• Edouard L Fu, Juan-Jesus Carrero, Yingying Sang, Marie Evans, Junichi Ishigami, Lesley A Inker, Morgan E Grams, Andrew S Levey, Josef Coresh, and Shoshana H Ballew.
• Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden; Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands (E.L.F.).
• Ann. Intern. Med. 2024 Mar 1; 177 (3): 269279269-279.

BackgroundThe commonly accepted threshold of glomerular filtration rate (GFR) to define chronic kidney disease (CKD) is less than 60 mL/min/1.73 m2. This threshold is based partly on associations between estimated GFR (eGFR) and the frequency of adverse outcomes. The association is weaker in older adults, which has created disagreement about the appropriateness of the threshold for these persons. In addition, the studies measuring these associations included relatively few outcomes and estimated GFR on the basis of creatinine level (eGFRcr), which may be less accurate in older adults.ObjectiveTo evaluate associations in older adults between eGFRcr versus eGFR based on creatinine and cystatin C levels (eGFRcr-cys) and 8 outcomes.DesignPopulation-based cohort study.SettingStockholm, Sweden, 2010 to 2019.Participants82 154 participants aged 65 years or older with outpatient creatinine and cystatin C testing.MeasurementsHazard ratios for all-cause mortality, cardiovascular mortality, and kidney failure with replacement therapy (KFRT); incidence rate ratios for recurrent hospitalizations, infection, myocardial infarction or stroke, heart failure, and acute kidney injury.ResultsThe associations between eGFRcr-cys and outcomes were monotonic, but most associations for eGFRcr were U-shaped. In addition, eGFRcr-cys was more strongly associated with outcomes than eGFRcr. For example, the adjusted hazard ratios for 60 versus 80 mL/min/1.73 m2 for all-cause mortality were 1.2 (95% CI, 1.1 to 1.3) for eGFRcr-cys and 1.0 (CI, 0.9 to 1.0) for eGFRcr, and for KFRT they were 2.6 (CI, 1.2 to 5.8) and 1.4 (CI, 0.7 to 2.8), respectively. Similar findings were observed in subgroups, including those with a urinary albumin-creatinine ratio below 30 mg/g.LimitationNo GFR measurements.ConclusionCompared with low eGFRcr in older patients, low eGFRcr-cys was more strongly associated with adverse outcomes and the associations were more uniform.Primary Funding SourceSwedish Research Council, National Institutes of Health, and Dutch Kidney Foundation.

21 keywords...

hide…