Abnormal glucose metabolism in non-diabetic patients presenting with an acute stroke: prospective study and systematic review

Background: Non-diabetic patients presenting with an acute stroke often have hyperglycaemia. In most populations it is unknown whether the hyperglycaemia is transient and due to the acute stress response or whether it represents undiagnosed abnormal glucose metabolism. Aim: To evaluate the prevalence and predictors of persistent hyperglycaemia in non-diabetic patients with an acute stroke. Design: Prospective observational study. Methods: Non-diabetic patients over 40 years old with an acute stroke were enrolled over a 2-year period. On admission patients were evaluated with an HbA(1c) and a 75 g oral glucose tolerance test (OGTT). The OGTT was repeated 3 months later. A meta-analysis was performed to interpret our results in the context of published data. Results: One hundred and seven patients were analysed. On admission 26 (24%) patients had diabetes, 39 (37%) had impaired glucose tolerance and 42 (39%) had normal glucose tolerance. Forty-four (68%) patients with hyperglycaemia on admission were re-investigated at least 3 months after discharge. 12 (27%) Of had these, 6 (14%) had diabetes, impaired glucose tolerance and 26 (59%) had normal glucose tolerance. A 2-h post-load glucose value >= 10 mmol/l predicted persistent hyperglycaemia with 72.2% sensitivity, 65.4% specificity and a positive predictive value and negative predictive value of 59.1 and 77.3%, respectively. A meta-analysis of prevalence data of impaired glucose metabolism in non-diabetic individuals 3 months after having had an acute stroke revealed a combined prevalence of 58% (95% confidence interval 25.4-90.5%). Conclusion: In this study hyperglycaemia in the setting of an acute stroke was transient in the majority of patients.