TOPLINE:

In adults with diabetes, baseline plasma B-type natriuretic peptide (BNP) levels predicted a sustained decline of at least 30% in estimated glomerular filtration rate (eGFR). A clinical model including BNP as a marker of progression of chronic kidney disease (CKD) performed as well as models adding traditional urinary markers. In addition, BNP showed a graded association with decline in kidney function even within the conventional normal range (≤ 18.4 pg/mL); when combined with albuminuria, it identified those at the highest risk.

METHODOLOGY:

• BNP is the gold standard marker of cardiac wall stress and may reflect a broader cardiorenal risk, but its ability to signal progression of CKD, particularly at subclinical concentrations, remains unknown.
• Researchers analyzed data from 636 adults with diabetes (mean age, 64.5 years; 53.8% male) from a medical center in Japan, with a median follow-up of 5.4 years, to evaluate the prognostic value of BNP in comparison with traditional urinary markers for progression of CKD. They also assessed BNP’s incremental value when combined with the urinary albumin-to-creatinine ratio.
• At baseline, all participants underwent standardized blood tests as well as a urine test using a single random spot urine sample to determine dipstick proteinuria, the urinary albumin-to-creatinine ratio, and the urinary protein-to-creatinine ratio; plasma BNP levels were measured using a chemiluminescent assay.
• The primary outcome was progression of CKD, defined as a sustained decline of at least 30% in eGFR from baseline, confirmed by at least two consecutive measurements.

TAKEAWAY:

• During follow-up, 74 (11.6%) participants experienced progression of CKD; adding BNP to the clinical base model significantly improved 5-year discrimination for a decline of at least 30% in eGFR.
• In a head-to-head comparison, no significant differences in performance were observed between the model with BNP added and those with the urinary albumin-to-creatinine ratio, the urinary protein-to-creatinine ratio, or dipstick proteinuria added.
• BNP remained independently associated with progression of CKD after adjusting for the urinary albumin-to-creatinine ratio and covariates (adjusted hazard ratio, 1.55 per log₁₀ 1-SD increase; P = .002).
• Restricted cubic spline analyses demonstrated a graded association across the entire BNP range, including concentrations within the conventional normal range (≤ 18.4 pg/mL; P for nonlinearity = .01).
• Combined elevations in both BNP levels (> 18.4 pg/mL) and the urinary albumin-to-creatinine ratio (≥ 30 mg/g) identified individuals at the highest risk for progression of CKD; those with neither marker elevated had the lowest risk.

IN PRACTICE:

“BNP provides robust, graded prognostic information for kidney function decline even within the normal range, highlighting its role as a distinct hemodynamic indicator,” the authors of the study wrote.

SOURCE:

The study was led by Maki Murakoshi, Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan. It was published online in Diabetes Research and Clinical Practice.

LIMITATIONS:

This was a single-center study with a relatively modest sample size, and validation was not performed in an external cohort, which may limit generalizability. Urinary albumin-to-creatinine ratio and urinary protein-to-creatinine ratio were based on a single spot urine sample, which may have introduced intraindividual variability. Only a small proportion of participants were treated with SGLT2 inhibitors or GLP-1 receptor agonists at baseline; therefore, the potential impact of these agents on kidney outcomes was not considered.

DISCLOSURES:

The study was partially supported by JSPS KAKENHI, Japan. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.