Albuminuria Change Shows Surrogate Signal for Kidney Failure

Key Takeaways

• Treatment-related 6-month albuminuria change tracked later clinical kidney outcomes across randomized CKD trials.
• A trial-level association was reported between treatment effects on UACR and the clinical kidney endpoint.
• Researchers found no clear variation by CKD etiology, and the authors said the findings support albuminuria change as a surrogate endpoint in CKD trials.

That estimate came from an individual participant data meta-analysis of 48 randomized CKD trials involving 85,681 participants. Investigators linked treatment-related changes in albuminuria at 6 months with subsequent clinical kidney outcomes across the pooled trials. The endpoint combined kidney failure with doubling of serum creatinine concentrations, and the association was assessed using a treatment-versus-control comparison at the trial level. The analysis examined whether early albuminuria change tracked later kidney outcomes, rather than treating that biomarker relationship as definitive proof.

Researchers pooled individual participant data from 48 randomized controlled trials that enrolled 85,681 people with chronic kidney disease. They examined treatment effects on 6-month urinary albumin:creatinine ratio change against the clinical endpoint of kidney failure or doubling of serum creatinine concentrations. The comparison used the geometric mean UACR in the treatment group relative to the control group. The analysis asked whether short-term biomarker shifts aligned with differences in a recognized clinical kidney outcome across randomized trials. At its center was whether albuminuria change at 6 months tracked later clinical events in the trial setting.

The reported association was accompanied by a 95% Bayesian credible interval spanning a 5% to 30% lower hazard for the clinical endpoint. Investigators also reported a median coefficient of determination, or R2, of 0.66 across trials. Its 95% Bayesian credible interval ranged from 0.06 to 0.98, indicating variable but measurable trial-level fit around the association. That fit metric was separate from the hazard association and described how closely treatment effects on UACR tracked treatment effects on outcomes. Together, these results indicated that earlier UACR shifts and later clinical kidney outcomes moved in the same direction across the randomized evidence base.

Across the pooled evidence, researchers found no clear evidence that the association differed by chronic kidney disease etiology. Authors interpreted the findings as adding further support for albuminuria change as a surrogate endpoint in chronic kidney disease clinical trials. That interpretation reflected the observed linkage between 6-month treatment-related UACR differences and subsequent kidney failure or serum creatinine doubling outcomes. Within the abstract’s reported scope, the results positioned albuminuria change as a candidate surrogate endpoint that tracked clinical endpoints across randomized CKD trials.