Association Between Stress Hyperglycemia Ratio and Early Neurological Deterioration After Acute Ischemic Stroke: A Retrospective Cohort Study

Background Stress hyperglycemia ratio (SHR) has emerged as a more accurate indicator of stress-related hyperglycemia than absolute glucose levels. However, its relationship with early neurological deterioration (END) after acute ischemic stroke (AIS) remains unclear. Methods We retrospectively analyzed 1,479 AIS patients admitted within 24 hours of symptom onset. END was defined as an increase of ≥ 2 points in the NIHSS total or motor score within 72 hours. SHR was calculated as the ratio of fasting plasma glucose to estimated average glucose derived from HbA1c and categorized into quartiles. Logistic regression, generalized additive models (GAM), two-piecewise logistic regression, and causal mediation analyses were performed. Results Among 1,479 patients, 270 (18.3%) developed END. Higher SHR was independently associated with increased END risk (fully adjusted OR = 6.19, 95% CI: 2.68–14.28, P < 0.0001), showing a clear dose-response relationship across quartiles (P for trend = 0.0015). GAM revealed a non-linear relationship, and two-piecewise regression identified a potential inflection point at SHR ≈ 1.06. Subgroup analysis showed a stronger association in non-diabetic patients (interaction P = 0.0033), with no significant interactions for other variables. Sensitivity analysis adjusting for C-reactive protein (CRP) and white blood cell (WBC) count remained robust after adjustment. Mediation analysis indicated that CRP and WBC partially mediated the SHR-END association, with mediation proportions of 12.89% and 8.03%, respectively. Conclusions Elevated SHR is significantly associated with an increased risk of END in AIS patients, in a non-linear and threshold-dependent manner. This association is partly mediated by systemic inflammatory markers and appears stronger in non-diabetic populations. These findings highlight the potential utility of SHR for early risk stratification and warrant further prospective validation.