Hypoglycemia

Question 1

Hypoglycemia is characterized by what Bl glucose levels?

Answer 1

Less than 55 or even 40mg/dl (2.2mM while normal is 5mM)

Question 2

What can cause Adrenergic symptoms?

Answer 2

When the bl glucose levels falls quickly and when epinephrine release is stimulated.

Question 3

What can cause Neuroglycopenia symptoms?

Answer 3

Due to gradual decline in bl glucose depriving the brain of glucose. Epinephrine is not released.

Question 4

Differentiate between the symptoms of Adrenergic and Neuroglycopenia?

Answer 4

Adrenergic symptoms: anxiety, palpitation, tremor, sweating

Neuroglycopenia: symptoms: headache, confusion, slurred speech, coma, death (more serious bc the brain has no glucose)

Question 5

Transient hypoglycemia can lead to what?

Answer 5

cerebral dysfunction

Question 6

Why are injections of glucagon or epinephrine used to treat hypoglycemia?

Answer 6

To help release glucose from liver into bl via glycogen degradation.

Question 7

How does the pituitary gland / ACTH counteract insulin and normalize bl glucose levels?

Answer 7

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.

Question 8

How does the autonomic nervous system counteract insulin and normalize bl glucose levels?

Answer 8

It stimulates the release of norepinephrine to stimulate glycogenolysis (doesn’t affect gluconeogenesis)

Question 9

Prolonged hypoglycemia leads to what?

Answer 9

coma and even death

Question 10

How does the low bl glucose acting on alpha cells of pancreas normalize bl glucose levels?

Answer 10

Stimulates release of glucogon which will will stimulate both glycogen breakdown and gluconeogenesis.

Question 11

What occurs in response to low bl glucose levels?

Answer 11

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)

Question 12

What is postprandial hypoglycemia and how can it be prevented?

Answer 12

exaggerated insulin release after meal; transient hypoglycemia. Can be prevented by having small meals often

Question 13

What can cause insulin induced hypoglycemia?

Answer 13

pt accidentally injects too much insulin and insulinoma

Question 14

What is insulinoma and what is it characterized by?

Answer 14

Tumor of pancreatic cells resulting in severe hypoglycemia; characterized by high levels of insulin, C-peptide and proinsulin

Question 15

What are indicators of increased endogenous insulin production?

Answer 15

high levels of insulin, C-peptide and proinsulin

Question 16

What is the treatment for mild and severe hypoglycemia?

Answer 16

Mild: oral intake of carbohydrate like orange juice; severe: glucagon administration

Question 17

What can result in fasting hypoglycemia?

Answer 17

serious medical problems/ genetic defects:

1) glycogen storage diseases
2) abnormal frucotose/ galactose metabolism
3) abnormal carnitine shuttle or abnormal metabolism of FA degradation

Question 18

What glycogen storage disease results in severe fasting hypoglycemia?

Answer 18

Von Gierke’s disease

Question 19

What is deficient in Von Gierke’s disease?

Answer 19

glucose 6 phosphatase which will inhibit both glycogen degradation of liver and gluconeogenesis

Question 20

What are some symptoms that characterize Von Gierke’s disease?

Answer 20

Severe hypoglycemia, high levels of glycogen in liver and kidney, lactic acidemia and gout

Question 21

What glucogen storage disease result in milder hypoglycemia?

Answer 21

Hers disease and Cori disease

Question 22

What is deficient in Cori disease?

Answer 22

debranching enzyme, limit dextrinosis.

Question 23

What is deficient in Hers disease?

Answer 23

liver phosphorylase

Question 24

Pts with Hereditary fructose intolerance have deficiency of what enzyme? what will accumulate?

Answer 24

aldolase B w/ accumulation of Fructose 1-P in liver

Question 25

How do u treat the severe fasting hypoglycemia in Hereditary fructose intolerance?

Answer 25

By removing sucrose, fructose, and sorbitol from diet bc sorbitol can form fructose via sorbitol DH resulting in increase of F-1P

Question 26

What is deficient in classical galactosemia?

Answer 26

galactose 1P uridytransferase (GALT)

Question 27

What is found in pts with classical galactosemia?

Answer 27

fasting hypoglycemia, accumulation of galactose 1P and galactitol in liver, nerve, lens and kidney. Pts will have liver damage, severe mental retardation and cataracts.

Question 28

Treatment for hypoglycemia in classical galactosemia?

Answer 28

Remove lactose and galactose from diet.

Question 29

What accumulates in MCAD deficiency?

Answer 29

medium chain fatty acyl carnitines and dicarboxylic acids (in Bl/ urine)

Question 30

Why are hereditary defects of B-oxidation (especially MCAD) life threatening?

Answer 30

Results in fasting hypoglycemia. MCAD (medium chain fatty acyl CoA deydrogenase) necessary to provide E for gluconeogenesis during fasting.

Question 31

What can cause carnitine shuttle related fasting hypoglycemia?

Answer 31

Carnitine def or def of CPT1 in liver. (Severe form leads to early death in childhood)

Question 32

What type of pts are most vulnerable to fasting hypoglycemia induced by high ethanol levels?

Answer 32

undernourished or dehydrated pts

Question 33

Why does high alcohol consumption result in fasting hypoglycemia?

Answer 33

High alcohol consumption results in high NADH/ NAD ratio in cytosol which will decrease usable precursors for gluconeogenesis

Question 34

What characterizes exogenous administration of insulin?

Answer 34

high levels of insulin with low levels of C-peptide and proinsulin.

Question 35

What can cause Factitious hypoglycemia?

Answer 35

Injection of insulin (exogenous administration) or intake of Sulfonylurea in the absence of diabetes (endogenous administration)

Question 36

How does sulonylurea cause hypoglycemia in pts w/out DM?

Answer 36

Drug used for DM type II pts that stimulates pancreas to secrete insulin

Question 37

What are facticious disorders and what is the most severe form?

Answer 37

mental / personality disorders; most severe: Munchhausen syndrome: come up w/ different diseases (stimulate diseases)