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Mikiyasu Shirai - One of the best experts on this subject based on the ideXlab platform.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in vivo rat heart
Biophysical Journal, 2015Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Aims: The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO).Main methods: Using microdialysis technique in anaesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine.Key Findings: Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60-80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60-80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40-60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration.Significance: Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in rat heart
Life Sciences, 2014Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Abstract Aims The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO). Main methods Using microdialysis technique in anesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine. Key findings Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60–80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60–80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40–60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration. Significance Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
Dong Yun Zhan - One of the best experts on this subject based on the ideXlab platform.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in vivo rat heart
Biophysical Journal, 2015Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Aims: The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO).Main methods: Using microdialysis technique in anaesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine.Key Findings: Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60-80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60-80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40-60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration.Significance: Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in rat heart
Life Sciences, 2014Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Abstract Aims The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO). Main methods Using microdialysis technique in anesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine. Key findings Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60–80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60–80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40–60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration. Significance Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
Tsuyoshi Akiyama - One of the best experts on this subject based on the ideXlab platform.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in vivo rat heart
Biophysical Journal, 2015Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Aims: The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO).Main methods: Using microdialysis technique in anaesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine.Key Findings: Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60-80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60-80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40-60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration.Significance: Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
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myocardial interstitial serotonin and its major metabolite 5 hydroxyindole acetic acid levels determined by microdialysis technique in rat heart
Life Sciences, 2014Co-Authors: Dong Yun Zhan, Tsuyoshi Akiyama, Takashi Sonobe, Tadakatsu Inagaki, Mikiyasu ShiraiAbstract:Abstract Aims The aim of this study was to elucidate myocardial interstitial serotonin (5-HT) kinetics in the heart, including 5-HT reuptake and enzymatic degradation to 5-hydroxyindole acetic acid (5-HIAA) via monoamine oxidase (MAO). Main methods Using microdialysis technique in anesthetized rats, we simultaneously monitored myocardial interstitial levels of 5-HT and its major metabolite, 5-HIAA, in the left ventricle and examined the effects of local administration of a MAO inhibitor, pargyline, or a 5-HT uptake inhibitor, fluoxetine. Key findings Pargyline increased Dialysate 5-HT concentration from 1.8 ± 0.3 at baseline to 3.9 ± 0.5 nM but decreased Dialysate 5-HIAA concentration from 20.7 ± 1.0 at baseline to 15.8 ± 1.4 nM at 60–80 min of administration. Fluoxetine increased Dialysate 5-HT concentration from 1.9 ± 0.4 at baseline to 6.5 ± 0.9 nM at 60–80 min of administration, but did not change Dialysate 5-HIAA concentration. Local administration of ADP (100 mM) increased Dialysate 5-HT and 5-HIAA concentrations. Pargyline did not affect ADP-induced increase in Dialysate 5-HT concentration but suppressed ADP-induced increase in Dialysate 5-HIAA concentration during 60 min of ADP administration. Fluoxetine increased Dialysate 5-HT concentration at 40–60 min of ADP administration, but did not affect ADP-induced increase in Dialysate 5-HIAA concentration. Significance Simultaneous monitoring of myocardial interstitial 5-HT and 5-HIAA levels provides valuable information on 5-HT kinetics including reuptake and enzymatic degradation by MAO, which play a role in the regulation of myocardial interstitial 5-HT levels at baseline and when 5-HT levels are elevated.
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adrenergic inhibition of endogenous acetylcholine release on postganglionic cardiac vagal nerve terminals
Cardiovascular Research, 2000Co-Authors: Tsuyoshi Akiyama, Toji YamazakiAbstract:Objective: The aim was to examine the adrenergic modulation of endogenous acetylcholine (ACh) release from vagal nerve terminals in the in vivo heart. Methods: Using dialysis technique in anesthetized cats, we investigated the influence of exogenous noradrenaline on Dialysate ACh response. Dialysis probes were implanted in the left ventricular myocardium and perfused with Krebs–Henseleit buffer containing eserine (10−4 M) at 3 μl/min. Dialysate ACh concentration was measured as an index of ACh release from cardiac vagal nerve terminals. The Dialysate ACh response to vagal nerve stimulation was examined before and after local administration of noradrenaline (10−5 M) through dialysis probes. Results: Noradrenaline significantly attenuated the Dialysate ACh response to vagal nerve stimulation (10 Hz) from 9.5±1.8 to 5.4±1.2 nM ( n =7). In the presence of the α-adrenergic antagonist phentolamine (10−4 M), noradrenaline did not attenuate the Dialysate ACh response (from 9.8±2.7 to 9.4 ±2.8 nM, n =6). The N-type Ca2+ channel blocker ω-conotoxin GVIA (10−5 M) significantly attenuated the Dialysate ACh response from 9.6±1.2 to 4.5±0.7 nM ( n =8). In the presence of ω-conotoxin GVIA, noradrenaline did not attenuate the Dialysate ACh response (from 3.8±1.4 to 3.5±1.3 nM, n =7). Conclusions: Our results suggest the presynaptic adrenergic inhibition of ACh release on postganglionic cardiac vagal nerve terminals. Adrenergic inhibition of Ca2+ influx through the N-type Ca2+ channels could play a predominant role in the decrease in ACh release.
Andrew Davenport - One of the best experts on this subject based on the ideXlab platform.
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the effect of glucose absorption from peritoneal Dialysates on changes in lipid profiles in prevalent peritoneal dialysis patients
Peritoneal Dialysis International, 2021Co-Authors: Steven Law, Andrew DavenportAbstract:The majority of peritoneal Dialysates contain glucose, which can potentially be absorbed from the peritoneal cavity. Previous studies have reported an observation between Dialysate glucose exposure...
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why does the choice of Dialysate sodium concentration remain controversial
Hemodialysis International, 2018Co-Authors: Kamonwan Tangvoraphonkchai, Andrew DavenportAbstract:The choice of the ideal Dialysate sodium concentration remains controversial. Most dialysis centers have a standard Dialysate concentration. In theory, choosing a Dialysate sodium concentration lower than serum sodium should result in an additional loss of sodium by diffusion with a reduction in the prevalence of hypertension and interdialytic weight gains (IDWGs) on one hand, but with potential increased risk of intradialytic hypotension and cramps on the other hand, and the opposite effects may accompany the choice of Dialysate sodium concentrations greater than serum concentration. Although most studies have reported a reduction in IDWG with lower Dialysate sodium concentrations, the effects on blood pressure control, and adverse intradialytic events have been variable. Different outcomes between studies may be partially explained by patient selection, with differences in dietary sodium intake, urinary sodium losses, and sodium stores in the body. In addition, multicenter trials potentially introduce additional confounders, including differences in local quality control of delivered Dialysate sodium concentration and sodium measurements. Although there may be advantages for lower Dialysate sodium concentration, observational studies have reported a survival advantage for higher Dialysate sodium concentrations for those patients with lower serum sodium concentrations pre-dialysis. As there is no current consensus for a universal Dialysate sodium concentration, attention has turned to considering an individualized approach to choosing a Dialysate sodium concentration.
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Reliability of delivered Dialysate sodium concentration.
Hemodialysis International, 2016Co-Authors: Nasirul J. Ekbal, Jahm Persaud, Anne Consalus, Andrew DavenportAbstract:Background The results of studies investigating the effects of hyponatraemic Dialysates have been mixed, with some reporting positive effects including reduction in blood pressure and inter-dialytic weight gains, whereas others have not been able to demonstrate any effect. These studies assume that setting a lower Dialysate sodium results in the delivery of a hyponatraemic Dialysate. We therefore measured delivered sodium to determine reliability. Methods We measured Dialysate sodium in 10 BBraun Dialog+® and 6 Fresenius 4008H dialysis machines, which had been set up to deliver a sodium of 136 mmol/L, using flame photometry and indirect ion selective electrode (ISE) methods. Results Dialysate conductivity was 13.85 ± 0.05 mS/cm, but Dialysate sodium measured by flame photometry was 141.8 ± 2.9 mmol/L, and 142.5 ± 2.4 mmol/L by ISE. Both dialysis machines delivered a Dialysate sodium in excess of the 136 mmol/L set, with a mean bias of 7.0 ±2.1 mmol/L for the Dialog+®, and 3.7 ± 2.6 for the 4008 with the flame photometer method, and a mean bias of 6.3 ± 1.3 mmol/L for the Dialog+®, and 6.8 ± 3.7 for the 4008 by ISE. Conclusion It is assumed when setting a Dialysate sodium concentration that this sodium concentration is delivered. However we found that the Dialysate sodium concentration delivered was greater than that set, despite the dialysis machines reporting a conductivity measurement in keeping with a lower sodium Dialysate. Trials of lowered Dialysate sodium therefore need to measure Dialysate sodium concentrations to ensure what has been set is delivered.
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indirect ion selective electrode methods potentially overestimate peritoneal Dialysate sodium losses
Therapeutic Apheresis and Dialysis, 2014Co-Authors: Jahm Persaud, Michael B Thomas, Andrew DavenportAbstract:Measurements of Dialysate sodium are used to estimate peritoneal dialysis sodium losses and sodium sieving, a measure of hydraulic permeability of the peritoneum. Peritoneal Dialysates differ from serum samples in terms of pH, osmolality, protein and glucose concentration. We wished to determine whether these factors affected sodium measurement. Dialysate samples were taken from 52 consecutive peritoneal dialysis patients attending for a standard peritoneal dialysis equilibrium test (PET), 20 with standard lactate Dialysate and 32 with neutral pH Dialysate and sodium was measured by both flame photometry and indirect ion selective electrode (ISE). Sodium measured by ISE consistently overestimated that measured by flame photometer, mean bias 1.5 mmol/L (95% confidence limits 1.2 to 1.8), P < 0.001. Sodium was lower in fresh neutral pH Dialysates by both methods - flame 125.3 ± 1.17 vs. 131.6 ± 0.39 mmol/L, than standard lactate Dialysates ISE 127.4 ± 1.05 vs 132.7 ± 0.27 mmol/L, P < 0.001. Glucose was higher in fresh neutral pH Dialysates 122.7 ± 1.1 vs. standard lactate Dialysates 116.7 ± 0.4 mmol/L, P < 0.001. On multiple regression analysis, only glucose was found to be an independent factor for sodium measurement, F = 14.78, β = -0.0851, SEM 0.022, 95% confidence limits -1.28 to -0.042. In this study there was a small but consistent difference between sodium measurements by ISE and flame photometry during the PET. Sodium measurements by either method appeared to be affected by hypertonic Dialysates, but there were differences with pH. This may potentially lead to errors in both overestimating peritoneal sodium losses and the proportion of patients with ultrafiltration failure due to loss of sodium sieving.
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does a reduction in Dialysate sodium improve blood pressure control in haemodialysis patients
Nephrology, 2012Co-Authors: Anoop D Shah, Andrew DavenportAbstract:Introduction: There has been debate as to the value of lower sodium Dialysates to control blood pressure in haemodialysis patients, as sodium is predominantly removed by ultrafiltration. Methods: Re-audit of clinical practice following reduction in Dialysate sodium concentration. Results: Overall Dialysate sodium concentration decreased from 138.9 ± 1.7 to 137.8 ± 1.7 mmol/L (mean ± standard deviation), resulting in a reduction in pre- and post-dialysis mean arterial pressure (MAP) of 4 mmHg (from 100.6 ± 15.6 to 97.1 ± 15.6, P < 0.01 and from 91.7 ± 15.6 to 87.1 ± 14.6, P < 0.001 respectively), yet fewer patients were prescribed antihypertensives (49.6 vs 60.6%), and less antihypertensive medications/patient (mean 0.86 vs 1.05), ultrafiltration requirements (2.8% vs 3.2% body weight, P < 0.001), and symptomatic intradialytic hypotension (0.19 vs 0.28 episodes per week, P < 0.001). A multivariable model showed that for a Dialysate sodium of 136 mmol/L, younger patients had higher MAP than older patients (0.35 mmHg lower MAP/year older; but with a Dialysate sodium of 140 mmol/L, there was minimal association of MAP with age (0.07 mmHg higher MAP/year older). Conclusion: Change in clinical practice, amounting to a modest reduction in Dialysate sodium was associated with a reduction not only in pre- and post-dialysis blood pressures, but also ultrafiltration requirements and symptomatic intradialytic hypotension. However, this effect on blood pressure was most marked for older patients and women, within minimal effects for younger patients, and lesser effects for men, suggesting that Dialysate sodium reduction alone may help improve blood pressure control, but requires additional factors such as dietary sodium restriction to be effective in younger male patients.
Angelo Karaboyas - One of the best experts on this subject based on the ideXlab platform.
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Dialysate potassium serum potassium mortality and arrhythmia events in hemodialysis results from the dialysis outcomes and practice patterns study dopps
American Journal of Kidney Diseases, 2017Co-Authors: Angelo Karaboyas, Allen R Nissenson, Steven M Brunelli, Jarcy Zee, Len A Usvyat, Daniel E Weiner, Franklin W Maddux, Michel Jadoul, F Locatelli, Wolfgang C WinkelmayerAbstract:Background Sudden death is a leading cause of death in patients on maintenance hemodialysis therapy. During hemodialysis sessions, the gradient between serum and Dialysate levels results in rapid electrolyte shifts, which may contribute to arrhythmias and sudden death. Controversies exist about the optimal electrolyte concentration in the Dialysate; specifically, it is unclear whether patient outcomes differ among those treated with a Dialysate potassium concentration of 3 mEq/L compared to 2 mEq/L. Study Design Prospective cohort study. Setting & Participants 55,183 patients from 20 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 1 to 5 (1996-2015). Predictor Dialysate potassium concentration at study entry. Outcomes Cox regression was used to estimate the association between Dialysate potassium concentration and both all-cause mortality and an arrhythmia composite outcome (arrhythmia-related hospitalization or sudden death), adjusting for potential confounders. Results During a median follow-up of 16.5 months, 24% of patients died and 7% had an arrhythmia composite outcome. No meaningful difference in clinical outcomes was observed for patients treated with a Dialysate potassium concentration of 3 versus 2 mEq/L (adjusted HRs were 0.96 [95% CI, 0.91-1.01] for mortality and 0.98 [95% CI, 0.88-1.08] for arrhythmia composite). Results were similar across predialysis serum potassium levels. As in prior studies, higher serum potassium level was associated with adverse outcomes. However, Dialysate potassium concentration had only minimal impact on serum potassium level measured predialysis (+0.09 [95% CI, 0.05-0.14] mEq/L serum potassium per 1 mEq/L greater Dialysate potassium concentration). Limitations Data were not available for delivered (vs prescribed) Dialysate potassium concentration and postdialysis serum potassium level; possible unmeasured confounding. Conclusions In combination, these results suggest that approaches other than altering Dialysate potassium concentration (eg, education on dietary potassium sources and prescription of potassium-binding medications) may merit further attention to reduce risks associated with high serum potassium levels.
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Dialysate sodium prescription and blood pressure in hemodialysis patients
American Journal of Hypertension, 2014Co-Authors: Manfred Hecking, Angelo Karaboyas, Hugh C Rayner, Rajiv Saran, Ananda Sen, Masaaki Inaba, Jurgen Bommer, Walter H Horl, Ronald L Pisoni, Bruce M RobinsonAbstract:background Diffusive sodium removal has been recommended to control hypertension in hemodialysis patients. Recent evidence on hospitalizations and mortality, however, challenged the benefit of lower Dialysate sodium prescriptions and ignited a debate in the dialysis community. We therefore studied the relationship between Dialysate sodium and blood pressure over the longer term. methods We used multiply adjusted linear mixed models to estimate the association between Dialysate sodium and predialysis systolic blood pressure (SBP) as well as change in SBP (delta SBP; postdialysis minus predialysis) in 23,962 patients from the international Dialysis Outcomes and Practice Patterns Study. results We found that 43% of hemodialysis facilities had variable (individualized) Dialysate sodium prescriptions (125–155 mEq/L), whereas 57% had uniform Dialysate sodium prescriptions (135–145 mEq/L) for ≥90% patients. Between-group comparisons of these 2 facility types suggested that Dialysate sodium, when variably prescribed, might have been used to modify predialysis SBP (Pinteraction = 0.01) and perhaps delta SBP levels (Pinteraction = 0.08). Within facilities not prone to indication bias, because Dialysate sodium was not variable, higher uniform Dialysate sodium (per 2 mEq/L) was associated with slightly higher SBP (+0.9 mm Hg, 95% confidenc e interval (CI) = 0.1–1.6 among all patients; +1.7 mm Hg, 95% CI = 0.1–3.2 among patients not treated with blood pressure medication) and no increase in delta SBP. conclusions Patients assigned to hemodialysis facilities with uniformly higher Dialysate sodium do not have markedly higher predialysis SBP, providing rather limited support for lowering Dialysate sodium to control hypertension, particularly in view of hospitalization and mortality risks associated with lower Dialysate sodium.
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association of Dialysate bicarbonate concentration with mortality in the dialysis outcomes and practice patterns study dopps
American Journal of Kidney Diseases, 2013Co-Authors: Francesca Tentori, Angelo Karaboyas, Hugh C Rayner, Ananda Sen, Bruce M Robinson, Hal Morgenstern, Jinyao Zhang, Alp T Ikizler, Rachel B Fissell, Raymond VanholderAbstract:Background Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different Dialysate bicarbonate levels, and the optimal concentration remains uncertain. Study Design The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. Setting & Participants This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002-2011). Predictor Dialysate bicarbonate concentration. Outcomes All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of Dialysate bicarbonate concentration, adjusting for potential confounders. Measurements Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. Results Mean Dialysate bicarbonate concentration was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the United States. Prescription of high Dialysate bicarbonate concentration (≥38 mEq/L) was most common in the United States (45% of patients). Approximately 50% of DOPPS facilities used a single Dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was associated positively with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01-1.15]; HR for Dialysate bicarbonate ≥38 vs 33-37 mEq/L, 1.07 [95% CI, 0.97-1.19]). Results were consistent across levels of pre–dialysis session serum bicarbonate and between facilities that used a single Dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate concentration with mortality was stronger in patients with longer dialysis vintage. Limitations Due to the observational nature of the present study, we cannot rule out that the reported associations may be biased by unmeasured confounders. Conclusions High Dialysate bicarbonate concentrations, especially prolonged exposure, may contribute to adverse outcomes, likely through the development of postdialysis metabolic alkalosis. Additional studies are warranted to identify the optimal Dialysate bicarbonate concentration.