Prediabetes in acute stroke: prevalence and impact on early clinical outcomes.

AIMS: We aimed to characterize the burden of dysglycemia in acute stroke and evaluate whether HbA₁c, even below the diabetic threshold, is associated with neurological severity and embolic risk.

METHODS

We conducted a prospective study of patients with ischemic stroke or transient ischemic attack (TIA) over six months at a German stroke center. Glycemic status was defined by glycated hemoglobin (HbA₁c) and fasting glucose per American Diabetes Association (ADA) criteria. Associations with stroke subtype, age, sex, and severity were analyzed.

RESULTS

Abnormal glucose metabolism was present in 449 of 714 patients (62.9%), including 236 with prediabetes (33.1%) and 213 with diabetes (29.8%). Dysglycemia was most frequent in lacunar (34/40, 85.0%), atherosclerotic stroke (77/110, 70.0%), and cryptogenic strokes (68/ 98, 69.4%). Prediabetes peaked at age 75-84 (r = 0.21; 95% CI, 0.07-0.34; p = 0.0026) and was highest in men ≥ 85 years (51.7% vs. 15.4%). Height of HbA₁c significantly correlated with stroke severity (r = 0.54; 95% CI, 0.43-0.63; p < 10⁻15) and CHA₂DS₂-VASc scores (r = 0.37; 95% CI, 0.22-0.52; p = 0.003).

CONCLUSION

Prediabetes is highly prevalent across all stroke entities and independently associated with worse neurological outcomes. HbA₁c may serve as a clinical marker for risk stratification even below diabetic thresholds. Early detection and subsequent intervention may improve stroke outcomes; however, whether prediabetes constitutes a modifiable risk factor remains to be determined in future interventional studies.