CDCES Pathophysiology of Diabetes

Question 1

Which autoantibody is most specific for type 1 diabetes and is present in approximately 70-80% of newly diagnosed patients?

Accepted Answer

Glutamic acid decarboxylase antibody (GADA)

Answer

Anti-insulin antibody (IAA)

Answer

Islet cell antibody (ICA)

Answer

Zinc transporter 8 antibody (ZnT8A)

Question 2

In type 2 diabetes, which physiological defect is considered the PRIMARY initiating mechanism in the majority of patients?

Accepted Answer

Peripheral insulin resistance with compensatory hyperinsulinemia

Answer

Absolute insulin deficiency due to beta-cell destruction

Answer

Glucagon deficiency causing fasting hypoglycemia

Answer

Excessive GLP-1 secretion stimulating excess insulin

Question 3

The incretin effect refers to which physiological phenomenon?

Accepted Answer

Enhanced insulin secretion in response to oral glucose compared to IV glucose due to gut hormones

Answer

Glucagon suppression by dietary fat ingestion

Answer

Delayed gastric emptying caused by high-fiber foods

Answer

Increased insulin sensitivity from regular aerobic exercise

Question 4

Which statement about gestational diabetes mellitus (GDM) pathophysiology is correct?

Accepted Answer

GDM results from placental hormones increasing insulin resistance, unmasking inadequate beta-cell reserve

Answer

GDM is caused by destruction of pancreatic beta cells by placental autoantibodies

Answer

GDM is always permanent and progresses to type 1 diabetes postpartum

Answer

GDM is solely caused by excessive weight gain during pregnancy

Question 5

Diabetic ketoacidosis (DKA) occurs primarily because of which underlying pathophysiological mechanism?

Accepted Answer

Absolute or near-absolute insulin deficiency combined with counter-regulatory hormone excess driving unregulated lipolysis and ketogenesis

Answer

Excess dietary fat intake causing ketone accumulation

Answer

Impaired renal excretion of glucose causing toxic glucose accumulation

Answer

Excessive insulin causing hypoglycemia that triggers compensatory ketone production

Question 6

Which mechanism explains how chronic hyperglycemia causes microvascular complications such as diabetic retinopathy?

Accepted Answer

Advanced glycation end-products (AGEs), polyol pathway activation, and oxidative stress damage endothelial cells

Answer

Hyperglycemia directly destroys the optic nerve through osmotic pressure

Answer

Excess insulin causes vasoconstriction that reduces retinal blood flow

Answer

High glucose levels increase HDL cholesterol, depositing in retinal vessels