Albumin-specific metric better measure of kidney disease than protein
Urinary albumin–creatinine ratio showed a slightly stronger association with development of kidney failure and other adverse renal outcomes than urinary protein–creatinine ratio, a meta-analysis found.
Urinary albumin–creatinine ratio (UACR) was more strongly associated with development of kidney failure than urinary protein–creatinine ratio (UPCR), supporting the former's use as the preferred measure to assess chronic kidney disease (CKD), a meta-analysis found.
The individual patient-level meta-analysis included 38 cohort studies to compare the performance of albumin and protein ratios. It used data from 148,994 participants who had UACR and UPCR measured on the same day, and measured outcomes included incident kidney failure with kidney replacement, myocardial infarction, stroke, heart failure, and cardiovascular death. The findings were published Nov. 4 in Annals of Internal Medicine.
Both UACR and UPCR were associated with CKD-related adverse clinical outcomes. However, the association with kidney failure was somewhat stronger for UACR (adjusted hazard ratio [HR] per SD increment, 2.55; 95% CI, 2.36 to 2.74) than UPCR (HR, 2.40; 95% CI, 2.28 to 2.53) (P for comparison<0.001). The results were consistent to slightly stronger in subgroups with UACR greater than 30 mg/g, UPCR greater than 500 mg/g, eGFR less than 60 mL/min/1.73 m2, diabetes, and glomerular disease. The associations of UACR and UPCR with cardiovascular outcomes were generally similar but favored UACR in subgroups with moderately to severely elevated UACR.
The study authors wrote that a more uniform approach to proteinuria assessment would aid diagnosis, monitoring, and prognostication of kidney disease in clinical practice, and noted that their findings could also help with comparing results between clinical trials and translating results to improved patient care.
“The comparative advantage of UACR was particularly prominent for participants with high-risk CKD, specifically those with higher baseline UACR, lower eGFR, diabetes, or glomerulonephritis,” the authors wrote. “Given increasing access to and affordability of UACR and capacity to standardize UACR assays, these data support use of UACR as the preferred measure to stratify patients at risk for CKD-related clinical outcomes.”