when insulin levels rise again.
Insulin stimulates glycolysis. True or false?
True
Insulin inhibits fatty acid synthesis. True or false?
False
Insulin inhibits lipolysis. True or false?
True
Insulin stimulates lipogenesis. True or false?
True
During the fasting or diabetic state, _____ and _____ are elevated.
epinephrine; glucagon
Urea is exported to the _____ and excreted in _____.
kidney; urine
Which TCA cycle intermediate is diverted to gluconeogenesis?
Oxaloacetate
Glucose is exported via the bloodstream to the _____.
brain
Fatty acids from adipose tissue are oxidized as fuel, producing what?
Acetyl-CoA
Acetyl-CoA synthesis favors _____ synthesis.
ketone body
Ketone bodies are exported to the brain to be used as what?
Fuel
Where do excess ketone bodies end up?
Urine
A lack of insulin secretin or response to insulin means what for glucose reabsorption?
It’s significantly reduced.
What contributes to high blood glucose levels in diabetic patients aside from the reduced glucose absorption?
Gluconeogenesis in the liver still occurs even though there’s enough glucose available.
In diabetic patients, lipoprotein lipase is [promoted/inhibited]. What does this result in?
inhibited
This results in high concentrations of VLDL and chylomicrons in the blood
In type I diabetes, no insulin secretin leads to ____ and ____.
lipolysis; ketoacidosis (excessive production of ketone bodies)
Type II diabetes patients are insulin resistant, which means what?
Receptors on liver/muscle cells are insensitive
In type __ diabetes patients, beta cells don’t make enough insulin to either inhibit gluconeogenesis or stimulate glucose uptake.
II
Why do insulin-resistant diabetic patients rarely have ketoacidosis?
Lipolysis in adipose cells is still inhibited by insulin.
How does glucose regulate insulin secretion in beta cells?
Glucose enters the cell via GLUT2 and undergoes glycolysis, the TCA cycle, and oxidative phosphorylation, which increases [ATP].
The increase in ATP closes the ATP-gated K+ channel, which depolarizes the cell because K+ can’t leave.
Voltage-gated Ca2+ channels allow Ca2+ to flow in. The ER takes in the Ca2+, releasing insulin in secretory granules to be secreted outside the cell.
What drugs treat type II diabetes?
Sulfonylurea drugs
How do sulfonyl drugs work?
They target ATP-gated K+ channels and increase insulin release from pancreatic beta cells.
What’s glycation?
A nonenzymatic attachment of glucose to proteins
What leads to glycation? Why is this bad?
Elevated blood glucose levels leads to glycation of proteins, which negatively affects their function.
Describe the glycation reaction.
It’s a nonenzymatic reaction of glucose with lysine residues and N-termini of proteins.
Glycation leads to damage in what?
Kidneys, retinas, cardiovascular system (Small blood vessels)
What is the glucose measuring device that determines your blood glucose concentrations called?
Glucometer
Your blood glucose concentrations change [slowly/rapidly].
rapidly
What is hemoglobin a1c? Does it change slowly or rapidly?
A glycated form of hemoglobin
It gives an indication of blood glucose concentrations over past weeks/months. It changes slowly.
How does hemoglobin glycation relate to hemoglobin a1c tests?
Glycated protein level is proportional to blood glucose concentrations and used to estimate blood glucose concentrations over weeks (Hemoglobin a1c levels)
Why is high glucose is bad?
It leads to inappropriate glycation of proteins, which causes blurred vision and increases the risk of cardiovascular disease
What is hypoglycemia? How does it happen, and what does it result in?
Low blood sugar
It happens very fast when too much insulin is injected. It can lead to coma and death.
What does diabetic ketoacidosis cause? How does it happen?
It causes dehydration, labored breathing, coma, and death.
It happens more slowly when insulin isn’t present or insulin response is too low. The liver makes an excessive amount of ketone bodies from lipolysis and fatty acid beta oxidation.
What are some chronic diabetes-related complications?
Cardiovascular disease and stroke, high blood pressure, blindness, renal disease, nerve disease, and amputations
What are some treatment options for type II diabetes?
Diet can control diabetes in some patients. Losing weight will increase the number of peripheral insulin receptors, improving insulin sensitivity.
Drugs and oral/inhaled insulin could also help.
