An example of a once daily insulin regimen
- Start with 8–10 units of protophane or Humulin NPH usually before bed e.g. 9 to 11pm
- Continue oral metformin at current dose e.g. 1 g twice daily
- Minimum SMBG for this regimen is:
- Pre-breakfast to titrate the dose and check for morning hypoglycaemia
- Pre-evening meal to check for hypo or hyperglycaemia and give information for varying the regimen if control is
- Two hours post-evening meal to check for surging glucose level as this may require a different insulin regimen
- Once stable, SMBG should be done as often as required to allow freedom from hypoglycaemia
and to give information to keep HbA1c at the target level e.g. three to four times a day, two to three
days per week.
- Dose should be titrated aiming to achieve a pre-breakfast glucose of 6 mmol/L.
For the majority of patients, starting insulin as an evening dose is recommended. This is because high morning fasting
glucose levels, due to excessive glucose production overnight, are characteristic of poorly controlled type 2 diabetes.
Some elderly patients who have higher levels in the afternoon however may respond better to insulin given in the morning.
Once initiated, adjust the insulin dose slowly
Once initiated, slow increases in insulin dose are recommended.16 This is likely to reduce the risk of hypoglycaemia
and increase both patient and doctor confidence. Depending on fasting SMBG results, the dose of insulin should be increased
every one to two weeks as necessary.
One suggested method of titration is to increase the insulin dose by:16
- 2 units if pre-breakfast glucose readings are consistently above 6 mmol/L
- 4 units if pre-breakfast glucose readings are consistently above 8 mmol/L
These gradual increases can continue for the first two to three months and then the HbA1c should be rechecked.
Ideally there should be a reduction in HbA1c of about 1%. If this is not the case then check the patient is
still using the insulin and also continuing to take their oral metformin.
Over the next six to twelve months, further gradual increases in insulin dose may be required depending on HbA1c levels.
The majority of people with type 2 diabetes are insulin resistant so the insulin doses required may be higher than expected.18 People
who are obese and those who had high initial HbA1c levels are likely to need the highest doses.
Normalising blood sugar
Slow is best. Sudden normalisation of long standing high blood glucose levels can in some cases cause temporary progression
of complications e.g. diabetic retinopathy, insulin neuritis (acute symptomatic neuropathy) or pseudo hypos (hypo symptoms
at normal glucose levels). These usually settle with time.
If HbA1c remains above target level once fasting glucose levels are normalised, information from SMBG (pre-evening
meal and two hours after meals) will help guide a change of insulin regimen. This may require a move to a twice daily
premixed insulin regimen (e.g. Penmix 30:70 or Humalog Mix 25) or the addition of rapid acting insulin pre-meals. At
this stage advice from a specialist diabetes team is often useful.