Extracellular fluid volume is associated with incident end-stage kidney disease and mortality in patients with chronic kidney disease

Sex and the Risk of Atheromatous and Nonatheromatous Cardiovascular Disease in CKD: Findings From the CKD-REIN Cohort Study

RATIONALE & OBJECTIVE

Sex differences in cardiovascular disease (CVD) are well established, but whether chronic kidney disease (CKD) modifies these risk differences and whether they differ between atheromatous CVD (ACVD) and nonatheromatous CVD (NACVD) is unknown. Assessing this interaction was the principal goal of this study.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Adults enrolled in the CKD-REIN (CKD-Renal Epidemiology and Information Network) cohort, a nationally representative sample of 40 nephrology clinics in France, from 2013 to 2020.

EXPOSURE

Sex.

OUTCOMES

Fatal and nonfatal composite ACVD events (ischemic coronary, cerebral, and peripheral artery disease) and composite NACVD events (heart failure, hemorrhagic stroke, and arrhythmias).

ANALYTICAL APPROACH

Multivariable cause-specific Cox proportional hazards models.

RESULTS

1,044 women and 1,976 men with moderate to severe CKD (median age, 67 vs 69y; mean estimated glomerular filtration rate [eGFR], 32±12 vs 33±12mL/min/1.73m2) were studied. During a median follow-up of 5.0 (IQR, 4.8-5.2) years, the ACVD rate (per 100 patient-years) was significantly lower in women than in men, at 2.1 (95% CI, 1.6-2.5) versus 3.6 (3.2-4.0; P<0.01), whereas the NACVD rate was not, at 5.7 (5.0-6.5) versus 6.4 (5.8-7.0; P=0.55). NACVD had a steeper relationship with eGFR than did ACVD. There was an interaction (P<0.01) between sex and baseline eGFR and the ACVD hazard: the adjusted HR for women versus men was 0.42 (0.25-0.71) at 45mL/min/1.73m2 and gradually attenuated at lower levels of eGFR, reaching 1.00 (0.62-1.63) at 16mL/min/1.73m2. In contrast, the NACVD hazard did not differ between sexes across the eGFR range studied.

LIMITATIONS

Cardiovascular biomarkers and sex hormones were not assessed.

CONCLUSIONS

This study shows how the lower risk of ACVD among women versus men attenuates fully with kidney disease progression. The equal risk of NACVD between sexes across CKD stages and its steeper association with eGFR suggest an important contribution of CKD to the development of this CVD type.

PLAIN-LANGUAGE SUMMARY

Sex differences in the risks of atheromatous and nonatheromatous cardiovascular disease (CVD) are well established in the general population. If or how chronic kidney disease (CKD) might modify these risks is unknown. In this large cohort of 3,010 patients with CKD, women had a lower risk than men of atheromatous CVDs such as coronary artery disease or stroke when they were at an early stage of CKD. This advantage, partly due to women's better cardiovascular risk profile, tended to attenuate as CKD progressed to kidney failure. In contrast, the risk of nonatheromatous CVDs such as heart failure for women with CKD appeared similar to that of men with CKD at all kidney function levels.

Predictors of daytime blood pressure, nighttime blood pressure, and nocturnal dipping in patients with chronic kidney disease

Increasing attention has recently been paid to discrepancies between office and ambulatory blood pressure (BP) control in patients with chronic kidney disease (CKD), but information on mechanisms underlying circadian BP variations in CKD remains scarce. We described circadian BP patterns and their predictors in patients with CKD stages 1 to 5 referred for kidney function testing in a French tertiary hospital: 1122 ambulatory BP measurements from 635 participants. Factors associated with daytime and nighttime systolic BP (SBP) as well as with nocturnal SBP dipping (ratio of average nighttime to daytime SBP) were analyzed with linear mixed regression models. Participants (mean age 55 ± 16 years; 36% female, mean GFR 51 ± 22 mL/min/1.73m2) had a mean daytime and nighttime SBP of 130 ± 17 and 118 ± 18 mm Hg, respectively. The prevalence of impaired dipping (nighttime over daytime SBP ratio ≥ 0.9) increased from 32% in CKD stage 1 to 68% in CKD stages 4-5. After multivariable adjustment, measured GFR, diabetes, and sub-Saharan African origin were more strongly associated with nighttime than with daytime SBP, which led to significant associations with altered nocturnal BP dipping. For a 1 SD decrease in measured GFR, nighttime BP was 2.87 mmHg (95%CI, 1.44-4.30) higher and nocturnal SBP dipping ratio was 1.55% higher (95%CI, 0.85-2.26%). In conclusion, the prevalence of impaired nocturnal BP dipping increases substantially across the spectrum of CKD. Along with sub-Saharan African origin and diabetes, lower measured GFR was a robust and specific predictor of higher nighttime BP and blunted nocturnal BP decline.

Prevalence and factors associated with masked hypertension in chronic kidney disease

OBJECTIVES

Optimal blood pressure (BP) control is key to prevent cardiovascular complications in patients with chronic kidney disease (CKD). We described the prevalence and factors associated with masked hypertension in CKD.

METHODS

We analyzed 1113 ambulatory 24-h BP monitoring (ABPM) records of 632 patients referred for kidney function evaluation. Masked hypertension was defined as office BP less than 140/90 mmHg but daytime BP at least 135/85 mmHg or nighttime BP at least 120/70 mmHg. Factors associated with masked hypertension were assessed with mixed logistic regression models.

RESULTS

At inclusion, 424 patients (67%) had controlled office BP, of whom 56% had masked hypertension. In multivariable analysis conducted in all visits with controlled office BP ( n  = 782), masked hypertension was positively associated with male sex [adjusted OR (95% confidence interval) 1.91 (1.16-3.27)], sub-Saharan African origin [2.51 (1.32-4.63)], BMI [1.11 (1.01-1.17) per 1 kg/m 2 ], and albuminuria [1.29 [1.12 - 1.47] per 1 log unit), and was negatively associated with plasma potassium (0.42 [0.29 - 0.71] per 1 mmol/L) and 24-h urinary potassium excretion (0.91 [0.82 - 0.99] per 10 mmol/24 h) as well as the use of renin-angiotensin-aldosterone (RAAS) blockers (0.56 [0.31 - 0.97]) and diuretics (0.41 [0.27 - 0.72]).

CONCLUSION

Our findings support the routine use of ABPM in CKD, as more than half of the patients with controlled office BP had masked hypertension. Weight control, higher potassium intake (with caution in advanced CKD), correction of hypokalemia, and larger use of diuretics and RAAS blockers could be potential levers for better out-of-office BP control.

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

RATIONALE & OBJECTIVE

Both hypervolemia and hypovolemia are associated with chronic kidney disease (CKD) progression. Although longitudinal monitoring of B-type natriuretic peptide (BNP) may aid physicians' decision making about the optimization of volume status, its clinical benefit remains uncertain in CKD. This study assessed the association between BNP monitoring and the risk of incident kidney replacement therapy (KRT).

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A total of 2,998 outpatients with stages 3-5 of nondialyzed CKD referred to the department of nephrology at an academic hospital.

EXPOSURE

BNP monitoring.

OUTCOME

KRT, acute kidney injury (AKI), and heart failure hospitalization.

ANALYTICAL APPROACH

Marginal structural models, which create a balanced pseudo population at each time point, were applied to account for potential time-dependent confounders. Inverse probability weighted pooled logistic regression models were employed to estimate hazard ratios.

RESULTS

At baseline, the median age and estimated glomerular filtration rate were 66 years and 38.1mL/min/1.73m2, respectively. During the follow-up period (median, 5.9 [IQR, 2.8-9.9] years), 449 patients required KRT, 765 had AKI, and 236 were hospitalized for heart failure. After adjustment for time-updated clinical characteristics and physician-specific practice styles, BNP monitoring was associated with lower risks of KRT (HR, 0.44 [95% CI, 0.21-0.92]), AKI (HR, 0.36 [95% CI, 0.18-0.72]), and heart failure hospitalization (HR, 0.37 [95% CI, 0.14-0.95]). The association between BNP monitoring and KRT was attenuated after additional adjustment for AKI or heart failure hospitalization as a time-varying covariate.

LIMITATIONS

Residual confounding by measured and unmeasured variables or indications for BNP measurements.

CONCLUSIONS

BNP monitoring was associated with a lower risk of KRT among patients with CKD that did not require dialysis. This association is potentially mediated through a reduced risk of AKI or heart failure hospitalization.

PLAIN-LANGUAGE SUMMARY

Both volume overload and volume depletion are deleterious to kidney function. B-type natriuretic peptide (BNP) is a biomarker that reflects volume status not only in heart failure but also in nondialysis chronic kidney disease (CKD). Although longitudinal BNP monitoring may aid physicians' decision making about the optimization of volume status, its clinical benefit remains uncertain in CKD. In this cohort study analyzing 2,998 patients with nondialyzed CKD, BNP monitoring was associated with a lower risk of kidney replacement therapy, acute kidney injury, and heart failure hospitalization over the follow-up period. The association with kidney replacement therapy may be mediated through a reduced risk of acute kidney injury or heart failure hospitalization. BNP monitoring may aid physicians in optimal fluid management, potentially conferring better kidney outcomes.

A nationwide cohort study comparing the effectiveness of diuretics and calcium channel blockers on top of renin-angiotensin system inhibitors on chronic kidney disease progression and mortality

It is unknown whether initiating diuretics on top of renin-angiotensin system inhibitors (RASi) is superior to alternative antihypertensive agents such as calcium channel blockers (CCBs) in patients with chronic kidney disease (CKD). For this purpose, we emulated a target trial in the Swedish Renal Registry 2007-2022 that included nephrologist-referred patients with moderate-advanced CKD and treated with RASi, who initiated diuretics or CCB. Using propensity score-weighted cause-specific Cox regression, we compared risks of major adverse kidney events (MAKE; composite of kidney replacement therapy [KRT], experiencing over a 40% eGFR decline from baseline, or an eGFR under 15 ml/min per 1.73m2), major cardiovascular events (MACE; composite of cardiovascular death, myocardial infarction or stroke), and all-cause mortality. We identified 5875 patients (median age 71 years, 64% men, median eGFR 26 ml/min per 1.73m2), of whom 3165 started a diuretic and 2710 a CCB. After a median follow-up of 6.3 years, 2558 MAKE, 1178 MACE and 2299 deaths occurred. Compared to CCB, diuretic use was associated with a lower risk of MAKE (weighted hazard ratio 0.87 [95% confidence interval: 0.77-0.97]), consistent across single components (KRT: 0.77 [0.66-0.88], over 40% eGFR decline: 0.80 [0.71-0.91] and eGFR under 15ml/min/1.73m2: 0.84 [0.74-0.96]). The risks of MACE (1.14 [0.96-1.36]) and all-cause mortality (1.07 [0.94-1.23]) did not differ between therapies. Results were consistent when modeling the total time drug exposure, across sub-groups and a broad range of sensitivity analyses. Thus, our observational study suggests that in patients with advanced CKD, using a diuretic rather than a CCB on top of RASi may improve kidney outcomes without compromising cardioprotection.

Combining robust urine biomarkers to assess chronic kidney disease progression

BACKGROUND

Urinary biomarkers may improve the prediction of chronic kidney disease (CKD) progression. Yet, data reporting the applicability of most commercial biomarker assays to the detection of their target analyte in urine together with an evaluation of their predictive performance are scarce.

METHODS

30 commercial assays (ELISA) were tested for their ability to quantify the target analyte in urine using strict (FDA-approved) validation criteria. In an exploratory analysis, LASSO (Least Absolute Shrinkage and Selection Operator) logistic regression analysis was used to identify potentially complementary biomarkers predicting fast CKD progression, determined as the ⁵¹CrEDTA clearance-based measured glomerular filtration rate (mGFR) decline (>10% per year) in a subsample of 229 CKD patients (mean age, 61 years; 66% men; baseline mGFR, 38 mL/min) from the NephroTest prospective cohort.

FINDINGS

Among the 30 assays, directed against 24 candidate biomarkers, encompassing different pathophysiological mechanisms of CKD progression, 16 assays fulfilled the FDA-approved criteria. LASSO logistic regressions identified a combination of five biomarkers including CCL2, EGF, KIM1, NGAL, and TGF-α that improved the prediction of fast mGFR decline compared to the kidney failure risk equation variables alone: age, gender, mGFR, and albuminuria. Mean area under the curves (AUC) estimated from 100 re-samples was higher in the model with than without these biomarkers, 0.722 (95% confidence interval 0.652-0.795) vs. 0.682 (0.614-0.748), respectively. Fully-adjusted odds-ratios (95% confidence interval) for fast progression were 1.87 (1.22, 2.98), 1.86 (1.23, 2.89), 0.43 (0.25, 0.70), 1.10 (0.71, 1.83), 0.55 (0.33, 0.89), and 2.99 (1.89, 5.01) for albumin, CCL2, EGF, KIM1, NGAL, and TGF-α, respectively.

INTERPRETATION

This study provides a rigorous validation of multiple assays for relevant urinary biomarkers of CKD progression which combination may improve the prediction of CKD progression.

FUNDING

This work was supported by Institut National de la Santé et de la Recherche Médicale, Université de Paris, Assistance Publique Hôpitaux de Paris, Agence Nationale de la Recherche, MSDAVENIR, Pharma Research and Early Development Roche Laboratories (Basel, Switzerland), and Institut Roche de Recherche et Médecine Translationnelle (Paris, France).

A profile of SGLT-2 inhibitors in hyponatremia: The evidence to date

Hyponatremia is the most common electrolyte disorder in clinical practice, which may lead to life-threatening complications. Several lines of evidence suggest that hyponatremia is associated not only with significant increases in length of stay, cost, and financial burden, but also with increased morbidity and mortality. Hyponatremia is also considered to be a negative prognostic factor in patients with heart failure and cancer. Although multiple therapeutic methods are available for treating hyponatremia, most have some limitations, such as poor compliance, rapid correction of serum Na⁺, other negative side effects and high cost. Given these limitations, identifying novel therapies for hyponatremia is essential. Recent clinical studies have shown that SGLT-2 inhibitors (SGLT 2i) significantly increased serum Na⁺ levels and were well tolerated by patients who underwent this treatment. Therefore, oral administration of SGLT 2i appears to be an effective treatment for hyponatremia. This article will briefly review the etiology of hyponatremia and integrated control of sodium within the kidney, current therapies for hyponatremia, potential mechanisms and efficacy of SGLT 2i for hyponatremia, and the benefits in cardiovascular, cancer, and kidney disease by regulating sodium and water balance.

Twenty-four-hour Urinary Salt Excretion on Admission Predicts Significant Weight Loss with Seven-day Dietary Salt Restriction in Hospitalized Patients with Chronic Kidney Disease: A Single-center Study

In patients with chronic kidney disease (CKD), restricting dietary salt is recommended to prevent fluid retention. Rapid weight loss is often observed when CKD patients with a high salt intake are hospitalized and started on a low-salt diet. We investigated the effects of 7-day dietary salt restriction on weight loss in hospitalized patients with CKD. During the 7-day hospitalization, a low-salt (6 g/day) and low-protein (0.6-0.8 g/kg/day ideal body weight) diet was served to all patients. Urine samples were collected for the first 24 h after admission, and patients were divided into quartiles (Q1-Q4) by urinary salt excretion. Body weight was measured on days 1 and 7. Weight loss after admission was compared among the groups. Factors associated with weight loss were evaluated by multivariate logistic regression. The mean age of the patients was 70.3 ± 11.7 years, and 73% were male. Mean weight loss was 1.6 ± 1.7 kg on day 7. Weight loss was significantly greater in Q3 and Q4 than in Q1 (P = 0.009 and P <0.001, respectively). In the univariate analysis, weight loss correlated positively with 24-h urinary salt excretion on admission (γ2 = 0.146) and body mass index (γ2 = 0.223). The 24-h urinary salt excretion on admission and BMI were independently associated with weight loss of >2 kg. The adjusted odds ratios (95% confidence interval) were 1.24 (1.13-1.36) and 1.15 (1.07-1.22), respectively. Twenty-four-hour urinary salt excretion on admission is useful for predicting significant weight loss with short-term dietary salt restriction.

The predictive value of bioimpedance-derived fluid parameters for cardiovascular events in patients undergoing hemodialysis

Background

It is becoming increasingly evident that the accurate assessment of fluid status is critical to ensure optimal care in patients undergoing hemodialysis (HD). Various fluid parameters, including overhydration (OH) and overhydration/extracellular water (OH/ECW%), which can be obtained using a bioimpedance spectroscopy device have been used to indicate the hydration status in such patients. This study aimed to explore the effect of these fluid parameters on cardiovascular events and determine which parameter was a better predictor of cardiovascular events (CVEs).

Methods

A total of 227 patients who underwent HD at the Hangzhou Hospital of Traditional Chinese Medicine were enrolled in this prospective study between December 2017 and August 2018. Clinical data were collected, and the fluid status of patients was assessed using a body composition monitor. The patients were followed up until December 2020. The primary outcomes were CVEs. The association between fluid parameters and CVEs was analyzed using Cox proportional hazards models. The areas under the curve (AUCs) of receiver operating characteristic analysis and improvement in the global chi-squared value were used to compare the predictive values of fluid parameters for CVEs.

Results

During a median follow-up of 31 months, 66 CVEs were recorded. The patients with a higher absolute hydration index (OH) and a relative hydration index (OH/ECW%) exhibited an increased risk of developing CVEs. After adjusting for confounding factors, both OH [hazard ratio (HR) 1.279 per L, 95% confidence interval (CI) 1.047–1.562; p = 0.016] and OH/ECW% (HR 1.061 per %, 95% CI 1.017–1.108; p = 0.006) were independently associated with CVEs. The predictive ability of the absolute hydration index was superior to the relative hydration index based on AUC calculations for CVEs. Furthermore, a greater change in χ² in predicting CVEs was noted for the absolute hydration index.

Conclusions

Both absolute hydration index and relative hydration index were found to be independent predictors of CVEs in univariate and multivariate analyses. Furthermore, the absolute hydration index had a better additive predictive value than the relative hydration index in predicting CVEs.

Considerations and possibilities for sodium-glucose cotransporter 2 inhibitors in pediatric CKD

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) were originally developed as glucose-lowering agents. These medications function by inhibiting glucose and sodium reabsorption in the S1 segment of the proximal tubule. Early clinical trials in adults with type 2 diabetes mellitus (T2DM) suggested a significant improvement in kidney and cardiovascular outcomes with SGLT2i therapy. Since then, SGLT2is have become a mainstay treatment for adult patients with CKD. A growing body of research has explored deploying these medications in new clinical contexts and investigated the mechanisms underlying their physiologic effects. However, patients under the age of 18 years have been largely excluded from all major trials of SGLT2i. This review aims to summarize the available clinical evidence, physiology, and mechanisms relating to SGLT2is to inform discussions about their implementation in pediatrics.

Revisiting diuretic choice in chronic kidney disease

PURPOSE OF REVIEW

Existing guidelines offer little direction about the use of thiazide and loop diuretics in patients with chronic kidney disease (CKD). This review summarizes recent studies impacting indications and safety considerations for these agents in patients with CKD.

RECENT FINDINGS

Chlorthalidone reduces blood pressure compared to placebo in patients with advanced CKD, challenging the belief that thiazide diuretics lose efficacy at lower glomerular filtration rates (GFR). Existing studies show no clear impact of thiazide or loop diuretic use on kidney or cardiovascular outcomes in patients with CKD. Sodium-glucose co-transporter type 2 (SGLT2) inhibitors have diuretic effects, but concomitant use of a diuretic does not diminish the preventive benefits of these agents against acute kidney injury (AKI). Despite theoretical concerns, thiazide diuretics likely do not worsen circulating vasopressin levels or cyst progression in polycystic kidney disease and may be useful for alleviating polyuria from tolvaptan. Diuretics cause multiple adverse effects, including electrolyte abnormalities, hemodynamic-mediated decrease in estimated GFR, and AKI.

SUMMARY

Recent evidence supports expanded indications for diuretics in patients with kidney disease, including chlorthalidone for hypertension in advanced CKD. Monitoring electrolytes and estimated GFR is critical to ensure patient safety when prescribing these agents for patients with CKD.

Natriuretic peptides, extracellular volume, and subclinical cardiovascular changes in chronic kidney disease stages 1-3: a pilot study

Natriuretic peptide levels are elevated in persons with chronic kidney disease (CKD) stages 1-3, but it remains unclear whether this is associated with extracellular volume excess or early cardiovascular changes. We hypothesized that patients with CKD stages 1-3 would have evidence of cardiovascular changes, which would associate with brain natriuretic peptide (BNP), amino-terminal-pro-BNP (NT-pro-BNP), and patient-reported symptoms.Outpatients with CKD stages 1-3 and non-CKD controls were enrolled. Cardiovascular parameters included extracellular water (ECW) normalized to body weight measured using whole-body multifrequency bioimpedance spectroscopy, and total peripheral resistance index (TPRI) and cardiac index measured by impedance cardiography. Dyspnea, fatigue, depression, and quality of life were quantified using questionnaires.Among 21 participants (13 with CKD), median (IQR) BNP was 47.0 (28.0-302.5) vs 19.0 (12.3-92.3) pg/mL, p=0.07, and NT-pro-BNP was 245.0 (52.0-976.8) vs 26.0 (14.5-225.8) pg/mL, p=0.08, in the CKD and control groups, respectively. Those with CKD had higher pulse pressure (79 (66-87) vs 64 (49-67) mm Hg, p=0.046) and TPRI (3721 (3283-4278) vs 2933 (2745-3198) dyn×s/cm5/m2, p=0.01) and lower cardiac index (2.28 (2.08-2.78) vs 3.08 (2.43-3.37) L/min/m2, p=0.02). In the overall cohort, natriuretic peptides correlated with pulse pressure (BNP r=0.59; NT-pro-BNP r=0.58), cardiac index (BNP r=-0.76; NT-pro-BNP r=-0.62), and TPRI (BNP r=0.48), p<0.05 for each, but not with ECW/weight. TPRI and blood pressure correlated moderately with symptoms.Elevated natriuretic peptides may coincide with low cardiac index and elevated peripheral resistance in patients with CKD stages 1-3. The role of these biomarkers to detect subclinical cardiovascular changes needs to be further explored.

Estimating extracellular fluid volume in healthy individuals: evaluation of existing formulae and development of a new equation

Introduction

Several clinical settings require an accurate estimation of the physiologically expected extracellular fluid volume (ECFV). We aimed to analyze the performances of existing ECFV-estimating equations and to develop a new equation.

Methods

The performances of 11 ECFV-estimating equations were analyzed in 228 healthy kidney donor candidates (Bichat Hospital, Paris, France) who underwent ECFV measurement using the distribution volume of ⁵¹Cr-labeled EDTA (⁵¹Cr-EDTA). An equation was developed using a penalized linear modeling approach (elastic net regression) and externally (Tenon Hospital, Paris, France, N = 142) validated.

Results

Participants from Bichat (mean age 45.2 ± 12.0 years, 43.0% men) and Tenon (47.8 ± 10.3 years, 29.6% men) hospitals had a mean measured ECFV of 15.4 ± 2.8 l and 15.1 ± 2.1 l, respectively. Available ECFV-estimating formulae have highly variable precision and accuracy. The new equation incorporating body weight, height, sex, and age had better precision and accuracy than all other equations in the external validation cohort, with a median bias of −0.20 (95% CI: −0.35 to −0.05) l versus −2.63 (−2.87 to −2.42) l to −0.57 (− 0.83 to −0.40) l and 0.21 (0.12 to 0.43) l to 2.89 (2.65 to 3.11) l, for underestimating and overestimating equations, respectively, an interquartile range for the bias of 0.88 (0.70 to 1.08) l versus 0.91 (0.71 to 1.20) l to 1.93 (1.67 to 2.25) l, and an accuracy within 10% of 90.9% (83.8 to 94.4) versus 88.0% (81.0 to 92.3) to 8.5% (4.2 to 13.4). These results were consistent across subgroups defined by sex, body mass index (BMI), body surface area (BSA), age, and ethnicity.

Conclusion

We developed and validated a new equation to estimate the individual reference value of ECFV, which is easily usable in clinical practice. Further validation in cohorts including individuals of extreme age and corpulence remains needed.

Role of hypertension in kidney transplant recipients

Cardiovascular events are one of the leading causes of mortality in kidney transplant recipients. Hypertension is the most common comorbidity accompanying chronic kidney disease, with prevalence remaining as high as 90% even after kidney transplantation. It is often poorly controlled. Abnormal blood pressure profiles, such as masked or white-coat hypertension, are also extremely common in these patients. The pathophysiology of blood pressure elevation in kidney transplant recipients is complex and includes transplantation-specific risk factors, which are added to the traditional or chronic kidney disease-related factors. Despite these observations, hypertension management has been an under-researched area in kidney transplantation. Thus, relevant evidence derives either from studies in the general population or from small trials in kidney transplant recipients. Based on the relevant guidelines in the general population, lifestyle modifications should probably be applied as the first step of hypertension management in kidney transplant recipients. The optimal pharmacological management of hypertension in kidney transplant recipients is also not clear. Dihydropyridine calcium channel blockers are commonly used as first line agents because of their lack of adverse effects on the kidney, while other antihypertensive drug classes are under-utilised due to fear of the possible haemodynamic consequences on renal function. This review summarizes the existing data on the pathophysiology, diagnosis, prognostic significance and management of hypertension in kidney transplantation.

Effects of enhanced versus reduced vasodilating treatment on brachial and central blood pressure in patients with chronic kidney disease: a randomized controlled trial

BACKGROUND

Blood pressure (BP) control is important in chronic kidney disease (CKD), but a reduction in brachial BP may not mirror changes in central aortic BP (cBP) during antihypertensive medication. We hypothesize that a fall in cBP is better reflected during enhanced vasodilation treatment (EVT) compared with reduced vasodilation treatment (RVT) because of different hemodynamic actions of these interventions.

METHODS

Eighty-one hypertensive CKD stage 3-4 patients (mean measured glomerular filtration rate 36 ml/min per 1.73 m2) were randomized to either EVT based on renin--angiotensin blockade and/or amlodipine or RVT based on nonvasodilating β-blockade (metoprolol). Before randomization and following 18 months of treatment, we performed 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis for estimation of cBP and augmentation index (AIx). Forearm resistance (Rrest) was determined by venous occlusion plethysmography and arterial stiffness by carotid--femoral pulse wave velocity (PWV). Matched healthy controls were studied once for comparison.

RESULTS

Compared with controls, CKD patients had elevated ABPM, cBP and PWV. Although ABPM remained unchanged from baseline to follow-up in both treatment groups, cBP decreased 4.7/2.9 mmHg (systolic/diastolic) during EVT and increased 5.1/1.5 mmHg during RVT (Δ=9.8/4.4 mmHg, P=0.02 for SBP, P = 0.05 for DBP). At follow-up, the difference between systolic cBP and 24-h ABPM (ΔBPsyst) was negatively associated with heart rate and positively associated with AIx and Rrest (all P < 0.01) but not PWV (P = 0.32).

CONCLUSION

In CKD patients, EVT and RVT have opposite effects on cBP and the difference between cBP and ambulatory BP is larger for EVT than RVT.

B-type natriuretic peptide levels and volume status in twice-weekly hemodialysis patients

Background

Twice-weekly hemodialysis (HD) could be regarded as an important part of incremental hemodialysis, volume status of this treatment model remains to be elucidated.

Methods

Patients undergoing regular twice-weekly or thrice-weekly hemodialysis in our unit on June 2015 were enrolled into the cohort study with an average of 2.02 years follow-up. Volume status of the subjects was evaluated by clinical characteristics, plasma B-type natriuretic peptide (BNP) levels and bioimpedance assessments with body composition monitor (BCM). Cox proportional hazards models and Kaplan–Meier analysis were used to compare patient survival between the two groups.

Results

Compared with patients on thrice-weekly HD, twice-weekly HD patients had significantly higher log-transformed BNP levels (2.54 ± 0.41 vs. 2.33 ± 0.49 pg/ml, p = 0.010). Overhydration (OH) and the ratio of overhydration to extracellular water (OH/ECW) in twice-weekly HD group were significantly higher than that of thrice-weekly HD (OH, 2.54 ± 1.42 vs. 1.88 ± 1.46, p = 0.033; OH/ECW, 0.17 ± 0.07 vs. 0.12 ± 0.08, p = 0.015). However, subgroup analysis of patients within 6 years HD vintage indicated that the two groups had similar hydration status. Multivariate Cox regression analysis showed that log-transformed BNP levels, serum albumin and diabetes status were predictors of mortality in hemodialysis patients. Kaplan–Meier survival analysis indicated that patients with BNP levels higher than 500 pg/ml had significantly worse survival compared with those with lower BNP levels (p = 0.014).

Conclusions

Twice-weekly hemodialysis patients had worse volume status than that of thrice-weekly HD patients especially for those with long-term dialysis vintage, BNP level was a powerful predictor of mortality in HD patients.

Higher extracellular water to total body water ratio was associated with chronic kidney disease progression in type 2 diabetes

AIM

We studied the association between extracellular volume status and chronic kidney disease (CKD) progression; and the role of extracellular volume excess as a potential mediator in the relationship between matrix metalloproteinases (MMP)-2 and CKD progression in Type 2 diabetes mellitus (T2DM).

METHODS

We conducted a prospective cohort study of 1079 T2DM patients. Bioelectrical impedance analysis (BIA) was performed to assess body fluid status.

RESULTS

After up to 8.6 years of follow-up, 471 (43.7%) patients experienced CKD progression. In the fully adjusted model, extracellular water (ECW)/ total body water (TBW)ratios 0.39-0.40 and > 0.40 were associated with 45% and 78% higher risk of CKD progression respectively. Patients with an increase in ECW/TBW ratio had 40% higher risk of CKD progression compared to those with no change or reduction of ECW/TBW ratio. Higher ECW/TBW ratio accounted for 17.4% of the relationship between MMP-2 and CKD progression in T2DM (p = 0.026).

CONCLUSIONS

Extracellular volume excess was independently associated with CKD progression in T2DM. Higher ECW/TBW ratio mediated the positive association between MMP-2 and CKD progression. Further studies are needed to elucidate the role of extracellular volume excess in deterioration of renal function.

Impact of extracellular-to-intracellular fluid volume ratio on albuminuria in patients with type 2 diabetes: A cross-sectional and longitudinal cohort study

AIMS/INTRODUCTION

Body fluid volume imbalance is common in patients with kidney failure, and is associated with all-cause mortality. This study aimed to investigate the association between fluid volume imbalance and albuminuria in patients with type 2 diabetes mellitus without kidney failure.

MATERIALS AND METHODS

Using data from one cohort study, a baseline cross-sectional study of 432 participants and a longitudinal cohort study of 368 participants who could follow up was carried out. Body fluid imbalance was determined by measuring the extracellular water (ECW)-to-intracellular water (ICW) ratio (ECW/ICW) using bioelectrical impedance analysis. A change in the urinary albumin-to-creatinine ratio (ACR) was defined as the ratio of urinary ACR at follow up to that at baseline. The ECW/ICW ratio was compared with the level of albuminuria.

RESULTS

In this cross-sectional study, the ECW/ICW ratio increased with the level of albuminuria. There was an association between the ECW/ICW ratio and logarithms of urinary ACR after adjusting for covariates (β = 0.205, P < 0.001). Furthermore, the ECW/ICW ratio was associated with a change in the urinary ACR after adjusting for covariates (β = 0.176, P = 0.004) in this longitudinal study. According to the receiver operating characteristic curve, the optimal cut-off point of the ECW/ICW ratio for incident macroalbuminuria, defined as ACR >300 mg/gCr, was 0.648 (area under the curve 0.78, 95% confidence interval 0.58-0.90).

CONCLUSIONS

The ECW/ICW ratio is independently associated with the level of albuminuria in patients with type 2 diabetes mellitus without kidney failure. This reinforces the importance of monitoring fluid balance in patients with type 2 diabetes mellitus.

Rapid Weight Change Over Time Is a Risk Factor for Adverse Outcomes in Patients With Predialysis Chronic Kidney Disease: A Prospective Cohort Study

OBJECTIVE

Both obesity and being underweight are risk factors for adverse outcomes in chronic kidney disease (CKD) patients. However, the effects of longitudinal weight changes on patients with predialysis CKD have not yet been studied. In this study, we analyzed the effects of weight change over time on the adverse outcomes in predialysis CKD population.

METHODS

Longitudinal data from a multicenter prospective cohort study (KNOW-CKD) were analyzed. In a total of 2,022 patients, the percent weight change per year were calculated using regression analysis and the study subjects were classified into five categories: group 1, ≤ -5%/year; group 2, -5< to ≤ -2.5%/year; group 3, -2.5< to <2.5%/year; group 4, 2.5≤ < 5%/year; and group 5, ≥5%/year. The incidences of end-stage renal disease (ESRD) and the composite outcome of cardiovascular disease (CVD) and death were calculated in each group and compared to group 3 as reference.

RESULTS

During a median 4.4 years of follow-up, 414 ESRD, and 188 composite of CVD and mortality events occurred. Both weight gain and loss were independent risk factors for adverse outcomes. There was a U-shaped correlation between the degree of longitudinal weight change and ESRD (hazard ratio 3.61, 2.15, 1.86 and 3.66, for group 1, 2, 4 and 5, respectively) and composite of CVD and death (hazard ratio 2.92, 2.15, 1.73 and 2.54, respectively), when compared to the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m².

CONCLUSION

Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in the advanced CKD.

Trajectory of extracellular fluid volume over time and subsequent risks of end-stage kidney disease and mortality in chronic kidney disease: a prospective cohort study

BACKGROUND

Extracellular fluid volume (ECF) is independently associated with chronic kidney disease (CKD) progression and mortality in patients with CKD, but the prognostic value of the trajectory of ECF over time beyond that of baseline value is unknown.

OBJECTIVES

To characterize ECF trajectory and evaluate its association with the risks of end-stage kidney disease (ESKD) and mortality.

METHODS

From the prospective tricentric NephroTest cohort, we included 1588 patients with baseline measured glomerular filtration rate (mGFR) ≥15 mL min^-1 /1.73 m² and ECF measurement. ECF and GFR were measured repeatedly using the distribution volume and clearance of ⁵¹ Cr-EDTA, respectively. ESKD and mortality were traced through record linkage with the national registries. Adjusted shared random-effect joint models were used to analyse the association between the trajectory of ECF over time and the two competing outcomes.

RESULTS

Patients were mean age 58.7 years, 66.7% men, mean mGFR of 43.6 ± 18.6 mL min^-1 /1.73 m² and mean ECF of 16.1 ± 3.6 L. Over a median follow-up of 5.3 [IQR: 3.0;7.4] years, ECF increased by 136 [95%CI 106;167] mL per year on average, whilst diuretic prescription and 24-hour urinary sodium excretion remained stable. ESKD occurred in 324 (20.4%) patients, and 185 (11.6%) patients died before ESKD. A higher current value of ECF was associated with increased hazards of ESKD (adjusted hazard ratio [aHR]: 1.12 [95%CI 1.06;1.18]; P < 0.001 per 1 L increase in ECF), and death before ESKD (aHR: 1.10 [95%CI 1.04;1.17]; P = 0.002).

CONCLUSIONS

The current value of ECF was associated with the risks of ESKD and mortality, independent of multiple potential confounders, including kidney function decline. This highlights the need for a close monitoring and adjustment of treatment to avoid fluid overload in CKD patients.

Overhydration Measured by Bioimpedance Spectroscopy and Urinary Serine Protease Activity Are Risk Factors for Progression of Chronic Kidney Disease

BACKGROUND

Overhydration (OH) is common in chronic kidney disease (CKD) and might be related to the excretion of urinary serine proteases. Progression of CKD is associated with proteinuria; however, the interrelations of urinary serine proteases, OH, and progression of CKD remain unclear.

METHODS

In n = 179 patients with stable nondialysis-dependent CKD of all stages, OH was measured using bioimpedance spectroscopy (Body Composition Monitor; Fresenius), and urinary serine protease activity was determined using the peptide substrate S-2302. After a median follow-up of 5.9 (IQR: 3.9-6.5) years, progression to end-stage renal disease (ESRD) was analyzed retrospectively.

RESULTS

OH correlated with baseline MDRD-eGFR, urinary albumin creatinine ratio (ACR), and urinary aprotinin-sensitive serine protease activity. Progression to ESRD occurred in n = 33 patients (19%) and correlated with OH and urinary serine protease activity as well as MDRD-eGFR and ACR. Patients were divided into 2 groups determined by cutoff values from receiver operating characteristics for MDRD-eGFR (32 mL/min/1.73 m2), ACR (43 mg/g creatinine), urinary serine protease activity (0.9 RU/g creatinine), and OH (1 L/1.73 m2). Across these cutoff values, Kaplan-Meier curves for renal survival showed significant separations of the groups. In Cox regression adjusted for MDRD-eGFR, ACR, P-NT-pro-BNP, systolic blood pressure, and diabetes mellitus, patients with OH >1 L/1.73 m2 had a 3.32 (95% CI: 1.26-8.76)-fold higher risk for progression to ESRD.

CONCLUSIONS

Our results corroborate that OH detected by bioimpedance spectroscopy in CKD patients is an independent risk factor for progression to ESRD in addition to GFR and albuminuria. Urinary serine protease activity is associated with OH and progression of CKD and provides a possible underlying mechanism.

Relative overhydration is independently associated with left ventricular hypertrophy in dialysis naïve patients with stage 5 chronic kidney disease

Patients with chronic kidney disease (CKD) have a high prevalence of left ventricular hypertrophy (LVH), which increases as kidney function decreases. LVH pathophysiology is complex, making it difficult to generalise its evolution in CKD. Therefore, early detection and prevention of risk factors are critical. Assessment and management of volume status can minimise cardiovascular complications including LVH. We retrospectively investigated the associations between fluid overload and LVH in patients with stage 5 CKD not undergoing dialysis in prospective cohort of 205 patients (age: 59.34 ± 13.51 years; women: 43.4%). All patients, free of intrinsic heart disease, were assessed for relative overhydration/extracellular water (OH/ECW) by bioimpedance spectroscopy. Our results show that markers reflecting fluid balance were significantly higher in the LVH group and as OH/ECW increased, the left ventricular mass index (LVMI) trended higher. Furthermore, our results show that systolic blood pressure, serum phosphorus levels, and OH/ECW were independently associated with LVMI and that OH/ECW was independently associated with LVH. Structural and functional evaluation of the heart using echocardiography and volume status assessment using bioimpedance should be performed simultaneously in patients with early-stage CKD, even in those without evident cardiovascular disease.

24-h Urine Collection: A Relevant Tool in CKD Nutrition Evaluation

Dietary management is a cornerstone of Chronic Kidney Disease (CKD) monitoring, and dietary surveys often difficult to perform. We studied in a CKD patient cohort with two years follow-up, whether validated 24-h urine ionogram would be a relevant tool for diet evaluation and compliance. We included 404 non-dialysis CKD patients, with three evaluations, including repeated measurements of fractional renal creatinine clearance and 24-h urine collection. Completeness of the 24-h urine collection, assessed by daily urine creatinine excretion extrapolated from fractional creatinine clearance, was 64.6%, 75.5%, and 78.2% at the first, second, and third visits, respectively. One hundred sixty-eight patients (41.6%) had three complete collections, with a measured glomerular filtration of 42.3 mL/min/1.73 m² at baseline and prevalence of anemia and secondary hyperparathyroidism of 13.9% and 26.2%, respectively, increasing during follow-up to 15% and 31.5% (p < 0.001 and p < 0.001). The urine analysis showed at baseline a urine volume of above 2 L/day, and estimated sodium and protein intake within targets in 51.6% and 40.3% of cases, which improved during follow-up only for protein (to 45.9%, p < 0.0001). Our data suggest that a 24-h urine ionogram is an interesting, reliable tool in CKD patients for dietary monitoring to achieve target recommendation noteworthy salt and protein intake.

Area Deprivation and Risk of Death and CKD Progression: Long-Term Cohort Study in Patients under Unrestricted Nephrology Care

BACKGROUND

Area deprivation index (ADI) associates with prognosis in non-dialysis CKD. However, no study has evaluated this association in CKD patients under unrestricted nephrology care.

METHODS

We performed a long-term prospective study to assess the role of deprivation in CKD progression and mortality in stage 1-4 CKD patients under regular nephrology care, living in Naples (Italy). We used ADI calculated at census block levels, standardized to mean values of whole population in Naples, and linked to patients by georeference method. After 12 months of "goal-oriented" nephrology treatment, we compared the risk of death or composite renal outcomes (end-stage kidney disease or doubling of serum creatinine) in the tertiles of standardized ADI. Estimated glomerular filtration rate (eGFR) decline was evaluated by mixed effects model for repeated eGFR measurements.

RESULTS

We enrolled 715 consecutive patients (age: 64 ± 15 years; 59.1% males; eGFR: 49 ± 22 mL/min/1.73 m2). Most (75.2%) were at the lowest national ADI quintile. At referral, demographic, clinical, and therapeutic features were similar across ADI tertiles; after 12 months, treatment intensification allowed better control of hypertension, proteinuria, hypercholesterolaemia, and anaemia with no difference across ADI tertiles. During the subsequent long-term follow-up (10.5 years [interquartile range 8.2-12.6]), 166 renal events and 249 deaths were registered. ADI independently associated with all-cause death (p for trend = 0.020) and non-cardiovascular (CV) mortality (p for trend = 0.045), while CV mortality did not differ (p for trend = 0.252). Risk of composite renal outcomes was similar across ADI tertiles (p for trend = 0.467). The same held true for eGFR decline (p for trend = 0.675).

CONCLUSIONS

In CKD patients under regular nephrology care, ADI is not associated with CKD progression, while it is associated with all-cause death due to an excess of non-CV mortality.

Lower prevalence of aortic dilatation among preemptive pediatric renal transplant recipients - A cross-sectional cohort study

BACKGROUND

Aortic dilatation is a cardiovascular complication in pediatric renal transplant recipients and may have an increased risk of aortic dissection, aortic rupture, and death. Studies failed to show an association between blood pressure and aortic dilatation; however, 24-hours ambulatory blood pressure monitoring (ABPM) was not performed. There was also no comparison between preemptive transplantation and dialysis.

METHODS

After ethics approval, a retrospective cross-sectional study was performed on all prevalent pediatric renal transplant recipients from a single tertiary care center. The presence of aortic dilatation was determined using standard echocardiographic measurements, and those with other risk factors for aortic dilatation were excluded. Associations between 24-hours ABPM, renal function, dialysis history, and aortic dimensions were determined.

RESULTS

We enrolled 37 participants with the following characteristics: 46% female, mean age 14.5 ± 3.7 years, 16% preemptive transplantation, and median end-stage renal disease (ESRD) combined vintage (time from ESRD onset to echocardiogram) 597 days (range 289-1290 days). We found 16/37 patients (43%) with aortic dilatation at any level, mostly mild. There was no association between 24-hours ABPM measurements and aortic dilatation. None of the preemptively transplanted children had aortic dilatation.

CONCLUSION

This study confirms a high prevalence of aortic dilatation among pediatric renal transplant recipients, which appears to be independent of hypertension on 24-hour ABPM. Patients with preemptive renal transplantation did not have aortic dilatation, suggesting that the effects of dialysis may contribute to the high prevalence of this complication. Pediatric cardiologists need to carefully assess aortic dimensions in these at-risk patients.

Intraoperative Continuous Renal Replacement Therapy During Liver Transplantation: A Meta-Analysis

Continuous renal replacement therapy (CRRT) is frequently used to treat recipients with renal failure before or after liver transplantation (LT), though evidence supporting its use during surgery remains unclear. Therefore, we conducted a quantitative meta-analysis to evaluate the effect of intraoperative continuous renal replacement therapy (IORRT) in recipients with pretransplant severe renal dysfunction. We searched PubMed, Embase, and the Cochrane database for trials focusing on LT recipients supported with or without IORRT. Outcomes assessed were mortality, preoperative characteristics, intraoperative data, and predefined postoperative outcomes. Seven trials with 1051 recipients were eligible. Preoperatively, the IORRT group recipients had higher Model for End-Stage Liver Disease scores (weighted mean difference [WMD], 6.19; 95% confidence interval [CI], 2.51-9.87), Charlson scores (WMD, 0.45; 95% CI, 0.09-0.80), acute liver failure (odds ratio [OR], 1.82; 95% CI, 1.27-2.61), serum creatinine (WMD, 71.33 μmol/L; 95% CI, 1.98-140.69 μmol/L), total bilirubin level (WMD, 5.05 μmol/L; 95% CI, 1.75-8.35 μmol/L), intensive care unit admission (OR, 3.53; 95% CI, 1.23-10.13), vasoactive therapy (OR, 3.80; 95% CI, 2.64-5.46), ventilator care (OR, 2.52; 95% CI, 1.18-5.35), and renal replacement therapy (RRT) (OR, 29.37; 95% CI, 7.66-112.54) compared with control patients. IORRT patients also required more intraoperative blood product transfusion and had more post-LT RRT (OR, 25.67; 95% CI, 4.92-133.85). However, there were no significant differences in short-term mortality (OR, 2.12; 95% CI, 0.82-5.44) between the groups. In addition, worse longterm mortality was seen in the IORRT group. In conclusion, IORRT is feasible and safe and may help sicker recipients tolerate the LT procedure to achieve short-term clinical outcomes comparable with less ill patients without IORRT. More high-quality evidence is needed to verify our conclusion in the future.

Recent advances in the management of secondary hypertension: chronic kidney disease

Hypertension in chronic kidney disease (CKD) is the most commonly observed comorbidity and is a risk factor for end-stage renal disease (ESRD) as well as cardiovascular disease (CVD) and mortality. Therefore, suitable blood pressure (BP) control in CKD patients is very important in preventing both CVD and ESRD. We herein describe the recommendations of target BP and the pharmacological drug options from the evidence-based clinical practice guidelines for CKD in 2018 by the Japanese Society of Nephrology (JSN CKD 2018) and recent advances in the management of hypertension in CKD, including sodium-glucose cotransporter (SGLT) 2 inhibitors, mineralocorticoid receptor blockers, and renal denervation. In particular, SGLT2 inhibitors are a new class of "antihypertensive drugs" that have a homeostatic mechanism that regulates body fluid volume in addition to diuretic action, which may be closely associated with their cardiorenal protective properties.

A Randomized Trial of Distal Diuretics versus Dietary Sodium Restriction for Hypertension in Chronic Kidney Disease

BACKGROUND

Distal diuretics are considered less effective than loop diuretics in CKD. However, data to support this perception are limited.

METHODS

To investigate whether distal diuretics are noninferior to dietary sodium restriction in reducing BP in patients with CKD stage G3 or G4 and hypertension, we conducted a 6-week, randomized, open-label crossover trial comparing amiloride/hydrochlorothiazide (5 mg/50 mg daily) with dietary sodium restriction (60 mmol per day). Antihypertension medication was discontinued for a 2-week period before randomization. We analyzed effects on BP, kidney function, and fluid balance and related this to renal clearance of diuretics.

RESULTS

A total of 26 patients (with a mean eGFR of 39 ml/min per 1.73 m²) completed both treatments. Dietary sodium restriction reduced sodium excretion from 160 to 64 mmol per day. Diuretics produced a greater reduction in 24-hour systolic BP (SBP; from 138 to 124 mm Hg) compared with sodium restriction (from 134 to 129 mm Hg), as well as a significantly greater effect on extracellular water, eGFR, plasma renin, and aldosterone. Both interventions resulted in a similar decrease in body weight and NT-proBNP. Neither approaches decreased albuminuria significantly, whereas diuretics did significantly reduce urinary angiotensinogen and β2-microglobulin excretion. Although lower eGFR and higher plasma indoxyl sulfate correlated with lower diuretic clearance, the diuretic effects on body weight and BP at lower eGFR were maintained. During diuretic treatment, higher PGE2 excretion correlated with lower free water clearance, and four patients developed mild hyponatremia.

CONCLUSIONS

Distal diuretics are noninferior to dietary sodium restriction in reducing BP and extracellular volume in CKD. Diuretic sensitivity in CKD is maintained despite lower diuretic clearance.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

DD-study: Diet or Diuretics for Salt-sensitivity in Chronic Kidney Disease (DD), NCT02875886.

The extracellular volume status predicts body fluid response to SGLT2 inhibitor dapagliflozin in diabetic kidney disease

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an antihyperglycemic drug with diuretic action. We recently reported that the SGLT2 inhibitor dapagliflozin ameliorates extracellular volume expansion with a mild increase in urine volume. However, the impact of the pretreatment extracellular volume status on the body fluid response to SGLT2 inhibitors remains unclear.

METHODS

Thirty-six diabetic kidney disease (DKD) patients were treated with dapagliflozin. The body fluid volume, including intracellular water (ICW), extracellular water (ECW) and total body water (TBW), were measured on baseline and day 7 using a bioimpedance analysis (BIA) device. The ECW/TBW and ECW were used as markers of the extracellular volume status. For a comparison, the extracellular volume status responses to loop diuretic furosemide (n = 16) and vasopressin V2 receptor antagonist tolvaptan (n = 13) were analyzed.

RESULTS

The body weight, brain natriuretic peptide and body fluid parameters measured by a BIA (ICW, ECW, TBW, and ECW/TBW) were significantly decreased for 1 week after dapagliflozin administration. The change in the ECW/TBW in the high-ECW/TBW group (over the median value of 0.413) was significantly higher than in the low-ECW/TBW group (- 2.1 ± 0.4 vs. - 0.5 ± 0.4%, p = 0.006). Only with dapagliflozin treatment (not furosemide or tolvaptan treatment) was the baseline ECW/TBW significantly correlated with the changes in the ECW/TBW (r = - 0.590, p < 0.001) and ECW (r = - 0.374, p = 0.025).

CONCLUSIONS

The pretreatment extracellular volume status predicts the body fluid response to the SGLT2 inhibitor dapagliflozin in DKD patients. The diminished extracellular fluid reduction effect of dapagliflozin in patients without severe extracellular fluid retention may contribute to maintaining a suitable body fluid status.

Chronic Kidney Disease Has a Graded Association with Death and Cardiovascular Outcomes in Stable Coronary Artery Disease: An Analysis of 21,911 Patients from the CLARIFY Registry

: Chronic kidney disease (CKD) is associated with an increased cardiovascular risk in a broad spectrum of populations. However, the risk associated with a reduced estimated glomerular filtration rate (eGFR) in patients with stable coronary artery disease receiving standard care in the modern era, independently of baseline cardiovascular disease, risk factors, and comorbidities, remains unclear. We analyzed data from 21,911 patients with stable coronary artery disease, enrolled in 45 countries between November 2009 and July 2010 in the CLARIFY registry. Patients with abnormal renal function were older, with more comorbidities, and received slightly lower-although overall high-rates of evidence-based secondary prevention therapies than patients with normal renal function. The event rate of patients with CKD stage 3b or more (eGFR <45 mL/min/1.73 m2) was much higher than that associated with any comorbid condition. In a multivariable adjusted Cox proportional hazards model, lower eGFR was independently associated with a graded increased risk of cardiovascular mortality, with adjusted HRs (95% CI) of 0.98 (0.81-1.18), 1.31 (1.05-1.63), 1.77 (1.38-2.27), and 3.12 (2.25-4.33) for eGFR 60-89, 45-59, 30-44, and <30 mL/min/1.73 m2, compared with eGFR ≥90 mL/min/1.73 m2. A strong graded independent relationship exists between the degree of CKD and cardiovascular mortality in this large cohort of patients with chronic coronary artery disease, despite high rates of secondary prevention therapies. Among clinical risk factors and comorbid conditions, CKD stage 3b or more is associated with the highest cardiovascular mortality.