Treatment of prednisolone-induced hyperglycaemia in hospitalized patients: Insights from a randomized, controlled study

Aim: Prednisolone causes hyperglycaemia predominantly between midday and midnight. Consequently, glargine-based basal-bolus insulin regimens may under treat daytime hyperglycaemia and cause nocturnal hypoglycaemia. We investigated whether an isophane-based insulin regimen is safer and more effective than a glargine-based regimen in hospitalized patients. Materials and methods: Fifty inpatients prescribed ≥20 mg/day prednisolone acutely with (1) finger prick blood glucose level (BGL) ≥15 mmol/L or (2) BGLs ≥10 mmol/L within the previous 24 hours were randomized to either insulin isophane or glargine before breakfast and insulin aspart before meals. The initial daily insulin dose was 0.5 U/kg bodyweight or 130% of the current daily insulin dose. Glycaemic control was assessed using a continuous glucose monitoring system. Results: On Day 1, there were no significant differences in percentage of time outside a target glucose range of 4 to 10 mmol/L (41.3% ± 5.5% vs 50.0% ± 5.7%, P =.28), mean daily glucose (10.2 ± 0.7 vs 10.8 ± 0.8 mmol/L, P =.57) or glucose <4 mmol/L (2.2% ± 1.1% vs 2.0% ± 1.3%, P =.92) in patients randomized to isophane and glargine. In patients treated for 3 days, the prednisolone dose was reduced (P =.02) and the insulin dose was increased over time (P =.02), but the percentage of time outside the 4 to 10 mmol/L glucose range did not differ over time (P =.45) or between groups (P =.24). Conclusions: There were no differences in the efficacy or safety of the isophane and glargine-based insulin regimens. We recommend an initial daily insulin dose of 0.5 units/kg bodyweight if not on insulin, a greater than 30% increase in pre-prednisolone insulin dose and larger insulin dose adjustments in patients with prednisolone-induced hyperglycaemia.