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Adjusting your basal insulin

Do not adjust your insulin based on just one or two results unless you’ve had an unexplained hypo. Look for patterns and trends and identify any changes to diet and lifestyle.

Use this stepwise approach:

  1. What is the problem?
  2. Is it a regular problem?
  3. What might have caused the problem? (increased dietary intake, change of temperature, illness)
  4. What options will I try?
  5. During periods of illness refer to sick day rule guidance

When to monitor your blood glucose levels

You should monitor your blood glucose levels:

  • before meals and bedtime
  • when hypoglycaemia is suspected
  • when feeling unwell

You also need to monitor glucose levels:

  • at least two hours before driving
  • every two hours on longer journeys

Once daily injection

  • Onset – 2 hours
  • Peak – None
  • Duration – 14 to 36 hours

The time of action can vary with different insulins. For example:

  • Humulin I can last up to 14 hours
  • Toujeo can last up to 36 hours

How to adjust your basal insulin

Insulin doses should be reviewed every three to seven days rather than daily. The only exception is after an unexplained hypo (blood glucose below 4 mmol/L), in which case the relevant dose should be reduced the following day.

Blood glucose readings should be taken before breakfast for at least three days.

If readings are not within goals, then adjust the dose as below:

  • Below target range – reduce dose by four units
  • Within target range – continue same dose
  • Above target range – increase dose by two units

It is good practice to test blood glucose more than once a day in order to monitor diabetes control throughout the day.

Further information

Further formal education is available from Injectable Therapies, DAFNE and VICTOR programmes. Please contact your diabetes team for further information.

Having your long-term blood test (HbA1c) between 48 – 58mmol/mol reduces risk of long term complications such as:

  • heart attack
  • stroke
  • changes to eye health/vision
  • kidney function
  • nerve damage (neuropathy)

If you are unwell you should seek advice from:

  • your GP
  • Practice Nurse
  • NHS 24
  • Diabetes Team

Contact

If you need further advice please call:

Diabetes Advice Service: 01563 827642 (Monday to Friday, 8.30am to 12pm)