Assessment of hydration status in a large population

Use of Bioimpedance Spectroscopy for Postoperative Fluid Management in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass

OBJECTIVE

To assess whether bioimpedance spectroscopy analysis (BIA) can be used as a tool to guide postoperative fluid management in patients undergoing cardiac surgery.

DESIGN

An observational study.

SETTING

A single tertiary hospital.

PARTICIPANTS

Patients who underwent cardiac surgery with cardiopulmonary bypass between June and November 2023 who were able to undergo BIA measurements.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Correlations between BIA measurements of extracellular fluid (ECF) and total body water (TBW) volumes and daily changes in weight and 24-hour net intake and output (I/O) of fluids were assessed. Correlations between predischarge ECF volume as a percentage of TBW volume (ECF%TBW) and predischarge pro-B-type natriuretic peptide (Pro-BNP) levels and readmissions were analyzed. Changes in daily ECF volume significantly correlated with daily weight changes (p < 0.01) and 24-hour I/O (p < 0 .01). TBW volume significantly correlated with daily weight changes (p < 0.01) and with 24-hour I/O (p = 0.04). Daily weight changes did not correlate with 24-hour I/O (p = 0.06). The patients with predischarge ECF%TBW(%) greater than or equal to 51 had significantly higher predischarge Pro-BNP than those with ECF%TBW(%) less than 51 (p < 0.01). Patients who had heart failure revisits or admissions after discharge had a higher predischarge ECF%TBW(%) on index admission compared with patients who did not have heart failure readmissions (p = 0.01).

CONCLUSIONS

BIA measurements in postoperative cardiac surgery patients may be a valuable tool to quantitatively determine fluid status to help guide fluid management in this patient population. Further studies validating the use of BIA for postoperative care in this population are warranted.

Is mild dehydration a risk for progression of childhood chronic kidney disease?

Children with chronic kidney disease (CKD) can have an inherent vulnerability to dehydration. Younger children are unable to freely access water, and CKD aetiology and stage can associate with reduced kidney concentrating capacity, which can also impact risk. This article aims to review the risk factors and consequences of mild dehydration and underhydration in CKD, with a particular focus on evidence for risk of CKD progression. We discuss that assessment of dehydration in the CKD population is more challenging than in the healthy population, thus complicating the definition of adequate hydration and clinical research in this field. We review pathophysiologic studies that suggest mild dehydration and underhydration may cause hyperfiltration injury and impact renal function, with arginine vasopressin as a key mediator. Randomised controlled trials in adults have not shown an impact of improved hydration in CKD outcomes, but more vulnerable populations with baseline low fluid intake or poor kidney concentrating capacity need to be studied. There is little published data on the frequency of dehydration, and risk of complications, acute or chronic, in children with CKD. Despite conflicting evidence and the need for more research, we propose that paediatric CKD management should routinely include an assessment of individual dehydration risk along with a treatment plan, and we provide a framework that could be used in outpatient settings.

Drug Consumption and Hydration Status: Analysis of the Associations in an Elder Population

Hydration status plays a key role in healthy ageing, and it is potentially affected by several factors, including drug consumption. However, research on this issue to date is scarce, especially in highly vulnerable groups, such as the elderly. We aimed to study the relationship linking hydration status, analysed by means of a validated questionnaire, 24 h urine analysis, body composition assessment, and drug consumption in a sample of old adults. A total of 144 elders were included in the study. Cardiovascular drug consumption was significantly associated with a lower water intake in men (β = -0.282, p = 0.029). Moreover, urinary analysis revealed that total drug intake as well as the consumption of diuretics and cardiovascular drugs were associated with poorer hydration status, whereas genito-urinary drugs were associated with an opposite effect, and these results were confirmed in terms of body composition. Hence, total drug consumption (β = -0.205), diuretic (β = -0.408), cardiovascular (β = -0.297), and genito-urinary drugs (β = 0.298) were significantly associated (p < 0.05) with total body water. The obtained results confirmed the impact of chronic treatment with certain drugs on hydration status. Nutritional interventions may be of great interest in certain population groups in order to prevent complications due to altered hydration status.

Hydration status in adults with metabolic disorders in relation to socioeconomic, lifestyle and health factors

INTRODUCTION

Adequate hydration is essential for maintaining the health and functionality of the human body. This study aimed to examine the association between selected socioeconomic, lifestyle, and health factors and the hydration status of adults with metabolic disorders by analyzing their urine osmolality.

METHODS

The study involved 290 adults aged 18-70 years with metabolic disorders. Separate multivariate logistic regression models were conducted to evaluate the factors associated with urine osmolality in tertiles for women and men. Odds Ratios (OR) and 95% Confidence Intervals (95% CI) were calculated.

RESULTS

In women, the following factors of urine osmolality were identified in 1st tertile: age (OR:1.04), physical activity (moderate/high vs. no/low; OR:0.38), and headaches (no vs. yes; OR:1.55), in 2nd tertile: physical activity (moderate/high vs. no/low; OR:2.46) and fatigue during the day (sometimes vs. never/very rarely; OR:0.45), and in 3rd tertile: age (OR:0.94), professional status ('I work part-time/I study and I work' vs. 'I do not work/I study'; OR:0.27), fatigue during the day (very often vs. never/very rarely; OR:2.55), and headaches (no vs. yes; OR:0.44). In men, the following factors of urine osmolality were identified in 1st tertile: place of residence (city vs. village; OR:2.72) and health assessment (average vs. poor; OR:0.32).

CONCLUSION

Different factors affecting urine osmolality have been identified in women and men. These results highlight the need to implement studies to clarify the relationship between socioeconomic, lifestyle and health factors, and hydration status in adults with metabolic disorders.

Effect of Nebulization on Laryngeal Parameters: Analysis Using High-Speed Digital Videolaryngoscopy

INTRODUCTION

Superficial laryngeal hydration, obtained through nebulization, is related to the moisture level on the epithelial surfaces of the vocal folds, modifying their biomechanical and aerodynamic properties. Through high-speed videolaryngoscopy it is possible to obtain objective data for laryngeal analysis after nebulization and a better understanding of this phenomenon OBJECTIVE: To verify the effects of nebulization with saline solution on laryngeal parameters of digital videokymography obtained by high-speed videolaryngoscopy examination in women and men with and without laryngeal alterations METHOD: This is a clinical, comparative intra-subject study. Fifty-nine adults were selected, with and without laryngeal alterations, 30 females and 29 males. Digital videokymographs in the anterior, middle and posterior thirds of the vocal folds of the participants were analyzed before and after nebulization with 0.9% saline solution.

RESULTS

Women without laryngeal alterations showed more parameters changes after nebulization, in which there was a decrease in maximum and medium opening, amplitude of opening of the left and right vocal fold in the anterior glottal third, and an increase of the percentage of closure of the vocal folds. These results indicate a minor extent of lateral excursion of the vocal folds during phonation. In women with laryngeal alterations, the parameters that changed after nebulization were the increased frequency of opening of the left and right vocal folds in the topography of the posterior third. In men, nebulization did not change the variables studied, except for the amplitude of the right vocal fold in men with laryngeal alterations, in the analysis of the posterior glottic third.

CONCLUSION

The results suggest that surface hydration modifies laryngeal dynamics differently between genders. After nebulization with saline solution, women without laryngeal alterations showed a decrease in the lateralization of the vocal folds during phonation, suggesting a better phonatory efficiency.

Risk factors associated with indicators of dehydration among migrant farmworkers

OBJECTIVE

Farmworkers are at increased risk of adverse health outcomes related to occupational heat exposure and inadequate access to water, shade, or rest breaks. Presently, there is a dearth of studies examining the prevalence of dehydration and related factors in U.S. farmworkers. Our objectives were to characterize hydration status during typical workdays and to identify risk factors associated with increased dehydration in migrant farmworkers employed in Florida.

METHODS

Urine samples were collected and analyzed for urine specific gravity (USG) 2-3 times per person per day over five days in May 2021 and 2022. Data collection included demographic characteristics, wet-bulb-globe-temperature (WBGT), and information on working conditions (task type, duration, and crop units harvested), fluid intake, clothing worn, and heat safety behaviors. Multivariable mixed regression models were used to evaluate risk factors associated with change in USG levels (continuous) during a work shift.

RESULTS

A total of 111 farmworkers participated in this study providing 1020 cumulative USG measurements, of which 96.8% of end-of-shift USG samples were above 1.020 indicating potential dehydration. In multivariable models, dehydration assessed using change in USG levels significantly declined with age (β = -0.078; 95%CI: 0.150, -0.006) but showed significant increase with body mass index (β = 0.016; 95%CI: 0.003, 0.028), WGBT (β = 0.054; 95%CI:0.044, 0.064), mean shift duration, and state of primary residence. We did not find significant associations of dehydration with type of clothing worn, intake of employer-provided water, or crop units harvested during a shift in this sample of farmworkers.

CONCLUSION

Our findings underscore the need for additional research to evaluate adverse outcomes related to dehydration and to better understand recovery patterns from chronic dehydration across workweeks and harvest seasons in migrant farmworkers.

Need for a consensus definition of chronic dehydration: A scoping review

Dehydration is common in older adults and impacts their clinical outcomes. Chronic dehydration is especially important as it has been under-recognized. This scoping review aimed to summarize the available definitions of chronic dehydration to identify gaps between each definition and discuss future research needs. Four databases (Pubmed, CINAHL, Cochrane Library, Science Direct) were systematically searched for peer-reviewed articles that clearly described the definition of chronic dehydration published from inception to June 8th, 2023. Two researchers reviewed the articles independently, and any disagreement was solved upon discussion. We identified five articles with a wide range of subjects from children to older adults. Chronic dehydration was defined as a state of persistently elevated blood urea levels; weight loss ≥ 1% as a result of fluid loss; a ratio of blood urea nitrogen to creatinine > 20; serum osmolarity ≥ 295 mOsm/kg; and a dehydrated state lasting 72 hours or longer. The definition varied among studies, indicating the need to establish an international consensus on the definition of chronic dehydration.

Trends and Missing Links in (De)Hydration Research: A Narrative Review

Despite decades of literature on (de)hydration in healthy individuals, many unanswered questions remain. To outline research and policy priorities, it is fundamental to recognize the literature trends on (de)hydration and identify current research gaps, which herein we aimed to pinpoint. From a representative sample of 180 (de)hydration studies with 4350 individuals, we found that research is mainly limited to small-scale laboratory-based sample sizes, with high variability in demographics (sex, age, and level of competition); to non-ecological (highly simulated and controlled) conditions; and with a focus on recreationally active male adults (e.g., Tier 1, non-athletes). The laboratory-simulated environments are limiting factors underpinning the need to better translate scientific research into field studies. Although, consistently, dehydration is defined as the loss of 2% of body weight, the hydration status is estimated using a very heterogeneous range of parameters. Water is the most researched hydration fluid, followed by alcoholic beverages with added carbohydrates (CHO). The current research still overlooks beverages supplemented with proteins, amino acids (AA), and glycerol. Future research should invest more effort in "real-world" studies with larger and more heterogeneous cohorts, exploring the entire available spectrum of fluids while addressing hydration outcomes more harmoniously.

Association between Urine Specific Gravity as a Measure of Hydration Status and Risk of Type 2 Diabetes: The Kailuan Prospective Cohort Study

Diabetes, especially type 2 diabetes (T2D), poses an unprecedented challenge to global public health. Hydration status also plays a fundamental role in human health, especially in people with T2D, which is often overlooked. This study aimed to explore the longitudinal associations between hydration status and the risk of T2D among the Chinese population. This study used data from the large community-based Kailuan cohort, which included adults who attended physical examinations from 2006 to 2007 and were followed until 2020. A total of 71,526 participants who eventually met the standards were divided into five hydration-status groups based on their levels of urine specific gravity (USG). Multivariable and time-dependent Cox proportional hazards models were employed to evaluate the associations of baseline and time-dependent hydration status with T2D incidence. Restricted cubic splines (RCS) analysis was used to examine the dose-response relationship between hydration status and the risk of T2D. Over a median 12.22-year follow-up time, 11,804 of the participants developed T2D. Compared with the optimal hydration-status group, participants with dehydration and severe dehydration had a significantly increased risk of diabetes, with adjusted hazard ratios (95% CI) of 1.30 (1.04-1.63) and 1.38 (1.10-1.74). Time-dependent analyses further confirmed the adverse effects of impending dehydration, dehydration, and severe dehydration on T2D incidence by 16%, 26%, and 33% compared with the reference group. Inadequate hydration is significantly associated with increased risks of T2D among Chinese adults. Our findings provided new epidemiological evidence and highlighted the potential role of adequate hydration status in the early prevention of T2D development.

A Study of Fluid Intake, Hydration Status, and Body Composition of Pregnant Women in Their Third Trimester, and Relationships with Their Infant's Birth Weight in China: A Prospective Cohort Study

BACKGROUND

Water intake and hydration status may potentially influence maternal and child health. However, there is little research regarding this topic.

OBJECTIVES

This study aimed to investigate pregnant women's total fluid intake (TFI) levels, hydration status, and body composition and further explore their relationship with infant birth weight.

METHODS

A 7-day, 24 h fluid intake recorded was applied to determine participants' TFI levels. Morning urine samples were collected and tested to evaluate their hydration status. Maternal body compositions in their third trimester and infant birth weights were measured.

RESULTS

A total of 380 participants completed the study. The TFI was insufficient for pregnant women during their third trimester (median = 1574 mL), with only 12.1% of participants meeting the recommended adequate fluid intake level for pregnant women living in China (1.7 L per day). With the increasing TFI values, the urine osmolality decreased, which showed statistical significance among the four groups (χ2 = 22.637, p < 0.05). The participants displayed a poor hydration status. Meanwhile, the percentage of participants who were in dehydrated status decreased (χ2 = 67.618, p < 0.05), while body water content and basal metabolic rate increased with the increase in TFI levels (χ2 = 20.784, p < 0.05; χ2 = 14.026, p < 0.05). There were positive linear relationships between plain water intake, the basal metabolic rate of pregnant women and their infant birth weight (SE = 0.153, p < 0.05; SE = 0.076, p < 0.05).

CONCLUSIONS

Water intake was insufficient, and poor hydration status was common among pregnant women in China. There may be potential relationships between plain water intake, basal metabolic rate, and infant birth weight.

The severity of early fluid overload assessed by bioelectrical vector impedance as an independent risk factor for longer patient care after cardiac surgery

BACKGROUND AND AIMS

Fluid overload is a common postoperative complication in patients undergoing cardiac surgery. Although this condition is notably associated with relevant adverse outcomes, assessment of hydration status in clinical practice is challenging. Bioelectrical impedance vector analysis (BIVA) has emerged as a potentially effective method to monitor hydration changes, but the available evidence in critically ill patients undergoing cardiac surgery is limited and sometimes conflicting. The aim of this study was to explore by mean of BIVA the evolution over time of hydration status and its impact on relevant outcomes.

METHODS

Prospective observational study enrolling 130 patients undergoing cardiac surgery. Height normalized impedance was calculated both before surgery (baseline) and in the first five postoperative days. Relevant clinical and laboratory data were collected daily close to BIVA measurements. Length of mechanical ventilation (MV), intensive care unit (ICU) and hospital stay exceeding the 75th percentile of the study population were considered as study endpoints.

RESULTS

Compared to baseline, a significant reduction in impedance was found at first postoperative day, demonstrating a relevant fluid overload. An adjusted impedance at first postoperative day shorter than the best respective threshold was associated to longer MV (7.4 times), ICU stay (4.7 times) and hospital stay (5.6 times). A significant change in impedance and phase angle was documented throughout the observation days (p < 0.001), without returning to the baseline value. The co-existence of low impedance and high plasma osmolarity increased significantly the risk of incurring the study outcomes.

CONCLUSIONS

In patients with cardiac surgery-induced fluid overload, recovery to baseline conditions occurs slowly. A relevant early fluid overload should be considered predictive for longer time of MV, ICU and total hospital stay.

Dehydration associates with lower urinary tract symptoms in progressive multiple sclerosis

BACKGROUND

Lower urinary tract symptoms (LUTS) are common in persons with progressive multiple sclerosis (pwPMS), who may consequently limit their fluid intake. We aimed to investigate the hypothesis that LUTS associate with objective evidence of inadequate hydration status in pwPMS.

METHODS

In this prospective study, 55 pwPMS were studied over 2 years. A 6-monthly first-morning urine specimen was analysed for urinary osmolality and sodium as hydration markers. LUTS symptom severity in three categories (urgency, voiding and discomfort) was assessed and quantified using a questionnaire. Correlation between LUTS severity and hydration was assessed within subjects and between subjects, controlling for age.

RESULTS

Some 274 urine samples with accompanying LUTS data from 55 participants were analysed. Biochemical data showed the expected loss of urine-concentrating capacity with increasing age. Inadequate hydration was observed in 47% of participants. LUTS were very common (87% reported urgency and 89% voiding symptoms). Voiding and discomfort, but not urgency severity, were correlated with hydration markers, both within and between participants.

CONCLUSIONS

LUTS are very common in pwPMS, and associate with inadequate hydration. The causes and consequences of inadequate hydration in MS need further study, since (i) this will focus greater attention on LUTS management in pwPMS and (ii) dehydration has been associated with reversible cognitive dysfunction and physical underperformance.

Skin-interfaced microfluidic sweat collection devices for personalized hydration management through thermal feedback

Non-electronic wearables that utilize skin-interfaced microfluidic technology have revolutionized the collection and analysis of human sweat, providing valuable biochemical information and indicating body hydration status. However, existing microfluidic devices often require constant monitoring of data during sweat assessment, thereby impeding the user experience and potentially missing anomalous physiological events, such as excessive sweating. Moreover, the complex manufacturing process hampers the scalability and large-scale production of such devices. Herein, we present a self-feedback microfluidic device with a unique dehydration reminder through a cost-effective "CAD-to-3D device" approach. It incorporates two independent systems for sweat collection and thermal feedback, including serpentine microchannels, reservoirs, petal-like bursting valves and heating chambers. The device operates by sequentially collecting sweat in the channels and reservoirs, and then activating thermal stimulators in the heating chambers through breaking the valves, initiating a chemical exothermic reaction. Human trials validate that the devices effectively alert users to potential dehydration by inducing skin thermal sensations triggered by sweat sampling. The proposed device offers facile scalability and customizable fabrication, and holds promise for managing hydration strategies in real-world scenarios, benefiting individuals engaged in sporting activities or exposed to high-temperature settings.

Origins of thirstiness sensation and current food solutions

The sensation of thirstiness is the desire to drink water. In certain situations, the ingestion of liquid water can be restricted. As a result, thirstiness is not relieved, resulting in an uncomfortable and distressing situation. The present review describes thirstiness and hydration, the food products and beverages that cause thirstiness, and the beverages and food products currently available to quench thirstiness in individuals with restricted access to liquid ingestion. It also discusses how to measure the effectiveness of calming thirstiness. To diminish thirstiness distress, different alternatives to liquids are proposed. Individuals with swallowing disorders are given thickened water, individuals with restricted water ingestion are given ice cubes or ice popsicles of different flavors, and sportspeople are given energy gels. However, current beverage solutions seem not to relieve thirst fully, although some stimuli like iced water, flavors (especially lemon and mint), or acids seem to work better than plain stimuli and could be added to existing products. Therefore, there is still a need to incorporate these strategies into beverage and food formulations and to test their effectiveness.

The Importance of Optimal Hydration in Patients with Heart Failure-Not Always Too Much Fluid

Heart failure (HF) is a leading cause of morbidity and mortality and a major public health problem. Both overhydration and dehydration are non-physiological states of the body that can adversely affect human health. Congestion and residual congestion are common in patients hospitalized for HF and are associated with poor prognosis and high rates of rehospitalization. However, the clinical problem of dehydration is also prevalent in healthcare and community settings and is associated with increased morbidity and mortality. This article provides a comprehensive review of the issue of congestion and dehydration in HF, including HF guidelines, possible causes of dehydration in HF, confirmed and potential new diagnostic methods. In particular, a full database search on the relationship between dehydration and HF was performed and all available evidence in the literature was reviewed. The novel hypothesis of chronic subclinical hypohydration as a modifiable risk factor for HF is also discussed. It is concluded that maintaining euvolemia is the cornerstone of HF management. Physicians have to find a balance between decongestion therapy and the risk of dehydration.

Hypohydration, Functional Constipation, and Physical Activity in Elementary School Students

This school-based, cross-sectional study aimed to evaluate whether hypohydration is related to functional constipation and physical activity in school-aged children. The study included 452 students aged 6-12 years. Hypohydration, defined as urinary osmolality >800 mOsm/kg, was more prevalent ( P = 0.002) in boys (72.1%) than in girls (57.5%). The difference in the prevalence of functional constipation according to sex (20.1% in boys and 23.8% in girls) was not statistically significant ( P = 0.81). In bivariate analysis, functional constipation was associated with hypohydration in girls (odds ratio = 1.93, 95% confidence interval: 1.07-3.49), and multiple logistic regression did not reach statistical significance ( P = 0.082). Low proportions of active commuting to school in both sexes were associated with hypohydration. However, there were no associations between functional constipation, active commuting to school, and physical activity scores. In conclusion, multiple logistic regression did not demonstrate an association between hypohydration and functional constipation in school-aged children.

The association between hydration status and body composition in healthy children and adolescents

OBJECTIVES

Children 10-20 years old in the US are currently obese, showing suboptimal hydration as 60% fail to meet the US Dietary Reference Intakes for water. Studies have shown a significant inverse association between hydration status and body composition in children, although most failed to use the Dual-X-Ray Absorptiometry Scan (DEXA), the gold standard for body composition. Limited studies used an objective marker to measure hydration, such as urine specific gravity (USG) from a 24-h urine collection. Therefore, this study aimed to examine the association between hydration status (measured from USG in a 24-h urine sample and assessed from three 24-h dietary recalls) and body fat % and lean mass (assessed from a DEXA scan) in children (10-13 years, n=34) and adolescents (18-20 years, n=34).

METHODS

Body composition was measured using DEXA, total water intake (mL/d) was assessed from three 24-h dietary recalls and analyzed using the Nutrition Data System for Research (NDSR). Hydration status was objectively measured using USG via 24-h urine collection.

RESULTS

Overall body fat % was 31.7 ± 7.31, total water intake was 1746 ± 762.0 mL/d, and USG score was 1.020 ± 0.011 uG. Linear regressions showed significance between total water intake and lean mass (B=12.2, p<0.05). Logistic regressions showed no significant association between body composition and USG and total water intake.

CONCLUSIONS

Findings showed total water intake was significantly associated with lean mass. Future research should be conducted to explore other objective markers of hydration and with a larger sample.

The association between hydration status and total fluid intake in healthy children and adolescents

BACKGROUND

Children 10-20 years old in the US have suboptimal hydration status. Hydration is best assessed using an objective marker, such as urine specific gravity (USG) from a 24-h urine collection. There are limited studies associating hydration from an objective marker with intake assessed from 24-h recalls in children. The objective of the study was to evaluate which foods or beverages are significantly associated with an objective marker of hydration (USG) in a sample of children and adolescents.

METHODS

Intake was assessed from three 24-h dietary recalls and analyzed using the Nutrition Data System for Research (NDSR). Hydration status was objectively measured using USG via 24-h urine collection. Associations were assessed with logistic regressions.

RESULTS

A total of 68 children and adolescents were recruited (50% females). Average overall USG score was 1.020 ± 0.011 uG with 39.7% categorized as dehydrated. After adjusting for age and sex, fruit juice (1.009, 95% CI: 1.001, 1.018) and all beverages (1.001, 95% CI: 1.000, 1.002) were significantly associated with higher odds of being euhydrated.

CONCLUSIONS

The main predictors of hydration were fruit juice and all beverages intake. Future research should be conducted to explore differences in dietary patterns in a larger, more generalizable sample.

IMPACT

Findings showed that the main predictors of hydration were water and fruit juice intake in children and water intake in adolescents in southern Florida. This is the first study to examine which type of beverages and foods are associated with USG, an objective marker of hydration status, in US children and adolescents. Provides further insight into the use of objective markers to assess hydration status, while providing data to assist epidemiological studies that may have limited resources to examine beverages and foods that contribute to hydration.

Urinary Hydration Biomarkers and Water Sources in Older Adults with Neurocognitive Disorder

The risk of dehydration in older adults with neurocognitive disorder (NCD) is controversial. The purpose of this study was to assess hydration status, its determinants, and water intake sources in older adults with NCD. A sample of 30 participants (≥60 years) was included. Sociodemographic, clinical data and one 24-h urine sample were collected. Urinary osmolality, sodium, potassium, volume, and creatinine were quantified. Inadequate hydration status corresponded to urine osmolality > 500 mOsm/Kg, or a negative Free Water Reserve (FWR). Two 24-h food recalls were used to assess dietary intake and water sources. The adequacy of total water intake (TWI) was estimated according to EFSA. The contribution of food and beverages to TWI was calculated, and their associations with the urinary osmolality median were tested. Of the total number of participants, 30% were classified as having inadequate hydration status, with no differences between sexes. Regarding TWI, 68.4% of women and 77.8% of men did not reach the reference values. Water (23%), followed by soup (17%), contributed the most to TWI, while vegetables (2%) and alcoholic/other beverages (3%) contributed the least. According to the median urinary osmolality, there was no significant difference in sociodemographic/clinical characteristics. It is critical not to overlook hydration in this vulnerable population.

A systematic review of measurement methods used to estimate fluid and beverage intake in free-living, working-age adults

BACKGROUND

Beverage intake in employees is important to quantify due to the potential of dehydration to increase the risk of errors and reduced work performance. This systematic review aimed to (1) characterise existing fluid intake measurement tools used in the workplace setting or among free-living, healthy adults of working age and (2) report the current validation status of available assessment tools for use in a UK setting.

METHODS

Three electronic databases were searched for publications measuring beverage intake using a defined tool or method. Additional studies were identified by hand from trial registers, grey literature and reference lists. Eligibility was determined using predefined inclusion/exclusion criteria. Study quality was assessed using a modified Strengthening the Reporting of Observational Studies in Epidemiology framework. Narrative synthesis was performed.

RESULTS

The review identified 105 studies. The most frequently reported beverage assessment methods were total diet diaries/records (n = 22), fluid specific diaries/records (n = 18), food and fluid frequency questionnaires (n = 17), beverage-specific frequency questionnaires (n = 23) and diet recalls (n = 11). General dietary measurement tools (measuring beverages as part of total diet) were used in 60 studies, and 45 studies used a beverage-specific tool. This review identified 18 distinct dietary assessment tools, of which 6 were fluid/beverage specific. Twelve tools published relative validity for a beverage-related variable and seven tools for total daily fluid intake (from whole diet or from beverages only).

CONCLUSIONS

Several fluid intake assessment tools were identified; however, few have been fully evaluated for total beverage intake, and none in a UK working population.

Hydration monitoring and rehydration guidance system for athletes based on urine color’s L*a*b* parameters

Maintaining proper hydration is essential for athletes to sustain optimal performance and preserve their physical health. Existing studies have confirmed that urine color is one of the effective indicators for the subjective evaluation of athletes’ hydration through the urine color chart. However, the use of urine color charts to evaluate hydration is easily affected by the test environment, urine container and subjective feeling. At present, there are few hydration monitoring instruments based on quantitative analysis of urine color. In recent years, the L*a*b* color model has been widely used in the objective quantitative analysis of color. The L* value represents the luminance change from black to white, the a* value represents the chromaticity change from green to red, and the b* value represents the chromaticity change from blue to yellow. Our previous research has confirmed that the urine color b ∗ value is an effective new indicator to evaluate the hydration of athletes. The research team developed a urine hydration monitoring and rehydration guidance system based on the urine color’s L*a*b* parameters via wireless network technology and digital image technology. The hardware structure of the system is composed of a cuvette, a standard light source, a camera, an image collector, a host system, and a touch screen system. The system software is composed of functional modules, such as user information, image acquisition, image processing, and image recognition. The system operation process includes starting the system, filling in basic information, putting the sample, testing the sample, local data review, local data upload, and cloud data review. The system exhibits stable performance, a friendly operation interface, and simple and fast testing. It can objectively and accurately evaluate the hydration of athletes and provide personalized rehydration guidance. The system offers a new method for solving practical problems in sports training, and it has broad application prospects.

The Impact of Water and Other Fluids on Pediatric Nephrolithiasis

Pediatric nephrolithiasis cases have been on the rise in the past several years, resulting in increased healthcare costs and other burdens on the juveniles with this ailment. Recent research has shown that present trends in pediatric nephrolithiasis have changed as a result of fluid intake, including water consumption, nutrition, obesity prevalence, lifestyle, and imaging procedures. A specific cause, meanwhile, is still elusive. Trends in pediatric nephrolithiasis need to be thoroughly researched. Furthermore, variables specific to pediatric nephrolithiasis that could cause greater difficulties in an affected child elevate the level of worry with cumulative prevalence. Doctors should rigorously assess patients who present with kidney stones when they have dynamics such as varied clinical presentation, high recurrence of kidney stones linked to metabolic and urinary tract problems, and the potential existence of rare genetic kidney stone illnesses. This review aims to identify adaptive risk factors and anomalies that call for specialized treatment and prescription. More specifically, the major goals of medical and surgical treatments are to eliminate kidney stone risk and stop relapse while concurrently lowering interventional barriers. A dedicated nephrolithiasis clinic run by a pediatric nephrologist, nutritionist, urologist, and clinical nurse may sometimes be beneficial for patients in serious danger. Such a clinic offers significant chances to learn more about pediatric nephrolithiasis, which has been linked to water consumption and hence fosters urgently required study in this area.

Diarrhoea, malnutrition, and dehydration associated with school water, sanitation, and hygiene in Metro Manila, Philippines: A cross-sectional study

INTRODUCTION

Diarrhoea, malnutrition, and dehydration threaten the lives of millions of children globally due to inadequate water, sanitation, and hygiene (WaSH). Our study aimed to identify environmental and behavioural risk factors of these health outcomes among schoolchildren in Metro Manila, Philippines.

MATERIALS AND METHODS

We analysed data from a multistage cluster sample of schoolchildren in grades 5, 6, 7, 9, and 10 (ages ~10-15 years old) to investigate WaSH facilities and hygiene practices. Outcomes were: self-reported diarrhoea, measured via questionnaire; observed malnutrition (stunting, undernutrition [underweight/thin and wasted/severely thin], over-nutrition [overweight and obese]), measured via anthropometry; dehydration, measured via urine specific gravity/urine test strips. We used multiple logistic regression to explore correlates.

RESULTS

We included 1558 students from 15 schools in three cities. Over 28% (421) of students had diarrhoea and 68% (956) were dehydrated. Over 15% (227) of students were stunted, ~9% (127) were undernourished, and >21% (321) were over-nourished. Diarrhoea was associated with poor handwashing, while dehydration was associated with the lack of water in school restrooms. Stunting was linked with not using the school restroom, the lack of water in school restrooms, and the lack of hygiene lessons in school. Undernutrition was associated with the lack of a school restroom cleaning policy. Risks of diarrhoea, stunting, and undernutrition decreased as the number of school restrooms increased. Risks of stunting and overnutrition decreased as the numbers of school toilets increased. Having more than seven handwashing basins was associated with decreased risk of dehydration.

DISCUSSION

Findings from our cross-sectional study cannot describe causation. We have found associations that suggest that school restroom cleaning policies, adequate water supply, improved handwashing, and hygiene education are needed to prevent disease. School-based WaSH interventions are recommended to provide water in school WaSH facilities, promote handwashing, and improve hygiene-related knowledge.

Urine specific gravity to identify and predict hydration need in ALS

Introduction: Multiple factors contribute to increased risk of dehydration in amyotrophic lateral sclerosis (ALS), which contributes to shortened survival independent of nutritional status. The assessment of hydration by doubly labeled water is restricted due to the limited availability of this gold standard technique for clinical use. This prompted us to examine the utility of urine-specific gravity (USG) as a predictor of hydration need in ALS subjects. Material and Methods: Using data from a multicenter study of 80 ALS subjects with 250 visits, we conducted a secondary analysis of the original data set from doubly labeled water experiments. We used a cross-section of the data (one visit per 75 subjects) in the model selection step ("test set"), and a repeated measures analysis in the validation step with data from 63 subjects and 142 follow-up visits. The sensitivity to detect inadequate water turnover rate (a surrogate for water intake) was the goal of the predictive model presented for clinical use. Results and discussion: The final predictive model to estimate water requirement included USG, gender, body mass index, and the ALSFRS gross motor subscale score. We developed a best-fit equation to estimate water intake from USG, determine hydration status, and improve clinical care of real-world ALS subjects.

Coughing Can Be Modulated by the Hydration Status in Adolescents with Asthma

A lower thirst sensitivity frequently characterizes children and adolescents. The daily water intake can be frequently insufficient for the homeostasis and the integrity of their airway epithelium. Little is known about the real-life relationship between dehydration and coughing in young students with asthma. The aim was to investigate the effect of dehydration on coughing in asthmatic students aged ≤16 years. A validated questionnaire aimed to investigate their respiratory history and cough incidence was used. Urine samples were also collected for assessing osmolality. Wilcoxon test, the Pearson Chi Square and the Fisher Exact Test were used; p < 0.05 was assumed as significant. Valid data were obtained from 305 healthy and 56 asthmatic students. Mean urine osmolality was significantly higher in asthmatic than in healthy students (1012 ± 197.7 vs. 863.0 ± 223.0 mOsm/kg, respectively; p < 0.001), particularly in symptomatic asthmatic students (1025 ± 191.6 mOsm/kg, p < 0.01). Both the incidence and duration of coughing episodes were directly related to the degree of urine osmolality (both p < 0.001). Dehydration affects the prevalence and the duration of a cough in asthmatic students aged ≤16 years. Adequate daily water intake should be stimulated in these subjects in order to contain their basic cough attitude.

Validity of Urine Color Scoring Using Different Light Conditions and Scoring Techniques to Assess Urine Concentration

CONTEXT

Urine color (Uc) is used to asses urine concentration when laboratory techniques are not feasible.

OBJECTIVE

To compare the accuracy of Uc scoring using 4 light conditions and 2 scoring techniques with a 7-color Uc chart. Additionally, to assess the results' generalizability, a subsample was compared with scores obtained from fresh samples.

DESIGN

Descriptive laboratory study.

SAMPLES

A total of 178 previously frozen urine samples were scored, and 78 samples were compared with their own fresh outcomes.

MAIN OUTCOME MEASURE(S)

Urine color and accuracy for classifying urine samples were calculated using receiver operating characteristics analysis, allowing us to compare the diagnostic capacity against a 1.020 urine specific gravity cutoff and defining optimal Uc cutoff value.

RESULTS

Urine color was different among light conditions (P < .01), with the highest accuracy (80.3%) of correct classifications of low or high urine concentrations occurring at the brightest light condition. Lower light intensity scored 1.5 to 2 shades darker on the 7-color Uc scale than bright conditions (P < .001), but no further practical differences in accuracy occurred between scoring techniques. Frozen was 0.5 to 1 shade darker than freshly measured Uc (P < .004), but the values were moderately correlated (r = 0.64). A Bland-Altman plot showed that reporting bias mainly affected darker Uc without affecting the diagnostic ability of the method.

CONCLUSIONS

Urine color scoring, accuracy, and Uc cutoff values were affected by lighting condition but not by scoring technique, with greater accuracy and a 1-shade-lower Uc cutoff value at the brightest light (ie, light-emitting diode flashlight).

Dehydration Status Aggravates Early Renal Impairment in Children: A Longitudinal Study

Dehydration is common in children for physiological and behavioral reasons. The objective of this study was to assess changes in hydration status and renal impairment across school weekdays. We conducted a longitudinal study of three repeated measures of urinalysis within one week in November 2019 in a child cohort in Beijing, China. We measured urine specific gravity (USG) to determine the dehydration status, and the concentration of β₂-microglobulin (β₂-MG) and microalbumin (MA) to assess renal function impairment among 1885 children with a mean age of 7.7 years old. The prevalence of dehydration was 61.9%, which was significantly higher in boys (64.3%). Using chi-square tests and linear mixed-effects regression models, we documented the trends of the renal indicators’ change over time among different hydration statuses. Compared to Mondays, there were apparent increases of β₂-MG concentrations on Wednesdays (β = 0.029, p < 0.001) and Fridays (β = 0.035, p < 0.001) in the dehydrated group, but not in the euhydrated group. As for the MA concentrations, only the decrease on Fridays (β = −1.822, p = 0.01) was significant in the euhydrated group. An increased trend of elevated β₂-MG concentration was shown in both the euhydrated group (Z = −3.33, p < 0.001) and the dehydrated group (Z = −8.82, p < 0.001). By contrast, there was a decreased trend of elevated MA concentrations in the euhydrated group (Z = 3.59, p < 0.001) but not in the dehydrated group. A new indicator ratio, β₂-MG/MA, validated the consistent trends of renal function impairment in children with dehydration. Renal impairment trends worsened as a function of school days during the week and the dehydration status aggravated renal impairment during childhood across school weekdays, especially tubular abnormalities in children.

Comparing thirst and spot urine concentrations in humans of differing body sizes: An observational study

Elevated body mass index (BMI) has been associated with elevated urine osmolality (UOsm), despite having higher total water intake, but it is unclear if overweight/obese individuals have reduced thirst. In this observational study, we found that overweight/obese individuals had higher UOsm compared to normal-weight individuals (749 ± 37 vs. 624 ± 35 mmol•kg^-1; P < 0.01) while possessing similar thirst ratings (56.4 ± 3 vs. 51.6 ± 3 mm; P = 0.3). In this observational study, overweight/obese individuals possessed more concentrated urine in the absence of higher thirst perception.

The Relationships between Water Intake and Hydration Biomarkers and the Applications for Assessing Adequate Total Water Intake among Young Adults in Hebei, China

Water is an essential nutrient for humans. A cross-sectional study was conducted among 159 young adults aged 18–23 years in Hebei, China. The total drinking fluids and water from food were obtained by 7-day 24 h fluid intake questionnaires and the duplicate portion method, respectively. Pearson’s correlation coefficients were performed to determine the relationship between fluid intake and 24 h urinary biomarkers and plasma biomarkers. A multivariable partial least squares (PLS) model was used to identify the key predictors in modeling the total water intake (TWI) with 24 h urine biomarkers. Logistic regressions of the TWI against binary variables were performed, and the receiver operating characteristic curve (ROC) was analyzed to determine the cutoff value of the TWI for the optimal hydration status and dehydration without adjustments to favor either the sensitivity or specificity. In total, 156 participants (80 males and 76 females) completed the study. Strong relationships were found between the total drinking fluids, TWI, and 24 h urine biomarkers among young adults, especially for the 24 h urine volume (r = 0.784, p < 0.001; r = 0.747, p < 0.001) and osmolality (r = −0.589, p < 0.001; r = −0.477, p < 0.001), respectively. As for the FMU and plasma biomarkers, no strong relationships were found. The percentages of the variance in TWI explained by the PLS model with 13 urinary biomarkers were 66.9%. The optimal TWI values for assessing the optimal hydration and dehydration were 2892 mL and 2482 mL for young males, respectively, and 2139 mL and 1507 mL for young females, respectively. Strong relationships were found between the TWI, total drinking fluids, and 24 h urine biomarkers, but not with the FMU and plasma biomarkers, among young adults, including males and females. The 24 h urine biomarkers were more sensitive than the first morning urinary biomarkers in reflecting the fluid intake. The TWI was a reliable index for assessing the hydration statuses for young adults in free-living conditions.

Estimates of fluid intake, urine output and hydration-levels in women from Somaliland: a cross-sectional study

The study objective was to measure fluid intake and associations with background characteristics and hydration biomarkers in healthy, free-living, non-pregnant women aged 15–69 years from Hargeisa city. We also wanted to estimate the proportion of euhydrated participants and corresponding biomarker cut-off values. Data from 136 women, collected through diaries and questionnaires, 24h urine samples and anthropometric measurements, were obtained with a cross-sectional, purposeful sampling from fifty-two school and health clusters, representing approximately 2250 women. The mean (95 % CI) 24 h total fluid intake (TFI) for all women was 2⋅04 (1⋅88, 2⋅20) litres. In multivariate regression with weight, age, parity and a chronic health problem, only weight remained a predictor (P 0.034, B 0.0156 (l/kg)). Pure water, Somali tea and juice from powder and syrup represented 49⋅3, 24⋅6 and 11⋅7 % of TFI throughout the year, respectively. Mean (95 % CI) 24 h urine volume (Uvol) was 1⋅28 (1⋅17, 1⋅39) litres. TFI correlated strongly with 24 h urine units (r 0.67) and Uvol (r 0.59). Approximately 40 % of the women showed inadequate hydration, using a threshold of urine specific gravity (Usg) of 1⋅013 and urine colour (Ucol) of 4. Five percent had Usg > 1⋅020 and concomitant Ucol > 6, indicating dehydration. TFI lower cut-offs for euhydrated, non-breast-feeding women were 1⋅77 litres and for breast-feeding, 2⋅13 litres. Euhydration cut-off for Uvol was 0⋅95 litre, equalling 9⋅2 urine units. With the knowledge of adverse health effects of habitual hypohydration, Somaliland women should be encouraged to a higher fluid intake.

Effect of a Hydration Management Program on Older Adults' Fluid Consumption and Dehydration Parameters: A Quasi-Experimental Study

The purpose of the current study was to assess effects of a hydration management program on the fluid consumption and dehydration parameters (i.e., dehydration risk scores, urine specific gravity, and urine color) of older adults. The study was conducted as a pre-/post-test quasi-experimental study with a control group (intervention group: n = 42, control group: n = 37). The hydration management program applied to the intervention group was completed in 1 week. After the intervention, the knowledge and awareness of the intervention group regarding fluid consumption increased (p = 0.001). The dehydration risk score of the intervention group was significantly lower than that of the control group (p = 0.0001). There was a significant change in average 3-day water intake (p = 0.0001), urine specific gravity value (p = 0.01), and urine color scale score (p = 0.0001) in the intervention group between pre- and post-test. The hydration management program provided a significant improvement in daily water intake and dehydration risk score and increased knowledge and awareness among older adults concerning the importance of fluid intake. [Journal of Gerontological Nursing, 47(9), 40-48.].

Fluid intake and urinary osmolality in pediatric patients with functional constipation

PURPOSE

This study aimed to evaluate fluid intake and urinary osmolality in pediatric patients with functional constipation.

METHODS

This was a cross-sectional, case-control study that prospectively included two groups: 36 pediatric patients older than 4 years with functional constipation (Rome III criteria) who were consecutively admitted in a public tertiary pediatric gastroenterology outpatient clinic and 93 controls with normal bowel habits. The control group was recruited from a public school and did not have any of the characteristics of the Rome III criteria. Fluid and food intakes were assessed using a daily diet inquiry and 24 h recording method. Hypohydration was defined as osmolality greater than 800 mOsm/kg H₂O in a spot urine sample.

RESULTS

The age of the functional constipation group (median, 8.9 years; range 7.3-10.0 years) and the control group (8.8 years) was similar (p = 0.51). The proportion of boys in the functional constipation group (76.6%; 25/36) was higher (p = 0.01) than that in the control group (45.2%; 41/93). The total water intake of the functional constipation group (median 1566 mL) was lower (p < 0.001) than that of the control group (median 2177 mL). Urinary osmolality was higher (p = 0.039) in the functional constipation group (median 859 mOsm/kg H₂O) than in the control group (median 775 mOsm/kg H₂O). The association between hypohydration and functional constipation did not reach statistical significance (Odds ratio 2.06; 95% confidence interval 0.93-4.55; p = 0.073).

CONCLUSION

Compared to the control group, patients with functional constipation have lower fluid intake and higher urinary osmolality.

Impaired hydration status in acutely admitted older patients: prevalence and impact on mortality

BACKGROUND

impaired hydration is common in the older people, however studies of its effects on outcome in the acute setting are limited.

OBJECTIVES

to assess (i) the prevalence of impaired hydration, (ii) its relationship with laboratory markers of altered hydration and with (iii) short- and long-term mortality.

DESIGN

retrospective cohort study.

SETTING

University Hospital-Internal Medicine Department.

SUBJECTS

a total of 5,113 older patients consecutively acutely admitted from October 2015 to July 2016.

METHODS

according to calculated serum osmolarity at admission hydration status was stratified in: low osmolarity (<275 mmol/L), euhydration (275-295 mmol/L), impending (296-300 mmol/L) and current dehydration (>300 mmol/L). Relationships with serum sodium, potassium, glucose, urea, estimated glomerular filtration rate (eGFR), haematocrit, urea/creatinine ratio (Urea/Cr) and urine specific gravity (USG) were determined. Charlson Comorbidity Index, Modified Early Warning Score, Glasgow Prognostic Score, Norton score and Nutritional Risk Screening-2002 were calculated.

RESULTS

current and impending dehydration, euhydration and low-osmolarity were detected in 51.7, 17.1, 28.5 and 2.7% of the patients, respectively. Osmolarity correlated with urea (r = 0.846). Associations with serum sodium, creatinine, eGFR and urea/Cr were low but significant, being negligible that with USG and haematocrit. Serum sodium and urea increased in the transition from low- to high-osmolarity (P < 0.001 in all pairwise comparisons). In multivariate modelling current dehydration, functional dependence, clinical instability and high nutritional risk were associated (P < 0.001) with reduced short- and long-term survival.

CONCLUSIONS

impaired hydration is common in older people acutely admitted to medical care and is associated with poor outcome. Early assessment of calculated serum osmolarity is mandatory to target dehydration and hypoosmolar disorders.

Fluid Intake Monitoring Systems for the Elderly: A Review of the Literature

Fluid intake monitoring is an essential component in preventing dehydration and overhydration, especially for the senior population. Numerous critical health problems are associated with poor or excessive drinking such as swelling of the brain and heart failure. Real-time systems for monitoring fluid intake will not only measure the exact amount consumed by the users, but could also motivate people to maintain a healthy lifestyle by providing feedback to encourage them to hydrate regularly throughout the day. This paper reviews the most recent solutions to automatic fluid intake monitoring both commercially and in the literature. The available technologies are divided into four categories: wearables, surfaces with embedded sensors, vision- and environmental-based solutions, and smart containers. A detailed performance evaluation was carried out considering detection accuracy, usability and availability. It was observed that the most promising results came from studies that used data fusion from multiple technologies, compared to using an individual technology. The areas that need further research and the challenges for each category are discussed in detail.

Hydration status, body composition, and anxiety status in aeronautical military personnel from Spain: a cross-sectional study

BACKGROUND

An adequate hydration status is critical to ensure efficiency during mental and physical activities. Our goal was to assess the hydration status of a Spanish group of aeronautical military men and to determine the association of hydration status with body composition and anxiety.

METHODS

A total of 188 men were evaluated through a validated hydration questionnaire, anthropometric and biochemical parameters, and an anxiety questionnaire. Based on these methods, the criteria of hydration were established.

RESULTS

Of the total sample, 81% met the hydration criteria (urine color = well hydrated, water balance ≥ 0 ml, and total water intake/weight ≥ 35 ml/kg), and 19% did not meet the hydration criteria (urine color = not sufficiently hydrated or dehydrated, water balance < 0 ml, and total water intake/weight < 35 ml/kg). Subjects not meeting the hydration criteria had lower urine pH, negative water balance, and lower water intake. The latter also had higher anxiety status (score = 4 vs. 3, P = 0.026), weight [(84.7 ± 10.5) vs. (80.5 ± 10.2) kg], body mass index [(26.3 ± 3.1) vs. (25.2 ± 2.8)]kg/m2, body fat [(22.3 ± 5.6) vs. (18.3 ± 6.5)] %, urine specific gravity, and urine color. Using a logistic binary regression model, hydration status was related significantly with the percentage of body fat (P = 0.004), but no relation was found with age, comorbidities, or medications. Furthermore, total water intake/weight was positively correlated with percentage of body water (r = 0.357, P = 0.000) and negatively with body fat (kg) (r = - 0.427, P = 0.000), percentage of body fat (r = - 0.405, P = 0.000), and waist/hip ratio (r = - 0.223, P = 0.002). Based on a linear regression model, total water intake/weight was related significantly with percentage of body fat (P = 0.001) and percentage of body water content (P = 0.035). No relation was found, however, with waist/hip ratio, age, comorbidities, or medications.

CONCLUSIONS

These findings all suggest a relationship between hydration status and body composition but also set the bases for future studies that relate hydration status and anxiety status. These results can be used to improve the hydration status and body composition of military personnel.

"I know it's just pouring it from the tap, but it's not easy": Motivational processes that underlie water drinking

Water drinking behaviour is under-researched despite the prevalence and adverse health consequences of underhydration. We conducted a qualitative exploration into the motivational processes underlying water drinking, informed by a grounded cognition perspective on desire and motivated behaviour. We interviewed and analysed data from 60 participants stratified by age, gender, and education level using thematic analysis, to generate three key themes. "Water as situated habits," suggests that participants form and maintain situated water drinking habits, so that within certain situations they regularly drink water. However, participants who situated their water intake only in one key situation (e.g., work routine), had low and inconsistent intake when they left this situation. Some situations happened so infrequently during the day (e.g., before bed) that participants' daily water intake was low. Many participants reported drinking water in reaction to thirst cues, but these were easily suppressed or ignored, so that water drinking was inconsistent. Participants who saw drinking water as part of their self-identity had consistent and high water intake across a variety of situations. "Knowledge and attitudes," suggests that few participants had knowledge or attitudes that promoted water intake (e.g., perceived water as positive or understood the importance of hydration). "Strategies underlying attempts to increase intake" suggests that many participants lacked insight into strategies to increase water intake, although they spontaneously discussed attempts to drink more. This lead to ineffective attempts at behaviour change. Participants' mentions of dehydration and their responses to a urine colour chart suggested that many participants were possibly underhydrated. Our findings suggest that interventions and practitioners attempting to increase water intake need to increase knowledge about the importance of hydration, and encourage individuals to develop effective situated water drinking habits.

Athletes' Self-Assessment of Urine Color Using Two Color Charts to Determine Urine Concentration

Our objective was to determine self-reported accuracy of an athletic population using two different urine color (Uc) charts (8-color vs. 7-color Uc chart). After approval by the Institutional Review Board, members of an athletic population (n = 189, 20 (19–22) year old student- or tactical athletes and coaches, with n = 99 males and n = 90 females) scored their Uc using two charts. To determine the diagnostic value of Uc, results were compared with urine concentration (osmolality and urine specific gravity, USG). Uc was scored slightly darker with the 8-color vs. 7-color Uc chart (2.2 ± 1.2 vs. 2.0 ± 1.2, respectively, p < 0.001), with a moderate correlation between charts (r = 0.76, 95% CI: 0.69–0.81). Bland-Altman analysis showed a weak reporting bias (r = 0.15, p = 0.04). The area under the curve for correct urine sample classification ranged between 0.74 and 0.86. Higher accuracy for both methods was found when Uc scores were compared to USG over osmolality, indicated by 4.8–14.8% range in difference between methods. The optimal Uc cut-off value to assess a low vs. a high urine concentration for both Uc charts varied in this study between 1 and ≤2 while accuracy for charts was similar up to 77% when compared to USG.

Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies

A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.

Incidence and risk factors of urinary tract infections in hospitalised patients with spinal cord injury

AIMS AND OBJECTIVES

To investigate the incidence of urinary tract infection and analyse its risk factors among hospitalised patients with spinal cord injury.

BACKGROUND

While the incidence of urinary tract infection varies widely according to the healthcare setting and patients' clinical characteristics, formal reports are limited in quantity. There has been no consensus regarding the risk factors for urinary tract infection.

DESIGN

A retrospective descriptive study.

METHODS

Electronic medical records of 964 subjects between 2010-2017 were reviewed. Urinary tract infection status was examined to identify newly occurred cases. Data included demographic and clinical characteristics, hydration status and length of hospitalisation. The reporting of the study followed the EQUATOR Network's STROBE checklist.

RESULTS

Of the sample, 31.7% had urinary tract infection (95% confidence interval: 1.288 to 1.347, p < .001). Sex, completeness of injury, type of bladder emptying, detrusor function and urethral pressure were significant factors affecting urinary tract infection. Patients who were male and those with injury classifications A, B and C had higher risk of urinary tract infection. Patients with urinary or suprapubic indwelling catheters, as well as those with areflexic detrusor combined with normotonic urethral pressure or overactive detrusor combined with normotonic urethral pressure, showed higher risk. Length of hospitalisation in patients with urinary tract infection was greater than that in uninfected patients, which implies the importance of prevention of urinary tract infection.

CONCLUSIONS

Nurses should carefully assess risk factors to prevent urinary tract infection in patients with spinal cord injury in the acute and sub-acute stages of the disease trajectory and provide individualised nursing care.

RELEVANCE TO CLINICAL PRACTICE

This study contributes evidence for up-to-date clinical nursing practice for the comprehensive management of urinary tract infection. This can lead to improvements in nursing care quality and patient outcomes, including length of hospitalisation.

Evaluation of hydration status of children with obesity-a pilot study

OBJECTIVES

To compare the hydration status between children with obesity and normal-weighted children and to determine whether obesity is related to less water consumption.

METHODS

Children aged between 7 and 18 years with obesity (Group 1, n=31) were compared with nonobese healthy volunteers (Group 2, n=30) in terms of body composition analysis, urine density and daily fluid intake.

RESULTS

The fluid intake per body surface of Group 1 was found significantly less than Group 2 (p<0.001). The urine density was found significantly higher in Group 1 (1020 (10) vs. 1015(10), p<0.001). Subjects in Group 1 had a higher percentage of body fat (p<0.001), lower percentages of total body water and fat-free mass (p=0.007 and <0.001, respectively). While 55% of subjects in Group 1 satisfied the recommended daily fluid intake, this was 80% in Group 2 (p=0.036). The consumption of SSBs was 71% in Group 1 and 20% in Group 2, with higher amount in Group 1 (median 200 vs. 0 mL, p<0.001).

CONCLUSIONS

Children with obesity had less fluid consumption, lower TBW percentages and higher urine density. The results of this cross-sectional study showed that children with obesity were less hydrated than normal weighted children.

Hydration and water intake practices of commercial long-distance drivers in Ghana: what do they know and why does it matter?

BACKGROUND

The World Health Organization indicates that hydration is indispensable to human life. A long-period of dehydration can result in fatigue, drowsiness and mental confusion which can result in committing serious blunders. For commercial drivers, however, these blunders can be life-threatening and their hydration cannot be overemphasized.

AIM

This study was therefore undertaken to assess the water intake practices of Commercial Long-Distance drivers (CLDDs). The study was also aimed at assessing their knowledge levels on the role of water in promoting a healthy body and the consequences of dehydration.

SETTING

CLDDs in Ghana who ply between Accra - Cape Coast - Takoradi or Accra - Kumasi.

METHODS

A cross-sectional study which involved 256 CLDDs was conducted at six (6) commercial bus stations in Accra and Cape Coast from December 2019 to January 2020. Structured questionnaires were administered to obtain socio-demographic and water intake practices of CLDDs. SPSS was used to generate descriptive statistics based on the data collected.

RESULTS

A high proportion (57.8%) of the CLDDs reported that they drunk about 2500ml-3000ml of water on a daily basis. Most (53.1%) relied on their thirst feeling to prompt them to drink water. A little over half (51.1%) consumed energy drinks believed to hydrate the body. A major barrier to drinking water regularly was to avoid frequent stop-overs to use the washroom while travelling.

CONCLUSION

The findings reveal concerns about knowledge gaps with regard to the importance of water consumption and barriers to adequate drinking of water among CLDDs. Findings also suggest that many CLDDs relied on their thirst perceptions to prompt them to drink water. Health Education programmes targeting CLDDs should include conveying the importance of water intake and healthy hydration practices for optimal physical and cognitive performance.

Exosomal miRNAs in urine associated with children's cardiorenal parameters: a cross-sectional study

Aims:

The authors sought to examine associations between urinary exosomal miRNAs (exo-miRs), emerging biomarkers of renal health, and cardiorenal outcomes in early childhood.

Materials & methods:

The authors extracted exo-miRs in urine from 88 healthy Mexican children aged 4–6 years. The authors measured associations between 193 exo-miRs and cardiorenal outcomes: systolic/diastolic blood pressure, estimated glomerular filtration rate and urinary sodium and potassium levels. The authors adjusted for age, sex, BMI, socioeconomic status, indoor tobacco smoke exposure and urine specific gravity.

Results:

Multiple exo-miRs were identified meeting a false discovery rate threshold of q < 0.1. Specifically, three exo-miRs had increased expression with urinary sodium, 17 with urinary sodium-to-potassium ratio and one with decreased estimated glomerular filtration rate.

Conclusions:

These results highlight urinary exo-miRs as early-life biomarkers of children's cardiorenal health.

Tear Osmolarity in the Diagnosis of Systemic Dehydration and Dry Eye Disease

Systemic dehydration due to inadequate water intake or excessive water loss, is common in the elderly and results in a high morbidity and significant mortality. Diagnosis is often overlooked and there is a need for a simple, bedside diagnostic test in at-risk populations. Body hydration is highly regulated with plasma osmolality (pOsm) being tightly controlled over a wide range of physiological conditions. By contrast, normal tear osmolarity (tOsm) is more variable since the tear film is exposed to evaporation from the open eye. While plasma hyperosmolality is a diagnostic feature of systemic dehydration, tear hyperosmolality, with other clinical features, is diagnostic of dry eye. Studies in young adults subjected to exercise and water-deprivation, have shown that tOsm may provide an index of pOsm, with the inference that it may provide a simple measure to diagnose systemic dehydration. However, since the prevalence of both dry eye and systemic dehydration increases with age, the finding of a raised tOsm in the elderly could imply the presence of either condition. This diagnostic difficulty can be overcome by measuring tear osmolality after a period of evaporative suppression (e.g., a 45 min period of lid closure) which drives tOsm osmolality down to a basal level, close to that of the pOsm. The arguments supporting the use of this basal tear osmolarity (BTO) in the diagnosis of systemic dehydration are reviewed here. Further studies are needed to confirm that the BTO can act as a surrogate for pOsm in both normally hydrated subjects and in patients with systemic dehydration and to determine the minimum period of lid closure required for a simple, "point-of-care" test.

Are older adults with excessive sodium intake at increased risk of hypohydration?

BACKGROUND

Sodium intake is expected to affect water needs, although compensation mechanisms may not work efficiently particularly in older adults. The aim of this cross-sectional study was to quantify the association between sodium excretion and hydration status in a representative sample of Portuguese older adults.

METHODS

A cluster sampling approach was used, representing Portuguese older adults (≥65 years) according to sex, education level and region. From a sample size of 1500 participants, 1318 were eligible for the present analysis. A 24-h urine sample was collected, and volume, osmolality, creatinine and sodium were quantified. Free water reserve (FWR) was used to assess hydration status. Excessive sodium intake was defined as above 2000 mg day^-1 as recommended by the World Health Organization. A multivariable binary logistic regression model was used to estimate the association between FWR and sodium excretion. Odds ratios (OR) and respective 95% confidence intervals (95% CI) were calculated.

RESULTS

Excessive sodium excretion was observed in 80.0% of women and 91.5% of men, whereas hypohydration affected 10.9% of women and 23.6% of men. After adjusting for confounders, excessive sodium excretion was associated with an increased risk of hypohydration among men (OR = 2.75; 95% CI = 1.06-7.15).

CONCLUSIONS

These results stress the positive association between excessive sodium intake and hypohydration in men and highlight the need for implementing strategies regarding the reduction of salt consumption and the promotion of water intake.

[Evaluation of the fluid balance in geriatric patients-What contribution can abdominal ultrasound make?]

The assessment of the fluid balance as well as the identification of hyperhydration and dehydration often represent a diagnostic challenge, especially in older patients. In principle, various diagnostic procedures and approaches are suitable for assessment of the various facets, by which such a disorder can be recognized. The contribution of abdominal ultrasound is described and evaluated in the context of the different diagnostic procedures. An overview of the current situation with respect to assessment of the vena cava is provided. In many respects there is no strict consensus concerning the thresholds of the individual measurements and the value of the different measurements. Currently, an orthograde diameter of the inferior vena cava > 2 cm is accepted as being a good indicator for hyperhydration. Less certain are analogously derived thresholds as indicators for dehydration.

Physiological interactions with personal-protective clothing, physically demanding work and global warming: An Asia-Pacific perspective

The Asia-Pacific contains over half of the world's population, 21 countries have a Gross Domestic Product <25% of the world's largest economy, many countries have tropical climates and all suffer the impact of global warming. That 'perfect storm' exacerbates the risk of occupational heat illness, yet first responders must perform physically demanding work wearing personal-protective clothing and equipment. Unfortunately, the Eurocentric emphasis of past research has sometimes reduced its applicability to other ethnic groups. To redress that imbalance, relevant contemporary research has been reviewed, to which has been added information applicable to people of Asian, Melanesian and Polynesian ancestry. An epidemiological triad is used to identify the causal agents and host factors of work intolerance within hot-humid climates, commencing with the size dependency of resting metabolism and heat production accompanying load carriage, followed by a progression from the impact of single-layered clothing through to encapsulating ensembles. A morphological hypothesis is presented to account for inter-individual differences in heat production and heat loss, which seems to explain apparent ethnic- and gender-related differences in thermoregulation, at least within thermally compensable states. The mechanisms underlying work intolerance, cardiovascular insufficiency and heat illness are reviewed, along with epidemiological data from the Asia-Pacific. Finally, evidence-based preventative and treatment strategies are presented and updated concerning moisture-management fabrics and barriers, dehydration, pre- and post-exercise cooling, and heat adaptation. An extensive reference list is provided, with >25 recommendations enabling physiologists, occupational health specialists, policy makers, purchasing officers and manufacturers to rapidly extract interpretative outcomes pertinent to the Asia-Pacific.

Combining urine color and void number to assess hydration in adults and children

BACKGROUND/OBJECTIVES

To test the diagnostic ability of two combined practical markers for elevated urine osmolality (underhydration) in free-living adults and children.

SUBJECTS/METHODS

One hundred and one healthy adults (females n = 52, 40 ± 14 y, 1.70 ± 0.95 m, 76.7 ± 17.4 kg, 26.5 ± 5.5 kg/m²) and 210 children (females = 105, 1.49 ± 0.13 m, 43.4 ± 12.6 kg, 19.2 ± 3.2 kg m^-2) collected urine for 24-h. Urine was analyzed for urine osmolality (UOsm), color (UC), while the number of voids (void) was also recorded. Receiver Operating Characteristic (ROC) analysis was performed for UC, void, and combination of UC and void, to determine markers' diagnostic ability for detecting underhydration based on elevated UOsm (UOsm ≥ 800 mmol kg^-1).

RESULTS

Linear regression analysis revealed that UC was significantly associated with UOsm in both adults (R² = 0.38; P < 0.001) and children (R² = 0.45; P < 0.001). Void was significantly associated with UOsm in both adults (R² = 0.13; P < 0.001) and children (R² = 0.15; P < 0.001). In adults, when UC > 3 and void <7 were combined, the overall diagnostic ability for underhydration was 97% with sensitivity and specificity of 100% and 88%, respectively. In children, UC > 3 and void <5 had an overall diagnostic ability for underhydration of 89% with sensitivity and specificity of 100% and 62%, respectively.

CONCLUSIONS

Urine color alone and the combination of urine color with void number can a valid and simple field-measure to detect underhydration based on elevated urine osmolality.