Chapter 33: Diabetes Flashcards
What are the 2 different aspects of pancreatic function?
Exocrine Pancreas: digestive juices through duct into duodenum
Endocrine Pancreas: release hormones into blood
What is the endocrine section of the pancreas called?
Islets of Langerhans
What are the 4 type of cells and the hormones they secrete in the islets of langerhans
ALPHA: glucagon
BETA: insulin and amylin
DELTA: somatostatin
PP: pancreatic polypeptide
What does glucagon do in the body.
Causes cells to release stored glucose
What does insulin do in the body?
allows cells to uptake BG
What does amylin do in the body?
slows glucose absorption in small intestine and supresses glucagon secretion
What does somatostatin do in the body?
decreases GI activity and supresses glucagon and insulin secretion
When was diabetes mellitus first discovered?
in the 1st century AD
What are the 4 causes of diabetes mellitus?
1) absolute insulin DEFICIENCY
2) impaired RELEASE of insulin
3) inadequate or defective insulin RECEPTORS
4) production of INACTIVE insulin or DESTRUCTION of insulin
Describe DM type 1
it is absolute insulin deficiency d/t autoimmune destruction
What two autoantibodies can cause type 1 DM?
Islet cell autoantibodies
Insulin autoantibodies
What are 3 causes/RF of type 1 DM?
1) genetic predisposition (childhood onset)
2) environmental triggers
3) T-mediated hypersensitivity reactions against beta cell antigens
Describe DM type 1B
Intermittent ketoacidosis with remissions of VARIABLE insulin dependency
IDIOPATHIC with no sign of autoimmune destruction
What are the 2 RF for type 1B DM?
African or Asian decent
Strongly inherited
What percentage of DM is type 2?
90-95 percent
DM type 2 is a result of one or more of…. (3 things, list them)
1) Insulin resistance
2) Inc liver production of glucose
3) beta cell dysfunction
List the RF of DM type 2
Genetic
Environmental
Physical inactivity
OBESITY
What percentage of people with DM type 2 are obese?
90 percent
What type of obesity (body type) is most at risk for developing DM type 2
Apple shaped
Upper body obesity
Explain what insulin resistance is
Failure of target tissue to respond to insulin resulting in
1) decreased uptake
2) does not impair liver production of glucose, resulting in high glucose especially postprandial
What are the 6 things that beta cell dysfunction can be caused by.
Dec mass (genetic/prenatal
Inc apoptosis or dec regeneration
exhaustion (due to chronic insulin resistance)
desensitization (d/t chronic glucotoxicity)
destruction (lipotoxicity)
toxins/deposits (amyloid)
When DM type 2 is diagnosed, what can typically be said about beta cells?
dysfunction has already progressed
What is gestational diabetes mellitus?
Glucose intolerance developing during pregnancy
What are the RF for gestational diabetes mellitus (7)
1) Glycosuria
2) Family hx of type 2 DM
3) Hispanic, native American, African American descent
4) Severe obesity
5) Polycystic ovary disease
6) Prior h/o GDM
7) previous delivery of large baby
What are the fetal complications of gestational diabetes mellitus? (5)
MACROSOMIA: excessive birth weight
HYPOGLYCEMIA
HYPOCALCEMIA: d/t dec parathyroid gland function
POLYCYTHEMIA
HYPERBILIRUBINEMIA
What percentage of mothers with gestational diabetes progress to DM type 2 within 5-10 yrs
50 percent
Describe the onset of symptoms for DM type 1 and DM type 2
Type 1 is rapid onset
Type 2 is insidious
Which type of DM has weight loss and which has weight gain?
type 1: wt loss d/t fluid loss and use of fat stores
Type 2: weight gain
What are the three polys of DM? explain each
POLYURIA: glomeruli in kidneys unable to reabsorb glucose and glucose pulls water with it
POLYDIPSIA: loss of water -> intracellular dehydration -> thirst
POLYPHAGIA: (more with type 1) use of stores triggers this
List and describe the four general DM manifestations
BLURRED VISION: hyperosmolar fluid affects lens and retina
WKNESS/FATIGUE: dec fluid in cardiovascular system and inability to use glucose
PARESTHESIA: peripheral sensory nerve dysfunction
INFECTION: organisms thrive with abundant sugar
How long do you need to fast for Fasting Plasma Glucose test? what is the normal value?
8 hours
< 5.7 mmol/L
What is the random blood glucose test?
BG with no regard for last meal/glucose intake
Ex capillary BG (glucometer)
Describe what Oral Glucose Tolerance test is (OGTT).
measures ability to store glucose
75 g of concentrated glucose solution given at intervals
normal response is to return to normal BG levels in 2-3 hrs
2 hr GTT < 7.8mmol/L
Describe what the Glycosylated Hemoglobin test is. (A1C)
HGB becomes glycosylated to form A1C
Indicates average plasma glucose over long period (lvls for 6-12 wks)
sign of chronic hyperglycemia
Normal range 3.9-5.6 percent
When can Glycosylated Hemoglobin test (A1C) be misleading?
with anemia and pregnancy
For what type of DM is urine testing more important for?
For type 1 DM as a measurement of ketones