Basal Insulin Titration

Basal insulin titration is the stepwise adjustment of the dose to bring fasting glucose into target without hypoglycaemia. Most people reach target within 8 to 12 weeks with a simple self-titration plan. Titration stops when the dose reaches about 0.5 units/kg, because further increases add risk without benefit.

Fasting glucose target. 4 to 7 mmol/L in most adults. Use 6 to 10 mmol/L in frail older adults, advanced liver disease, or recurrent hypoglycaemia.

Overbasalisation. Signs are a basal dose over 0.5 units/kg, a bedtime-to-morning glucose drop of 3 mmol/L or more, nocturnal hypoglycaemia, high glucose variability, and a high HbA1c despite normal fasting glucose.

If fasting target is met but HbA1c is over target. Add a GLP 1 receptor agonist, an SGLT2 inhibitor or mealtime insulin, not more basal.

If hypoglycaemia occurs. Reduce the dose first, then review other agents such as sulphonylureas.

Patient self-titration. Increase the dose by 2 units every 3 days until fasting glucose is 4 to 7 mmol/L on 3 consecutive days. If fasting glucose is over 10 mmol/L, increase by 4 units every 3 days. Stop increasing if any glucose is under 4 mmol/L.

Clinician titration. Increase by 10 to 15% (or 2 to 4 units) once or twice weekly.

After hypoglycaemia. If glucose is under 4 mmol/L, reduce the dose by 10 to 20% (about 4 units). For a severe event, reduce by 20 to 30% and review the cause.

Isophane insulin. Adjust bedtime dose for fasting glucose. If nocturnal hypoglycaemia occurs at 02:00 to 04:00, move the dose to later at night or switch to a long-acting analogue.

Changing between preparations. Glargine U100 to glargine U300: start with 10 to 18% more units. Glargine U100 to degludec: same units. Reduce units by 20% when moving from twice daily to once daily if control was tight.

Illness. Do not stop basal insulin during illness; check glucose more often, and check ketones in type 1 diabetes.

Special groups. - Kidney impairment: slow titration; reduce dose by 25% if eGFR is 10 to 50. - Liver disease: titrate by 2 units every 3 days with a target of 6 to 10 mmol/L. - Pregnancy: more frequent specialist titration with tighter targets. - Older adults: use steps of 1 to 2 units and wider targets. - Steroid therapy: raise doses in the afternoon with isophane, and reduce when steroids fall.

Monitoring. Daily fasting glucose, and a 7-point profile once during titration or when HbA1c is over target despite normal fasting values. HbA1c every 3 months.

Stopping. Taper and stop basal insulin only if glucose is under target with a very low dose (under 10 units daily) and with other agents in place.

Referral and escalation. Refer when total dose passes 0.5 units/kg without reaching target, or for recurrent hypoglycaemia without a clear cause.