Is hyperglycaemia an independent predictor of poor outcome after acute stroke? Results of a long-term follow up study

Abstract

Objective: To determine whether raised plasma glucose concentration independently influences outcome after acute stroke or is a stress response reflecting increased stroke severity.

Design: Long-term follow up study of patients admitted to an acute stroke unit.

Setting: Western Infirmary, Glasgow.

Subjects: 811 patients with acute stroke confirmed by computed tomography. Analysis was restricted to the 750 non-diabetic patients.

Main outcome measures: Survival time and placement three months after stroke.

Results: 645 patients (86%) had ischaemic stroke and 105 patients (14%) haemorrhagic stroke. Cox's proportional hazards modelling with stratification according to Oxfordshire Community Stroke Project categories identified increased age (relative hazard 1.36 per decade; 95% confidence interval 1.21 to 1.53), haemorrhagic stroke (relative hazard 1.67; 1.22 to 2.28), time to resolution of symptoms > 72 hours (relative hazard 2.15; 1.15 to 4.05), and hyperglycaemia (relative hazard 1.87; 1.43 to 2.45) as predictors of mortality. The effect of glucose concentration on survival was greatest in the first month.

Conclusions: Plasma glucose concentration above 8 mmol/l after acute stroke predicts a poor prognosis after correcting for age, stroke severity, and stroke subtype. Raised plasma glucose concentration is therefore unlikely to be solely a stress response and should arguably be treated actively. A randomised trial is warranted.