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Impact of Nuun Electrolyte Tablets on Fluid Balance in Active Men and Women.
Pence, J, Bloomer, RJ
Nutrients. 2020;(10)
Abstract
BACKGROUND Maintaining adequate hydration is important for overall health and has major implications for athletes involved in physically demanding tasks. While water is viewed as an effective means to rehydrate, and is inexpensive and readily available, electrolyte beverages appear to be more beneficial, in particular for athletes who routinely lose electrolytes through sweating. Nuun tablets contain a mix of electrolytes and are quickly dissolved in water to create an electrolyte-rich beverage. We determined the impact of Nuun tablets on the fluid balance of healthy, exercise-trained men and women at rest. METHODS Eight men (25.9 ± 4.5 yrs) and 10 women (28.2 ± 9.4 yrs) ingested either water only or water with Nuun electrolyte tablets, at both a single and double strength concentration, in random order, on three separate occasions separated by approximately one week, in a fasted and euhydrated state. A total of 1 liter of fluid was ingested at each visit over a 30 minute period. Urine was collected from each subject at 0, 1, 2, 3, and 4 hours post-ingestion. Urine mass values were used to calculate fluid balance and the beverage hydration index (BHI; i.e., the volume of urine produced after drinking the Nuun beverages, relative to that of water only-control condition). Heart rate and blood pressure were measured throughout the four-hour period, while body weight was measured at the start and end of the experiment. RESULTS Neither heart rate nor blood pressure were impacted by beverage consumption. Nuun tablets resulted in a lower urine output compared to water, with fluid balances for both concentrations more favorable compared to water (p < 0.05), beginning at 2 h post-ingestion and continuing at the 3 h and 4 h times. Body weight loss was less with Nuun at the single dose (0.38 kg; p = 0.02) and double dose (0.43 kg; p = 0.08), compared to water (0.57 kg). The BHI was higher for Nuun (single dose in particular) compared to water at both 2 h (p = 0.05) and 4 h (p = 0.02). CONCLUSION The addition of Nuun electrolyte tablets to water improves the fluid balance and BHI in healthy men and women. Results were similar for both concentrations, suggesting that additional electrolytes are not necessary when in a rested state. Future studies should determine the impact of various concentrations of the Nuun beverage during physical exercise-in particular, exercise in the heat, when sweat loss may be highest.
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A Journey through the Early Evidence Linking Hydration to Metabolic Health.
Vanhaecke, T, Perrier, ET, Melander, O
Annals of nutrition & metabolism. 2020;:4-9
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Abstract
The idea that water intake or hydration may play an intrinsic, independent role in modulating metabolic disease risk is relatively recent. Here, we outline the journey from early experimental works to more recent evidence linking water and hydration to metabolic health. It has been known for decades that individuals with existing metabolic dysfunction experience challenges to body water balance and have elevated arginine vasopressin (AVP), a key hormone regulating body fluid homeostasis. Later, intervention studies demonstrated that altering fluid balance in these individuals could worsen their condition, suggesting that hydration played a role in modulating glycemic control. More recently, observational and interventional studies in healthy individuals have implicated the hydration-vasopressin axis in the pathophysiology of metabolic diseases. Individuals with higher AVP (or its surrogate, copeptin) are at higher risk for developing type 2 diabetes and components of the metabolic syndrome, an association that remains even when controlling for known risk factors. Supporting preclinical work also suggests a causal role for AVP in metabolic dysfunction. It is known that individuals who habitually drink less fluids tend to have higher circulating AVP, which may be lowered by increasing water intake. In the short term, water supplementation in habitual low drinkers with high copeptin may reduce fasting glucose or glucagon, generating a proof of concept for the role of water supplementation in reducing incident metabolic disease. A large randomized trial is ongoing to determine whether water supplementation for 1 year in subjects with low water intake can meaningfully reduce fasting glucose, risk of new-onset diabetes, and other cardiometabolic risk factors.
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Efficacy of Ingesting an Oral Rehydration Solution after Exercise on Fluid Balance and Endurance Performance.
Fan, PW, Burns, SF, Lee, JKW
Nutrients. 2020;(12)
Abstract
This study investigated the efficacy of ingesting an oral rehydration solution (DD) that has a high electrolyte concentration after exercise on fluid balance and cycling performance in comparison with a sports drink (SD) and water (WA). Nine healthy males aged 24 ± 2 years (mean ± SD), with peak oxygen uptake (VO2 peak) 55 ± 6 mL·kg-1·min-1 completed three experimental trials in a randomised manner ingesting WA, SD (carbohydrates: 62 g·L-1, sodium: 31 ± 3 mmol·L-1) or DD (carbohydrates: 33 g·L-1, sodium: 60 ± 3 mmol·L-1). On all trials, fluid was ingested during 75 min cycling at 65% VO2 peak (temperature: 30.4 ± 0.3 °C, relative humidity: 76 ± 1%, simulated wind speed: 8.0 ± 0.6 m·s-1) and during 2 h of recovery (temperature: 23.0 ± 1.0 °C, relative humidity: 67 ± 2%), with the total volume equivalent to 150% of sweat loss during the ride. A 45 min pre-load cycling time trial at a 65% VO2 peak followed by a 20 km time trial was conducted after a further 3 h of recovery. Fluid retention was higher with DD (30 ± 15%) than WA (-4 ± 19%; p < 0.001) and SD (10 ± 15%; p = 0.002). Mean ratings of palatability were similar among drinks (WA: 4.25 ± 2.60; SD: 5.61 ± 1.79; DD: 5.40 ± 1.58; p = 0.33). Although time trial performance was similar across all three trials (WA: 2365 ± 321 s; SD: 2252 ± 174 s; DD: 2268 ± 184 s; p = 0.65), the completion time was faster in eight participants with SD and seven participants with DD than with WA. Comparing SD with DD, completion time was reduced in five participants and increased in four participants. DD was more effective at restoring the fluid deficit during recovery from exercise than SD and WA without compromising the drink's palatability with increased sodium concentration. Most individuals demonstrated better endurance exercise time trial performance with DD and SD than with WA.
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Sensing of tubular flow and renal electrolyte transport.
Verschuren, EHJ, Castenmiller, C, Peters, DJM, Arjona, FJ, Bindels, RJM, Hoenderop, JGJ
Nature reviews. Nephrology. 2020;(6):337-351
Abstract
The kidney is a remarkable organ that accomplishes the challenge of removing waste from the body and simultaneously regulating electrolyte and water balance. Pro-urine flows through the nephron in a highly dynamic manner and adjustment of the reabsorption rates of water and ions to the variable tubular flow is required for electrolyte homeostasis. Renal epithelial cells sense the tubular flow by mechanosensation. Interest in this phenomenon has increased in the past decade since the acknowledgement of primary cilia as antennae that sense renal tubular flow. However, the significance of tubular flow sensing for electrolyte handling is largely unknown. Signal transduction pathways regulating flow-sensitive physiological responses involve calcium, purinergic and nitric oxide signalling, and are considered to have an important role in renal electrolyte handling. Given that mechanosensation of tubular flow is an integral role of the nephron, defective tubular flow sensing is probably involved in renal disease. Studies investigating tubular flow and electrolyte transport differ in their methodology, subsequently hampering translational validity. This Review provides the basis for understanding electrolyte disorders originating from altered tubular flow sensing as a result of pathological conditions.
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A physiological approach to fluid and electrolyte management of the preterm infant: Review.
Segar, JL
Journal of neonatal-perinatal medicine. 2020;(1):11-19
Abstract
Despite the fact that hundreds of thousands of preterm infants receive parenteral fluids each year, study of optimal fluid and electrolyte management in this population is limited. Compared to older children and adults, preterm infants have an impaired capacity to regulate water and electrolyte balance. Appropriate fluid and electrolyte management is critical for optimal care of low birth weight or sick infants, as fluid overload and electrolyte abnormalities pose significant morbidity. This review highlights basic physiological principles which need to be applied when prescribing parenteral fluids and builds upon published literature to outline a rational approach to initial fluid and electrolyte management of the preterm infant.
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Kidney Physiology in Pregnancy.
Beers, K, Patel, N
Advances in chronic kidney disease. 2020;(6):449-454
Abstract
A woman's body undergoes a myriad of changes throughout the course of a normal gestation. The kidneys play a central role in driving adjustments that guarantee maternal and fetal well-being, including a dramatic increase in glomerular filtration rate, alterations in tubular function, and changes in electrolyte and acid/base handling. Early in gestation, systemic vasodilation, driven by both a change in quantity of and response to various hormones, leads to increased renal blood flow and glomerular filtration rate. Vasodilation also results in activation of the renin-angiotensin-aldosterone axis, which combined with changing tubular handling causes alterations in total body stores of electrolytes and total body water, resulting in a lower serum sodium concentration. In addition, mild proteinuria, glucosuria, and a decrease in serum calcium and magnesium are common. The primary acid/base change seen in pregnancy is a mild respiratory alkalosis due to progesterone effects. This article provides an overview of the current understanding of the healthy response of the kidneys to pregnancy, an understanding of which is key to caring for the pregnant patient, and early identification of alterations that may indicate underlying kidney pathology in pregnancy.
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Fluid overload after coronary artery bypass graft in patients on maintenance hemodialysis is associated with prolonged time on mechanical ventilation.
da Silva, SC, Consolim-Colombo, FM, Rodrigues, RG, Gaiotto, FA, Hajjar, LA, Moysés, RMA, Elias, RM
BMC anesthesiology. 2020;(1):60
Abstract
BACKGROUND Fluid overload is a risk factor for morbidity, mortality, and prolonged ventilation time after surgery. Patients on maintenance hemodialysis might be at higher risk. We hypothesized that fluid accumulation would be directly associated with extended ventilation time in patients on hemodialysis, as compared to patients with chronic kidney disease not on dialysis (CKD3-4) and patients with normal renal function (reference group). METHODS This is a prospective observational study that included patients submitted to isolated and elective coronary artery bypass surgery, divided in 3 groups according to time on mechanical ventilation: < 24 h, 24-48 h and > 48 h. The same observer followed patients daily from the surgery to the hospital discharge. Cumulative fluid balance was defined as the sum of daily fluid balance over the first 5 days following surgery. RESULTS Patients requiring more than 48 h of ventilation (5.3%) had a lower estimated glomerular filtration rate, were more likely to be on maintenance dialysis, had longer anesthesia time, needed higher dobutamine and noradrenaline infusion following surgery, and had longer hospitalization stay. Multivariate analysis revealed that the fluid accumulation, scores of sequential organ failure assessment in the day following surgery, and the renal function (normal, chronic kidney disease not on dialysis and maintenance hemodialysis) were independently associated with time in mechanical ventilation. Among patients on hemodialysis, the time from the surgery to the first hemodialysis session also accounted for the time on mechanical ventilation. CONCLUSIONS Fluid accumulation is an important risk factor for lengthening mechanical ventilation, particularly in patients on hemodialysis. Future studies are warranted to address the ideal timing for initiating dialysis in this scenario in an attempt to reduce fluid accumulation and avoid prolonged ventilation time and hospital stay.
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Feasibility of Assessing Sodium-Associated Body Fluid Composition in End-Stage Renal Disease.
Clark-Cutaia, MN, Reisinger, N, Anache, MR, Ramos, K, Sommers, MS, Townsend, RR, Yu, G, Fargo, J
Nursing research. 2019;(3):246-252
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Abstract
BACKGROUND Cardiovascular disease accounts for more than half of all deaths in the hemodialysis (HD) population. Although much of this mortality is associated with fluid overload (FO), FO is difficult to measure, and many HD patients have significant pulmonary congestion despite the absence of clinical presentation. Cohort studies have observed that FO, as measured by bioimpedance spectroscopy (BIS), correlates with mortality. Other studies have observed that lower sodium intake is associated with less fluid-related weight gain, improved hypertension, and survival. Whether sodium intake influences FO in HD patients as measured by BIS is not known. OBJECTIVE The aims of the study were to determine the feasibility of assessing the impact of sodium restriction on body fluid composition as measured by BIS among patients with three levels of sodium intake and to determine if there are statistical and/or clinical differences in BIS measures across sodium intake groups. METHODS We used a double-blinded randomized controlled trial design with three levels of sodium restriction, 2,400 mg per day, 1,500 mg per day, and unrestricted (control group), to test our aims. Forty-two HD patients from a tertiary acute care academic institution associated with three urban DaVita dialysis centers were enrolled. Participants remained in the inpatient center for 5 days and 4 nights and were randomly assigned to sodium intake groups. Body fluid composition was measured with BIS. RESULTS Recruitment, enrollment, and retention statistics supported the feasibility of the study design. Regression analyses showed that there were no statistically significant differences among sodium intake groups on any of the outcomes. DISCUSSION Our data suggest the need for additional research into the effects of sodium restriction on body fluid composition.
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Fluid Intake But Not Fluid Balance Is Associated With Poor Outcome in Nontraumatic Subarachnoid Hemorrhage Patients.
Rass, V, Gaasch, M, Kofler, M, Schiefecker, AJ, Ianosi, BA, Steinkohl, F, Beer, R, Pfausler, B, Gizewski, ER, Thomé, C, et al
Critical care medicine. 2019;(7):e555-e562
Abstract
OBJECTIVES Optimal fluid management is important in patients with acute brain injury, including subarachnoid hemorrhage. We aimed to examine the relationship between daily fluid intake and fluid balance with hospital complications and functional outcome. DESIGN Retrospective observational cohort study. SETTING Neurocritical care unit at a tertiary academic medical center. PATIENTS Two-hundred thirty-seven consecutive nontraumatic subarachnoid hemorrhage patients admitted to the neurologic ICU between 2010 and 2016. INTERVENTIONS Total daily amount of fluids and fluid balance were calculated over 15 days. Using multivariate generalized estimating equation models the association of daily fluid intake and fluid balance with disease severity, hospital complications and poor functional outcome (3-mo modified Rankin Score ≥ 3) was investigated. Additionally, we described the composition of fluids given. MEASUREMENTS AND MAIN RESULTS Patients presented with a median admission Hunt and Hess grade of 3 (interquartile range, 1-5) and were 57 years old (interquartile range, 47-67 yr old). A higher daily fluid intake was associated with higher admission Hunt and Hess grade (odds ratio, 1.61; 95% CI, 1.47-1.76; p < 0.001), increased pulmonary fluid accumulation (adjusted odds ratio, 1.11; 95% CI, 1.01-1.21; p = 0.033), prolonged mechanical ventilation (Wald statistic = 20.08; degrees of freedom = 1; p < 0.001), higher daily Subarachnoid hemorrhage Early Brain Edema Score (adjusted odds ratio, 1.11; 95% CI, 1.01-1.22; p = 0.034), occurrence of anemia (adjusted odds ratio, 1.36; 95% CI, 1.20-1.54; p < 0.001), delayed cerebral ischemia (adjusted odds ratio, 1.31; 95% CI, 1.14-1.51; p < 0.001), and poor functional outcome (adjusted odds ratio, 1.25; 95% CI, 1.10-1.41; p < 0.001). Daily fluid balance was associated with higher admission Hunt and Hess grade (odds ratio, 1.09; 95% CI, 1.05-1.13; p < 0.001) and anemia (adjusted odds ratio, 1.17; 95% CI, 1.03-1.33; p = 0.019). The main contributors to fluids were nutritional compounds (31%), IV drugs (30%), and volume substitution (17%). CONCLUSIONS Our study demonstrates a significant association of fluid intake but not fluid balance with hospital complications and poor functional outcome in subarachnoid hemorrhage patients. A larger prospective study is needed to confirm our results.
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Positive Cumulative Fluid Balance Is Associated With Mortality in Pediatric Acute Respiratory Distress Syndrome in the Setting of Acute Kidney Injury.
Zinter, MS, Spicer, AC, Liu, KD, Orwoll, BE, Alkhouli, MF, Brakeman, PR, Calfee, CS, Matthay, MA, Sapru, A
Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 2019;(4):323-331
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Abstract
OBJECTIVES As acute kidney injury and elevated cumulative fluid balance commonly co-occur in pediatric acute respiratory distress syndrome, we aimed to identify risk factors for their development and evaluate their independent relationships with mortality. We hypothesized that acute kidney injury and elevated cumulative fluid balance would be associated with markers of inflammation and that children with elevated cumulative fluid balance and concomitant acute kidney injury would have worse outcomes than other children. DESIGN Prospective observational study using the pediatric Risk, Injury, Failure, Loss, End-Stage acute kidney injury classification. SETTING Five academic PICUs. PATIENTS Two-hundred sixty patients 1 month to 18 years old meeting the Berlin definition of acute respiratory distress syndrome between 2008 and 2014. INTERVENTIONS None. MEASUREMENTS AND RESULTS PICU mortality was 13% (34/260). Relative to survivors, nonsurvivors had greater cumulative fluid balance on day 3 of acute respiratory distress syndrome (+90.1 mL/kg; interquartile range 26.6-161.7 vs +44.9 mL/kg; interquartile range 10.0-111.3; p = 0.008) and also had higher prevalence of acute kidney injury on day 3 of acute respiratory distress syndrome (50% vs 23%; p = 0.001). On stratified analysis, greater cumulative fluid balance on day 3 of acute respiratory distress syndrome was associated with mortality among patients with concomitant acute kidney injury (+111.5 mL/kg for nonsurvivors; interquartile range 82.6-236.8 vs +58.5 mL/kg for survivors; interquartile range 0.9-176.2; p = 0.041) but not among patients without acute kidney injury (p = 0.308). The presence of acute kidney injury on acute respiratory distress syndrome day 3 was associated with mortality among patients with positive cumulative fluid balance (29.1% vs 10.4% mortality; p = 0.001) but not among patients with even or negative cumulative fluid balance (p = 0.430). Day 1 plasma interleukin-6 levels were associated with the development of day 3 positive cumulative fluid balance, day 3 acute kidney injury, and PICU mortality and the association between elevated day 1 interleukin-6 and PICU mortality was partially mediated by the interval development of day 3 positive cumulative fluid balance and day 3 acute kidney injury (p < 0.001). CONCLUSIONS In pediatric acute respiratory distress syndrome, elevated cumulative fluid balance on day 3 of acute respiratory distress syndrome is associated with mortality specifically in patients with concomitant acute kidney injury. Plasma interleukin-6 levels are associated with the development of positive cumulative fluid balance and acute kidney injury, suggesting a potential mechanism by which inflammation might predispose to mortality.