Flashcards in Hypoglycemia Deck (37)
Hypoglycemia is characterized by what Bl glucose levels?
Less than 55 or even 40mg/dl (2.2mM while normal is 5mM)
What can cause Adrenergic symptoms?
When the bl glucose levels falls quickly and when epinephrine release is stimulated.
What can cause Neuroglycopenia symptoms?
Due to gradual decline in bl glucose depriving the brain of glucose. Epinephrine is not released.
Differentiate between the symptoms of Adrenergic and Neuroglycopenia?
Adrenergic symptoms: anxiety, palpitation, tremor, sweating
Neuroglycopenia: symptoms: headache, confusion, slurred speech, coma, death (more serious bc the brain has no glucose)
Transient hypoglycemia can lead to what?
Why are injections of glucagon or epinephrine used to treat hypoglycemia?
To help release glucose from liver into bl via glycogen degradation.
How does the pituitary gland / ACTH counteract insulin and normalize bl glucose levels?
by stimulating adrenal cortex to release cortisol to stimulate gluconeogenesis (not glycogenolysis)
Stimulates adrenal medulla to release epinephrine which will stimulate glycogenoglysis but not gluconeogenesis.
How does the autonomic nervous system counteract insulin and normalize bl glucose levels?
It stimulates the release of norepinephrine to stimulate glycogenolysis (doesn't affect gluconeogenesis)
Prolonged hypoglycemia leads to what?
coma and even death
How does the low bl glucose acting on alpha cells of pancreas normalize bl glucose levels?
Stimulates release of glucogon which will will stimulate both glycogen breakdown and gluconeogenesis.
What occurs in response to low bl glucose levels?
Insulin production decreases, epinephrine / glucogon increases, Growth hormone increases, adrenergic symptoms begins (anxiety, palpitation, tremor and sweating), then neuroglycopenia symptoms begins (headaches, confusion, slurred speech, seizures, coma) begins (in this order)
What is postprandial hypoglycemia and how can it be prevented?
exaggerated insulin release after meal; transient hypoglycemia. Can be prevented by having small meals often
What can cause insulin induced hypoglycemia?
pt accidentally injects too much insulin and insulinoma
What is insulinoma and what is it characterized by?
Tumor of pancreatic cells resulting in severe hypoglycemia; characterized by high levels of insulin, C-peptide and proinsulin
What are indicators of increased endogenous insulin production?
high levels of insulin, C-peptide and proinsulin
What is the treatment for mild and severe hypoglycemia?
Mild: oral intake of carbohydrate like orange juice; severe: glucagon administration
What can result in fasting hypoglycemia?
serious medical problems/ genetic defects:
1) glycogen storage diseases
2) abnormal frucotose/ galactose metabolism
3) abnormal carnitine shuttle or abnormal metabolism of FA degradation
What glycogen storage disease results in severe fasting hypoglycemia?
Von Gierke's disease
What is deficient in Von Gierke's disease?
glucose 6 phosphatase which will inhibit both glycogen degradation of liver and gluconeogenesis
What are some symptoms that characterize Von Gierke's disease?
Severe hypoglycemia, high levels of glycogen in liver and kidney, lactic acidemia and gout
What glucogen storage disease result in milder hypoglycemia?
Hers disease and Cori disease
What is deficient in Cori disease?
debranching enzyme, limit dextrinosis.
What is deficient in Hers disease?
Pts with Hereditary fructose intolerance have deficiency of what enzyme? what will accumulate?
aldolase B w/ accumulation of Fructose 1-P in liver
How do u treat the severe fasting hypoglycemia in Hereditary fructose intolerance?
By removing sucrose, fructose, and sorbitol from diet bc sorbitol can form fructose via sorbitol DH resulting in increase of F-1P
What is deficient in classical galactosemia?
galactose 1P uridytransferase (GALT)
What is found in pts with classical galactosemia?
fasting hypoglycemia, accumulation of galactose 1P and galactitol in liver, nerve, lens and kidney. Pts will have liver damage, severe mental retardation and cataracts.
Treatment for hypoglycemia in classical galactosemia?
Remove lactose and galactose from diet.
What accumulates in MCAD deficiency?
medium chain fatty acyl carnitines and dicarboxylic acids (in Bl/ urine)
Why are hereditary defects of B-oxidation (especially MCAD) life threatening?
Results in fasting hypoglycemia. MCAD (medium chain fatty acyl CoA deydrogenase) necessary to provide E for gluconeogenesis during fasting.
What can cause carnitine shuttle related fasting hypoglycemia?
Carnitine def or def of CPT1 in liver. (Severe form leads to early death in childhood)
What type of pts are most vulnerable to fasting hypoglycemia induced by high ethanol levels?
undernourished or dehydrated pts
Why does high alcohol consumption result in fasting hypoglycemia?
High alcohol consumption results in high NADH/ NAD ratio in cytosol which will decrease usable precursors for gluconeogenesis
What characterizes exogenous administration of insulin?
high levels of insulin with low levels of C-peptide and proinsulin.
What can cause Factitious hypoglycemia?
Injection of insulin (exogenous administration) or intake of Sulfonylurea in the absence of diabetes (endogenous administration)
How does sulonylurea cause hypoglycemia in pts w/out DM?
Drug used for DM type II pts that stimulates pancreas to secrete insulin