Glycerol hyperhydration: physiological responses during cold-air exposure

2005 ◽  
Vol 99 (2) ◽  
pp. 515-521 ◽  
Author(s):  
Catherine O'Brien ◽  
Beau J. Freund ◽  
Andrew J. Young ◽  
Michael N. Sawka
Keyword(s):  
Total Body Water ◽  
Water Immersion ◽  
Physiological Responses ◽  
Free Water ◽  
Fluid Retention ◽  
Body Water ◽  
Urine Flow ◽  
Air Exposure ◽  
Cold Air ◽  
Total Body

Hypohydration occurs during cold-air exposure (CAE) through combined effects of reduced fluid intake and increased fluid losses. Because hypohydration is associated with reduced physical performance, strategies for maintaining hydration during CAE are important. Glycerol ingestion (GI) can induce hyperhydration in hot and temperate environments, resulting in greater fluid retention compared with water (WI) alone, but it is not effective during cold-water immersion. Water immersion induces a greater natriuresis and diuresis than cold exposure; therefore, whether GI might be effective for hyperhydration during CAE remains unknown. This study examined physiological responses, i.e., thermoregulatory, cardiovascular, renal, vascular fluid, and fluid-regulating hormonal responses, to GI in seven men during 4 h CAE (15°C, 30% relative humidity). Subjects completed three separate, double-blind, and counterbalanced trials including WI (37 ml water/l total body water), GI (37 ml water/l total body water plus 1.5 g glycerol/l total body water), and no fluid. Fluids were ingested 30 min before CAE. Thermoregulatory responses to cold were similar during each trial. Urine flow rates were higher ( P = 0.0001) with WI (peak 11.8 ml/min, SD 1.9) than GI (5.0 ml/min, SD 1.8), and fluid retention was greater ( P = 0.0001) with GI (34%, SD 7) than WI (18%, SD 5) at the end of CAE. Differences in urine flow rate and fluid retention were the result of a greater free water clearance with WI. These data indicate glycerol can be an effective hyperhydrating agent during CAE.

scholarly journals P0310FLUID OVERLOAD AND MARKERS OF CARDIOVASCULAR DAMAGE IN SEVERE NEPHROTIC SYNDROME

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Anna Matyjek ◽  
Aleksandra Rymarz ◽  
Stanisław Niemczyk
Keyword(s):  
Nephrotic Syndrome ◽  
Total Body Water ◽  
Fluid Retention ◽  
Body Water ◽  
Intracellular Water ◽  
Control Group ◽  
Extracellular Water ◽  
Cardiovascular Damage ◽  
Water Compartments ◽  
Total Body

Abstract Background and Aims One of the major symptoms of severe nephrotic syndrome is fluid retention. Fluid overload can induce cardiovascular damage. NT-proBNP (N-terminal pro-brain natriuretic peptide) and hsTnT (high sensitivity troponin T) are well known markers of this disorder. The aim of the study was to evaluate the association between volumes of body water compartments and markers of cardiovascular damage in patients with severe nephrotic syndrome (SNS) defined as nephrotic range proteinuria and hypalbuminaemia ≤ 2.5 g/dl. Method 40 patients with SNS and eGFR >30 ml/min/1.73m2 formed the study group (SNSG) and 40 healthy volunteers without SNS matched according to age, sex, height, body mass and kidney function formed the control group (CG). In all participants serum creatinine, serum albumin concentration, daily proteinuria, hsTnT and NT-proBNP were measured. Body water compartments such as extracellular water (ECW), intracellular water (ICW), total body water (TBW), overhydration (OH) were assessed using Body Composition Monitor, Fresenius Medical Care. For statistical analysis Spearman’s correlation coefficients, chi2 or Mann-Whitney U tests were used (Statistica v 13.1). Results SNSG included 28 males (70%) and 12 females. Median age was 55 years (IQR 30-65), the mean daily proteinuria was 10.5 ±5.0 g. The characteristics of the study parameters in two groups are described in the table. Significantly higher hsTnT (18 vs 6 ng/l, p=0.0001) and NT-proBNP (294.8 vs 47.1 pg/ml, p=0.0003) levels were observed in the severe nephrotic syndrome group in comparison (SNSG) to CG. In SNSG extracellular water was significantly higher (20.9 ±5,2 vs 17.4 ±3.3 L, p=0.001) and intracellular water (ICW) was significantly lower (18.9 ±5.2 vs 21.4 ±4.8 L, p=0.034) in comparison to CG. Interestingly total body water (TBW) did not differ between the groups (39.8 ±8.6 vs 38.8 ±7.7 L, p=0.603). Also overhydration which is a derivative of ECW, was higher in SNSG (OH: 4.2 vs 0.3 L, p<0.0001) than in CG. Significant, positive correlation was observed between OH and NT-proBNP (R=0.56, p<0.0001) as well as hsTnT (R=0.60, p<0.0001). We did not observed significant correlation between ECW and NT-proBNP or hsTnT. Conclusion In the severe nephrotic syndrome group fluid retention was associated with the increase in ECW and the decrease in ICW whereas TBW was the same in both groups. Such constellation can indicate for intracellular underhydration which was not describe so far. Overhydration, which is a derivative of ECW, positively correlated with markers of cardiovascular damage and can be important for patients with resistant SNS and can influence their prognosis.

scholarly journals Vasopressin Antagonists and Dilutional Hyponatremia

2004 ◽  
Vol 18 (2) ◽  
pp. 117-118 ◽  
Author(s):  
D Mohamed Babatin ◽  
Samuel S Lee
Keyword(s):  
Total Body Water ◽  
Free Water ◽  
Body Water ◽  
Vasopressin Antagonists ◽  
Advanced Cirrhosis ◽  
Cirrhotic Patients ◽  
Dilutional Hyponatremia ◽  
Total Body

The paradox of dilutional hyponatremia, as described by Ovid two millennia ago, continues to apply to patients with advanced cirrhosis today: they have unremitting thirst despite vastly increased total body water. Hyponatremia of less than 130 mmol/L occurs in 30% of cirrhotic patients (1), and is mainly due to the reduced capacity of their kidneys to excrete free water.

Glycerol hyperhydration: hormonal, renal, and vascular fluid responses

1995 ◽  
Vol 79 (6) ◽  
pp. 2069-2077 ◽  
Author(s):  
B. J. Freund ◽  
S. J. Montain ◽  
A. J. Young ◽  
M. N. Sawka ◽  
J. P. DeLuca ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Free Water ◽  
Fluid Retention ◽  
Urine Flow ◽  
Plasma Aldosterone ◽  
Water Reabsorption ◽  
Free Water Clearance ◽  
Flow Rates ◽  
Total Body ◽  
Water Clearance

Glycerol ingestion has been shown to mediate hyperhydration; however, the mechanism(s) responsible for this improved fluid retention is not well understood. This study examined the hormonal, renal, and vascular fluid responses to glycerol hyperhydration in 11 resting male volunteers who ingested one of two experimental solutions and then a water bolus. The volume of fluid ingested was determined from the subjects' measured total body water (TBW; total volume = 37 ml/l TBW, 1,765 +/- 162 ml). Experimental solutions (5.0 ml/l TBW) were matched for color and taste and differed only in that one contained 1.5 g glycerol/l TBW (total osmolar load = 777 +/- 24 mosmol). Nine of the 11 subjects also completed a control trial during which no fluid was ingested. Glycerol ingestion (GI) resulted in greater fluid retention than the ingestion of water alone (WI; 60 vs. 32% 3-h posthyperhydration, P < 0.01). This improved fluid retention with GI resulted from lower urine flow rates (peak 6.2 vs. 10.5 ml/min, P < 0.01) associated with lower free water clearance rates (peak = 1.2 vs. 8.2 ml/min, P < 0.01). Hyperhydration had no effect on plasma atrial natriuretic peptide concentrations. Changes in plasma aldosterone were unrelated to differences in fluid retention. Antidiuretic hormone concentrations (ADH) were significantly reduced from prehyperhydration levels during both hyperhydration trials but tended (P = 0.07) to rise during GI compared with WI at the very time urine flow and free water clearance differences were also evident. This suggests that ADH may, in part, be responsible for glycerol's effectiveness, although differences in ADH concentrations were small and near the assay's sensitivity limits. Alternatively, glycerol's effectiveness may result from its directly increasing the kidneys' medullary concentration gradient and, hence, water reabsorption.

Effect of total body water estimates via bioimpedance on bod pod-based three-compartment body fat models

2021 ◽  
Author(s):  
Brett S. Nickerson ◽  
Samantha V. Narvaez ◽  
Mitzy I. Juarez ◽  
Stefan A. Czerwinski
Keyword(s):  
Body Fat ◽  
Total Body Water ◽  
Body Water ◽  
Bod Pod ◽  
Total Body

scholarly journals Effects of a 14-Day Hydration Intervention on Individuals with Habitually Low Fluid Intake

2021 ◽  
Author(s):  
Aaron R. Caldwell ◽  
Megan E. Rosa-Caldwell ◽  
Carson Keeter ◽  
Evan C. Johnson ◽  
François Péronnet ◽  
...  
Keyword(s):  
Body Weight ◽  
Total Body Water ◽  
Fluid Intake ◽  
Urine Volume ◽  
Urine Osmolality ◽  
Body Water ◽  
Control Group ◽  
Intervention Phase ◽  
Total Body ◽  
Experimental Group

<b><i>Background:</i></b> Debate continues over whether or not individuals with low total water intake (TWI) are in a chronic fluid deficit (i.e., low total body water) [<xref ref-type="bibr" rid="ref1">1</xref>]. When women with habitually low TWI (1.6 ± 0.5 L/day) increased their fluid intake (3.5 ± 0.1 L/day) for 4 days 24-h urine osmolality decreased, but there was no change in body weight, a proxy for total body water (TBW) [<xref ref-type="bibr" rid="ref2">2</xref>]. In a small (<i>n</i> = 5) study of adult men, there were no observable changes in TBW, as measured by bioelectrical impedance, after increasing TWI for 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>]. However, body weight increased and salivary osmolality decreased indicating that the study may have been underpowered to detect changes in TBW. Further, no studies to date have measured changes in blood volume (BV) when TWI is increased. <b><i>Objectives:</i></b> Therefore, the purpose of this study was to identify individuals with habitually low fluid intake and determine if increasing TWI, for 14 days, resulted in changes in TBW or BV. <b><i>Methods:</i></b> In order to identify individuals with low TWI, 889 healthy adults were screened. Participants with a self-reported TWI less than 1.8 L/day (men) or 1.2 L/day (women), and a 24-h urine osmolality greater than 800 mOsm were included in the intervention phase of the study. For the intervention phase, 15 participants were assigned to the experimental group and 8 participants were assigned to the control group. The intervention period lasted for 14 days and consisted of 2 visits to our laboratory: one before the intervention (baseline) and 14 days into the intervention (14-day follow-up). At these visits, BV was measured using a CO-rebreathe procedure and deuterium oxide (D<sub>2</sub>O) was administered to measure TBW. Urine samples were collected immediately prior, and 3–8 h after the D<sub>2</sub>O dose to allow for equilibration. Prior to each visit, participants collected 24-h urine to measure 24-h hydration status. After the baseline visit, the experimental group increased their TWI to 3.7 L for males and 2.7 L for females in order to meet the current Institute of Medicine recommendations for TWI. <b><i>Results:</i></b> Twenty-four-hour urine osmolality decreased (−438.7 ± 362.1 mOsm; <i>p</i> &#x3c; 0.001) and urine volume increased (1,526 ± 869 mL; <i>p</i> &#x3c; 0.001) in the experimental group from baseline, while there were no differences in osmolality (−74.7 ± 572 mOsm; <i>p</i> = 0.45), or urine volume (−32 ± 1,376 mL; <i>p</i> = 0.89) in the control group. However, there were no changes in BV (Fig. <xref ref-type="fig" rid="f01">1</xref>a) or changes in TBW (Fig. <xref ref-type="fig" rid="f01">1</xref>b) in either group. <b><i>Conclusions:</i></b> Increasing fluid intake in individuals with habitually low TWI increases 24-h urine volume and decreases urine osmolality but does not result in changes in TBW or BV. These findings are in agreement with previous work indicating that TWI interventions lasting 3 days [<xref ref-type="bibr" rid="ref2">2</xref>] to 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>] do not result in changes in TBW. Current evidence would suggest that the benefits of increasing TWI are not related changes in TBW.

Prediction of Total Body Water using Scaled Conjugate Gradient Artificial Neural Network

2020 ◽  
Author(s):  
Marife A. Rosales ◽  
Maria Gemel B. Palconit ◽  
Argel A. Bandala ◽  
Ryan Rhay P. Vicerra ◽  
Elmer P. Dadios ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Conjugate Gradient ◽  
Total Body Water ◽  
Body Water ◽  
Scaled Conjugate Gradient ◽  
Artificial Neural ◽  
Total Body
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