Association of Longitudinal B-Type Natriuretic Peptide Monitoring With Kidney Failure in Patients With CKD: A Cohort Study

Water and sodium conservation response induced by SGLT2 inhibitor ipragliflozin in Dahl salt-sensitive hypertensive rats

Sodium-glucose cotransporter 2 (SGLT2) inhibitors increase urine volume with glucosuria and natriuresis. We recently reported that osmotic diuresis by the SGLT2 inhibitor ipragliflozin induces fluid homeostatic action via the stimulation of fluid intake and vasopressin-induced water reabsorption in euvolemic rats. However, the effects of SGLT2 inhibitors on these parameters in hypervolemic animals remain unclear. In this study, Dahl salt-sensitive hypertensive rats, a hypervolemic rat model, were fed a low-salt (0.3%) or high-salt (8%) diet for 14 days, then divided into vehicle or ipragliflozin (0.01%) groups. During 7 days of treatment, the high-salt diet groups significantly increased fluid intake and urine volume. In the ipragliflozin groups, fluid intake and urine volume increased by 63% and 235%, respectively, in rats fed a normal-salt diet and by 46% and 72%, respectively, in rats fed a high-salt diet. Ipragliflozin increased urinary vasopressin by 200% and solute-free water reabsorption by 196% in the normal-salt group but by only 44% and 38%, respectively, in the high-salt group. A high-salt diet significantly increased fluid balance (fluid intake - urine volume) and Na+ balance (Na+ intake - urinary Na+), but ipragliflozin did not change fluid and Na+ balance in normal- or high-salt groups. A high-salt diet significantly increased systolic blood pressure, but ipragliflozin did not significantly change systolic blood pressure in normal- or high-salt groups. In conclusion, SGLT2 inhibitor ipragliflozin did not change fluid and Na+ balance regardless of basal fluid retention, suggesting the potential of SGLT2 inhibitors to maintain body water and Na+.

N-terminal pro-B-type natriuretic peptide, eGFR, and progression of kidney disease in chronic kidney disease patients without heart failure

Background

Cardiorenal syndrome highlights the bidirectional relationship between kidney and heart dysfunction. N-terminal pro-B-type natriuretic peptide (NT-proBNP), which is the gold standard biomarker in heart failure (HF), may be an important biomarker for chronic kidney disease (CKD) progression. However, NT-proBNP is negatively related with estimated glomerular filtration rate (eGFR). In this study, we investigated the association of NT-proBNP, eGFR, and progression of kidney disease in CKD patients without HF.

Methods

This multicentric retrospective cohort study recruited 23 860 CKD patients without HF, who had at least one NT-proBNP record from China Renal Data System database. Linear regression model evaluated the relationship between eGFR and NT-proBNP. Cox regression analysis assessed the association between NT-proBNP and CKD progression. Sensitivity analysis examined the robustness of the main findings.

Results

This study involved 23 860 CKD patients without HF, distributed across different CKD stages: 10 526 in stages G1-2, 4665 in G3a, 3702 in G3b, 2704 in G4, and 2263 in G5. NT-proBNP was negatively correlated with eGFR, particularly in stages 4-5 CKD. A 15-unit decrease in eGFR was associated with increases in log (NT-proBNP) levels by 1.04-fold, 1.27-fold, 1.29-fold, 1.80-fold, and 3.50-fold for stages 1-2, 3a, 3b, 4, and 5, respectively. After excluding patients who developed CKD progression within 1 year, the Cox regression analysis revealed that the relationship between NT-proBNP and CKD progression was not significant in stages 4 and 5. However, for stages 1-3, each standard deviation increase in log (NT-proBNP) was associated with a 26%, 36%, and 28% higher risk of CKD progression, with P interaction ≤.001. The hazard ratios were 1.26 (95% confidence intervals (CI), 1.18 to 1.35), 1.36 (95% CI, 1.22 to 1.51), and 1.28 (95% CI, 1.14 to 1.43) for stages 1-2, stage 3a, and stage 3b, respectively.

Conclusions

Despite its strong inverse association with eGFR, NT-proBNP was positively associated with the risk of progression of kidney disease in CKD patients with stages 1-3 without HF. Future studies should investigate the effectiveness of NT-proBNP as a predictive biomarker for the progression of kidney disease across diverse racial groups and healthcare settings.

Plasma B-type natriuretic peptide is independently associated with cardiovascular events and mortality in patients with chronic kidney disease

The association between B-type natriuretic peptide (BNP) and cardiovascular (CV) events and mortality has not been well characterized in patients with chronic kidney disease (CKD). We prospectively investigated whether BNP was associated with CV events or mortality beyond cardiac alterations in 1078 patients with CKD. Participants were divided into the following 3 groups according to circulating BNP concentration: < 40 pg/mL, low; 40-100 pg/mL, middle; and > 100 pg/mL, high. Primary outcome was fatal or nonfatal CV events, and alternative outcome was a composite of fatal or nonfatal CV events, or non-CV deaths. During a median follow-up of 2.6 years, CV and composite events occurred in 158 and 248 participants, respectively. Cox analyses after adjustment for covariates, including cardiac parameters, showed that the hazard ratios (HRs) (95% confidence intervals [CIs]) for CV events of middle and high groups were 1.00 (0.63, 1.58) and 1.72 (1.06, 2.79), respectively, compared with low group. Additionally, similar results were obtained for composite events; the HRs (95% CIs) of middle and high groups were 1.10 (0.77, 1.57) and 1.54 (1.04, 2.27), respectively, compared with low group. Thus, in CKD, high BNP concentrations were independently associated with CV events and mortality, independent of cardiac alterations.

A Study of Abnormal Echocardiogram Findings in Patients With Chronic Kidney Disease With Reference to Cardiac Biomarkers

Background Chronic kidney disease (CKD) is prevalent, especially in populations with multiple risk factors, such as undiagnosed and untreated hypertension and diabetes mellitus. Cardiovascular diseases (CVDs) leading to poor quality of life or even death have been noted as an increasing trend among CKD patients. This study aims to use cardiac biomarkers to evaluate their association with abnormal echocardiogram findings in CKD patients, which may allow for the improvement of quality of life with early treatment. Methods and materials This observational, cross-sectional study was conducted on 103 diagnosed CKD patients at the Department of Medicine, Dr. D.Y. Patil Medical College, Hospital, and Research Centre in Pimpri, Pune, from January 2023 to January 2024. Ethical approval was acquired, and written consent was obtained from participants. The study utilised cardiac biomarkers such as N-terminal pro-B type natriuretic peptide (NT-proBNP), troponin I (Trop I), and a radiological tool, transthoracic echocardiography (TTE). All patients with diagnosed stages 3, 4, and 5 CKD between the ages of 18-80 years were included, and the exclusion criteria consisted of patients who had already undergone cardiac interventional procedures or known cases of CVDs. Results In our study, out of 103 participants, the majority were aged between 51 and 60 years (35, 34%). The study had a majority of male participants (76, 73.8%). Major risk factors were considered, noting hypertension in 63 (61.2%) and diabetes mellitus in 81 (78.6%). Participants were divided into stages of CKD. Cardiac biomarkers such as NT-proBNP and Trop I levels were assessed in all participants in the different stages of CKD showing elevated levels of NT-proBNP across all stages. Transthoracic echocardiogram (TTE) screening tests were also evaluated for all patients, showing diastolic dysfunction (DD) as the most common finding in stage 3 (5, 41.67%), stage 4 (25, 62.5%), and stage 5 (35, 68.83%), followed by left ventricular hypertrophy (LVH) as a common finding in stage 3 (4, 33.3%), stage 4 (20, 50%), and stage 5 (30, 58.2%) CKD. Furthermore, the association between raised cardiac biomarkers and abnormal echocardiogram findings across the stages of CKD was evaluated, resulting in a statistically significant association with p-values < 0.05. Conclusion This research sheds light on the association between cardiac biomarkers and abnormal echocardiogram findings in CKD patients and helps us determine if there is any added benefit or predictive value in screening these individuals at different stages of the disease to allow early intervention and improvement in treatment and quality of life.

Fluid homeostatic action of dapagliflozin in patients with chronic kidney disease: the DAPA-BODY Trial

Sodium glucose cotransporter 2 (SGLT2) inhibitors have both glucose-lowering and diuretic effects. We recently reported that the SGLT2 inhibitor dapagliflozin exerts short-term fluid homeostatic action in patients with chronic kidney disease (CKD). However, the long-term effects of SGLT2 inhibitors on body fluid status in patients with CKD remain unclear. This was a prospective, non-randomized, open-label study that included a dapagliflozin treatment group (n = 73) and a control group (n = 24) who were followed for 6 months. Body fluid volume was measured using a bioimpedance analysis device. The extracellular water-to-total body water ratio (ECW/TBW), a predictor of renal outcomes, was used as a parameter for body fluid status (fluid retention, 0.400 ≤ ECW/TBW). Six-month treatment with dapagliflozin significantly decreased ECW/TBW compared with the control group (-0.65% ± 2.03% vs. 0.97% ± 2.49%, p = 0.0018). Furthermore, dapagliflozin decreased the ECW/TBW in patients with baseline fluid retention, but not in patients without baseline fluid retention (-1.47% ± 1.93% vs. -0.01% ± 1.88%, p = 0.0017). Vasopressin surrogate marker copeptin levels were similar between the control and dapagliflozin groups at 6 months (32.3 ± 33.4 vs. 30.6 ± 30.1 pmol/L, p = 0.8227). However, dapagliflozin significantly increased the change in copeptin levels at 1 week (39.0% ± 41.6%, p = 0.0010), suggesting a compensatory increase in vasopressin secretion to prevent hypovolemia. Renin and aldosterone levels were similar between the control and dapagliflozin groups at 6 months, while epinephrine and norepinephrine (markers of sympathetic nervous system activity) were significantly lower in the dapagliflozin group than in the control group. In conclusion, the SGLT2 inhibitor dapagliflozin ameliorated fluid retention and maintained euvolemic fluid status in patients with CKD, suggesting that SGLT2 inhibitors exert sustained fluid homeostatic actions in patients with various fluid backgrounds. Clinical trial registration: https://www.umin.ac.jp/ctr/, identifier [UMIN000048568].