Treatment of prednisolone‐induced hyperglycaemia in hospitalized patients: I nsights 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 D ay 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.