Summary: In a secondary analysis of 1,116 US veterans with type 2 diabetes and macroalbuminuric diabetic kidney disease (VA NEPHRON-D), higher baseline urinary epidermal growth factor (EGF) and uromodulin (UMOD) were each independently associated with a lower risk of disease progression (adjusted HR 0.68, 95% CI 0.47 to 0.99 per doubling of EGF; HR 0.85, 95% CI 0.75 to 0.98 per doubling of UMOD). The findings are associational and prognostic, not interventional.
PICO Summary
| Element | Detail |
|---|---|
| Population | n=1,116 adults with type 2 diabetes, UACR ≥300 mg/g, and eGFR 30 to 89.9 mL/min/1.73m2 (mean age 65 years; mean eGFR 56; median UACR 840 mg/g). Secondary biomarker analysis of the VA NEPHRON-D randomised trial cohort, United States. |
| Intervention | Higher baseline urinary EGF and UMOD concentrations, and slower decline in these distal-nephron biomarkers between baseline and 12 months (prognostic exposures, not a treatment). Whole cohort, n=1,116. |
| Comparison | Lower baseline biomarker concentrations and faster biomarker decline (modelled per 2-fold difference within the same cohort; no separate comparator arm). |
| Outcome | DKD progression occurred in 144 participants (13%) over a median 2.2 years (IQR 1.3 to 3.1). Per 2-fold higher concentration, adjusted HR for progression was 0.68 (95% CI 0.47 to 0.99) for EGF and 0.85 (95% CI 0.75 to 0.98) for UMOD. A slower decline in biomarkers was associated with lower progression risk after adjustment for baseline levels. No p-values or NNT reported; absolute risk reduction not applicable to a prognostic association. |
Expert Commentary
This secondary analysis of the VA NEPHRON-D cohort adds distal-nephron markers to a literature dominated by proximal tubular and glomerular signals, and the message is internally consistent: higher tubular health, reflected by greater EGF and uromodulin excretion, tracks with a lower risk of progression. The effect sizes are modest, with both confidence intervals approaching the null (0.99 and 0.98), so these biomarkers refine rather than transform risk estimation. The principal limitation is design. This is an associational, prognostic analysis nested in a trial cohort, so causation cannot be inferred, and a marker of relatively preserved nephron mass may simply be a proxy for less advanced disease rather than an independent driver. The cohort is also highly selected, being predominantly older male veterans with macroalbuminuria, which constrains generalisability. Can I use this with my patients? Not yet, because urinary EGF and uromodulin are not standardised clinical assays and no validated threshold or reclassification benefit over eGFR and UACR has been demonstrated. The work was funded by the National Institutes of Health rather than industry, which reduces sponsorship-related interpretation bias, and the reported associations are plausible rather than implausibly strong. External validation in more diverse cohorts, with assay standardisation and a demonstration of incremental discrimination, should precede any move toward clinical use.
References
Tamargo CL, Coca SG, Thiessen Philbrook H, et al. The distal nephron biomarkers associate with diabetic kidney disease progression. JCI Insight. 2025;10(12):e186836. doi:10.1172/jci.insight.186836