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AMC CAT MCQ Examination (AMC Part 1)

Diabetes diagnosis and ongoing care

Q: A 58-year-old man with a 7-year history of type 2 diabetes presents to his general practitioner for a routine chronic disease management review. His current medications include metformin 1000 mg twice daily and perindopril 5 mg daily. His body mass index is 31 kg/m2, blood pressure is 134/82 mmHg, and pulse is 72 bpm. Laboratory tests demonstrate an HbA1c of 8.4% (68 mmol/mol), serum creatinine of 118 umol/L, and an estimated glomerular filtration rate (eGFR) of 56 mL/min/1.73 m2. A spot urine albumin-to-creatinine ratio is 14.8 mg/mmol on two consecutive specimens. Under Australian Therapeutic Guidelines and PBS prescribing criteria, which add-on oral agent is the most appropriate next step in therapy?

Initiate oral empagliflozin 10 mg once daily and provide education regarding sick-day medication rules. In patients with type 2 diabetes and persistent microalbuminuria or established chronic kidney disease with an eGFR above 20 mL/min/1.73 m2, sodium-glucose co-transporter 2 (SGLT2) inhibitors such as empagliflozin or dapagliflozin are the preferred second-line agents added to metformin under Australian guidelines and PBS criteria. Large-scale cardiovascular and renal outcome trials have demonstrated that SGLT2 inhibitors significantly reduce the progression of diabetic nephropathy, slow eGFR decline, reduce heart failure hospitalisations, and decrease cardiovascular mortality. Because SGLT2 inhibitors carry a known risk of euglycaemic diabetic ketoacidosis, patients must receive clear education on sick-day rules: withholding the medication during acute intercurrent illness, vomiting, dehydration, or 2 to 3 days prior to elective surgery. While DPP-4 inhibitors like sitagliptin are well tolerated and weight-neutral, they lack the proven renoprotective and cardiovascular benefits of SGLT2 inhibitors. Sulfonylureas increase the risk of hypoglycaemia and weight gain without renal protection. Basal insulin is generally reserved for patients failing dual or triple oral therapies or presenting with severe symptomatic hyperglycaemia.

Q: A 52-year-old woman with a 3-year history of diet-controlled type 2 diabetes attends her general practice clinic for an annual review. She feels well and reports no urinary symptoms, visual changes, or neuropathic pain. Her blood pressure is 126/78 mmHg, and her body mass index is 27 kg/m2. Her physical examination, including visual acuity and monofilament foot testing, is completely normal. Which investigation represents the most appropriate screening test for diabetic nephropathy according to Australian clinical guidelines?

Measurement of albumin-to-creatinine ratio on an early morning spot urine specimen. Australian clinical practice guidelines from the Australian Diabetes Society and Kidney Health Australia recommend annual screening for diabetic nephropathy in all patients with type 2 diabetes starting at diagnosis. The screening investigation of choice is an early morning spot urine albumin-to-creatinine ratio (ACR). Early morning specimens correlate closely with 24-hour urine collections and avoid false elevations caused by daytime exercise, upright posture, or dietary protein loads. Microalbuminuria is defined as an ACR between 2.5 and 30 mg/mmol in men and 3.5 to 30 mg/mmol in women. Standard urine dipsticks are insensitive to early microalbuminuria and only detect macroscopic proteinuria once urine albumin exceeds 300 mg/L. A 24-hour urine collection is cumbersome, prone to collection errors, and no longer recommended for routine screening. Renal tract ultrasound is useful for evaluating structural kidney disease or obstruction, but it cannot detect early glomerular microvascular pathology.

Key Takeaways

Confirm abnormal results in asymptomatic patients using the diagnostic pathway.
HbA1c can be unreliable with altered red-cell survival or recent transfusion.
PBS eligibility and clinical suitability are related but separate prescribing questions.

Last updated: October 2026

Type 1 & 2 Diabetes, Diabetic Ketoacidosis & Hyperglycaemic Hyperosmolar State

Diabetes mellitus is one of the most prevalent chronic health conditions in Australia, affecting over 1.3 million registered individuals. Mastery of diagnostic thresholds, Australian Pharmaceutical Benefits Scheme (PBS) stepped pharmacotherapy, immediate protocols for acute glycaemic emergencies (DKA and HHS), and systematic microvascular/macrovascular surveillance is foundational for clinical practice and medical licensing assessments.

Diagnostic Criteria for Diabetes Mellitus

According to the Australian Diabetes Society (ADS) and World Health Organization (WHO) guidelines, diabetes mellitus is established through venous plasma glucose or standardised glycated haemoglobin (HbA1c) assays.

Diagnostic Thresholds Matrix

Fasting Plasma Glucose (FPG): Normal: $< 6.1\text{ mmol/L}$ ; Impaired Fasting Glycaemia (IFG) / Impaired Glucose Tolerance (IGT): $6.1 - 6.9\text{ mmol/L}$ (IFG); Diabetes Mellitus: $\ge 7.0\text{ mmol/L}$
2-hour 75g Oral Glucose Tolerance Test (OGTT): Normal: $< 7.8\text{ mmol/L}$ ; Impaired Fasting Glycaemia (IFG) / Impaired Glucose Tolerance (IGT): $7.8 - 11.0\text{ mmol/L}$ (IGT); Diabetes Mellitus: $\ge 11.1\text{ mmol/L}$
Glycated Haemoglobin (HbA1c): Normal: $< 6.0\%$ ( $< 42\text{ mmol/mol}$ ); Impaired Fasting Glycaemia (IFG) / Impaired Glucose Tolerance (IGT): $6.0 - 6.4\%$ ( $42 - 47\text{ mmol/mol}$ ) (Prediabetes); Diabetes Mellitus: $\ge 6.5\%$ ( $\ge 48\text{ mmol/mol}$ )
Random Plasma Glucose: Normal: $< 7.8\text{ mmol/L}$ ; Impaired Fasting Glycaemia (IFG) / Impaired Glucose Tolerance (IGT): —; Diabetes Mellitus: $\ge 11.1\text{ mmol/L}$ with classic symptoms

Clinical Rules for Confirmation

Symptomatic Patients: A single elevated value in the diabetic range in an individual with unequivocal osmotic symptoms (polyuria, polydipsia, unexplained weight loss, lethargy) confirms diabetes mellitus without requiring repeat testing.
Asymptomatic Patients: A single elevated result never confirms diabetes. A second confirmatory venous test must be performed on a separate day (preferably using the same assay type). If two different tests (e.g. FPG and HbA1c) are discordant, the test that exceeded the diagnostic cutoff should be repeated.
When HbA1c Is Unreliable: Conditions altering red blood cell turnover invalidate HbA1c. In patients with haemoglobinopathies (e.g. thalassaemias, sickle cell disease), severe haemolytic anaemia, recent blood transfusion ( $< 3\text{ months}$ ), end-stage kidney disease on haemodialysis, or pregnancy (gestational diabetes), diagnosis must rely strictly on venous plasma glucose criteria (FPG or 75g OGTT).

Stepped Pharmacotherapy for Type 2 Diabetes in Australia

The Australian Diabetes Society and Royal Australian College of General Practitioners (RACGP) recommend target-driven, stepped pharmacotherapy following lifestyle optimization (medical nutrition therapy and structured physical activity).

Pharmacotherapy Classes and Clinical Characteristics

Biguanides: Examples: Metformin; Mechanism of Action: Activates hepatic AMP-activated protein kinase (AMPK), inhibiting gluconeogenesis and enhancing peripheral insulin sensitivity; Clinical Benefits & Target Populations: First-line choice in all newly diagnosed T2DM; weight neutral; low hypoglycaemia risk; cardiovascular safety; Adverse Effects & Safety Caveats: Gastrointestinal upset (nausea, diarrhoea; mitigate by slow titration); vitamin B12 malabsorption; lactic acidosis risk. Renal cutoff: reduce dose if eGFR $< 45\text{ mL/min/1.73 m}^2$ ; cease if eGFR $< 30\text{ mL/min/1.73 m}^2$
SGLT2 inhibitors: Kidney thresholds depend on the medicine and indication. Check current Australian product information and PBS restrictions; thresholds for heart failure/CKD use differ from glycaemic efficacy. Discuss genital infection, volume depletion, ketoacidosis and sick-day interruption.
GLP-1 Receptor Agonists: Examples: Semaglutide, Dulaglutide; Mechanism of Action: Incretin mimetic: stimulates glucose-dependent insulin secretion, suppresses postprandial glucagon, slows gastric emptying; Clinical Benefits & Target Populations: Significant weight loss ( $5-15\%$ ), major adverse cardiovascular event (MACE) reduction in established ASCVD; Adverse Effects & Safety Caveats: Nausea, vomiting, diarrhoea, gastroparesis; rare acute pancreatitis; check the specific Australian product information for contraindications and precautions; US thyroid-tumour label restrictions must not be presented as a universal Australian class contraindication
DPP-4 Inhibitors: Examples: Sitagliptin, Linagliptin; Mechanism of Action: Inhibits dipeptidyl peptidase-4 enzyme, prolonging endogenous incretin hormone (GLP-1 and GIP) half-life; Clinical Benefits & Target Populations: Weight neutral; excellent tolerability; low hypoglycaemia risk. Linagliptin requires no renal dose adjustment (biliary excretion); Adverse Effects & Safety Caveats: Nasopharyngitis, rare acute pancreatitis, joint pain. Do not combine with GLP-1 receptor agonists (no additive efficacy)
Sulfonylureas: Examples: Gliclazide, Glimepiride; Mechanism of Action: Binds to $\text{K}_{\text{ATP}}$ channel on pancreatic $\beta$ -cell membranes, stimulating insulin release independently of glucose; Clinical Benefits & Target Populations: Rapid glycaemic lowering; inexpensive oral option; Adverse Effects & Safety Caveats: Hypoglycaemia (especially in elderly and renal impairment), weight gain. Gliclazide modified-release (MR) has lower hypoglycaemic risk than older agents (glibenclamide)
Basal Insulins: Examples: Insulin glargine, Insulin degludec; Mechanism of Action: Long-acting human insulin analogues providing peakless, steady 24-hour basal insulinisation; Clinical Benefits & Target Populations: Unrestricted efficacy; indicated when multi-drug oral therapy fails to achieve glycaemic targets; Adverse Effects & Safety Caveats: Hypoglycaemia, weight gain, injection site lipodystrophy. Commenced at $10\text{ units}$ or $0.1-0.2\text{ units/kg}$ subcutaneously at bedtime

PBS Prescribing Rules in Australia

Metformin is the default first-line agent.
PBS access: Drug subsidy depends on the current item’s indication and restriction. Do not equate clinical guideline suitability with automatic PBS eligibility, or apply a single HbA1c threshold to every GLP1/SGLT2 indication.
Fixed-dose combination tablets (e.g. metformin + empagliflozin, metformin + sitagliptin) streamline pill burden and improve long-term adherence.

Primary references (checked 7 October 2026): 2024 hyperglycaemic-crisis consensus.

Australian Ozempic product information gives medicine-specific indications, contraindications and precautions.

Test Your Knowledge

A 58-year-old man with a 7-year history of type 2 diabetes presents to his general practitioner for a routine chronic disease management review. His current medications include metformin 1000 mg twice daily and perindopril 5 mg daily. His body mass index is 31 kg/m2, blood pressure is 134/82 mmHg, and pulse is 72 bpm. Laboratory tests demonstrate an HbA1c of 8.4% (68 mmol/mol), serum creatinine of 118 umol/L, and an estimated glomerular filtration rate (eGFR) of 56 mL/min/1.73 m2. A spot urine albumin-to-creatinine ratio is 14.8 mg/mmol on two consecutive specimens. Under Australian Therapeutic Guidelines and PBS prescribing criteria, which add-on oral agent is the most appropriate next step in therapy?

Initiate oral empagliflozin 10 mg once daily and provide education regarding sick-day medication rules

Add oral sitagliptin 100 mg once daily to achieve glycaemic control without affecting renal tubular transport

Add oral gliclazide modified-release 30 mg once daily and advise frequent capillary blood glucose testing

Commence once-daily bedtime subcutaneous insulin glargine at an initial dose of 10 units

Test Your Knowledge

A 52-year-old woman with a 3-year history of diet-controlled type 2 diabetes attends her general practice clinic for an annual review. She feels well and reports no urinary symptoms, visual changes, or neuropathic pain. Her blood pressure is 126/78 mmHg, and her body mass index is 27 kg/m2. Her physical examination, including visual acuity and monofilament foot testing, is completely normal. Which investigation represents the most appropriate screening test for diabetic nephropathy according to Australian clinical guidelines?

Collection of a 24-hour urine specimen for total protein and creatinine clearance calculation

Measurement of albumin-to-creatinine ratio on an early morning spot urine specimen

Renal tract ultrasonography to evaluate cortical thickness and exclude obstructive nephropathy

Standard dipstick urinalysis of a random spot urine sample to screen for macroscopic proteinuria

Sections you finish are checked off in the contents.

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DKA, HHS and complication monitoring

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