Combination of eGFR and UACR Better Predicts CKD Progression

The combination of kidney function decline and albuminuria is more prognostic for chronic kidney disease (CKD) progression within the general population than either measure alone, a new study finds.

Among 91,319 primary care patients from the UK’s Clinical Practice Research Datalink from 2000 to 2015 (including 77.7% with diabetes), a total of 2541 patients progressed to advanced CKD defined as a sustained estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73 m². Over 3 years, 28% of patients experienced a 30% or more increase in urinary albumin-creatinine ratio (UACR) and 5.0% experienced a 30% or more decrease in eGFR.

A 30% or greater increase in UACR (vs stable UACR) was associated with a 1.8-fold increased risk for advanced CKD. A 30% or greater decrease in eGFR (vs stable eGFR) was associated with a 7.5-fold increased risk. Having both UACR and eGFR changes combined, however, was associated with a 15.2-fold increased risk for advanced CKD, Brendon L. Neuen, MBBS, and colleagues from the George Institute for Global Health at the University of New South Wales in Australia reported in the American Journal of Kidney Diseases.

Separately, an increase in UACR and a decrease in eGFR of 30% or more were associated with 4.2- and 5.1-fold greater risks for end-stage kidney disease (ESKD), respectively. The combination of changes was associated with a 16.7-fold greater risk for ESKD, the investigators reported. 

These UACR and eGFR changes were also associated with increased risks for cardiovascular disease and all-cause mortality compared with maintaining stable values.

All of these associations were statistically significant.

“From a clinical perspective, these results underscore the prognostic value of considering changes in eGFR and albuminuria together to identify patients at highest risk of kidney disease progression who may benefit from established and emerging kidney protective therapies,” Dr Neuen’s team stated.

In an accompanying editorial, Josef Coresh, MD, PhD, from the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, and coauthors, pointed out key differences between real-world practice and clinical trials.

“In clinical trials, change in eGFR from the baseline randomization value is a powerful surrogate outcome, and change in albuminuria may also be helpful in certain scenarios and disease etiologies,” they wrote. “In clinical practice, however, past changes for individual patients may be of only marginal utility over and above current eGFR and albuminuria values, which integrate the combination of past baseline levels and treatment effects to guide future care.”