GDF15 and diabetes mellitus: GDF-15 levels at admission (D0) were correlated with age (Spearman's correlation coefficient = 0.49; P < 0.001), initial NIHSS score (Spearman's correlation coefficient = 0.32; P = 0.003) (Figure 1), hypertension (Spearman's correlation coefficient = 0.38; P < 0.001), and diabetes (Spearman's correlation coefficient = 0.33; P < 0.001).