Glucocorticoids are widely used drugs owing to their potent anti-inflammatory and immunosuppressive effects. Their use cuts across all clinical specialties. More recently, they have been used in Covid-19, where they have proven to be life-saving.

Despite the beneficial effects, use of glucocorticoids is associated with diverse adverse effects, which can vary from mild to severe in intensity. Among other adverse effects is their propensity to cause hyperglycemia in patients with or without diabetes mainly due to decrease in insulin secretion and insulin sensitivity, inhibition of peripheral glucose uptake and increased gluconeogenesis and glycogenolysis. In persons with diabetes mellitus, GCs can aggravate hyperglycemia; they can also unmask undiagnosed DM or precipitate GC-induced DM appearance. Predisposing factors include use of steroids in higher doses and for longer duration. Older age, family history of diabetes, HbA1c ≥6%, higher BMI, impaired glucose tolerance and history of gestational diabetes add to the risk.

Fasting blood glucose, in patients on steroids, may be normal and therefore falsely reassuring when assessing for steroid-induced hyperglycemia. The digressions in blood glucose levels depend on the type and dose of the GC used. High doses can cause marked hyperglycemia. Administration of intermediate acting GCs in the morning (once daily) may cause hyperglycemia by late afternoon and evening and when given in divided doses, significant hyperglycemia may persist all through the day. So is the case with long-acting GCs.

Therefore, patients being managed at home with steroids should be advised to monitor their capillary blood glucose (fasting and postprandial) and additionally evening blood glucose with a glucometer. Likewise, non-ICU hospitalized patients on steroids should be regularly monitored for capillary blood glucose levels, both fasting as well as after meals. The aim should be to achieve blood glucose less than 140 mg/dL (fasting) and less than 180 mg/dL (random). In terminally ill patients or in those with comorbidities, glycemic targets can be relaxed.

However, in ICU patients, blood glucose requires repeated monitoring since GCs are administered in high doses. Also, enteral and parenteral nutrition may cause significant hyperglycemia as do the inotropes. This monitoring frequency can be reduced depending on the stability of the blood glucose levels. The threshold for starting insulin therapy, usually as IV insulin infusions, is a blood glucose of 180 mg/dL. In these patients, blood glucose should be monitored every 30 minutes to every 2 hours to minimize the risk of hypoglycemia.

GC-induced hyperglycemia is both important and challenging. It needs to be proactively diagnosed and managed.

The pattern of hyperglycemia as well as the dose and duration of action of the glucocorticoid being used influence the choice of insulin preparation and its administration. “The type of steroid and type of insulin should match”.

If the steroids have to be continued after discharge, then patients should be educated about the need for “self-monitoring of blood glucose”, especially in the late afternoon or evening and accordingly self-titrate their insulin dose. “Glucovigilance” is particularly crucial, when steroids are being tapered to avoid hypoglycemia. Patients must be taught to recognize the warning signs of hypoglycemia and correct it swiftly. The disease for which steroids have been prescribed also merits a post-discharge review.

Reference

1. Shah P, Kalra S, Yadav Y, et al. Management of glucocorticoid-induced hyperglycemia. Diabetes Metab Syndr Obes: Targets Ther. 2022;15:1577-1588.