BNP Emerges as Key Predictor for Kidney Disease Progression in Diabetes Patients

The intricate relationship between cardiovascular dysfunction and renal impairment, known as cardiorenal interaction, demonstrates how damage to one organ can accelerate the deterioration of the other. This interdependence has gained increased attention, particularly with the advent of therapies like sodium–glucose cotransporter-2 inhibitors, which have shown protective effects for both the heart and kidneys. As a result, early identification of individuals at risk for kidney function decline is a clinical priority, especially among patients with diabetes who are more vulnerable to both cardiovascular disease and chronic kidney disease (CKD).

Kidney disease progression is typically assessed using urinary biomarkers such as the urinary albumin-to-creatinine ratio (UACR), urine protein-to-creatinine ratio (UPCR), and dipstick proteinuria. International guidelines recommend UACR as a reliable indicator, with studies showing that even values within the normal range may reflect an increased risk of CKD progression. B-type natriuretic peptide (BNP), traditionally a biomarker for cardiac wall stress and heart failure, has recently been linked to broader cardiorenal risk. However, its ability to predict CKD progression, especially at clinically normal levels, remained unclear.

The Research Question

To address this, researchers from Juntendo University conducted a study to determine if BNP independently predicts CKD progression and provides additional prognostic value alongside established urinary biomarkers.

Associate Professor Maki Murakoshi stated that the study's motivation was to reduce the number of patients progressing to end-stage kidney disease, as diabetic kidney disease is a leading cause globally.

The study was published in the journal Diabetes Research and Clinical Practice.

Study Methodology

The researchers conducted a longitudinal analysis involving 636 adults with diabetes, who were followed for a median of 5.4 years. Baseline blood samples were used to measure BNP levels, while urine samples assessed UACR, UPCR, and dipstick proteinuria. Kidney function was monitored using estimated glomerular filtration rate (eGFR).

The primary outcome was defined as a decline of at least 30% in eGFR, indicating significant deterioration in kidney function. Statistical analyses compared the prognostic performance of BNP with urinary markers and evaluated whether BNP improved predictive accuracy when added to models including UACR and other clinical factors.

Key Findings: BNP's Predictive Power

The findings showed that BNP had prognostic performance comparable to UACR, UPCR, and dipstick proteinuria in predicting chronic kidney disease progression.

Dr. Murakoshi noted that BNP, which is widely used in routine clinical practice for heart failure, is associated with CKD progression in individuals with diabetes even when BNP levels are within the normal range.

During follow-up, 74 participants experienced a ≥30% decline in eGFR. BNP remained independently associated with kidney function decline even after adjusting for UACR and other clinical variables. Further analyses revealed a graded relationship between BNP levels and CKD risk, with increasing risk observed even within clinically normal BNP levels. Individuals with elevations in both BNP and UACR showed the highest risk of kidney function deterioration, suggesting that combining these markers may improve risk stratification.

Implications for Clinical Practice

These findings highlight the potential role of BNP as a marker of cardiorenal vulnerability. BNP may provide additional prognostic information beyond traditional urinary markers and could help clinicians identify high-risk patients earlier, particularly in settings where urine testing is not routinely performed.

Dr. Murakoshi added that early identification of patients at high risk of CKD progression among individuals with diabetes, followed by appropriate therapeutic intervention, may help prevent not only progression to end-stage kidney disease but also the development of cardiovascular disease.

Conclusion

In conclusion, the study demonstrates that BNP is independently associated with chronic kidney disease progression and provides prognostic information comparable to established urinary markers. BNP can identify graded risk even within normal ranges, and its combination with UACR improves risk prediction, highlighting its potential role in improving early detection and management of kidney disease in patients with diabetes.