Lifestyle change and oral hypoglycaemic agents will initially be effective in achieving stable and on-target blood glucose levels in patients with type 2 diabetes. However, the time will come when insulin therapy has to be started.
- An A1c above 7% (BGL above 8 mmol/L) and certainly an A1c above 8% (BGL above 10 mmol/L) should prompt consideration of starting insulin therapy.
- Before starting insulin check the patient’s lifestyle, adherence to diabetes medications, the presence of other conditions and the other medications prescribed.
- Choosing the type of basal insulin depends on the pros and cons of the intermediate acting isophane insulin and the long acting insulin analogue and the patient’s choice of injection device. If the fasting BGL is high, the insulin should be used at bedtime; if the fasting BGL is on target but the evening BGL is high, the insulin should be used in the morning. The starting dose should be 10 units.
- When adjusting basal insulin, approach targets fast and fine tune slowly. ‘Going slow’ can take too long; ‘going fast’ can cause hypoglycaemia and weight gain.
- Once basal insulin and preprandial blood glucose are on target consider stopping oral hypoglycaemic agents, particularly sulfonylureas, and consider starting quick acting insulin before meals.
- Potential problems starting insulin include coping with practical details, hypoglycaemia, weight gain and psychological resistance.