SDC1 and acute kidney injury: Syndecan-1 levels were significantly higher in the AKI group [109.95 (73.67-221.40) vs.73.67 (54.59-109.95) ng/mL, <i>p</i> = 0.007], and RRI values were markedly elevated (0.69 ± 0.08 vs. 0.60 ± 0.06, <i>p</i> < 0.001) compared to non-AKI patients.