Type 2 diabetes is an independent negative prognostic factor in patients undergoing surgical resection of a WHO grade I meningioma

•There is significant outcome variability in WHO Grade I meningiomas.•Type 2 diabetes is independently associated with decreased survival in these patients.•Mean survival time in diabetics is 9 years less than non-diabetics after operation.•A diagnosis of diabetes should be considered when stratifying risk in these patients.

ObjectivesIn recent years, there has been increased recognition of the relationship between type 2 diabetes mellitus (DM) and poor outcomes following a variety of surgical procedures. We sought to study the role of type 2 DM as a prognostic factor affecting the long-term survival of patients undergoing surgical resection of a WHO Grade I meningioma.MethodsWe conducted a retrospective cohort study on 196 patients who had a WHO Grade I meningioma resected at our institution between 2001 and 2013. The medical record was reviewed to identify a pre-existing diagnosis of type 2 DM. Patient mortality was reviewed by medical record and Social Security Death Index (SSDI). Variables associated with survival in a univariate analysis were included in the multivariate Cox model if P < 0.10. Variables with probability values >0.05 were then removed from the multivariate model in a step-wise fashion.Results33 (17%) patients had pre-existing diagnoses of type 2 DM prior to clinical presentation. Mean survival time in diabetic patients was 52.1 months compared to 160.9 months in non-diabetics. The decreased survival rate and time in patients with type 2 DM were found to be statistically significant (p = 0.008 and p < 0.0001, respectively). In a multivariate Cox analysis, a pre-existing history of type 2 DM was independently associated with decreased survival following the resection of a WHO Grade I meningioma (HR = 2.6, p = 0.045).ConclusionsA pre-existing diagnosis of type 2 DM is an independent negative prognostic indicator following the resection of a WHO Grade I meningioma.