Diabetes: Hockerman Flashcards
What are the causes of Type 1 DM? (Obj 1)
autoimmune disruption of normal insulin secretion or function
autoantibodies may be made against insulin, pancreatic islet cells, insulin granule associated proteins
What are the causes of Type 2 DM? (Obj 1)
can be either a decrease in insulin production due to exhaustion of pancreatic cells or by insulin resistance in peripheral tissues
manifestations of diabetes (Obj 1)
three poly’s (polydipsia, polyuria, polyphagia)
unexplained weight loss
glucosuria
Which of the two types of diabetes predisposes individuals to ketoacidosis more? (Obj 2)
type 1
complete lack of endogenous insulin production makes these individuals more likely to excessively oxidize FA for fuel, as they cannot use glucose
Why do type 1 diabetics have to receive exogenous insulin? (Obj 2)
they cannot produce their own insulin due to destruction of beta cells
Which comorbidity is most often associated with T2DM? (Obj 2)
obesity
80% of T2DM population
How does the age of onset of T2DM differ between obese and non-obese individuals? (Obj 2)
Non-obese patients tend to develop T2DM earlier (before 25) than do obese patients (Usually after 35).
What are the 4 possible diagnostic criteria for diabetes? (Obj 1)
(1) Hgb A1C > 6.5%
(2) 2 hr OGTT >200 mg/dL
(3) any BG > 200 mg/dL
(4) FBG > 126 mg/dL
What is the effect of insulin on the liver? (Obj 3)
inhibition of gluconeogenesis, glycogenesis, inhibition of ketone body formation (at lower concentrations than are required for uptake by muscles)
What are the complications of diabetes on other body systems? (Obj 1)
CONNI
cardiovascular - increased blood pressure
ophthalmic - cataracts, glaucoma
neuropathy - damage to peripheral nerves by excessive alcohol production
nephropathy - damage to renal vasculature and glomerular bed
increased susceptibility to infections
There is a sharp increase in risk of retinopathy once fasting glucose levels rise above ____ mg/dL, which corresponsds to an A1C of ____.
110, 5.9
Which metabolic intermediate of glucose metabolism is responsible for inhibition of vasorelaxation? How does it do so?
methylglyoxal, inhibits acetylcholine mediated nitric oxide release
What is the polyol pathway? In what part of the body does this become a problem in diabetics?
metabolic pathway involving the depletion of reducing agents and production of osmotically active, alcohol rich sugars
issue in the nervous system, where nerves swell and are damaged
What are the roles of the alpha and beta subunits of the insulin receptor? (Obj 5)
alpha subunit - regulatory domain: suppresses beta subunit phosphorylation, suppression relieved by insulin
beta subunit - tyrosine catalytic domain
Which tissue is the most important player in lowering BG in response to insulin?
skeletal muscle
How does the disposal of glucose in response to insulin change between fed and fasting states?
In the fed state, 75% of glucose disposal is insulin-independent via the liver, brain, and GI system. The other 25% is done by skeletal muscle and is insulin dependent. after a meal, skeletal muscle becomes much more important in glucose uptake and is responsible for 80% of post-prandial glucose uptake. Another 5% is done in adipose tissue.
What happens to FFA levels in the blood when insulin is released? How does this affect glucose uptake by skeletal muscle?
FFA levels decrease, which enhances skeletal muscle’s ability to uptake glucose.
Which glucose receptor has the highest Km? the lowest?
highest belongs to the liver (GLUT2) and lowest belongs to the brain/neurons (GLUT3)
This makes sense because the NS should always have some constant supply of glucose.
Which hormone secreted with insulin is responsible for slowing gastric emptying and inhibits glucagon secretion?
amylin
What are the metabolic effects of glucagon? (Obj 3)
increase gluconeogenesis, increase glycogenolysis to raise BG
What are the metabolic effects of somatostatin? (Obj 3)
general inhibitor is secretion from alpha and beta cells
What modification has been made to NPH insulin? What effect does this have on absorption and duration of action? (Obj 6)
insulin is complexed with protamine (a protein), which slowly releases it and prolongs the duration of action
What is the appearance of NPH insulin? (Obj 6)
cloudy solution due to proteins