Admission hyperglycemia predicts a worse outcome in stroke patients treated with intravenous thrombolysis

Abstract

Objective: Admission hyperglycemia has been associated with worse outcomes in ischemic stroke. We hypothesized that hyperglycemia (glucose >8.0 mmol/l) in the hyperacute phase would be independently associated with increased mortality, symptomatic intracerebral hemorrhage (SICH), and poor functional status at 90 days in stroke patients treated with intravenous tissue plasminogen activator (IV-tPA).

Research design and methods: Using data from the prospective, multicenter Canadian Alteplase for Stroke Effectiveness Study (CASES), the association between admission glucose >8.0 mmol/l and mortality, SICH, and poor functional status at 90 days (modified Rankin Scale >1) was examined. Similar analyses examining glucose as a continuous measure were conducted.

Results: Of 1,098 patients, 296 (27%) had admission hyperglycemia, including 18% of those without diabetes and 70% of those with diabetes. After multivariable logistic regression, admission hyperglycemia was found to be independently associated with increased risk of death (adjusted risk ratio 1.5 [95% CI 1.2-1.9]), SICH (1.69 [0.95-3.00]), and a decreased probability of a favorable outcome at 90 days (0.7 [0.5-0.9]). An incremental risk of death and SICH and unfavorable 90-day outcomes was observed with increasing admission glucose. This observation held true for patients with and without diabetes.

Conclusions: In this cohort of IV-tPA-treated stroke patients, admission hyperglycemia was independently associated with increased risk of death, SICH, and poor functional status at 90 days. Treatment trials continue to be urgently needed to determine whether this is a modifiable risk factor for poor outcome.

Figure 1

Patient outcome at the 90-day follow-up by baseline glucose (unadjusted for other predictors of outcome). mRS 0–1, excellent outcome; mRS 2–3, moderate disability; mRS 4–5, severe disability; and mRS 6, dead.

Figure 2

A: Probability of SICH by baseline glucose level. Quadratic polynomial line of best fit with range and 95% CIs adjusted for age, baseline NIHSS score, sex, onset-to-treatment time, and atrial fibrillation. For each increase of 1 mmol/l of serum glucose, the relative risk of SICH rises by 10%. B: Probability of death by baseline glucose level. The line and 95% CIs are based upon a linear regression of predicted probability of death adjusted for age, baseline NIHSS score, sex, onset-to-treatment time, and baseline ASPECTS score. For every 1 mmol/l rise in the baseline serum glucose, the probability of death at 90 days increases by an absolute risk of 2%. C: Relationship between glucose and good outcome. The line and 95% CIs are derived from a fractional polynomial regression of baseline serum glucose and the predicted probability of good outcome adjusted for age, baseline NIHSS score, baseline ASPECTS, sex, and onset-to-treatment time. For every increase of 1 mmol/l of baseline serum glucose, the relative risk of a good outcome falls by 12%.