eGFRcr-cys Levels More Strongly Linked to Adverse Outcomes in Seniors

MONDAY, Jan. 29, 2024 (HealthDay News) -- In older patients, a low estimated glomerular filtration rate (eGFR) based on creatinine and cystatin C levels (eGFR_cr-cys) is more strongly associated with adverse outcomes compared with low eGFR based on creatinine level (eGFR_cr), according to a study published online Jan. 30 in the Annals of Internal Medicine.

Edouard L. Fu, Ph.D., from the Karolinska Institute in Stockholm, and colleagues note that the commonly accepted threshold of GFR to define chronic kidney disease (CKD) is <60 mL/min/1.73 m² and is based partly on the associations between eGFR and the frequency of adverse events, which are weaker in older adults. The authors assessed associations between eGFR_cr versus eGFR_cr-cys and eight outcomes in older adults. Data were included for 82,154 participants aged 65 years and older with outpatient creatinine and cystatin C testing.

The researchers observed monotonic associations between eGFR_cr-cys and outcomes, while most associations for eGFR_cr were U-shaped. Compared with eGFR_cr, eGFR_cr-cys was more strongly associated with outcomes. The adjusted hazard ratios (95 percent confidence intervals) for all-cause mortality were 1.2 (1.1 to 1.3) and 1.0 (0.9 to 1.0) for eGFR_cr-cys and eGFR_cr, respectively, for 60 versus 80 mL/min/1.73 m², and 2.6 (1.2 to 5.8) and 1.4 (0.7 to 2.8), respectively, for kidney failure with replacement therapy. In subgroups, including those with a urinary albumin-creatinine ratio below 30 mg/g, the findings were similar.

"The broad range of risks associated with CKD at older age is better appreciated when cystatin C is included in GFR estimation," the authors write.

Abstract/Full Text (subscription or payment may be required)

Editorial (subscription or payment may be required)