Urinary Indices of Hydration Status

1994 ◽  
Vol 4 (3) ◽  
pp. 265-279 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Carl M. Maresh ◽  
John W. Castellani ◽  
Michael F. Bergeron ◽  
Robert W. Kenefick ◽  
...  
Keyword(s):  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Field Studies ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Plasma Sodium ◽  
Strongly Correlated ◽  
Laboratory Studies ◽  
Urine Color ◽  
Precision And Accuracy

Athletes and researchers could benefit from a simple and universally accepted technique to determine whether humans are well-hydrated, euhydrated, or hypohydrated. Two laboratory studies (A, B) and one field study (C) were conducted to determine if urine color () indicates hydration status accurately and to clarify the interchangeability of , urine osmolality (), and urine specific gravity () in research. , , and were not significantly correlated with plasma osmolality, plasma sodium, or hemato-crit. This suggested that these hematologic measurements are not as sensitive to mild hypohydration (between days) as the selected urinary indices are. When the data from A, B, and C were combined, was strongly correlated with and U„sm. It was concluded that (a) may be used in athletic/industrial settings or field studies, where close estimates of or are acceptable, but should not be utilized in laboratories where greater precision and accuracy are required, and (b) and may be used interchangeably to determine hydration status.

scholarly journals Availability of a Flavored Beverage and Impact on Children’s Hydration Status, Sleep, and Mood

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1757
Author(s):  
Michael R. Szymanski ◽  
Gabrielle E. W. Giersch ◽  
Margaret C. Morrissey ◽  
Courteney L. Benjamin ◽  
Yasuki Sekiguchi ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Quality Index ◽  
Pittsburgh Sleep Quality Index ◽  
Intervention Group ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Control Group ◽  
Profile Of Mood States ◽  
Urine Color

Euhydration remains a challenge in children due to lack of access and unpalatability of water and to other reasons. The purpose of this study was to determine if the availability/access to a beverage (Creative Roots®) influences hydration in children and, therefore, sleep quality and mood. Using a crossover investigation, 46 participants were randomly assigned to a control group (CON) or an intervention group and received Creative Roots® (INT) for two-week periods. We recorded daily first morning and afternoon urine color (Ucol), thirst perception, and bodyweight of the two groups. Participants reported to the lab once per week and provided first morning urine samples to assess Ucol, urine specific gravity (USG), and urine osmolality (Uosmo). Participants also completed the questionnaires Profile of Mood States-Adolescents (POMS-a) and Pittsburgh Sleep Quality Index (PSQI). Dependent t-tests were used to assess the effects of the intervention on hydration, mood, and sleep quality. Uosmo was greater and Ucol was darker in the control group (mean ± SD) [Uosmo: INT = 828 ± 177 mOsm·kg−1, CON = 879 ± 184 mOsm·kg−1, (p = 0.037], [Ucol:INT = 5 ± 1, CON = 5 ± 1, p = 0.024]. USG, POMS-a, and PSQI were not significant between the groups. At-home daily afternoon Ucol was darker in the control group [INT = 3 ± 1, CON = 3 ± 1, p = 0.022]. Access to Creative Roots® provides a small, potentially meaningful hydration benefit in children. However, children still demonstrated consistent mild dehydration based on Uosmo, despite consuming the beverage.

Effects of Three Oral Nutritional Supplements on Human Hydration Indices

2016 ◽  
Vol 26 (4) ◽  
pp. 356-362 ◽  
Author(s):  
Lindsay A. Ellis ◽  
Brandon A. Yates ◽  
Amy L. McKenzie ◽  
Colleen X. Muñoz ◽  
Douglas J. Casa ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Urine Volume ◽  
Urine Osmolality ◽  
Ease Of Use ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Urine Color ◽  
Significant Difference ◽  
Oral Nutritional Supplements ◽  
Double Blinded

Urine color (Ucol) as a hydration assessment tool provides practicality, ease of use, and correlates moderately to strongly with urine specific gravity (Usg) and urine osmolality (Uosm). Indicative of daily fluid turnover, along with solute and urochrome excretion in 24-hr samples, Ucol may also reflect dietary composition. Thus, the purpose of this investigation was to determine the efficacy of Ucol as a hydration status biomarker after nutritional supplementation with beetroot (880 mg), vitamin C (1000 mg), and riboflavin (200 mg). Twenty males (Mean ± SD; age, 21 ± 2 y; body mass, 82.12 ± 15.58 kg; height, 1.77 ± 0.06 m) consumed a standardized breakfast and collected all urine voids on one control day (CON) and 1 day after consuming a standardized breakfast and a randomized and double-blinded supplement (SUP) over 3 weeks. Participants replicated exercise and diet for one day before CON, and throughout CON and SUP. Ucol, Usg, Uosm, and urine volume were measured in all 24-hr samples, and Ucol and Usg were measured in all single samples. Ucol was a significant predictor of single sample Usg after all supplements (p < .05). Interestingly, 24-hr Ucol was not a significant predictor of 24-h Usg and Uosm after riboflavin supplementation (p = .20, p = .21). Further, there was a significant difference between CON and SUP 24-h Ucol only after riboflavin supplementation (p < .05). In conclusion, this investigation suggests that users of the UCC (urine color chart) should consider riboflavin supplementation when classifying hydration status and use a combination of urinary biomarkers (e.g., Usg and Ucol), both acutely and over 24 hr.

scholarly journals Assessment of hydration status in a large population

2014 ◽  
Vol 113 (1) ◽  
pp. 147-158 ◽  
Author(s):  
Stephanie Baron ◽  
Marie Courbebaisse ◽  
Eve M. Lepicard ◽  
Gerard Friedlander
Keyword(s):  
Large Population ◽  
Plasma Osmolality ◽  
High Specificity ◽  
Urine Osmolality ◽  
The Elderly ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Technical Expertise ◽  
Urinary Markers ◽  
Large Sample

Both acute and chronic dehydration can have important implications for human behaviour and health. Young children, non-autonomous individuals and the elderly are at a greater risk of dehydration. Mild hypertonic dehydration could be related to less efficient cognitive and physical performance and has been reported to be associated with frequently occurring pathological conditions, especially nephrolithiasis. The assessment of hydration status in a large sample appears to be of interest for conducting epidemiological and large clinical studies aimed at improving preventive and curative care. Especially in large-population studies, methods that are used have to be accurate, cheap, quick and require no technical expertise. Body weight change is widely used to determine acute hydration changes, but seems to be insufficiently accurate in longitudinal studies. Bioimpedance analysis methods enable the assessment of total body water content, but their use is still under debate. Because plasma osmolality directly reflects intracellular osmolality, it constitutes a good marker to assess acute hydration changes, but not chronic hydration status because it changes constantly. Moreover, venepuncture is considered to be invasive and is not suitable for a large-sample study, especially in children. Urinary markers appear to be good alternatives for assessing hydration status in large populations. Collection of urine samples is non-invasive and cheap. High technical expertise is not required to perform urinary marker measurements and these measurements can be carried out quickly. Thus, methods based on urinary markers are very well suited for field studies. Urine colour is probably the least sensitive marker despite its high specificity. Urine osmolality and especially urine specific gravity could be easily used for determining hydration status in large-sample studies.

scholarly journals The Relationship between %BML, Urine Color, Thirst Level and Urine Indices of Hydration Status

2021 ◽  
Author(s):  
Yasuki Sekiguchi ◽  
Courteney L. Benjamin ◽  
Cody R. Butler ◽  
Margaret C. Morrissey ◽  
Erica M. Filep ◽  
...  
Keyword(s):  
Body Mass ◽  
Pairwise Comparison ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Venn Diagram ◽  
Hydration Status ◽  
Urine Color ◽  
Health Quality ◽  
No Gold Standard ◽  
The Relationship

<b><i>Introduction:</i></b> Dehydration is known to impair health, quality of daily life, and exercise performance [<xref ref-type="bibr" rid="ref1">1</xref>]. While several methods are utilized to assess fluid balance, there is no gold standard to assess hydration status [<xref ref-type="bibr" rid="ref2">2</xref>]. Cheuvront and Kenefick [<xref ref-type="bibr" rid="ref3">3</xref>] suggested the use of a Venn diagram, which consists of % body mass weight (BML), urine color, and thirst level (WUT) to measure hydration status and fluid needs. However, no study to date has examined the relationship between the WUT criteria and hydration status measured by urine indices. <b><i>Objective:</i></b> The purpose of this study was to investigate the relationships between urine-specific gravity (USG), urine osmolality (<i>U</i><sub>OSM</sub>), and the WUT criteria. <b><i>Methods:</i></b> Twenty-two females (mean ± SD; age, 20 ± 1 year; weight, 65.4 ± 12.6 kg) and twenty-one males (age, 21 ± 1 year; body mass, 78.7 ± 14.6 kg) participated in this study. First-morning body mass, urine color, USG, <i>U</i><sub>OSM</sub>, and thirst level were collected for 10 consecutive days. First 3 days were utilized to establish a euhydrated baseline body weight. %BML &#x3e;1%, urine color &#x3e;5, and thirst level ≥5 were used as the dehydration thresholds. The number of markers that indicated dehydration levels was summed when each variable met each threshold. One-way ANOVA with Tukey pairwise comparison was used to assess the differences in USG and <i>U</i><sub>OSM</sub>, followed by a calculation of effect size (ES). <b><i>Results:</i></b> Figure <xref ref-type="fig" rid="f01">1</xref> indicates the differences of <i>U</i><sub>OSM</sub> based on the WUT criteria. For <i>U</i><sub>OSM</sub>, “2 markers indicated” (mean [M] ± SD [ES], 705 ± 253 mOsmol [0.43], <i>p</i> = 0.018) was significantly higher than “1 marker indicated” (M ± SD, 597 ± 253 mOsmol). Additionally, “zero marker indicated” (509 ± 249 mOsmol) was significantly lower than “3 markers indicated” (M ± SD [ES], 761 ± 250 mOsmol, [1.01], <i>p</i> = 0.02) and “2 markers indicated” ([ES], [0.78], <i>p</i> = 0.004). However, there was no statistical difference between “3 markers indicated” ([ES], [0.65], <i>p</i> = 0.13) and “1 marker indicated.” For USG, “3 markers indicated” (M ± SD [ES], 1.021 ± 0.007 [0.57], <i>p</i> = 0.025) and “2 markers indicated” (M ± SD [ES], 1.019 ± 0.010 [0.31], <i>p</i> = 0.026) were significantly higher than “1 marker indicated” (M ± SD, 1.016 ± 0.009). Additionally, “zero marker indicated” (1.014 ± 0.005) was significantly lower than “3 markers indicated” ([ES], [1.21], <i>p</i> = 0.005) and “2 markers indicated” ([ES], [0.54], <i>p</i> = 0.009). <b><i>Conclusion:</i></b> When 3 markers indicated dehydration levels, <i>U</i><sub>OSM</sub> and USG were greater than euhydrated cut points. When 2 markers indicated dehydration levels, USG was higher than the euhydrated cut point. Additionally, <i>U</i><sub>OSM</sub> and USG were significantly lower when zero or 1 marker indicated dehydration levels. Thus, the WUT criteria are a useful tool to assess hydration status. Athletes, coaches, sports scientists, and medical professions can use this strategy in the field settings to optimize their performance and health without consuming money and time.

Relationships Between WUT (Body Weight, Urine Color, and Thirst Level) Criteria and Urine Indices of Hydration Status

2021 ◽  
pp. 194173812110384
Author(s):  
Yasuki Sekiguchi ◽  
Courteney L. Benjamin ◽  
Cody R. Butler ◽  
Margaret C. Morrissey ◽  
Erica M. Filep ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Mass Loss ◽  
Body Mass ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Venn Diagram ◽  
Hydration Status ◽  
Body Mass Loss ◽  
Living Situation ◽  
Urine Color

Background: A Venn diagram consisting of percentage body mass loss, urine color, and thirst perception (weight, urine, thirst [WUT]) has been suggested as a practical method to assess hydration status. However, no study to date has examined relationships between WUT and urine hydration indices. Thus, the purpose of this study was to investigate relationships between urine specific gravity, urine osmolality, and the WUT criteria. Hypothesis: Urine specific gravity and urine osmolality indicate hypohydration when the WUT criteria demonstrate hypohydration (≥2 markers). Study Design: Laboratory cohort study. Level of Evidence: Level 3. Methods: A total of 22 women (mean ± SD; age, 20 ± 1 years; mass, 65.4 ± 12.6 kg) and 21 men (age, 21 ± 1 years; body mass, 78.7 ± 14.6 kg) participated in this study. First morning body mass, urine color, urine specific gravity, urine osmolality, and thirst level were collected for 10 consecutive days in a free-living situation. Body mass loss >1%, urine color >5, and thirst level ≥5 were used as the dehydration thresholds. The number of markers that indicated dehydration levels were counted and categorized into either 3, 2, 1, or 0 WUT markers that indicated dehydration. One-way analysis of variance with Tukey pairwise comparisons was used to assess the differences in urine specific gravity and urine osmolality between the different number of WUT markers. Results: Urine specific gravity in 3 WUT markers (mean ± SD [effect size], 1.021 ± 0.007 [0.57]; P = 0.025) and 2 WUT markers (1.019 ± 0.010 [0.31]; P = 0.026) was significantly higher than 1 WUT marker (1.016 ± 0.009). Urine mosmolality in 2 WUT markers (705 ± 253 mOsmol [0.43]; P = 0.018) was significantly higher than 1 WUT (597 ± 253 mOsmol). Meeting at least 2 WUT markers resulted in sensitivities of 0.652 (2 WUT criteria met) and 0.933 (3 WUT criteria met) to detect urine osmolality >700 mOsmol. Conclusion: These results suggest that when 3 WUT markers are met, urine specific gravity and urine osmolality were greater than euhydration cutoff points. The WUT criterion is a useful tool to use in field settings to assess hydration status when first morning urine sample was used. Clinical Relevance: Athletes, coaches, sports scientists, and medical professionals can use WUT criteria to monitor dehydration with reduced cost and time.

Accuracy of Urine Specific Gravity and Osmolality as Indicators of Hydration Status

2005 ◽  
Vol 15 (3) ◽  
pp. 236-251 ◽  
Author(s):  
Robert A. Oppliger ◽  
Scott A. Magnes ◽  
LeRoy A. Popowski ◽  
Carl V. Gisolfi
Keyword(s):  
Body Weight ◽  
Specific Gravity ◽  
Decision Model ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Medical Decision ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Accurate Assessment ◽  
Factors Affecting

To reduce the adverse consequences of exertion-related and acute intentional dehydration research has focused on monitoring hydration status. This investigation: 1) compared sensitivity of urine specific gravity (Usg), urine osmolality (Uosm) and a criterion measurement of hydration, plasma osmolality (Posm), at progressive stages of acute hypertonic dehydration and 2) using a medical decision model, determined whether Usg or Uosm accurately reflected hydra-tion status compared to Posm among 51 subjects tested throughout the day. Incremental changes in Posm were observed as subjects dehydrated by 5% of body weight and rehydrated while Usg and Uosm showed delayed dehydration-related changes. Using the medical decision model, sensitivity and specificity were not significant at selected cut-offs for Usg and Uosm. At the most accurate cut-off values, 1.015 and 1.020 for Usg and 700 mosm/kg and 800 mosm/kg for Uosm, only 65% of the athletes were correctly classified using Usg and 63% using Uosm. Posm, Usg, and Uosm appear sensitive to incremental changes in acute hypertonic dehydration, however, the misclassified outcomes for Usg and Uosm raise concerns. Research focused on elucidating the factors affecting accurate assessment of hydration status appears warranted.

Urinary Indices during Dehydration, Exercise, and Rehydration

1998 ◽  
Vol 8 (4) ◽  
pp. 345-355 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Jorge A. Herrera Soto ◽  
Frank T. Hacker ◽  
Douglas J. Casa ◽  
Stavros A. Kavouras ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Urine Volume ◽  
Plasma Osmolality ◽  
Body Water ◽  
Hydration Status ◽  
Plasma Sodium ◽  
Oral Rehydration ◽  
Urine Color ◽  
Better Than

This investigation evaluated the validity and sensitivity of urine color (Ucol), specific gravity (Usg), and osmolality (Uosm) as indices of hydration status, by comparing them to changes in body water. Nine highly trained males underwent a 42-hr protocol involving dehydration to 3.7% of body mass (Day 1, −2.64 kg), cycling to exhaustion (Day 2, −5.2% of body mass, −3.68 kg), and oral rehydration for 21 hr. The ranges of mean (across time) blood and urine values were Ucol, 1-7; Usg, 1.004-1.029; U08m, 117-1,081 mOsm • kg−1; and plasma osmolality (Posm), 280-298 mOsm ⋅ kg−1. Urine color tracked changes in body water as effectively as (or better than) Uosm, Usg, urine volume, Posm, plasma sodium, and plasma total protein. We concluded that (a) Ucol, Uosm, and Usg are valid indices of hydration status, and (b) marked dehydration, exercise, and rehydration had little effect on the validity and sensitivity of these indices.

Quantification of chromatographic effects of vitamin B supplementation in urine and implications for hydration assessment

2015 ◽  
Vol 119 (2) ◽  
pp. 110-115 ◽  
Author(s):  
Robert W. Kenefick ◽  
K. R. Heavens ◽  
W. E. Dennis ◽  
E. M. Caruso ◽  
K. I. Guerriere ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Urine Osmolality ◽  
Vitamin Supplementation ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Vitamin B ◽  
Color Classification ◽  
Urine Color ◽  
Hydration Assessment

Changes in body water elicit reflex adjustments at the kidney, thus maintaining fluid volume homeostasis. These renal adjustments change the concentration and color of urine, variables that can, in turn, be used as biomarkers of hydration status. It has been suggested that vitamin supplementation alters urine color; it is unclear whether any such alteration would confound hydration assessment via colorimetric evaluation. We tested the hypothesis that overnight vitamin B2 and/or B12 supplementation alters urine color as a marker of hydration status. Thirty healthy volunteers were monitored during a 3-day euhydrated baseline, confirmed via first morning nude body mass, urine specific gravity, and urine osmolality. Volunteers then randomly received B2 ( n = 10), B12 ( n = 10), or B2 + B12 ( n = 10) at ∼200 × recommended dietary allowance. Euhydration was verified on trial days (two of the following: body mass ± 1.0% of the mean of visits 1–3, urine specific gravity < 1.02, urine osmolality < 700 mmol/kg). Vitamin purity and urinary B2 concentration ([B2]) and [B12] were quantified via ultraperformance liquid chromatography. Two independent observers assessed urine color using an eight-point standardized color chart. Following supplementation, urinary [B2] was elevated; however, urine color was not different between nonsupplemented and supplemented trials. For example, in the B2 trial, urinary [B2] increased from 8.6 × 104 ± 7.7 × 104 to 5.7 × 106 ± 5.3 × 106 nmol/l ( P < 0.05), and urine color went from 4 ± 1 to 5 ± 1 ( P > 0.05). Both conditions met the euhydrated color classification. We conclude that a large overnight dose of vitamins B2 and B12 does not confound assessment of euhydrated status via urine color.

scholarly journals Urine specific gravity as a diagnostic tool for dehydration in children

2010 ◽  
Vol 50 (5) ◽  
pp. 269 ◽  
Author(s):  
Kalis Joko Purwanto ◽  
Mohammad Juffrie ◽  
Djauhar Ismail
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Specific Gravity ◽  
Diagnostic Tool ◽  
Clinical Judgment ◽  
Plasma Osmolality ◽  
Body Weight Loss ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Urine Production

Background Using clinical judgment to diagnose dehydration can be highly subjective. To diagnose dehydration, it would be ideal to have an accurate, inexpensive, objective and easy-to-perform diagnostic tool. In cases of dehydration, plasma osmolality rises, causing an increase in antidiuretic hormone (ADH) secretion. The increased ADH reduces urine production and increases urine osmolality. Previous studies have show that urine osmolality correlates well to urine specific gravity. We investigated if urine specific gravity can be a reliable and objective detennination of dehydration status.Objective To assess the accuracy of using urine specific gravity as a diagnostic tool to determine dehydration status of children with diarrhea.Methods We conducted the study in the pediatric ward of Sardjito Hospital from September 2009 to December 2009. Using a refractometer we measured urine specific gravity from patients with diarrhea. This measurement was then compared to a standard of acute body weight loss, with dehydration defined as weight loss of 5% or more. The cut-off value for defining dehydration using specific gravity measurements was detennined by a receiver-operator curve (ROC).Results Out of 61 pediatric patients who were recruited in this study, 18 (30%) had dehydration as defined by a body weight loss of 5% or more. Based on the ROC, we determined the cut off  value for urine specific gravity to be 1.022. Using this value, urine specific gravity was 72% sensitive (95% CI 52 to 93), and 84% specific (95% CI 73 to 95) in determining dehydration status.Conclusion Urine specific gravity is less accurate than clinical judgment in determining dehydration status in children with diarrhea.

scholarly journals Effects of sex and menstrual cycle on volume-regulatory responses to 24-h fluid restriction

2020 ◽  
Vol 319 (5) ◽  
pp. R560-R565
Author(s):  
Gabrielle E. W. Giersch ◽  
Abigail T. Colburn ◽  
Margaret C. Morrissey ◽  
Cody R. Butler ◽  
Michaela L. Pruchnicki ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Specific Gravity ◽  
Body Mass ◽  
Urine Osmolality ◽  
Reproductive Hormones ◽  
Urine Specific Gravity ◽  
Fluid Restriction ◽  
Urine Color ◽  
Fluid Regulation ◽  
The Impact

Reproductive hormones have significant nonreproductive physiological effects, including altering fluid regulation. Our purpose was to explore the impact of sex and menstrual cycle (MC) phase on volume-regulatory responses to 24-h fluid restriction (24-h FR). Participants (men: n = 12, 20 ± 2 yr; women: n = 10, 20 ± 1 yr) were assigned two randomized and counterbalanced fluid prescriptions [Euhy: euhydrated, urine specific gravity (USG) < 1.020; Dehy: 24-h FR, USG > 1.020]. Men completed both (MEuhy, MDehy), while women completed both in the late-follicular ( days 10–13; FDehy, FEuhy) and midluteal ( days 18–22; LDehy, LEuhy) phases. We measured body mass, plasma and urine osmolality (Posm, Uosm), urine specific gravity (USG), urine color (Ucol), and serum copeptin; 24-h FR yielded mild dehydration without influence of sex or MC ( P > 0.05). Copeptin increased in men following Dehy (pre: 8.2 ± 5.2, post: 15.8 ± 12.6, P = 0.04) but not in women (FDehy pre: 4.3 ± 1.6, post: 10.5 ± 6.9, P = 0.06; LDehy pre: 5.6 ± 3.5, post: 10.4 ± 6.2, P = 0.16). In FDehy, Posm increased following FR (pre: 288 ± 2, post: 292 ± 1, P = 0.03) but not in men (pre: 292 ± 3, post: 293 ± 2, P = 0.46). No MC differences were observed between body mass loss, Posm, Uosm, USG, and copeptin ( P > 0.05). These results suggest that volume-regulatory responses to 24-h FR were present in men but not in women, without apparent effects of the menstrual cycle.

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