Stroke in patients with diabetes. The Copenhagen Stroke Study

Abstract

Background and purpose: Although diabetes is a strong risk factor for stroke, it is still unsettled whether stroke is different in patients with and without diabetes. This is true for stroke type, stroke severity, the prognosis, and the relation between admission glucose levels and stroke severity/mortality.

Methods: This community-based study included 1135 acute stroke patients (233 [20%] had diabetes). All patients were evaluated until the end of rehabilitation by weekly assessment of neurological deficits (Scandinavian Stroke Scale) and functional disabilities (Barthel Index). A computed tomographic scan was performed in 83%.

Results: The diabetic stroke patient was 3.2 years younger than the nondiabetic stroke patient (P < .001) and had hypertension more frequently (48% versus 30%, P < .0001). Intracerebral hemorrhages were six times less frequent in diabetic patients (P = .002). Initial stroke severity, lesion size, and site were comparable between the two groups. However, mortality was higher in diabetic patients (24% versus 17%, P = .03), and diabetes independently increased the relative death risk by 1.8 (95% confidence interval [CI], 1.04 to 3.19). Outcome was comparable in surviving patients with and without diabetes, but patients with diabetes recovered more slowly. Mortality increased with increasing glucose levels on admission in nondiabetic patients independent of stroke severity (odds ratio, 1.2 per 1 mmol/L; CI, 1.01 to 1.42; P = .04). This was not the case in diabetic patients.

Conclusions: Diabetes influences stroke in several aspects: in age, in subtype, in speed of recovery, and in mortality. Increased glucose levels on admission independently increase mortality from stroke in nondiabetic but not in diabetic patients. The effect of reducing high admission glucose levels in nondiabetic stroke patients should be examined in future trials.