Serum creatinine to cystatin C ratio and clinical outcomes in adults with non-dialysis chronic kidney disease

on behalf of the KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD) Study Group

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Background: Studies have suggested that the serum creatinine/cystatin C (Cr/CysC) ratio is a surrogate marker for muscle wasting is associated with adverse outcomes in several disease conditions. To clarify the utility of the Cr/CysC ratio as a prognostic marker in chronic kidney disease (CKD) we evaluated the association between the Cr/CysC ratio clinical outcomes in patients with non-dialysis CKD. Methods: This prospective observational cohort study included 1,966 participants of the KoreaN cohort study Outcomes in patients With CKD (KNOW-CKD). We evaluated associated factors with the serum Cr/CysC ratio and association between the serum Cr/CysC ratio and composite outcomes of all-cause death and cardiovascular events (CVEs). Results: The mean age was 54 ± 12 (SD) years and 61% were men. The mean serum Cr/CysC ratio was 10.97 ± 1.94 in men and 9.10 ± 1.77 in women. The Cr/CysC ratio correlated positively with urinary creatinine excretion, a marker of muscle mass. In the fully adjusted Cox proportional hazard model, the Cr/CysC ratio was associated with the occurrence of adverse outcomes through a median follow-up of 5.9 years [hazard ratio (HR) = 0.92, 95% confidence interval (CI) = 0.85–0.99 for the composite outcomes, HR = 0.87, 95% CI, 0.78 − 0.97 for all-cause death, and HR = 0.93; 95% CI, 0.84–1.04 for CVEs]. In subgroup analyses, there were interactions of the Cr/CysC ratio with age and sex for risk of the clinical outcomes, but not eGFR group. Conclusion: A higher Cr/CysC ratio is associated with a lower risk of the composite outcomes, especially all-cause mortality, even after adjusting for eGFR. These suggest that the Cr/CysC ratio is a useful prognostic marker in CKD.

Original languageEnglish
Article number996674
JournalFrontiers in Nutrition
Publication statusPublished - 2022 Sept 26

Bibliographical note

Funding Information:
This work was supported by Research Program funded by the Korea Centers for Disease Control and Prevention (grant nos. 2011E3300300, 2012E3301100, 2013E3301600, 2013E3301601, 2013E3301602, 2016E3300200, and 2016E3300201). The funding sources had no role in the design and conduct of study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.

Publisher Copyright:
Copyright © 2022 Hyun, Lee, Kim, Kim, Chung, Park, Han, Oh, Park and Oh.

All Science Journal Classification (ASJC) codes

  • Food Science
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics


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