Clinician’s Notepad: type 2 diabetes

Clinician’s Notepad: type 2 diabetes

Screening and diagnosis

• Test HbA_1c in people at high risk of type 2 diabetes of any age; the threshold for diagnosis is:
  • HbA_1c ≥ 50 mmol/mol
  • HbA_1c 41 – 49 mmol/mol classified as “pre-diabetes”

Management

• Select an appropriate glycaemic target based on patient age, co-morbidities, duration of diabetes, history of hypoglycaemia and overall health status:
  • HbA_1c < 48 mmol/mol, appropriate for younger people, e.g. aged < 40 years
  • HbA_1c < 53 mmol/mol, appropriate for most people
  • HbA_1c 54 – 70 mmol/mol, appropriate if hypoglycaemic risk outweighs benefits of lower target
• Follow a stepwise treatment progression:
  • Step 1: Lifestyle interventions + metformin (initiate at diagnosis)
  • Step 2: Add a second non-insulin glucose-lowering medicine, i.e. empagliflozin, dulaglutide, vildagliptin, a sulfonylurea or pioglitazone; a third medicine can be added instead of stepping up to insulin
  • Step 3: Add insulin (isophane insulin appropriate for most patients)
  • If HbA_1c > 64 mmol/mol at diagnosis, initiate two glucose-lowering medicines; if HbA_1c very high, e.g. 80 – 90 mmol/mol, initiate insulin
• Check adherence to the existing medicine regimen and diet and physical activity approaches before stepping up pharmacological treatment
• Encourage weight loss at any step to induce remission, slow progression, step down treatment intensity or delay treatment escalation
• Encourage consumption of low calorie and low GI foods, increase vegetable intake and minimise dietary fat, sugar and alcohol
• Connect patients to services that can assist with lifestyle changes and provide support
• Consider referral for bariatric surgery if BMI between 35 – 55 kg/m^{2 *} to assist with weight loss
• If patients are transitioning from a paediatric service, establish who is responsible for the patient’s diabetes care and ensure they are followed up regularly

^{* Referral criteria may differ; check with your local DHB}

Choosing a Step 2 medicine

• Consider contraindications, co-morbidities, risk of hypoglycaemia, effects on weight, medicines interactions, adverse effects and eligibility for funding
• Empagliflozin or dulaglutide are preferred for people with established CVD or at high risk (including Māori and Pacific peoples), or with heart failure or diabetic kidney disease
• Vildagliptin is preferred for patients who are not eligible for funded empagliflozin or dulaglutide treatment (and are not self-funding treatment)
• Consider other prescribed medicines and how additional diabetes medicines might affect adherence

Initiating insulin

• Initiate once-daily basal insulin, injected at night; isophane insulin is appropriate for most patients
• Determine initial basal insulin dose using body weight:
  • 0.1 units/kg daily if at least one of: HbA_1c < 64 mmol/mol, BMI < 18 kg/m², older age (e.g. aged > 65 years) or frailty, renal or liver failure
  • 0.2 units/kg daily if HbA_1c > 64 mmol/mol and BMI > 18 kg/m²
• Advise patients to begin self-monitoring blood glucose levels once daily before breakfast; goal is blood glucose levels 6 – 8 mmol/L
• Ensure patients understand how to up-titrate the insulin dose based on fasting blood glucose levels + how to manage hypoglycaemia
• If treatment intensification required, add bolus insulin to a basal regimen OR initiate a biphasic (premixed) insulin:
  • If starting basal-bolus regimen, add a rapid-acting insulin before largest meal (start with 4 units); increase by 2 units if blood glucose level increase with the meal is > 3 mmol/L on three occasions

Annual review

Standard of care for all people with type 2 diabetes; more frequent review may be indicated.

• Measure weight, waist circumference (optional), blood pressure
• Examine feet (including skin, nails, deformity), teeth and gums
• Request HbA_1c, urinary ACR, serum creatinine, LFTs, non-fasting lipid studies
• Review:
  • Retinal photoscreening up to date
  • CVD risk
  • Smoking status, alcohol intake and recreational drug use
  • Mental health
  • Contraception
  • Cervical, breast and bowel cancer screening up to date
  • Any other associated complications, e.g. sexual dysfunction, recurrent skin or genitourinary infection