Diabetes

Causes of Poor Blood Sugar Level (BSL) Control

• Incorrect insulin dose

• Poor medication compliance

• Incorrect storage of insulin (should not exceed 30 days at room temperature)

• Incorrect injecting technique

• SEs of meds (e.g., antipsychotics, steroids)

• Underlying infection

• Smoking and alcohol use

• Poor diet

• Sedentary lifestyle or lack of exercise

• Obesity

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Pharmacological Treatment (Stepwise Progression)

Before initiating pharmacotherapy: Trial 3 months of lifestyle changes if HbA1c < 8.5%​​.

1. First-line: Metformin (unless contraindicated)

2. Second-line: Add a DPP-4 inhibitor, SGLT-2 inhibitor, or sulfonylurea

3. Third-line: Any second-line agent not yet used + GLP-1 receptor agonist or insulin

4. Fourth-line: Intensify by switching or adding GLP-1 receptor agonist or insulin

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Notes:

• If already on a GLP-1 receptor agonist, proceed to insulin or add insulin as a fourth hypoglycaemic agent.

• Assess renal function regularly; avoid SGLT-2 inhibitors and metformin if eGFR < 30 mL/min.

• If glycaemic target is not achieved after 3 months of each step, progress to the next step​​.

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Criteria for IFG and IGT

• Impaired Fasting Glucose (IFG):

  • Fasting plasma glucose: 6.1 to 6.9 mmol/L (adults)​

  • Fasting plasma glucose: 5.6 to 6.9 mmol/L (children and adolescents)​

• Impaired Glucose Tolerance (IGT):

  • 2-hour plasma glucose during an OGTT: 7.8 to 11.0 mmol/L​

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When to Repeat Testing

• If asymptomatic with a positive result:

  • Confirm diagnosis by repeating the same test on a different day​.

• For prediabetes (IFG/IGT), monitor every 6–12 months to assess progression to diabetes​​.

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Frequency of Testing Based on HbA1c or Glucose Levels

• HbA1c ≥6.5% (48 mmol/mol): Diagnostic of diabetes; repeat testing unnecessary if symptomatic.

• HbA1c 6.0–6.4% (42–46 mmol/mol): Indicative of prediabetes; testing should be repeated in 6–12 months for progression monitoring​.

• Venous Glucose Levels: Retest annually (or sooner if clinically indicated) for glucose in prediabetes range (IFG or IGT).

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Preventative Screening Recommendations (Red book)

• Individuals at normal risk should undergo screening for diabetes risk using AUSDRISK every 3 years from the age of 40.

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Criteria for 'High Risk' Diabetes (AUSDRISK >12)

• 1st-degree relative with diabetes

• CVD history

• Belonging to high-risk ethnic groups: Indian subcontinent, Pacific Islanders, ATS), South Asian

• PCOS

• Use of antipsychotic meds

• GDM history

• Age >40 and BMI >25 kg/m²

• Hx of IFG or IGT

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ATSI-Specific Screening Recommendations

• ATSI people should have annual diabetes screening using FBG or HbA1c from the age of 18, bypassing AUSDRISK.

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How Often to Screen with Which Test

• High-risk diabetes: Monitor every 3 years with FBG or HbA1c.

• Impaired glucose tolerance or fasting glucose: Monitor annually using FBG or HbA1c.

Notes:

• All individuals <25 years with diabetes should be referred to an endocrinologist.

• In cases of previous GDM, an OGTT is recommended annually if planning another pregnancy.

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Insulin Initiation Counselling

• Injection technique:

  • Ensure correct insulin injection technique and educate on site rotation 

  • Avoid repeated use of the same injection site to prevent lipohypertrophy

• Monitoring blood glucose:

  • Teach pre- and post-prandial self-monitoring of blood glucose (BSL)

  • Targets:

    • Pre-prandial: 4–6 mmol/L (individualised)

    • Post-prandial: <10 mmol/L

• Timing of insulin:

  • Short-acting: Inject 15–30 minutes before meals

  • Long-acting: Typically at bedtime; post-meal

• Adjusting doses:

  • Adding or adjusting bolus insulin:

    • Start with 4 units SC or increase by 1–2 units based on the highest post-meal BSL​​.

• Managing hypoglycaemia:

  • Recognise sx (e.g., sweating, tremor, dizziness)

  • Treat with quick-acting carbohydrates (e.g., glucose tablets, juice)

  • Recheck blood glucose after 15 minutes

• Lifestyle considerations:

  • Explain the effect of exercise on lowering blood glucose and need for adjustment

  • Mitigation of weight gain associated with insulin therapy through diet and exercise

• Access to equipment:

  • Enrol the patient in the NDSS for subsidised insulin and equipment

• Driving considerations:

  • Notify local driving authorities (if required by law)

  • Advise monitoring BSLs before driving

• Individualised plan:

  • Customise counselling based on patient factors, including literacy, age, and comorbidities​​.

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Drugs for Diabetes

Biguanides

• Metformin (modified release)

• Start 500mg up to 2g daily (egfr >60)

• Start 500mg up to 1g daily (egfr 30-60)

Note: 1g max in immediate release total also

SGLT2

• Dapagliflozin 10mg od (only dose) (avoid egfr <45)

• Empagliflozin

• Ertugliflozin

SU

• Gliclazide modified release 30mg up to 120mg daily (egfr >30)

• Glipizide

• Glibenclamide

• Glimepiride

DPP-4

• Linagliptin 5mg od (can use all stages of ckd inc egfr <15)

• Saxagliptin

• Sitagliptin

GLP-1

• Liraglutide 0.6mg SC od, incr weekly up to max 1.8mg od (contraindicated egfr <30)

• Dulaglutide

• Exenatide

SGLT2

• Incr glucose release prox tubule of the kidneys → mild diuresis → mild lowering of BP → benefit in cardio patients (esp HF)

• Good for patient w CVD, diabetes, HF, or is fat (red risk of cardiovasc events and red HF hospitalisations)

• Not effective for glycaemic control in pts with poor renal function

• Caution w loop diuretics due to effects of diuresis

• Counselling

• Good for weight loss

• Incr risk of UTI

• Pre-op stop 3 days prior

• Avoid VLED or fasting due to DKA risk

GLP-1

• Incr gastric emptying → decr satiety → nausea

• incretin mimetic → incr insulin from pancreas → pancreatitis

• Good for patient w obesity or CVD (cardio benefits → likely from not being fat)

• Avoid if prev pancreatitis

• Weight loss drug (Saxenda - liraglutide)

DPP-4

• Inhibits GLP-1, hence no point adding to GLP-1

• Can also cause pancreatitis

• No weight loss thus less nausea/vomiting

• No cardio benefits, avoid in heart failure

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When to Commence Double Therapy

• Initiate double therapy if HbA1c >8.5%

• HbA1c target for most adults with diabetes is <7% (individualised based on patient factors such as age and comorbidities)

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Monitoring Targets

• Pre-prandial (fasting) blood glucose: 6–8 mmol/L

• Post-prandial blood glucose: <10 mmol/L

• Weekly blood glucose reviews to assess control

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Insulin Initiation and Titration

• Starting dose of basal insulin:

  • 0.2 units/kg subcutaneously at bedtime

• Titration:

  • Adjust dose by 10–20% weekly, depending on blood glucose control and risk of hypoglycaemia​​

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Sick-day Management

• General principles:

  • Do not stop basal insulin (risk of DKA if omitted)

  • Increase blood glucose and ketone monitoring to every 1–4 hours

  • Maintain adequate fluid and carbohydrate intake

  • Stop SGLT2 inhibitors to avoid euglycaemic DKA

• For persistent hyperglycaemia (>15 mmol/L):

  • Add supplemental rapid-acting insulin every 2–4 hours

  • Increase fluid intake

  • Assess for ketosis if blood glucose remains elevated or sx worsen

• Indications for hospital referral:

  • Persistent vomiting >4 hours

  • Severe or worsening hyperglycaemia

  • Blood ketones >1.5 mmol/L

  • Sx of DKA (e.g., abdominal pain, drowsiness, acetone breath)​​

Notes:

• Restart meds (e.g., metformin, SGLT2 inhibitors) once the patient is well, eating, and drinking normally​​.

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Cycle of Care

• Examinations (6-monthly):

  • Foot exam

  • Weight, height, and BMI

  • BP

• Investigations (annually):

  • HbA1c

  • Lipid profile

  • Urine ACR

  • eGFR

• Education (annually):

  • Reinforce self-care, including smoking cessation

  • Emphasise healthy diet and regular physical activity

  • Medication review

• Eye exam:

  • Optometry review every 1–2 years, depending on risk factors​​

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Non-pharmacological Management

• Lifestyle:

  • Smoking cessation

  • Limit alcohol intake to ≤2 std drinks per day

  • Aim for 5–10% weight loss in overweight or obese patients

• Exercise:

  • At least 150 mins/week of moderate-to-vigorous aerobic exercise, spread over at least 3 days (no more than 2 consecutive days without activity)

  • Resistance training 2–3 times per week (targeting all major muscle groups)

• Dietary advice:

  • Increase intake of wholegrains, vegetables, and low-calorie foods

  • Decrease intake of processed and high-fat foods

  • Follow evidence-based guidelines or refer to a dietitian for individualised dietary plans

• BP Management:

  • Aim for BP <140/90 mmHg

  • If albuminuria is present, target <130/80 mmHg

• Vaccinations:

  • Annual influenza vaccine

  • Pneumococcal vaccine

  • dTpa booster (if due)​​

• Others

  • Involve diabetic nurse educator

  • Organise annual podiatry review

  • Refer for biannual eye review by optometrist