Abstract WMP6: Genetic Variation In KLF5 Is Associated With Initial Stress Glucose Ratio In Acute Ischemic Stroke

Abstract

Introduction: Hyperglycemia has consistently been associated with worse outcome following an acute ischemic stroke (AIS). Recent studies have shown that a stress glucose ratio (SGR) may be a better predictor of critical illness than absolute hyperglycemia. An elevated initial stress glucose ratio (iSGR) was significantly associated with malignant cerebral edema and ICH after thrombectomy. We sought to identify genetic loci related to iSGR in a cohort of the GENISIS (Genetics of Early Neurological InStability after Ischemic Stroke) study. Methods: GENISIS is a multi-site international study that enrolled AIS patients within 6 hours of symptom onset. A sub-cohort with available initial glucose and HbA1c levels was selected. For all patients, Hg38 imputed genotypes were available. iSGR was calculated by dividing initial glucose by the estimated average glucose concentration (= 28.7 * A1c - 46.7) and normalized by log transformation for the GWAS. Association was adjusted by age, sex, baseline NIHSS, principal components and genotyping rounds. Samples were analyzed by country of origin and ethnicity using Plink2 and then meta-analyzed by ethnicity using METAL. Results: Three separate populations were identified (African-Americans n=299; European-Americans n=622; and Spanish n=625). Median age was 71 (IQR 60-80) with 46% female. Baseline NIHSS was 11 (IQR 5-16). A suggestive loci (chr13:rs9560146, p=9.88x10 -8 ) was identified in the meta-analysis. Gene-based analyses suggested that the loci in chromosome 13 is driven by KLF5 (p=0.002). In addition, rs9560146 is also associated with KLF5 gene expression in brain (eQTL p=3.30x10 -3 ; frontal cortex: Braineac). Conclusions: We demonstrated that a variant in KLF5 may be associated with iSGR in a cohort of AIS patients. KLF5 is induced under hypoxia conditions and interacts with HIF-1a to mediate glucose homeostasis. Recently, a pre-clinical study demonstrated that a micro RNA (miR-10b-3p) had neuroprotective effects against ischemia/reperfusion injury by targeting KLF5. Thus, investigating the genetic architecture of stress hyperglycemia may be informative and reveal variants, genes or pathways involved in ischemic brain injury. We plan to recruit a cohort for replication and sample size expansion.