IGFBP1 and Stroke: Additionally, some other statistically significant correlations were observed with small or very small magnitudes, i.e., r < 0.2 (Table 2), and are listed as follows: acute s-IGFBP-1, but not 3-month s-IGFBP-1, correlated inversely with National Institutes of Health Stroke Scale (NIHSS), i.e., stroke severity.