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Background: Sodium supplements are ubiquitous in endurance running, but their impact on performance has been subjected to much debate. The objective of the study was to assess the effect of sodium supplementation as a weight-based predictor of race performance in ultramarathon runners. Methods: Prospective observational study during an 80 km (50 mi) stage of a 6-stage 250 km (155 mi) ultramarathon in Chile, Patagonia, Namibia, and Mongolia. Finish line hydration status as measured by weight change, point-of-care serum sodium, and questionnaire provided sodium ingestion categories at 33rd percentile and 66th percentile both for weight-adjusted rate and total sodium consumption, then analyzed for significant relationships to race performance, dysnatremia, and hydration. Results: Two hundred sixty-six participants were enrolled, with 217 (82%) with complete sodium supplement rate data, 174 (80%) with finish line sodium, and 161 (74%) with both pre-race weights and total sodium ingestion allowing weight-based analysis. Sodium intake ranged from 131–533 mg/h/kg (2–7.2 gm), with no statistically significant impact on pace, race time, or quintile rank. These outcomes did not change when sodium intake was analyzed as a continuous variable or by sub-group analysis of the 109 (68%) normonatremic runners. When controlled for weight-adjusted sodium intake, performance was poorly correlated with hydration (r = − 0.152, 95% CI − 0.348–0.057). Dehydrated runners outperformed those overhydrated, with 11% of top 25th percentile finishers dehydrated (versus 2.8% overhydrated), with 3.6 min/km faster pace and time 4.6 h faster finishing time. Conclusions: No association was found between sodium supplement intake and ultramarathon performance. Dehydrated runners were found to have the best performance. This reinforces the message to avoid overhydration. [ABSTRACT FROM AUTHOR]

Background: Bioimpedance spectroscopy (BIS) with a whole-body model to distinguish excess fluid from major body tissue hydration can provide objective assessment of fluid status. BIS is integrated into the Body Composition Monitor (BCM) and is validated in adults, but not children. This study aimed to (1) assess agreement between BCM-measured total body water (TBW) and a gold standard technique in healthy children, (2) compare TBW_BCM with TBW from Urea Kinetic Modelling (UKM) in haemodialysis children and (3) investigate systematic deviation from zero in measured excess fluid in healthy children across paediatric age range.Methods: TBW_BCM and excess fluid was determined from standard wrist-to-ankle BCM measurement. TBW_D2O was determined from deuterium concentration decline in serial urine samples over 5 days in healthy children. UKM was used to measure body water in children receiving haemodialysis. Agreement between methods was analysed using paired t test and Bland-Altman method comparison.Results: In 61 healthy children (6-14 years, 32 male), mean TBW_BCM and TBW_D2O were 21.1 ± 5.6 and 20.5 ± 5.8 L respectively. There was good agreement between TBW_BCM and TBW_D2O (R2 = 0.97). In six haemodialysis children (4-13 years, 4 male), 45 concomitant measurements over 8 months showed good TBW_BCM and TBW_UKM agreement (mean difference − 0.4 L, 2SD = ± 3.0 L). In 634 healthy children (2-17 years, 300 male), BCM-measured overhydration was − 0.1 ± 0.7 L (10-90th percentile − 0.8 to + 0.6 L). There was no correlation between age and OH (p = 0.28).Conclusions: These results suggest BCM can be used in children as young as 2 years to measure normally hydrated weight and assess fluid status. [ABSTRACT FROM AUTHOR]

Purpose: Cardiovascular disease is the leading cause of mortality in dialysis patients with left ventricular hypertrophy (LVH) being an important predictor of mortality. We wanted to determine the prevalence of LVH in peritoneal dialysis (PD) patients and factors contributing to it. Methods: This is a cross-sectional study assessing LVH using echocardiogram in PD patients. Left ventricular mass index (LVMI) was calculated to determine LVH. Chronic fluid overload (overhydration) was assessed using the body composition monitor, and blood pressure (BP) was measured using 24-h ambulatory BP monitoring. Results: Thirty-one patients (21 females:10 males, 48.97 ± 14.50 years and dialysis vintage 40.0 ± 28.9 months) were studied. More than two-thirds (77.4 %) were hypertensive, and a third (35.5 %) were diabetic. Baseline data included mean serum albumin (37.34 ± 4.43 g/l), weekly Kt/V (2.02 ± 0.23), residual renal function of 68 (0-880) ml and ultrafiltration of 1,606.9 ± 548.6 ml. Majority of patients (80.6 %) had LVH on echocardiogram with LVMI of 136.5 ± 37.8 g/m and overhydration of 2.23 ± 1.77 l. Average systolic BP, diastolic BP and mean arterial pressure were 141.2 ± 23.3, 90.8 ± 19.7 and 107.6 ± 19.6 mmHg, respectively. Patients with LVH had a lower serum albumin ( p = 0.003), were more overhydrated ( p = 0.010) and were on higher number of anti-hypertensive agents ( p ≤ 0.001). Predictors of LVMI were overhydration ( p = 0.002), the presence of diabetes ( p = 0.008) and the number of anti-hypertensive agents used ( p = 0.026). However, overhydration ( p = 0.007) was the main predictor of LVH on multivariate analysis. Conclusion: Overhydration is strongly associated with LVH in PD patients. [ABSTRACT FROM AUTHOR]

In spite of high prevalence, congestion remains a poorly understood phenomenon in heart failure pathophysiology. Its negative impact on outcome has been widely recognised. Still, data from various registries reveal the failure of the contemporary treatment strategies to overcome congestion. This shortcoming is closely related to the fact that there are no universe means for congestion assessment and grading, making it a difficult process to recognise. CD146 is a novel blood biomarker of congestion that has been shown to reflect intravascular fluid accumulation in a number of experimental and clinical studies. This observation deserves special attention, given the huge gap of knowledge about decongestive strategies in acute and chronic heart failure. Randomised clinical trials testing the effect of CD146-guided management intervention are urgently needed to estimate its value in heart failure care. [ABSTRACT FROM AUTHOR]

Background: The assessment of hydration status remains a challenging task in hemodialysis (HD) management. There are only limited data available on the relevance of clinical decisions in the estimation of dialysis overhydration (OH). The objective of this study was to examine the significance of clinical judgment in the assessment of pre-dialysis OH. Methods: We compared the performance of three methods of OH assessment: (1) clinical judgment guided by a single clinical examination with (2) multifrequency bioimpedance analysis (BIA) and (3) complex systematic clinical approach. We additionally studied the associations of these methods with selected laboratory and imaging parameters. Results: Any of the single parameters alone reached a sufficient level of accuracy for reliable prediction of OH. Clinical judgment was the single most important factor in OH estimation, and also had the highest contribution when in combination with other parameters. BIA reliably measured extracellular fluid, but the automatically calculated OH exhibited a substantial degree of inaccuracy that precludes the use of BIA as a standard at present. The combination of clinical judgment with additional clinical parameters had the highest prediction accuracy for OH. Among the parameters studied, vena cava collapsibility index and calf circumference showed the strongest association with OH. Echocardiography, cardiothoracic index, atrial natriuretic peptide levels and spirometry did not have acceptable sensitivity. Conclusion: The systematic clinical approach combining physician and patient inputs, laboratory and imaging data enables an individualized decision and a superior accuracy in OH assessment. [ABSTRACT FROM AUTHOR]

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Introduction: Cardiovascular (CV) morbidity and mortality are greatly enhanced in patients with chronic kidney disease, partly due to increased arterial stiffness. Material and method: The study included 63 stable HD patients. Stiffness parameters were evaluated by applanation tonometry before the mid-week HD sessions. Pre-HD bioimpedance parameters were measured. A phase angle 6°. Overhydration increases arterial stiffness, but has no influence on either EID or ED vascular reactivity. Conclusion: In hemodialysis, volume overload is an important contributor to increased arterial stiffness and modifies cardiovascular status especially by LV hypertrophy. Achieving normohydration may significantly ameliorate cardiac abnormalities and arterial stiffness and may impact major clinical events and CV mortality. [ABSTRACT FROM AUTHOR]

Background: Bioimpedance spectroscopy (BIS) is used to assess volume status in peritoneal dialysis (PD) patients. However, it is proposed that it may be troubling in patients with abnormal fluid distribution and body geometry. It is not clear whether having an empty abdomen or not interferes with the BIS results and its relation with echocardiographic findings in PD patients. Methods: Twenty-five prevalent PD patients were enrolled. Echocardiography and body composition analysis using BIS technique (50 frequencies, the Body Composition Monitor, BCM) were performed. Overhydration (OH), extracellular water (ECW) in liters and OH/ECW ratio were used as volume status indices. Differences in volume and echocardiographic findings, in patients with empty and with full abdomen, and their correlations with echocardiographic parameters were investigated. Results: Mean age and PD duration were 61 ± 2.5 years and 42 ± 33 months, respectively. Sixty-four percent were male and 24% were diabetic. Mean left ventricular mass index (LVMi) was 131 ± 43 g/m mean left atrium diameter (LA) was 4.1 ± 0.1 cm, mean left ventricular ejection fraction (EF) was 64 ± 10%. Mean OH in patients with full abdomen were 1.67 ± 1.51 L and 1.68 ± 1.48 L, depending on the inclusion or exclusion of the dialysate volume, respectively. In patients with an empty abdomen, mean OHs were 2.12 ± 1.76 L and 1.91 ± 1.56 L, depending on the inclusion or exclusion of the dialysate volume. BIS measurements with an empty, but not with a full abdomen, was related to the echocardiographic parameters. Conclusion: BIS is a reliable method to evaluate volume status in PD patients. BIS performed after peritoneal equilibration test with an empty abdomen, better reflects overhydration and is related to echocardiographic parameters. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate the pharmacokinetics (PK) and pharmacodynamics (PD) of desmopressin in healthy male subjects at different levels of overhydration. Also, we examined if an indirect-response model could be related to renal physiology and the pharmacological action of desmopressin. Eight healthy male subjects participated in this open, randomized crossover study with three periods. Each subject was orally water loaded (0 to 20ml·kg−1 body weight) on 3 study days in order to achieve three different levels of hydration. After the initial water load, urine was voided every 15 min and the volumes were measured. To ensure continuous overhydration the subjects replaced their fluid loss with drinking-water. When a steady-state diuresis was achieved after approximately 2 hr, 0.396 μg of desmopressin was administered intravenously as a bolus injection. Blood was sampled and urine was collected at intervals throughout the study day (10 hr). An indirect-response model, where desmopressin was assumed to inhibit the elimination of response, was fit to the urine osmolarity data. There were no statistically significant effects of different levels of hydration, as expressed by urine flow rate at baseline, on the estimates of the PK and PD model parameters. The calculated terminal half-lives of elimination (t1/2 β) ranged between 2.76 and 8.37 hr with an overall mean of 4.36 hr. The overall means of plasma clearance and the volumes of distribution of the central compartment (Vc ) and at steady state (Vss ) were estimated to be 1.34 (SD 0.35) ml·min−1 ·kg−1 , 151 (SD28) ml·kg−1 , and 386 (SD 63) ml·kg−1 , respectively. High urine flow rate, indicating overhydration, produced a diluted urine and thus a low osmolarity at baseline (R0 ). The effect of the urine flow rate on the urine osmolarity at baseline was highly significant (p< 0.0001). The mean values for IC50 and the sigmoidicity factor (γ) were 3.7 (SD 1.2) pg·ml−1 and 13.0 (SD 3.5), respectively. In most cases when there was a high urine flow rate at baseline, the model and the estimated PD parameters could be related to the pharmacological action of desmopressin and renal physiology. Thus, the indirect-response model used in this study offers a mechanistic approach of modeling the effect of desmopressin in overhydrated subjects. [ABSTRACT FROM AUTHOR]

Hypertension and accelerated vascular damage in hemodialysis patients have been ascribed to the accumulation of sodium and water before hemodialysis and their rapid extraction during the successive 4-h hemodialysis. We hypothesized that oral administration of water-adsorbing polymers might increase stool sodium and water contents and prevent overhydration. We tested the solute adsorption capacities of the water-adsorbing polymers Akuarikku CA K-4, K-25, H-2, H-3, CS-7M, and SCN-50 in artificial gastric juice. The adsorbing capacity in the artificial gastric juice was less than one-twentieth of that in water for all of the polymers except CS-7M. CS-7M also maintained its adsorbing capacity after 5h. We administered 0.2g of Akuarikku CS-7M suspended in 2ml polyethylene glycol by a metal gastric tube to 300-g Sprague-Dawley rats. The fecal weights after 5 days of administration were 9.2±0.6 g/day in the polymer group ( n=5) and 7.3±0.6 g/day in control group ( n=5) ( P<0.01). Their dry weights were 4.2±0.2g and 3.2±0.3g/day ( P<0.01), respectively. Fecal nitrogen and sodium contents were higher in the polymer group than those in the control group ( P<0.01). There were no differences in potassium and phosphate contents. Oral administration of the water adsorbent to rats increased the water and nitrogen contents of feces. These observations might suggest the potential efficacy of water adsorbent as an additive for treatment of patients with severe overhydration. [ABSTRACT FROM AUTHOR]