Circulating corin concentration is associated with risk of mortality and acute kidney injury in critically ill patients

Elevated serum corin concentrations in patients with cardiac diseases have been associated with adverse cardiovascular events and progressive renal dysfunction. This study aimed to determine the role of serum corin levels in predicting the incidence of acute kidney injury (AKI) and mortality in critically ill patients admitted to intensive care units (ICUs). We screened 323 patients admitted to the ICU in our institution from May 2018 through December 2019. After excluding patients receiving renal replacement therapy, 288 subjects were enrolled. Cases were divided equally into high (n = 144) and low (n = 144) corin groups according to median serum corin levels, using 910 pg/mL as the cut-off point. Patient characteristics and comorbidities were collected from medical records. The primary outcome was AKI within 48 h after ICU admission, while the secondary outcome was all-cause of mortality within 1 year. Compared with the low corin group, patients in the high corin group had higher prevalence rates of diabetes, cirrhosis, and nephrotoxic agent exposure; higher Sequential Organ Failure Assessment scores, white blood cell counts, proteinuria, and serum N-terminal pro-brain natriuretic peptide levels; but had lower initial estimated glomerular filtration rates. Furthermore, elevated serum corin was associated with higher risks of AKI within 48h of ICU admission (43.1% vs. 18.1%, p < 0.001) and all-cause mortality within one year (63.9% vs. 50.0%, p = 0.024). High corin level showed strongly positive results as an independent predictor of AKI (OR 2.15, 95% CI 1.11-4.19, p = 0.024) but not for the all-cause mortality after adjusting for confounding factors in multivariate analyses. Elevated circulating corin predicted AKI in critically ill patients, but did not predict all-cause mortality within 1 year. As a key enzyme in renin-angiotensin-aldosterone system, corin expression may be regulated through a feedback loop following natriuretic peptide resistance and desensitization of natriuretic peptide receptors in different critically ill status.