Hypoglycemic States

Question 1

What are the six hormones that increase BG?

Answer 1

• Glucagon
• Cortisol
• GH
• Epi
• NE

Question 2

What is the molecule that is needed to convert pyruvate to lactate?

Answer 2

NADH

Question 3

What is the effect of leptin? Ghrelin?

Answer 3

Leptin decreases appetite

Ghrelin increases appetite

Question 4

What is the effect of insulin on serum [K]?

Answer 4

Decreases d/t increased uptake by cells

Question 5

What happens to the adrenergic system with hypoglycemia? What, then, are the ssx of hypoglycemia?

Answer 5

Increases

• Diaphoresis
• Tachycardia
• Anxiety

Question 6

What is the satiety center of the brain?

Answer 6

Ventromedial nucleus of the hypothalamus

Question 7

What is the thirst/cooling center of the brain?

Answer 7

Anterior hypothalamus

Question 8

What is the heating center of the brain?

Answer 8

Posterior hypothalamus

Question 9

What is the hunger center of the brain?

Answer 9

Lateral hypothalamus

Question 10

What are the most common causes of hypoglycemia in adults?

Answer 10

• EtOH
• Sepsis
• Adrenal insufficiency

Question 11

How can EtOH cause hypoglycemia? (2)

Answer 11

• EtOH metabolism reduces the amount of NADH, which is needed for the conversion of pyruvate to lactate for energy.
• Failure of the Cori cycle leads to hypoglycemia

Question 12

What is more common: hyper or hypoglycemia with sepsis? What is the prognosis of this?

Answer 12

Hyper, but hypo has a worse prognosis

Question 13

What is the mechanism through which there is hyper or hypoglycemia with sepsis?

Answer 13

Not totally known, but suspected to be 2/2 cytokine release

Question 14

What are the causes of fasting hypoglycemia?

Answer 14

• Islet cell tumor
• Liver failure
• Hypercatabolic state
• Prolonged EtOH consumption

Question 15

What are the etiologies that can produce postprandial hypoglycemia?

Answer 15

• Gastric resection
• Islet cell tumor
• Glycogen storage disease
• Heriditary fructose intolerance

Question 16

What is hereditary fructose intolerance?

Answer 16

Insufficient liver aldolase B

Question 17

What is type I GSD?

Answer 17

Van Gierke’s disease

-Deficiency in glucose-6-phosphatase leads to the inability to export new glucose

Question 18

What is type II GSD?

Answer 18

Pompe’s disease
-Defect in acid maltase (alpha glucosidase), which is required for the degradation of glycogen. –presents with cardiac hypertrophy

Question 19

What is type III GSD?

Answer 19

Cori’s disease

-Defect in the glycogen debranching enzyme, leading to large glycogen granules

Question 20

What is type V GSD?

Answer 20

Defect in muscle glycogen phosphorylase, which renders the muscles unable to utilize stored glycogen.

This presents as muscle cramps with a lack of lactic acid

Question 21

What is the treatment for postprandial hypoglycemia 2/2 gastric resection? Why does this occur?

Answer 21

Smaller meals more frequently

Gastric bypass leads to a hyperplasia of beta cells d/t compensation for lower calorie intake

Question 22

What abx can cause hypoglycemia?

Answer 22

Fluoroquinolones

Question 23

What NSAID can cause hypoglycemia?

Answer 23

Indomethacin

Question 24

What antimalarial drug can cause hypoglycemia?

Answer 24

Quinine

Question 25

What is Whipple's triad?

Answer 25

- Hypoglycemia - ssx of hypoglycemia - relief of ssx after restoration of normoglycemia

Question 26

How do you diagnose an Islet cell tumor?

Answer 26

FBG less than 40 mg/dL with an elevated insulin level

Question 27

How do you distinguish between an insulinoma and artifactual hypoglycemia?

Answer 27

Used a collection tube that contains an inhibitor of glycolysis

Question 28

What happens to ketogenesis with exogenous insulin administration?

Answer 28

Suppressed

Question 29

What is the ketone that should be measured with ketosis?

Answer 29

Beta-hydroxybutyrate

Question 30

How do you differentiate between insulinomas and sulfonylurea use?

Answer 30

Check levels of oral hypoglycemic agents

Question 31

What are the glucose, insulin, c-peptide, beta-hydroxybutyrate levels with autoimmune dz against insulin? How do you confirm?

Answer 31

Low glucose High insulin High c-peptide Low ketones Check abs

Question 32

What is the purpose of the 72 hour fast with hypoglycemia?

Answer 32

Checking for deficiency in glucose or too much insulin with fasting

Question 33

What BG level is diagnostic for an insulinoma after a 72 hour fast?

Answer 33

Less than 50 mg/dL, with high insulin levels

Question 34

What BG level is diagnostic for an insulinoma after a 72 hour fast and glucagon administration?

Answer 34

Rise above 50 for a while, but then sharply decline

Question 35

What are the ketone levels with an insulinoma after a prolonged fast?

Answer 35

Low

Question 36

How is tolbutamide used to diagnose and insulinoma?

Answer 36

(first gen sulfonylurea) It promotes insulin production, but BG should return to normal after 3 hours in normal patient. Will remain high if there is an insulinoma

Question 37

How is glucagon used to diagnose an insulinoma?

Answer 37

BG will increase initially, but then sharply decrease with an insulinoma

Question 38

What is the treatment for hypoglycemia?

Answer 38

- Oral sugar if conscious | - D5 or D10 IV + glucagon

Question 39

What is the treatment for an insulinoma?

Answer 39

Surgical resection

Question 40

What is the calcium stimulation test?

Answer 40

Injecting calcium will increase insulin secretion. This can help localize a tumor on imaging