HYPOGLYCEMIA Flashcards
What are the components of Whipple’s triad used to document hypoglycemia?
A. Elevated plasma insulin levels, fasting state, and normal glucose levels
B. Symptoms consistent with hypoglycemia, low plasma glucose, and symptom relief after glucose correction
C. Seizures, loss of consciousness, and elevated plasma glucose levels
D. Behavioral changes, prolonged fasting, and neurogenic manifestations
Answer: B. Symptoms consistent with hypoglycemia, low plasma glucose, and symptom relief after glucose correction
Rationale: Whipple’s triad confirms hypoglycemia by establishing the presence of relevant symptoms, biochemical evidence of low glucose, and resolution of symptoms after glucose correction.
Which of the following is the first defense mechanism against hypoglycemia in healthy individuals?
A. Increased glucagon secretion
B. Increased epinephrine secretion
C. Decreased insulin secretion
D. Increased cortisol secretion
Answer: C. Decreased insulin secretion
Rationale: The first physiological response to declining plasma glucose is the suppression of insulin secretion, which promotes hepatic glycogenolysis and gluconeogenesis.
What is the primary role of glucagon in counterregulation of hypoglycemia?
A. Reducing glucose utilization in peripheral tissues
B. Stimulating hepatic glycogenolysis and gluconeogenesis
C. Inducing lipolysis and proteolysis
D. Inhibiting insulin secretion
Answer: B. Stimulating hepatic glycogenolysis and gluconeogenesis
Rationale: Glucagon acts on the liver to stimulate glycogenolysis and gluconeogenesis, increasing plasma glucose during hypoglycemia.
2nd defense mechanism for hypoglycemia
Which of the following manifestations is classified as neuroglycopenic in hypoglycemia?
A. Palpitations
B. Tremor
C. Confusion
D. Sweating
Answer: C. Confusion
Rationale: * Neuroglycopenic manifestations of hypoglycemia are the direct result of central nervous system glucose deprivation.
* behavioral changes, confusion, fatigue, seizure, loss of consciousness, cardiac arrhythmias, and, if hypoglycemia is severe, death.
Which of the following drugs is most likely to cause hypoglycemia by suppressing gluconeogenesis?
A. Insulin
B. Ethanol
C. Glucagon
D. Epinephrine
Answer: B. Ethanol
Rationale: Ethanol inhibits gluconeogenesis but not glycogenolysis, leading to hypoglycemia, especially after prolonged alcohol consumption.
How does hypoglycemia caused by exogenous insulin differ from that caused by an insulin secretagogue?
A. Exogenous insulin causes elevated C-peptide levels, while insulin secretagogues cause low C-peptide levels
B. Exogenous insulin causes low C-peptide levels, while insulin secretagogues cause increased C-peptide levels
C. Both cause elevated C-peptide levels
D. Both cause low C-peptide levels
Answer: B. Exogenous insulin causes low C-peptide levels, while insulin secretagogues cause increased C-peptide levels
Rationale: Exogenous insulin suppresses endogenous insulin secretion, resulting in low C-peptide levels, while insulin secretagogues stimulate endogenous insulin production, leading to elevated C-peptide levels.
What is the recommended initial treatment for a conscious patient experiencing hypoglycemia?
A. IV glucose infusion
B. 15–20 g of oral glucose
C. Subcutaneous glucagon injection
D. High-protein meal
Answer: B. 15–20 g of oral glucose
Rationale: For a conscious patient, oral glucose (15–20 g) is the first-line treatment to rapidly correct hypoglycemia.
In cases where intravenous therapy is not practical for treating hypoglycemia, what is the recommended alternative?
A. Subcutaneous or intramuscular glucagon (1 mg in adults)
B. Oral high-carbohydrate meal
C. Subcutaneous insulin injection
D. Corticosteroid injection
Answer: A. Subcutaneous or intramuscular glucagon (1 mg in adults)
Rationale: When IV glucose administration is not feasible, glucagon (SC or IM) is used to stimulate glycogenolysis and restore plasma glucose levels.
Which of the following is the first physiologic response to declining plasma glucose concentrations?
A) Increase in epinephrine
B) Increase in cortisol and growth hormone
C) Decrease in insulin
D) Increase in glucagon
Correct Answer: C) Decrease in insulin
Rationale: Insulin secretion decreases first as plasma glucose concentrations fall, occurring at a glycemic threshold of 4.4–4.7 mmol/L (80–85 mg/dL). This reduction minimizes glucose utilization by insulin-sensitive tissues and promotes counterregulatory mechanisms.
Which counterregulatory hormone serves as the third line of defense against hypoglycemia and is critical when glucagon is deficient?
A) Epinephrine
B) Cortisol
C) Growth hormone
D) Insulin
.
Correct Answer: A) Epinephrine
Rationale: Epinephrine acts as the third defense against hypoglycemia at the same threshold as glucagon (3.6–3.9 mmol/L or 65–70 mg/dL). It enhances glycogenolysis and lipolysis, compensating when glucagon is deficient
What is the role of cortisol and growth hormone in glucose counterregulation during hypoglycemia?
A) Critical first-line response
B) Second-line response, primarily involving glycogenolysis
C) Involved in defense against prolonged hypoglycemia but not critical
D) Directly increase plasma glucose through insulin inhibition
Correct Answer: C) Involved in defense against prolonged hypoglycemia but not critical
Rationale: Cortisol and growth hormone responses occur at the same threshold as glucagon and epinephrine (3.6–3.9 mmol/L or 65–70 mg/dL). They are more involved in long-term defense mechanisms rather than acute glucose restoration.
Which of the following symptoms is a neuroglycopenic manifestation of hypoglycemia?
A) Tremor
B) Palpitations
C) Confusion
D) Hunger
Correct Answer: C) Confusion
Rationale: Neuroglycopenic symptoms, such as confusion, result from glucose deprivation in the central nervous system. Tremor, palpitations, and hunger are neurogenic symptoms caused by sympathoadrenal discharge.
What causes neurogenic (autonomic) symptoms of hypoglycemia?
A) Direct deprivation of glucose to the central nervous system
B) Sympathoadrenal discharge triggered by hypoglycemia
C) Prolonged hyperinsulinemia
D) Glycogen depletion in muscle cells
Correct Answer: B) Sympathoadrenal discharge triggered by hypoglycemia
Rationale: Neurogenic symptoms result from central nervous system–mediated activation of the sympathoadrenal system. This leads to adrenergic (e.g., palpitations, tremor, anxiety) and cholinergic (e.g., sweating, hunger, paresthesias) symptoms.
Which of the following findings suggests hypoglycemia caused by exogenous insulin administration?
A) Increased C-peptide levels
B) Low C-peptide levels
C) Elevated cytokine production
D) Increased glucose utilization
Correct Answer: B) Low C-peptide levels
Rationale: Exogenous insulin administration suppresses endogenous insulin secretion, resulting in low C-peptide levels. This finding helps differentiate it from hypoglycemia caused by insulin secretagogues, which elevate C-peptide levels.
What is the recommended initial treatment for a patient with hypoglycemia who is able and willing to take oral carbohydrates?
A) IV administration of 25 g of glucose
B) SC or IM glucagon (1.0 mg in adults)
C) 15–20 g of glucose via tablets, fluids, candy, or food
D) Glucose infusion followed by IV glucose
Correct Answer: C) 15–20 g of glucose via tablets, fluids, candy, or food
Rationale: In patients who are able and willing, oral treatment with 15–20 g of glucose is the first-line treatment for hypoglycemia. This can be achieved through glucose tablets, fluids, candy, or food.
