Diabetes Flashcards
What is the pathology of type 1 DM?
Autoimmune destruction of beta cells in the pancreas. Patients have little to no insulin
What is the pathology of type 2 DM?
Increased resistance to insulin. Patients have normal or elevated insulin
Which DM (type 1 or 2) is associated with juvenile onset?
Type 1; remember, type 2 is a later onset (familial, assc with obesity)
Which DM (type 1 or 2) absolutely requires exogenous insulin as a treatment?
Type 1
What glucose receptor is on the pancreatic beta cells?
GLUT 2
What glucose receptor is on muscle/adipose tissue?
GLUT 4
Describe a glucose tolerance test
Check the patient’s blood levels of glucose and insulin. Then, give the patient oral glucose. Then check their blood glucose measure BG and insulin again. Obviously in a diabetic, the BG will be elevated
Insulin is secreted as proinsulin, a single chain made of 3 components (alpha chain, beta chain, and C peptide). Which 2 of these are joined by disulfide bonds?
The alpha and beta chains
Insulin is secreted as proinsulin, a single chain made of 3 components (alpha chain, beta chain, and C peptide). Which of these components is measured in the blood as a marker of endogenous insulin production?
C peptide
Physiology review: List the steps in insulin secretion starting with GLUT 2 uptake of circulating glucose
- Glucose is elevated so GLUT 2 takes in circulating glucose (into pancreatic beta cell)
- Glucose is generated to ATP
- ATP closes the K channel of beta cell
- Cell is depolarized
- Depolarization –> influx of Calcium
- Influx of Ca causes exocytosis of insulin granules into blood
What do alpha cells of the islets of langerhans make?
Glucagon
What do beta cells of the islets of langerhans make?
Insulin
What do delta cells of the islets of langerhans make?
Somatostatin
What are 4 stimulants of insulin release?
- Increased blood glucose
- Increased blood amino acids
- Vagal stimulation
- Increased sulfonyl ureas
What are 2 amplifiers of insulin release?
- Enteric hormones: gastrin, cholecystokinin (CCK), and secretin
- Beta adrenergic stimulation
What are 3 inhibitors of insulin release?
- Somatostatin
- Drugs (such as diazoxide)
- Catecholamines (Epi, Norepi)
Describe a ketoacidotic coma
Caused by low insulin –> increased liver ketone production (beta-hydroxybutyrate & acetoacetate) –> decreased pH, fruity breath odor, Kussmaul breathing, hyperglycemia
How do you treat a ketoacidotic coma (diabetic ketoacidosis)?
Give insulin (also IV fluids if they are dehydrated)
Diabetic ketoacidosis is usually seen in type 1 or 2 DM?
Type 1
Describe a hypoglycemic coma
Caused by insulin overdose. It is so common that all comatose patients are given glucose while you wait for labs