Polymorphisms of IGFI contribute to the development of ischemic stroke.

Insulin-like growth factor 1 (IFG1) is neuroprotective in animal models of focal brain ischemia and correlates with ischemic stroke (IS) outcome in the elderly. In this study, we investigated whether single nucleotide polymorphisms (SNPs) of the IFG1 gene are associated with the development and clinical features of IS in a Korean population. A total of 119 patients with IS and 289 control subjects were recruited. Stroke patients were classified into subgroups according to the scores of the National Institutes of Health Stroke Survey (NIHSS; <6 and ≥6) and the Modified Barthel Index (MBI; <60 and ≥60). Among the SNPs of the IFG1 gene, five SNPs were selected and analyzed by direct sequencing: rs2162679 (intron), rs2195239 (intron), rs978458 (intron), rs1520220 (intron) and rs6214 (3' untranslated region; 3'UTR). Multiple logistic regression models were conducted to analyze genetic data. SNPStats, SNPAnalyzer Pro and Helixtree programs were used to calculate odds ratios (ORs), 95% confidence intervals (CIs) and p-values. Two SNPs, rs2162679 and rs6214, were associated with the development of IS. After Bonferroni correction (p(c)), the A and G alleles of rs2162679 and rs6214 had significant differences between patients with IS and the controls [rs2162679, OR (95% CI) = 1.64 (1.17-2.31), p=0.004, p(c)=0.02; rs6214, OR (95% CI) = 1.52 (1.12-2.07), p=0.007, p(c)=0.035], respectively. However, the five selected SNPs were not related to the NIHSS and MBI scores. These results suggest that IGF1 may be associated with the development of IS.