- Design
- Individual-patient meta-analysis of 49 randomised trials
- Population
- 66 449 participants in CKD progression trials
- Primary outcome
- Association of early GFR change with albuminuria change
- Effect
- Trial-level slope 0.00 (−0.08 to 0.09); within-patient UACR −8.0% vs −6.6% per SD GFR decline
An individual-patient meta-analysis in Kidney International pooled 49 randomised CKD progression trials with 66 449 participants. Investigators related early GFR change (baseline to 3 months) to albuminuria change (baseline to 6 months), both between trials and within individual patients.
Across trials, treatment effects on early GFR showed no relationship with treatment effects on albuminuria (slope 0.00, 95% credible interval −0.08 to 0.09). Within patients, a greater early fall in GFR went with a greater fall in albuminuria — about 8.0% per standard deviation in treatment arms and 6.6% in control arms. Because the association was nearly as strong without active treatment, the authors conclude that early changes in an individual may reflect natural history or other factors rather than the drug.
Clinicians commonly read an early albuminuria fall as proof a drug is working, or an early GFR dip as a sign of harm. This analysis suggests neither is reliable for an individual patient. Proven kidney-protective drugs are given for their long-term effect on outcomes; this supports continuing them rather than judging them on early numbers. The analysis is observational within trials, and the association did not hold for immunosuppressive treatments.
- Do not judge an individual's response to RAS blockade or SGLT2 inhibition by early albuminuria change alone.
- Similar early shifts occurred in placebo arms, so they may reflect the disease rather than the drug.
- Continue proven kidney-protective drugs unless there is a specific safety reason to stop.
- Interpret immunosuppressive therapy responses separately; the pattern differed there.
Why it matters
It challenges a habit of reading early lab shifts as personal proof of drug effect.
Don't overread it
This does not say albuminuria is unimportant; it remains a prognostic marker and a valid trial-level surrogate.
The statistics, in plain English
A meta-regression slope of 0.00 means trials that lowered albuminuria more did not change early GFR more. Similar within-patient associations in both arms point to shared natural history rather than drug action.
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