Glucocorticoid-induced diabetes in patients with metastatic spinal cord compression

Background The risk of developing diabetes mellitus (DM) during treatment with high-dose glucocorticoids is unknown and monitoring of glucose is random in many settings. Objective To determine incidence of and risk factors for induction of DM during high-dose glucocorticoid therapy of metastatic spinal cord compression (MSCC) in patients referred to radiotherapy. Furthermore, to describe the time course of development of DM. Subjects and methods 140 patients were recruited (131 were included in the analysis) with MSCC receiving high-dose glucocorticoid ≥100 mg prednisolone per day were included in a prospective, observational cohort study. The primary endpoint was development of DM defined by two or more plasma glucose values ≥11.1 mmol/L. Plasma glucose was monitored on a daily basis for 12 days during radiotherapy. Results Fifty-six of the patients (43%; 95% CI 35–52%) were diagnosed with DM based on plasma glucose measurements during the study period. Sixteen patients, 12% (95% CI 6–18%), were treated with insulin. At multivariate analysis, only high baseline HbA1c predicted the development of insulin-treated DM. An HbA1c-value <39 mmol/mol was associated with a negative predictive value of 96% for not developing DM needing treatment with insulin. The diagnosis of diabetes with need for insulin treatment was made within 7 days in 14 of the 16 (88%; 95% CI 72–100%) patients. Conclusion The risk of developing DM during treatment with high-dose glucocorticoids in patients with MSCC referred to radiotherapy is high in the first treatment week. Only referral HbA1c predicts the development of DM.