BACKGROUND: Steroids are normally used in neurosurgery, especially when treating brain edema and reducing the intracranial pressure. Methylprednisolone is known to increase the blood glucose concentration. However, the effect of a single methylprednisolone injection on the blood glucose concentration is unknown. Therefore, this study measured and compared the blood glucose concentration in a methylprednisolone group with that in a placebo group at the same interval.

METHODS: Thirty-three adult patients were enrolled in this study. The patients were scheduled to undergoing an elective craniotomy with the procedure lasting 4 hours or longer. The candidates were divided in two groups. One group was the methylprednisolone group (patients receiving methylprednisolone 125 mg, n = 18), and the other group was the placebo group (n = 15). The exclusion criteria were a clinical diagnosis of diabetes mellitus, an impaired glucose tolerance and had received steroid previously. Before injecting 125 mg of either methylprednisolone or the placebo, the blood glucose concentration was checked by glucose analyzer. After the injection, blood glucose concentration was checked every 30 minutes for more than 4 hours.

RESULTS: The blood glucose concentration increased significantly over time compared with the baseline concentration in both groups. The glucose concentration increased significantly in the methylprednisolone group than in the placebo group (P < 0.05). The magnitude of this difference was greater in those who received methylprednisolone (54 mg/dl increase over 4 hours) than in the placebo group (11 mg/dl increase over 4 hours).

CONCLUSIONS: In this study, compared with placebo controls, an injection of methylprednisolone (125 mg) produced a significant increase in the blood glucose concentration over a 4 hours period. Therefore, we recommend that the blood glucose level be monitored carefully in cases of brain surgery and/or when steroids are used.