The prognostic implication of chronic hyperglycemia in acute ischemic strokes of different etiologic subtypes

BACKGROUND: The relationship of chronic hyperglycemia (CH) reflected by glycated hemoglobin A1c (HbA1c) with functional recovery in patients having acute ischemic stroke (AIS) remains controversial. This study evaluated how HbA1c values at admission could influence functional recovery following AIS of various etiologies. METHODS: In total, 518 patients with AIS were included. Stroke etiology was determined by TOAST criteria. The modified Rankin Scale (mRS) was applied to evaluate the functional recovery. Independent-samples Mann-Whitney U test was applied to assess the distribution of HbA1c across different subtypes. The relationship between HbA1c levels and functional recovery was analyzed applying multivariate logistic regression for adjustment of variables. Models predicting poor functional recovery, without and with HbA1c were developed utilizing binary logistic regression. RESULTS: HbA1c levels were significantly elevated among patients with poor functional recovery (p <0.001). The highest HbA1c values, median (IQR) [8.15(6.5-10.9)] were observed in patients with large artery atherosclerosis (LAA) subtype. Subgroup analyses by stroke subtype revealed significant associations of elevated HbA1c levels with poor functional recovery in the SVO (p = 0.021), LAA (p = 0.027), and cardio-embolic(CE),p = 0.046 groups. Elevated HbA1c remained independently associated with poor functional recovery (p = <0.001; OR = 1.27; 95% CI = 1.12-1.45) after full adjustment for clinical variables. CONCLUSIONS: Elevated admission HbA1c levels showed a fair to modest association with poorer functional recovery among patients with SVO, LAA, and CE stroke subtypes, which requires further external validation to establish its clinical implications and to consider HbA1c as an independent prognostic biomarker.