BC ADM Comprehensive Diabetes Assessment & Diagnosis 5 — Questions and Answers
Question 1: Which finding on nerve conduction study is most consistent with diabetic peripheral polyneuropathy?
- Increased conduction velocity in sensory nerves
- Reduced amplitude and slowed conduction velocity in distal sensory nerves (Correct answer)
- Focal conduction block at the wrist
- Normal sural nerve action potential
Correct answer: Reduced amplitude and slowed conduction velocity in distal sensory nerves
Diabetic polyneuropathy produces a length-dependent pattern with reduced amplitude and slowed velocity in distal sensory nerves, reflecting axonal loss and demyelination.
Question 2: A patient with type 2 diabetes and a recent MI is started on an SGLT2 inhibitor. Which additional benefit beyond glucose lowering makes this appropriate?
- Reduction in HbA1c by ≥2%
- Cardiovascular and heart failure hospitalization reduction demonstrated in trials (Correct answer)
- Elimination of the need for ACE inhibitor therapy
- Prevention of diabetic retinopathy progression
Correct answer: Cardiovascular and heart failure hospitalization reduction demonstrated in trials
SGLT2 inhibitors (empagliflozin, canagliflozin, dapagliflozin) have demonstrated significant reductions in major adverse cardiovascular events and heart failure hospitalizations in high-risk patients.
Question 3: When assessing for diabetic autonomic neuropathy, which test specifically evaluates cardiovagal function?
- Quantitative sudomotor axon reflex test (QSART)
- Heart rate variability with deep breathing (E/I ratio) (Correct answer)
- Sympathetic skin response
- Tilt-table testing for orthostatic hypotension
Correct answer: Heart rate variability with deep breathing (E/I ratio)
The expiration-to-inspiration (E/I) heart rate ratio during deep breathing at 6 breaths/min assesses parasympathetic (vagal) control of heart rate, a validated cardiovagal function test.
Question 4: A clinician suspects cystic fibrosis-related diabetes (CFRD) in a 20-year-old patient. Which diagnostic approach is preferred?
- HbA1c ≥6.5%
- 2-hour OGTT with 75g glucose load (Correct answer)
- Fasting plasma glucose ≥126 mg/dL on two occasions
- Continuous glucose monitoring for 2 weeks
Correct answer: 2-hour OGTT with 75g glucose load
OGTT is the preferred test for CFRD because HbA1c is unreliable in CF (due to hemolytic anemia and chronic illness), and fasting glucose alone misses many cases.
Question 5: Which feature differentiates type 3c (pancreatogenic) diabetes from type 2 diabetes on clinical assessment?
- Age of onset before 30 years
- Exocrine pancreatic insufficiency with steatorrhea and history of pancreatitis (Correct answer)
- Positive islet autoantibodies
- Obesity and metabolic syndrome
Correct answer: Exocrine pancreatic insufficiency with steatorrhea and history of pancreatitis
Type 3c diabetes follows pancreatic damage (chronic pancreatitis, pancreatectomy, CF); exocrine insufficiency causing steatorrhea and a relevant pancreatic history are diagnostic clues.
Question 6: A fasting C-peptide of 0.8 ng/mL is measured in a patient with known diabetes on insulin therapy. How should this be interpreted?
- Indicates complete beta-cell failure consistent with type 1 diabetes
- Suggests residual beta-cell function, inconsistent with absolute insulin deficiency (Correct answer)
- Is within the normal range for a non-diabetic adult
- Confirms insulin resistance as the primary pathophysiology
Correct answer: Suggests residual beta-cell function, inconsistent with absolute insulin deficiency
A C-peptide of 0.8 ng/mL indicates residual endogenous insulin secretion, which would be atypical for established type 1 diabetes and should prompt re-evaluation of the diagnosis.
Question 7: According to the ADA, which blood pressure target is recommended for most adults with diabetes and hypertension to reduce cardiovascular and renal risk?
- <150/90 mmHg
- <140/90 mmHg
- <130/80 mmHg (Correct answer)
- <120/80 mmHg
Correct answer: <130/80 mmHg
ADA recommends a blood pressure target of <130/80 mmHg for most adults with diabetes and hypertension based on evidence from ACCORD-BP and meta-analyses showing cardiovascular benefit.
BC ADM Comprehensive Diabetes Assessment & Diagnosis 5
Which finding on nerve conduction study is most consistent with diabetic peripheral polyneuropathy?