BNP predicts kidney disease progression risk in diabetes patients

The relationship between cardiovascular dysfunction and renal impairment is widely recognized as the cardiorenal interaction, a complex physiological link in which damage to one organ can accelerate deterioration in the other. This interdependence has gained increasing attention in recent years, particularly with the emergence of therapies such as sodium–glucose cotransporter-2 inhibitors, which have demonstrated protective effects for both the heart and kidneys. As a result, identifying individuals at risk for kidney function decline at an early stage has become an important priority in clinical medicine, especially among patients with diabetes who are more vulnerable to both cardiovascular disease and chronic kidney disease (CKD).

In clinical practice, kidney disease progression is commonly assessed using urinary biomarkers such as the urinary albumin-to-creatinine ratio (UACR), urine protein-to-creatinine ratio (UPCR), and dipstick proteinuria. Among these, UACR is recommended by international guidelines as a reliable indicator of kidney damage, and studies show that even values within the normal range may reflect an increased risk of CKD progression. B-type natriuretic peptide (BNP), traditionally used as a biomarker for cardiac wall stress and heart failure, has recently been linked to broader cardiorenal risk. However, its ability to predict CKD progression, particularly at clinically normal levels, remains unclear.

To address this gap, researchers from Juntendo University conducted the present study to determine whether BNP independently predicts CKD progression and whether it provides additional prognostic value alongside established urinary biomarkers. Associate Professor Maki Murakoshi shares the motivation behind the study: "Diabetic kidney disease is the leading cause of end-stage kidney disease worldwide, and it is crucial to reduce the number of patients progressing to this condition as much as possible." The study was published in the journal Diabetes Research and Clinical Practice, volume 235 on May 01, 2026 and was first made available online on February 24, 2026. This research was carried out with contributions from Dr. Tomohito Gohda from the Department of Nephrology, Juntendo University Faculty of Medicine, Dr. Nozomu Kamei from the Department of Endocrinology and Metabolism, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, and Dr. Masato Furuhashi from the Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine.

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.

The findings showed that BNP had prognostic performance comparable to UACR, UPCR, and dipstick proteinuria in predicting chronic kidney disease progression. Dr. Murakoshi notes, "BNP, which is widely used in routine clinical practice as an established biomarker for heart failure, is associated with the progression of CKD 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.

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. "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," adds Dr. Murakoshi.

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.