Hypoglycemia

Question 1

What effect does insulin have?

Answer 1

anabolic effect except for glycolysis

Question 2

What effect does glucagon have?

Answer 2

catabolic effect except for gluconeogenesis

Question 3

Hypoglycemia characterized by

Answer 3

1. CNS symptoms, including confusion, aberrant behaviour, or coma
2. A simultaneous blood glucose level equal or less than 70 mg/dl
3. Symptoms being resolved within minutes following administration of glucose

Question 4

Is hypoglycemia considered a medical emergency

Answer 4

Yes, as CNS has absolute requirement for continuous supply of blood glucose
- body has a number of redundant systems that prevent and correct hypoglycemia

Question 5

Symptoms of hypoglycemia divided into two classes

Answer 5

1. Adrenergic
2. Neuroglycopenic

Question 6

Adrenergic

Answer 6

• Results from elevated epinephrine
• fear, tremors, sweating

Question 7

Neuroglycopenic

Answer 7

• Results from decreased brain glucose
• impaired brain function, confusion, seizures, coma or death

Question 8

Glucoregulatory systems

Answer 8

Humans have 2 overlapping glucose-regulating systems that are activated by hypoglycemia

Question 9

Glucose Regulating Systems

Answer 9

1. Pancreatic a-cells, which release glucagon
2. Receptors in the hypothalamus, which respond to low glucose
   - trigger secretion of catecholamine’s, cortisol and growth hormone
   - glucagon, catecholamines, cortisol and growth hormones sometimes called counter regulatory hormones as oppose action of insulin

Question 10

4 types of Hypoglycemia

Answer 10

1. Insulin induced- most common
2. Postprandial hypoglycemia- second most common
3. Fasting hypoglycemia- least common
4. Alcohol-related hypoglycemia

Question 11

1. Insulin Induced

Answer 11

• Occurs in diabetics being treated w/ insulin
• mild cases are treated w/ oral glucose administration
• severe cases typically given glucagon subcutaneously or intramuscularly

Question 12

2. Postprandial hypoglycemia

Answer 12

• Caused by exaggerated insulin release following a meal
• leads to transient hypoglycemia w/ mild adrenergic symptoms
• plasma glucose normalizes even if not fed
• treatment: small frequent meals

Question 13

3. Fasting Hypoglycemia

Answer 13

• Low blood glucose during fasting rare but serious medical problem
• produces neuroglycopenic symptoms
• caused by; hepatic damage, insufficient adrenal gland function, pancreatic B-cell cancer, low glycogen stores

Question 14

4. Alcohol-related hypoglycemia

Answer 14

• Alochol metabolized in liver by oxidation which produces NADH
• High NADH leads to pyruvate conversion to lactate and oxaloacetate to malate
• large amounts of ethanol inhibits gluconeogenesis and results in hypoglycemia in patients w/ low glycogen levels

Question 15

Feed-Fast Cycle

Answer 15

• Insulin and glucagon shift metabolism through feed-fast cycle

Question 16

Fed State: 2-4 hours after a meal

Answer 16

• Anabolic period
• absorption of nutrients
• insulin is predominant hormone

Question 17

Fasted State: begins if more food is not ingested after absorptive period

Answer 17

• Catabolic period
• focus on maintaining blood glucose for brain
• fatty acids mobilized for oxidation
• glucagon is predominant hormone