Diabetes Mellitus — Viva

Q1: Diagnostic criteria (2 min)

"Recite the diagnostic cut-offs for diabetes."

• Fasting plasma glucose ≥126 mg/dL (7.0 mmol/L)
• 2-hour 75 g OGTT ≥200 mg/dL (11.1 mmol/L)
• HbA1c ≥6.5% (48 mmol/mol)^[1]
• Random glucose ≥200 mg/dL with classic symptoms
• Repeat confirmatory test if asymptomatic (ADA convention)

Q2: Type 1 vs type 2 (2 min)

"How do you distinguish type 1 from type 2 at the bedside and with tests?"

• T1: younger/any age, leaner, short history, ketosis-prone, absolute insulin need; autoantibodies (GAD, IA-2, ZnT8), low C-peptide^[5]
• T2: metabolic syndrome phenotype, gradual onset, family history, may still present with ketosis in ketosis-prone T2
• Never delay insulin if uncertain and patient is catabolic/ketotic

Q3: Organ-protective drugs (3 min)

"Beyond glucose, which drugs reduce heart failure and CKD outcomes?"

• SGLT2 inhibitors — HF hospitalisation and CKD progression benefits^[4]
• GLP-1 receptor agonists — MACE reduction in many agents; weight loss
• ACE-I/ARB for albuminuric CKD; high-intensity statin for ASCVD risk
• Avoid TZDs in HF; counsel SGLT2i sick-day rules / euglycaemic DKA

Q4: Hypoglycaemia (2 min)

"How do you treat severe hypoglycaemia?"

• Conscious: 15–20 g fast carbohydrate, recheck 10–15 min^[2]
• Unconscious: IV 10% dextrose or IM glucagon 1 mg if no IV access^[2]
• Identify cause; reduce culprit drug; educate

Q5: Sick-day rules (2 min)

"What do you tell patients on SGLT2 inhibitors when they get gastroenteritis?"

• Hold SGLT2i during acute dehydrating illness
• Maintain hydration; continue basal insulin if insulin-treated; check ketones if unwell
• Seek care if vomiting, abdominal pain, dyspnoea (euglycaemic DKA risk)^[3]

References5ShowHide

1. [1]Duong KNC, Tan CJ, Rattanasiri S, et al. Comparison of diagnostic accuracy for diabetes diagnosis: A systematic review and network meta-analysis Front Med (Lausanne), 2023.PMID 36760402
2. [2]Villani M, de Courten B, Zoungas S Emergency treatment of hypoglycaemia: a guideline and evidence review Diabet Med, 2017.PMID 28477413
3. [3]Dhatariya KK. The management of diabetic ketoacidosis in adults-An updated guideline from the Joint British Diabetes Society for Inpatient Care Diabet Med, 2022.PMID 35224769
4. [4]McMurray JJV, Solomon SD, Inzucchi SE, et al. Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction N Engl J Med, 2019.PMID 31535829
5. [5]Jacobsen LM, Schatz DA. Type 1 Diabetes: A Review JAMA, 2026.PMID 41697686