Management of acute glucocorticoid-induced hyperglycaemia

Patients without pre-existing diabetes

The management of patients with acute glucocorticoid-induced hyperglycaemia, but without pre-existing diabetes is the same as for patients with type 2 diabetes taking glucocorticoids. Whether the patient has pre-existing diabetes or not, insulin is often required to treat patients with significant acute glucocorticoid-induced hyperglycaemia (eg blood glucose concentrations more than 12 mmol/L) and an ongoing need for the glucocorticoid.

Patients with type 2 diabetes

Glucocorticoids exacerbate hyperglycaemia in patients with type 2 diabetes. Ideally, teach all patients with type 2 diabetes to self-monitor blood glucose concentrations (if not already self-monitoring) before starting a glucocorticoid. See information on self-monitoring blood glucose concentrations in adults with type 2 diabetes.

When starting a glucocorticoid, advise patients to:

monitor blood glucose concentrations more frequently and at various times of the day (eg after lunch and evening meal, not just in the morning)
seek medical assistance if blood glucose concentrations are consistently more than 12 mmol/L.

Treatment for glucocorticoid-induced hyperglycaemia must be individualised for each patient and maintaining hydration is important for patients with hyperglycaemia. An increase in noninsulin antihyperglycaemic drugs may be sufficient to manage the hyperglycaemia, but insulin is often required with dosage tailored to match the expected pattern of blood glucose concentration fluctuations.

Note: Treatment for glucocorticoid-induced hyperglycaemia must be individualised.

If a very short course (only a few days) of a glucocorticoid is used, no additional treatment may be needed if blood glucose concentrations are less than 15 mmol/L and the patient is asymptomatic.

If a short course (1 week or less) of a glucocorticoid is used and a patient has mild hyperglycaemia (less than 15 mmol/L), a trial of a short-acting sulfonylurea (eg gliclazide) adjusted up to the maximum dose may be sufficient to manage the hyperglycaemia. Closely monitor blood glucose concentrations for morning hypoglycaemia, which requires a reduction in sulfonylurea dose, or for persisting hyperglycaemia (often occurring later in the day), which may require addition of insulin.

For patients on longer courses (more than 1 week) of glucocorticoids with significant hyperglycaemia (more than 15 mmol/L), insulin is likely to be required for the duration of the glucocorticoid treatment (see also Management of patients taking long-term low-dose glucocorticoids). Addition of a noninsulin antihyperglycaemic such as metformin or a sulfonylurea (if not contraindicated) could be tried and may reduce insulin requirements.

For patients taking repeated short courses of high-dose glucocorticoids (eg prednisolone for exacerbations of chronic obstructive pulmonary disease [COPD]), insulin is often given each time the glucocorticoid is started. The dose of insulin should be decreased and then stopped as the glucocorticoid dose is decreased and stopped.

For patients with type 2 diabetes who are already using insulin, insulin doses may need to be adjusted to target the expected times of hyperglycaemia. When prednisolone is taken in the morning, treatment should be targeted towards the anticipated midmorning and afternoon postprandial blood glucose concentration rise, for example by using short- or intermediate-acting insulin. In contrast, dexamethasone is long-acting and hyperglycaemia occurs throughout the day, so long-acting basal insulin is more effective. For suggested insulin dosage regimens for a patient with significant prednisolone-induced hyperglycaemia, see Suggested subcutaneous insulin dosage regimens for management of significant prednisolone-induced hyperglycaemia.

Warn patients that the required increase in insulin dose may be much larger than they expect; doses two to three times more than their usual insulin doses are sometimes required. If blood glucose concentrations are difficult to stabilise, seek advice from a specialist or multidisciplinary diabetes team.

When the glucocorticoid dose is reduced or stopped, a reduced requirement for insulin should be anticipated; reduce the insulin dose and take precautions against hypoglycaemia (eg increase frequency of blood glucose concentration monitoring).

Table 1. Suggested subcutaneous insulin dosage regimens for management of significant prednisolone-induced hyperglycaemia
[NB1] [NB2]
patients not already using insulin patients already using a long-acting basal insulin regimen patients already using a multiple daily injection (basal–bolus) insulin regimen
Patients not already using insulin
Start a morning (breakfast) dose of intermediate-acting insulin (eg isophane [Humulin NPH, Protaphane]) at a dose of 0.3 units/kg (maximum 40 units). Increase the insulin dose by 10 to 20% of the daily dose every few days to optimise BGCs in the late afternoon. Afternoon BGCs are likely to be high and fasting BGCs may not be elevated. If high-dose prednisolone is continuing and BGCs are not maintained within target range with intermediate-acting insulin alone, additional rapid- or short-acting bolus insulin may be required. See the relevant option for patients already using long-acting basal insulin to guide addition of rapid- or short-acting bolus insulin.
Patients already using long-acting basal insulin regimen
Continue the usual long-acting basal insulin (eg glargine [Optisulin]) dose and use additional insulin to minimise the hyperglycaemia occurring during the day. The dose of additional insulin is 30% of the usual total daily basal insulin dose. Use one of the following options: add a morning dose of intermediate-acting insulin (eg isophane [Humulin NPH, Protaphane]) to the usual long-acting basal insulin dose, or add a lunchtime dose of a fixed-dose combination (biphasic premixed) insulin (containing intermediate-acting insulin) to the usual long-acting basal insulin dose, or add rapid- or short-acting bolus insulin doses with meals. The total daily bolus insulin dose (ie 30% of the usual total daily basal insulin dose) can be divided as follows: 20% given before breakfast 50% given before lunch 30% given before the evening meal. Adjust the additional insulin dose by 10 to 20% every 2 to 3 days to optimise BGCs in the late afternoon. Increase basal long-acting insulin if the fasting BGCs are elevated.
Patients already using a multiple daily injection (basal–bolus) insulin regimen
The dose of additional insulin is 30% of the total daily insulin dose (sum of all doses of insulin given daily, irrespective of formulation). Give this 30% extra insulin as rapid- or short-acting insulin with meals in addition to the usual bolus insulin dose. Divide the extra insulin as follows: 20% given before breakfast (plus usual bolus dose) 50% given before lunch (plus usual bolus dose) 30% given before the evening meal (plus usual bolus dose). Increase the basal insulin dose if the fasting BGCs are elevated.
Note: BGC = blood glucose concentration NB1: Insulin is often required to treat significant prednisolone-induced hyperglycaemia (BGC more than 15 mmol/L). NB2: For insulin formulations, see Action profiles of insulin formulations.

Patients with type 1 diabetes

Advise patients with type 1 diabetes who are starting glucocorticoids to monitor their blood glucose concentrations more frequently and expect an increase in insulin requirements. Ideally, before starting glucocorticoids, seek advice on insulin management from the patient’s diabetes specialist.

Anticipate that the doses of insulin required to correct glucocorticoid-induced hyperglycaemia will be higher than the patient’s usual doses. Supplemental (correction) doses of insulin should not be given more often than every 3 to 4 hours to avoid accumulation of rapid-acting insulin (insulin stacking) and hypoglycaemia (see Supplemental (correction) insulin doses for information about supplemental doses).