BC ADM Diabetes Pathophysiology 4

Question 1

In hyperosmolar hyperglycemic state (HHS), why is ketoacidosis typically absent despite severe hyperglycemia?

Accepted Answer

Residual insulin secretion is sufficient to suppress lipolysis and ketogenesis but not to control glucose

Answer

In HHS, enough endogenous insulin remains to inhibit lipolysis and hepatic ketogenesis, preventing significant ketone accumulation despite extreme hyperglycemia.

Question 2

Which pathway of glucose metabolism is responsible for the synthesis of diacylglycerol (DAG), which activates protein kinase C (PKC) and contributes to diabetic vascular complications?

Accepted Answer

De novo glycerol-3-phosphate synthesis from excess glucose

Answer

Excess intracellular glucose is diverted to glycerol-3-phosphate synthesis, increasing DAG levels that activate PKC isoforms driving vascular inflammation and permeability changes.

Question 3

What is the primary mechanism by which the hexosamine biosynthesis pathway contributes to insulin resistance?

Accepted Answer

UDP-GlcNAc O-glycosylates serine/threonine residues on IRS-1, blocking insulin signaling

Answer

Excess glucose flux through the hexosamine pathway elevates UDP-GlcNAc, which O-GlcNAc–modifies IRS-1 at sites that compete with phosphorylation, impairing downstream insulin signal transduction.

Question 4

Which type of diabetes results from exocrine pancreatic disease (e.g., chronic pancreatitis or cystic fibrosis) affecting both insulin and glucagon secretion?

Accepted Answer

Type 3c diabetes (pancreatogenic diabetes)

Answer

Type 3c diabetes occurs secondary to pancreatic exocrine disease; loss of both alpha and beta cells creates a brittle, hypoglycemia-prone state distinct from type 1 or 2.

Question 5

In mitochondrial diabetes (MIDD), which mutation is most commonly responsible and what clinical feature distinguishes it?

Accepted Answer

m.3243A>G tRNA-Leu mutation associated with maternally inherited deafness

Answer

The m.3243A>G mitochondrial mutation impairs oxidative phosphorylation in beta cells and cochlear cells, causing maternally inherited diabetes with sensorineural hearing loss (MIDD).

(BC ADM) Advanced Diabetes Management Certification Practice Test

(BC ADM) Advanced Diabetes Management Certification Practice Test

BC ADM Diabetes Pathophysiology 4