Hypoglycemia Flashcards
What is hypoglycemia charcterized by?
BGL less than 55 or even 40 (2.2 mM)
when do adrenergic symptoms usually occur?
when the blood glucose levels fall abruptly and epinephrine release is stimulated (regulated by hypothalamus)
-anxiety, palpitation, tremor, sweating
when do neuroglycopenia symptoms usually occur?
from a gradual decline in blood glucose, often below 40 mg/dL. the slow decline deprives the brain of glucose, but fails to trigger the epinepherine response.
-headache, confusion, slirred speech, coma, death
how can the symptoms of hypoglycemia be resolves?
administering glucose
what can transcient hypoglycemia lead to?
cerebral dysfunction
what can prolonged, severe hypoglycemia cause?
come and death
what are injections with glucagon or epinephrine used for?
treatment in order to released glucose from the liver into the blood
at low BGL, what systems are working to normalize the BGL?
- pituitary gland ACTH
- ANS
- directly, via the low serum BGL acting on the alpha cells of the pancreas
what is released in response to low BGL?
catecholamines + cortisol
adrenergic and neuroglycopenia symptoms
what are the 2 types of hypoglycemia related to blood insulin levels?
- postprandial hypoglycemia
- insulin-induced hypoglyemia
what is postprandial hypoglycemia?
due to exaggerated insulin release in people
what is insulin induced hypoglyemia ?
in patients treated with insulin or in patients with insulinoma
what is the second most common hypoglycemia?
postprandial hypoglycemia
in postprandial hypoglycemia, what type of hypoglycemia do you get with what type of symptoms?
transicent hypoglycemia
adrenergic symptoms (mild)
with postprandial hypoglycemia, how do plasma glucose levels return to normal?
w/o eating
how is postprandial hypoglycemia prevented?
frequent small meals
how is mild hypoglycemia with insulin induced hypoglycemia treated?
with oral administration of carbs like OJ
how is severe hypoglycemia with insulin induced hypoglycemia treated?
glucagon administration
what is insulinoma?
tumor of pancreatic islet cells
why is there severe hypoglycemia with insulinoma?
during fasting due to uptake of glucose into muscle and fat cells
with an insulinoma, abnormally high levels of what do what?
insulin
block the action of the fasting state hormones
what will a patient with insulinoma present with?
high insulin levels
C peptide and proinsulin in blood
*indicators of increased endogenous insulin production
what can hypoglycemia often indicate?
serious medical problems - hereditary
alcohol intoxication
what diseases is hypoglycemia found in?
glycogen storage diseases
abnormal fructose/galactose metabolism
abnormal metabolism of FA degradation
abnormal carnitine shuttle during fasting
why is severe fasting hypoglycemia found in Von Gierke’s disease?
glucose cannot be released into the blood by the liver, due to hereditary deficiency of G-6-Phosphatase
what else do you find in patients with Von Gierke’s disease?
extremely high levels of glycogen in liver and kidney
lactic acidemia
gout
what diseases is milder hypoglycemia during fsating found?
Hers disease - deficiency of liver phosphorylase
cori disease - deficiency of deb ranching enzyme - limit dextrinosis
*both are GSD
why is severe hypoglycemia found after ingestion of fructose in patients with hereditary fructose intolerance ?
due to deficiency of aldolase B
fructose -1-P accumulates in the liver which leads to reduced cellular levels of inorganic phosphate.
pi is needed as example for ATP synthase and glycogen phosphorylase
what has to be removed from the diet in peolpe with HFI?
sucrose
fructose
sorbitol - is used in liver to form fructose catalyzed by sorbitol DH
why is there severe hypoglycemia in patients after ingesting galatose with Classical galacotsemia?
hereditary deficiency of galatose 1-P uridyltransferase (GALT)
leads to galatose-1-P and galactitol
where does galatitol accumulate?
in the liver
in the nerve
lens
kidney
causes liver damage, severe mental retardation and cataracts
what has to be removed from diet in people with CG?
lactose and galactose
why is there severe hypoglyemia during fasting in hereditary defects in Beta oxidation?
Medium chain FA Co! DH are needed to provide energy for gluconeogenesis during fasting - deficiency can lead to death
what does MCAD deficiency lead to (levels)?
high levels of medium chain FA carnitines
dicarboxylic acids in blood and urine
why is there severe hypoglyemia during fasting with defects in carnitine shuttle?
- due to carnitine deficiency
- due to hereditary deficiency of CPT1 in liver
why is there hypoglycemia with alcohol ingestion?
high ethanol in heptocytes = high NADH/NAD+ ratio in cytosol - gluconeogenesis doesn’t work!
what should you measure if factitious hypoglycemia is suspected?
insulin
C-peptide
proinsulin
detection fo sulfonylurea in blood
what is sulfonylurea used for?
treatment for DM type II
acts by stimulating endogenous insulin secretion from pancreas
what does endogenous insulin production leads to high levels of?
insulin
C-peptide
proinsulin
what does exogenous administration of insulin show ?
high levels of insulin
low levels of C-peptide and low proinsulin
what results are found in factitious hypoglycemia involving injecting insulin without having DM?
high insulin
low C peptide
low proinsulin
sulfonylura is absent
what results are found in factitious hypoglycemia involving sulfonylurea consumption in non DM?
high insulin
high C peptide
high proinsulin
high sulfonylurea levels
what types of disordered are factitious disorders?
mental/ personality
what is the most severe form of factitious disorders?
Munchhausen syndrome
stimulation of disease is central activity of these patients
