Impact of serum albumin levels on the body fluid response to tolvaptan in chronic kidney disease patients

Association of Body Water Balance, Nutritional Risk, and Sarcopenia with Outcome in Patients with Acute Ischemic Stroke: A Single-Center Prospective Study

In the present study, we examined the inter-relationships between body water balance, nutritional risk, sarcopenia, and outcome after acute ischemic stroke (AIS) in patients who were living independently. We defined abnormal body water balance as overhydration, with an extracellular fluid/total body water ratio > 0.390. A geriatric nutritional risk index (GNRI) < 98 was considered low GNRI. Sarcopenia was defined according to the 2019 Asian Working Group for sarcopenia criteria. Poor outcome was defined as a modified Rankin scale (mRS) score ≥ 3 at discharge. Among 111 eligible patients (40 females, median age: 77 years), 43 had a poor prognosis, 31 exhibited overhydration, 25 had low GNRI, and 44 experienced sarcopenia. Patients with poor outcomes had significantly higher National Institutes of Health Stroke Scale (NIHSS) scores, which were significantly more common with overhydration, low GNRI, and sarcopenia (p < 0.001 for all). Concomitant overhydration, low GNRI, and sarcopenia were associated with poorer outcomes. In multivariate analysis, overhydration [odds ratio (OR) 5.504, 95% confidence interval (CI) 1.717-17.648; p = 0.004], age (OR 1.062, 95%CI 1.010-1.117; p = 0.020), and NIHSS score (OR 1.790, 95%CI 1.307-2.451; p < 0.001) were independent prognostic factors for poor outcome. The results indicated that the combination of overhydration, low GNRI, and sarcopenia predict poor outcomes following AIS. Overhydration was particularly associated with poor outcomes.

Sodium-Glucose Cotransporter 2 Inhibitor Combined with Conventional Diuretics Ameliorate Body Fluid Retention without Excessive Plasma Volume Reduction

We previously reported that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert sustained fluid homeostatic actions through compensatory increases in osmotic diuresis-induced vasopressin secretion and fluid intake. However, SGLT2 inhibitors alone do not produce durable amelioration of fluid retention. In this study, we examined the comparative effects of the SGLT2 inhibitor dapagliflozin (SGLT2i group, n = 53) and the combined use of dapagliflozin and conventional diuretics, including loop diuretics and/or thiazides (SGLT2i + diuretic group, n = 23), on serum copeptin, a stable, sensitive, and simple surrogate marker of vasopressin release and body fluid status. After six months of treatment, the change in copeptin was significantly lower in the SGLT2i + diuretic group than in the SGLT2i group (-1.4 ± 31.5% vs. 31.5 ± 56.3%, p = 0.0153). The change in the estimated plasma volume calculated using the Strauss formula was not significantly different between the two groups. Contrastingly, changes in interstitial fluid, extracellular water, intracellular water, and total body water were significantly lower in the SGLT2i + diuretic group than in the SGLT2i group. Changes in renin, aldosterone, and absolute epinephrine levels were not significantly different between the two groups. In conclusion, the combined use of the SGLT2 inhibitor dapagliflozin and conventional diuretics inhibited the increase in copeptin levels and remarkably ameliorated fluid retention without excessively reducing plasma volume and activating the renin-angiotensin-aldosterone and sympathetic nervous systems.

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].

Nephrotic syndrome: pathophysiology and consequences

In patients with kidney disease, nephrotic syndrome can lead to several complications including progressive kidney dysfunction. Proteinuria may lead to the formation of cellular or fibrous crescents with reciprocal development of rapidly progressive glomerulonephritis or focal glomerulosclerosis. Proteinuria may also cause overload and dysfunction of tubular epithelial cells, eventually resulting in tubular atrophy and interstitial fibrosis. Hypoalbuminemia is usually associated with increased risk of mortality and kidney dysfunction. Dyslipidemia may increase the risk of atherosclerotic complications, cause podocyte dysfunction and contribute to vascular thrombosis. Urinary loss of anticoagulants and overproduction of coagulation factors may facilitate a hypercoagulable state. Edema, hypogammaglobulinemia, loss of complement factors, and immunosuppressive therapy can favor infection. Treatment of these complications may reduce their impact on the severity of NS. Nephrotic syndrome is a kidney disorder that can worsen the quality of life and increase the risk of kidney disease progression.

Predictors of Poor Very Early Diuretic Response and Effectiveness of Early Tolvaptan in Symptomatic Acute Heart Failure

BACKGROUND

Diuretic response (DR) in patients with symptomatic acute decompensated heart failure (ADHF) has an impact on prognosis. This study aimed to identify predictive factors influencing acute 6 h poor DR and to assess DR after early administration of tolvaptan (TLV).

METHODS

This multicenter retrospective study included 1670 patients who were admitted for ADHF and received intravenous furosemide within 1 h of presentation in clinical scenario 1 or 2 defined based on initial systolic blood pressure ≥100 mmHg with severe symptoms (New York Heart Association class III or IV (n = 830). The score for the poor DR factors in the very acute phase was calculated in patients treated with furosemide-only diuretics (n = 439). The DR to TLV administration was also assessed in patients who received an additional dose of TLV within 6 h (n = 391).

RESULTS

The time since discharge from the hospital for a previous heart failure < 3 months (odds ratio [OR] 2.78, 95% confidence interval [CI] 1.34-5.83; p = 0.006), loop diuretics at admission (OR 3.05, 95% CI 1.74-5.36; p < 0.0001), and estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m² (OR 2.99, 95% CI 1.58-5.74; p = 0.0007) were independent determinants of poor DR. The frequency of poor DR according to the risk stratification group was low risk (no risk factor), 18.9%; middle risk (one risk factor), 33.1%; and high risk (two to three risk factors), 58.0% (p < 0.0001). All risk groups demonstrated a significantly lower incidence of poor DR with early TLV administration: 10.7% in the early TLV group versus 18.9% in the loop diuretics group (p = 0.09) of the low-risk group; 18.4% versus 33.1% (p = 0.01) in the middle-risk group, and 20.2% versus 58.0% (p < 0.0001) in the high-risk group.

CONCLUSION

Early administration of TLV in patients with predicted poor DR contributed to a significant diuretic effect and suppression of worsening renal function.

Impact of urine cyclic AMP relative to plasma arginine vasopressin on response to tolvaptan in patients with chronic kidney disease and heart failure

BACKGROUND

The clinical utility of tolvaptan in chronic kidney disease (CKD) patients with heart failure remains uncertain. The level of urine cyclic adenosine monophosphate (AMP) relative to plasma arginine vasopressin (AVP) indicates the residual function of the collecting ducts in response to AVP stimulation and might be a key to predicting response of tolvaptan.

METHODS

CKD patients who were hospitalized to treat their congestive heart failure refractory to conventional loop diuretics were considered to receive tolvaptan and included in this prospective study. The impact of urine cyclic AMP/plasma AVP ratio for prediction of response to tolvaptan, which was defined as any increase in urine volume at day 7 from day 0, was investigated.

RESULTS

A total of 30 patients (median 75 years old, 24 men, and median estimated glomerular filtration rate 14.4 mL/min/1.73 m²) were included. As compared to baseline, urine volume increased at day 7 in 17 responders, whereas urine volume decreased at day 7 in 13 non-responders. Baseline urine cyclic AMP/plasma AVP ratio distributed between 0.25 and 4.01 with median 1.90. The urine cyclic AMP/plasma AVP ratio was a significant predictor of response to tolvaptan, which was adjusted for 6 potential confounders with a cutoff of 1.24.

CONCLUSIONS

Baseline urine cyclic AMP/plasma AVP ratio is an independent predictor of response to tolvaptan in advanced CKD patients with heart failure.

CLINICAL TRIAL REGISTRATION

UMIN000022422.

Efficacy and safety of intravenous OPC-61815 compared with oral tolvaptan in patients with congestive heart failure

AIMS

This multicentre, randomized, controlled, double-blind, parallel-group Phase III study was conducted to confirm the non-inferiority of OPC-61815 (tolvaptan sodium phosphate) intravenous injections to oral tolvaptan tablets in patients with congestive heart failure and volume overload despite receiving diuretics other than vasopressin antagonists.

METHODS AND RESULTS

Congestive heart failure patients with volume overload despite receiving diuretics other than vasopressin antagonists were randomly assigned (1:1) to receive OPC-61815 (16-mg injection; n = 149) or oral tolvaptan (15-mg tablet; n = 145) once daily for 5 days. Most patients were male; the mean age and weight were 74.7 years and 62.1 kg, respectively; other demographic and clinical characteristics were similar between groups. In this study, the primary endpoint was the change in body weight from baseline to the day after the last dose. Secondary endpoints included improvement from baseline in congestive findings and New York Heart Association classification. The change in body weight was -1.67 kg [95% confidence interval (CI): -1.93, -1.41] and -1.36 kg (95% CI: -1.62, -1.10) in the OPC-61815 group and tolvaptan group, respectively; the difference in the least squares mean between the groups was -0.31 kg (95% CI: -0.68, 0.06). Given the upper CI did not exceed the pre-specified limit of 0.48, this confirmed the non-inferiority of injectable OPC-61815 to oral tolvaptan. Daily urine volume and daily fluid intake increased, and daily fluid balance was negative throughout the treatment period; changes were similar for both groups. All evaluated congestive symptoms and New York Heart Association classifications showed improvement and safety findings were similar between the groups. The incidence of hyperkalaemia was higher in the OPC-61815 group, and the incidence of thirst and dry mouth was higher in the tolvaptan group. Most treatment-emergent adverse events were mild to moderate; one serious treatment-emergent adverse event of hyperkalaemia in the OPC-61815 group was considered treatment related.

CONCLUSIONS

OPC-61815 (16-mg injection) was confirmed as non-inferior to oral tolvaptan (15-mg tablet) in patients with congestive heart failure and inadequate response to diuretics; no new safety concerns were observed.

Tolvaptan Reduces Extracellular Fluid per Amount of Body Fluid Reduction Less Markedly than Conventional Diuretics

Objective Tolvaptan, a vasopressin V2 receptor antagonist, is a water diuretic, removing electrolyte-free water from the kidneys and affecting the water balance between the intracellular and extracellular fluid. We previously reported that tolvaptan efficiently reduced the intracellular fluid volume, suggesting its utility for treating cellular edema. Furthermore, tolvaptan is known for its low incidence of worsening the renal function, with conventional diuretics use associated with worsening of the renal function Methods In this retrospective observational study, five chronic kidney disease (CKD) patients with fluid retention were assessed by the bioelectrical impedance (BIA) method twice (before and after tolvaptan therapy). Tolvaptan was used with conventional diuretics. The post/pre ratio of extracellular water (ECW)/total body water (TBW) in the tolvaptan group was compared with that in 18 CKD patients undergoing body fluid reduction with conventional diuretics alone (conventional diuretics groups), taking the reduced amount of body fluid into consideration. Results Removing body fluid, either by tolvaptan or by conventional diuretics alone, decreased the ECW/TBW ratio. Of note, the reduction in extracellular fluid was milder in the tolvaptan group than in the conventional diuretics group. Conclusion Tolvaptan reduces the extracellular fluid per amount of body fluid reduction less markedly than conventional diuretics.

New Strategies for Volume Control in Patients with Diabetes Mellitus, a Narrative Review

Sodium is reabsorbed all along the renal tubules. The positive impacts of sodium-glucose cotransporter-2 inhibitors (SGLT2i), angiotensin receptor neprilysin inhibitor (ARNI) and mineralocorticoid receptor antagonists (MRA) on hard renal and/or cardiac endpoints calls for the role of diuretics in nephroprotection and cardioprotection in patients with diabetes mellitus to be reviewed. Here, we review: (a) the mechanisms of action of the available natriuretics; (b) the physiological adaptations to chronic loop diuretic usage that lead to increased sodium reabsorption in the proximal and distal convoluted tubules; (c) the physiology of sodium retention in patients with diabetes mellitus; and (d) the mechanisms of aldosterone breakthrough. We show the rationale for combined diuretics to target not only the loop of Henle, but also the proximal and distal convoluted tubules. Indeed, higher residual proteinuria in patients treated with renin-angiotensin-aldosterone system (RAAS) blockers portends poorer renal and cardiovascular outcomes. Diuretics are known to optimize the reduction of proteinuria, in addition to RAAS blockers, but may favor aldosterone breakthrough in the absence of MRA. The aim of our study is to support a combined diuretics strategy to improve the management of patients with diabetes mellitus and chronic kidney disease or heart failure.

Consistency of the estimated target weights and ECW/TBW using BIA after hemodialysis in patients between standing and lying-down positions

Background

As hemodialysis is administered with the patient lying down, the distribution of body fluid is stable in the lying position, which is why this position is recommended for bioimpedance analysis (BIA). Although the InBody S10 is widely used for hemodialysis patients in the lying position, clinicians must make the measurements in person. In contrast, patients can use the InBody 770 to obtain measurements by themselves in the standing position, which may be more convenient. Therefore, this study compared the measurements of hemodialysis patients’ estimated target weight and ECW/TBW obtained lying down using the S10 to those obtained in the standing position using the 770.

Methods

This study was conducted among maintenance hemodialysis patients at Chuncheon Sacred Heart Hospital in October 2020. Measurements from 56 patients before and after hemodialysis were obtained using the 2 machines. Each (S10 or 770) estimated target weight, both pre- and post-hemodialysis, was considered ideal when the ECW/TBW ratio was 0.380. R² was calculated and the Bland-Altman test was performed.

Results

The patients’ median age was 64 years old, and 51% were men. The actual ultrafiltration was 2 kg, and the mean TBW change measured using the InBody devices was 1.5 L (R² = 0.718) for the S10 and 1.7 L (R² = 0.616) for the 770. The estimated target weight at pre- and post-hemodialysis showed a remarkably high correlation with the patients’ actual pre- and post-hemodialysis weight (R² > 0.095). The correlation between these measurements (lying vs. standing) before and after hemodialysis was also very close (R² = 1.0000). In addition, ECW/TBW had a good correlation (R2 ≥ 0.970) The Bland-Altman test of dry weight and ECW/TBW yielded similar results.

Conclusions

This study showed that patients’ estimated target weights in the lying position using the InBody S10 device and in the standing position using the InBody 770 device were consistent in both pre- and post-hemodialysis states.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02737-3.

Comparative Impact of Isolated Ultrafiltration and Hemodialysis on Fluid Distribution: A Bioimpedance Study

INTRODUCTION

Isolated ultrafiltration (IUF) is an alternative treatment for diuretic-resistant patients with fluid retention. Although hemodialysis (HD) predominantly decreases extracellular water (ECW), the impact of IUF on fluid distribution compared with HD remains unclear.

METHODS

We compared the effect of HD (n = 22) and IUF (n = 10) sessions on the body fluid status using a bioimpedance analysis device (InBody S10).

RESULTS

The total ultrafiltration volume was similar between HD and IUF (HD 2.5 ± 0.3 vs. ICF 2.1 ± 0.3 L/session, p = 0.196). The reduction rate of ECW was significantly higher than that of intracellular water (ICW) after HD (ECW -7.9% ± 0.8% vs. ICW -3.0% ± 0.9%, p < 0.001) and IUF (ECW -5.8% ± 0.9% vs. ICW -3.6% ± 0.8%, p = 0.048). However, the change in the ratio of ECW to total body water in HD was significantly larger than that in IUF (HD -3.2% ± 0.3% vs. ICF -1.1% ± 0.4%, p < 0.001). The reduction rates in serum tonicity (effective osmolality) were higher after HD than after IUF (HD -1.8% ± 0.5% vs. IUF -0.6% ± 0.2%, p = 0.052). Among the components of effective osmolality, the reduction rates of serum K+ and glucose levels after HD were significantly higher than those after IUF (serum K+: HD -30.5% ± 1.6% vs. IUF -0.5% ± 3.8%, p < 0.001; serum glucose: HD -15.4% ± 5.0% vs. IUF 0.7% ± 4.8%, p = 0.026), while the serum Na+ level was slightly and similarly reduced (HD -0.8% ± 0.4% vs. IUF -0.8% ± 0.4%, p = 0.500). The reduction in the osmolal gap value (measured osmolality-calculated osmolarity) was significantly greater after HD sessions than after IUF sessions (HD -12.4 ± 1.4 vs. IUF 2.0 ± 1.0 mOsm/kg, p = 0.001).

CONCLUSION

The extracellular fluid reduction effect of HD is stronger than that of IUF. The different changes in effective osmolality and osmolal gap after HD and IUF sessions may be related to the different effects of HD and IUF on fluid distribution.

Potential protective effect of leptin and uncoupling protein-2 genes polymorphism in Egyptian patients with chronic kidney disease

BACKGROUND

Kidney disease is a serious public health problem worldwide. It is the fifth top-ranking cause of death in Egypt, causing approximately 3.98% of all deaths. This study's objective was to examine whether an association exists between leptin (- 2548G/A) and uncoupling protein-2 45 bp I/D genes, individually and collectively, in CKD and progression to ESRD.

METHODS

One hundred patients (69 males, 31 females) aged (47.1 ± 16.11 years) with ESRD, 40 patients (19 males, 21 females) aged (43.15 ± 10.00 years with CKD, and 50 healthy controls (23 males, 27 females) aged (37.84 ± 1.95 years) were enrolled. Polymerase chain reaction (PCR) was employed to measure variation in gene expression among the study groups. The frequency of single nucleotide polymorphisms (SNP) genotypes were identified in controls, CKD and ESRD patients.

RESULTS

Leptin genotypes were associated with lower CKD incidence in control versus study subjects (95% CI = (0.08-0.63), P = 0.01) with risk value equal to 0.22 < 1, G/A genotype was significantly lower in CKD than ESRD groups. There was no correlation between UCP-2 I/D genotype and CKD (P = 0.27). There was no correlation between the UCP-2 gene and the progression to ESRD.

CONCLUSIONS

This study suggests that, Leptin - 2548G/A gene may be a promising marker for early detection of ESRD in Egyptian patients. G/A genotype might inhibit the development of CKD to ESRD.

Differences in pharmacological property between combined therapy of the vasopressin V2-receptor antagonist tolvaptan plus furosemide and monotherapy of furosemide in patients with hospitalized heart failure

BACKGROUND

Tolvaptan has been shown to improve congestion in heart failure patients. The purpose of this study was to evaluate the pharmacology and clinical efficacy of combined tolvaptan and furosemide therapy.

METHODS

This study included 40 patients with systemic volume overload who were hospitalized for heart failure. Patients who showed no improvement in the condition after receiving 20 mg intravenous furosemide were included and were randomly selected to receive tolvaptan as an add-on to furosemide or to receive an increased dose of furosemide. We evaluated the bioelectrical impedance analyzer parameters, the parameters of the inferior vena cava using echocardiography, vital signs, body weight, urine output, and laboratory data for 5 days.

RESULTS

In the changes from baseline between intracellular water volume (ICW) and extracellular water volume (ECW) after additional use of tolvaptan or furosemide from Day 1 to Day 5, there were no significant differences observed between ICW and ECW over 5 days in the tolvaptan + furosemide group, although differences were found in the furosemide group from Day 2 onward. Changes in the respiratory collapse of inferior vena cava increased significantly, and systolic blood pressure decreased significantly only in the furosemide group.

CONCLUSIONS

The present study clearly demonstrates that combined therapy with tolvaptan and furosemide removed excess ICW and ECW to an equal extent, while furosemide alone primarily removed ECW, including intravascular water.

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.