CDE Pathophysiology 5

Question 1

Maturity-onset diabetes of the young (MODY) is characterized by which distinctive genetic feature?

Accepted Answer

Autosomal dominant single-gene mutations impairing beta-cell function

Answer

MODY is caused by autosomal dominant mutations in single genes (e.g., HNF-1alpha, glucokinase, HNF-4alpha) that impair beta-cell development or function, distinguishing it from polygenic type 2 diabetes.

Question 2

In gestational diabetes mellitus (GDM), placental hormones contribute to insulin resistance primarily through which mechanism?

Accepted Answer

Placental lactogen and progesterone impairing post-receptor insulin signaling

Answer

Human placental lactogen, progesterone, and cortisol secreted by the placenta antagonize insulin signaling at the post-receptor level, creating physiologic insulin resistance that unmasks GDM in susceptible women.

Question 3

Diabetic autonomic neuropathy affecting the cardiovascular system most characteristically presents as:

Accepted Answer

Resting tachycardia followed by fixed heart rate unresponsive to maneuvers

Answer

Cardiovascular autonomic neuropathy initially causes resting tachycardia from vagal denervation, then progresses to a fixed heart rate as both parasympathetic and sympathetic cardiac innervation is lost.

Question 4

Which of the following correctly describes the pathophysiology of hypoglycemia unawareness in diabetes?

Accepted Answer

Recurrent hypoglycemia shifts the glycemic threshold for counterregulatory responses to lower glucose levels

Answer

Recurrent hypoglycemia causes both the threshold for counterregulatory hormone release and the threshold for symptom perception to shift to lower glucose values, reducing or eliminating warning symptoms.

Question 5

Secondary diabetes mellitus caused by chronic pancreatitis differs from type 1 and type 2 in that it features:

Accepted Answer

Impaired glucagon secretion from alpha-cell damage making hypoglycemia more severe

Answer

In pancreatogenic (type 3c) diabetes, destruction of both alpha and beta cells means glucagon secretion is also impaired, resulting in labile glucose control and increased severe hypoglycemia risk without glucagon rescue.

Certified Diabetes Educator Test Practice Test

Certified Diabetes Educator Test Practice Test

CDE Pathophysiology 5