Kidney Function Declines Along 4 Distinct Trajectories, Study Finds

Older patients with kidney disease can be stratified into 4 distinct trajectories of renal function decline, according to a new study that aims to help physicians better predict which patients are at the highest risk of accelerated decline.

Patients with chronic kidney disease experience a progressive decrease in kidney function over time, and some patients will progress to end-stage renal disease, which has become an increasingly common affliction worldwide, according to corresponding author Josefina Santos, MD, of the University Hospital Center of Porto, Portugal, and colleagues.

Tracking changes in a patient’s estimated glomerular filtration rate (eGFR) is one way to understand how a patient’s kidney disease is progressing, but it can be hard to interpret because some patients experience nonlinear disease progression, and some patients can have long periods without progression.

In hopes of giving physicians a better idea of what course a patient’s kidney disease is likely to take, Santos and colleagues used a number of models to analyze the cases of 378 patients with chronic kidney disease who were 65 years of age or older and who started dialysis at a single healthcare organization between 2009 and 2015. The results of their analysis were published in the journal Renal Failure.

Clinical data used in the analysis included sex, age, body mass index, comorbities, and smoking status, among others. Laboratory data, care practices, and mortality data were also included in the analysis.

Four pre-dialysis trajectories emerged: slower decline (18.3%), gradual decline (18.3%), early rapid decline (41.2%), and rapid decline (22.2%).

A number of factors were associated with a faster decline, including diabetes, cognitive impairment, and pre-dialysis hospitalization. Rapid-decline patients also tended to be younger and were more likely female. The finding that women were more likely to experience rapid decline contradicts some earlier research that suggested men had faster disease progression. However, Santos and colleagues said the existing literature is mixed.

“[I]t is not clear whether sex is independently associated with faster renal disease progression, or whether the association reflects confounding by imbalances between men and women of non-controlled factors associated with renal disease progression,” they wrote.

A patient’s trajectory group was also associated with mortality, though not at first—the higher risk of death for those in the rapid decline groups only appeared after they had been on dialysis for at least one year.

One factor that did not make a difference in groupings was acute kidney injury, despite the fact that such injuries have been linked with quicker progression to ESRD. Neither inpatient diagnosis of acute kidney injury nor the presence of such an injury at the start of dialysis correlated with trajectory. Santos and colleagues said the lack of an association in their study might simply be due to the fact that a high number of patients in their cohort had acute kidney injuries.

The investigators said their study could be used to develop or strengthen electronic health record-based clinical decision tools.

“The identification and risk stratification of patients at the highest risk for worse outcomes, based on trajectory analysis of eGFR, may help to guide decision support systems and inform the patient in a shared decision-making process,” they wrote.

Reference

Santos J, Oliveira P, Severo M, Lobato L, Cabrita A, Fonseca I. Different kidney function trajectory patterns before dialysis in elderly patients: clinical implications and outcomes. Ren Fail. 2021;43(1):1049-1059. doi:10.1080/0886022X.2021.1945464