Water Intake and Hydration Indices in Healthy European Adults: The European Hydration Research Study (EHRS)

Investigating Water Balance as a Nutritional Determinant in Breastfeeding: A Comparative Study of Water Consumption Patterns and Influencing Factors

BACKGROUND

Ensuring adequate hydration is critical for breastfeeding women, yet their water consumption patterns and hydration status is poorly understood. This study investigates the water consumption patterns and estimated water balance among women, practicing exclusive, mixed, and no breastfeeding methods.

METHODS

529 healthy women completed the Nursing Water Balanced Questionnaire (N-WBQ). Participants were distributed across breastfeeding groups as follows: exclusive (39.7%), mixed (31.9%), and no breastfeeding (28.4%).

RESULTS

Significant differences were noted in water consumption patterns among breastfeeding groups regarding intake from beverages (p < 0.001), juices (p = 0.019), coffee (p < 0.001), and milk (p = 0.015). Water intake from liquids, except for drinking water (p < 0.001), juices (p = 0.024) and coffee (p < 0.001) differed significantly among groups in women with adequate total water intake based on recommendation, with exclusive breastfeeding mothers prioritizing plain water over other beverages. Total water loss (p < 0.001) and estimated water balance (p < 0.001) significantly varied among breastfeeding groups, with exclusive breastfeeding mothers to exhibit the lowest water balance (-475.36 mL/day), indicating potential dehydration risk. Apart from plain water, water from foods, coffee and milk significantly contributed to positive water balance.

CONCLUSIONS

Our findings highlight a risk of dehydration in this population, while water consumption patterns are influenced by breastfeeding method, likely affected by varying lactational demands and lifestyle factors. Further research to develop more accurate and individualized methods for assessing water balance in breastfeeding women is needed.

Is the NICE Guideline for maintenance fluid therapy in adults in hospital appropriate?

BACKGROUND AND AIMS

The National Institute for Health and Care Excellence's (NICE) Guideline for Maintenance Fluid Therapy in Adults in Hospital is widely used, but the recommendations have not been evaluated properly. In this study, we investigated whether the recommendation of providing 25-30 mL/kg/day of fluid and 1 mmol/kg each of sodium and potassium is sufficient for human needs.

METHODS

First, we calculated the distribution of fluid between the extracellular fluid volume (ECV) and intracellular fluid volume (ICV) during a cross-over infusion experiment where 12 volunteers received 25 mL/kg/day of either a high-sodium (154 mmol/L) or low-sodium (54 mmol/L) solution over 48 h. Second, urine samples from 719 volunteers and clinical patients were used to quantify their renal water conservation and excretion of sodium and potassium. Third, retrospective analysis of a diet study was used to extrapolate how large the fluid intake and the electrolyte excretion likely had been in the 719 volunteers and hospital patients who delivered urine.

RESULTS

The high-sodium fluid maintained the ECV but the ICV had decreased by 1.3 L after 48 h. The low-sodium fluid resulted in a volume deficit of 1.7 L that equally affected the ECV and the ICV. Regression equations based on the diet study suggested that the daily intake of water in the 719 subjects averaged 2.6 L and that 2 mmol/kg of sodium and 1 mmol/kg of potassium was excreted.

CONCLUSION

The NICE guideline recommends too little water and sodium for a human to adequately maintain the ECV and ICV.

CLINICAL TRIAL REGISTRATIONS

EudraCT 2016-001846-24 and ISRCTN 12215472.

Psychometric Properties of the Knowledge of Hydration among Foreign Students of Óbuda University, Hungary

It is known that the quantity, makeup, and distribution of bodily fluids have a significant impact on the cognitive health, physiological health, and cell activity of human beings. This narrative could be influenced by the level of knowledge about hydration, dehydration, and the practice of Adequate Water Intake (AWI) of an individual based on the recommended daily Total Water Intake (TWI) by either the World Health Organization (WHO) or the European Food Safety Authority (EFSA). In this study, we have developed and validated a scale to adequately measure knowledge of the recommended daily Total Water Intake (TWI) practices among foreign students at Óbuda University, Hungary. Hence, we implemented an 11-item scale to measure the Knowledge of Hydration (KH-11) and evaluate its psychometric properties among students. This study is an online cross-sectional study assessing water intake knowledge with the use of the KH-11 tool among 323 students with ages ranging from 18 to 35 years, who have enrolled for at least two semesters at the University. The statistical analysis performed was reliability (using Cronbach alpha ≥ 70%) and factor analysis. Knowledge levels were categorized as poor (<50%), intermediate (50-70%), or adequate (71-100%). The intraclass correlation, chi-square, and rotated component matrix were also estimated and reported. Data were analyzed using SPSS version 25. Cronbach's alpha analysis revealed that the KH-11 had an overall good reliability with a value of 0.80, where the survey items had an acceptable level of consistency ranging from 0.75 to 0.81 and demonstrated sufficient independence from each other as Pearson's R within factors was positive and ranged from 0.02 to 0.74. In evaluating the participants' knowledge of hydration, the total possible score for the scale is 72, while the mean score for the KH-11 was 55.2 ± 11.61 SD, and the factor analysis model yielded an acceptable fit (χ2 = 3259.4, p = 0.000). We recorded a high-level positive concordance of 0.770 with an average intraclass correlation of 0.80 at a 95% CI, where p-value = 0.000. Our findings show that the majority (66.3%) of the students have a good knowledge of hydration. However, the skewed distribution of the knowledge scores suggests that some may have lower levels of knowledge, which may warrant further study to improve knowledge in those students.

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.

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.

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.

Urine concentration impairment in sickle cell anemia: genuine nephrogenic diabetes insipidus or osmotic diuresis?

The urine concentration impairment responsible for hyposthenuria in sickle cell nephropathy is currently thought to be a consequence of renal medulla lesions, which lead to nephrogenic diabetes insipidus. The objective of the present study was to investigate the mechanism of hyposthenuria in patients with sickle cell anemia. We performed an observational study of patients with homozygous SS sickle cell anemia and data available on the fasting plasma antidiuretic hormone (ADH) concentration. A total of 55 patients were analyzed. The fasting plasma ADH values ranged from 1.2 to 15.4 pg/mL, and 82% of the patients had elevated ADH values and low fasting urine osmolality (<505 mosmol/kgH2O). Plasma ADH was positively associated with plasma tonicity and natremia (P < 0.001). None of the patients experienced polyuria and fasting free water clearance was negative in all cases, thus, ruling out nephrogenic diabetes insipidus. The tertile groups did not differ with regard to fasting urine osmolality, plasma renin level, mGFR, or several hemolysis biomarkers. The negative fasting free water clearance in all cases and the strong association between 24-h osmolal clearance and 24-h diuresis favors the diagnosis of osmotic diuresis due to an impaired medullary gradient, rather than lesions to collecting tubule.NEW & NOTEWORTHY The urine concentration impairment in sickle cell anemia is an osmotic diuresis related to an impaired renal medullary gradient leading to an ADH plateau effect. The fasting plasma ADH was high in the context of a basic state of close-to-maximal urine concentration probably driven by short nephrons maintaining a cortex-outer medullary gradient (about 400 milliosmoles). The patients had a low daily osmoles intake without evidence of thirst dysregulation so no one experienced polyuria.

Detection of low urine output by measuring urinary biomarkers

BACKGROUND

Urine output < 1 L per 24 h is a clinical warning sign that requires attention from hospital staff, who should determine whether the low flow is due to low habitual intake of water or disease-induced dehydration. The incidence of this condition is unclear.

METHODS

A cohort of 20 healthy volunteers (mean age 42 years, range 23-62 years) recorded their food and water intakes daily for 8 days. They also collected and measured all urine and delivered first morning urine samples for analysis of osmolality and creatinine. Optimal cutoffs for these biomarkers to indicate urine output of < 1 L or 15 mL/kg during the preceding 24 h were applied with and without correction for age to cross-sectional data from 1,316 subjects in various clinical settings, including healthy volunteers, preoperative patients, patients seeking acute care at a hospital, and patients receiving institutional geriatric care.

RESULTS

The urine output amounted to < 1 L during 22 of the 159 evaluable study days and was indicated by urine osmolality > 760 mosmol/kg or urine creatinine > 13 mmol/L, which had sensitivity and specificity of approximately 80%. Days with urine output < 1 L were associated with significantly less intake of both water (-41%) and calories (-22%) compared to other days. Application of age-corrected biomarker cutoffs to the 1,316 subjects showed a stronger dependency of low urine output on age than the clinical setting, occurring in 44% of the 72 participants aged 15-30 years and 18% of the 62 patients aged 90-104 years.

CONCLUSION

Biomarkers measured in morning urine of young and middle-aged volunteers indicated urine output of < 1 L with good precision, but the cutoffs should be validated in older age groups to yield reliable results.

TRIAL REGISTRATIONS

ISRCTN12215472 at http://www.isrctn.com ; NCT01458678 at ClinicalTrials.gov, and ChiCTR-TNRC-14,004,479 at the chictr.org/en.

The association of copeptin with metabolic risk markers is modified by region of origin

Iraqi born immigrants in Sweden have higher prevalence of metabolic diseases compared to native Swedes. Copeptin, a marker for vasopressin, is associated with increased risk of metabolic disease. In this cross-sectional population study based on the MEDIM cohort we investigated differences in copeptin levels between Iraqi and Swedish born individuals and if the association between copeptin and cardiometabolic risk markers differed by region of origin. We included 1109 Iraqi and 613 Swedish born participants (58% men, mean age 47 years). The Swedish participants had a higher concentration of copeptin compared to the Iraqi born group after age and sex adjustment (p < 0.001). This difference existed only among male individuals with the highest copeptin concentrations, i.e. belonging to copeptin quartile 4 (median (25th; 75th percentile) 20.07 (15.27;33.28) pmol/L for the Swedish born versus 15.57 (13.91;19.00) pmol/L for the Iraqi born, p < 0.001). We found a significant interaction between copeptin (continuous ln-transformed) and being born in Iraq regarding the association with plasma triglycerides (Pinteraction = 0.006). The association between copeptin and BMI was stronger amongst the Iraqi born individuals compared to the Swedish born. Together, this could indicate that copeptin is a more potent marker of metabolic disease among individuals born in Iraq compared to Sweden.

Exploring the Impact of Sociodemographic Characteristics and Health Literacy on Adherence to Dietary Recommendations and Food Literacy

This study investigates food literacy-related abilities and adherence to dietary recommendations in relation to sociodemographic characteristics and health-related features (health literacy, self-rated health and morbidity) in the North-Western region of Romania. This is a secondary analysis of cross-sectional data collected in 2019 from a representative and randomised sample of 1572 individuals. A questionnaire was employed to record participants' sociodemographic characteristics, food-related and health-related features. Most participants were non-adherent to dietary recommendations for fruit and vegetables (83.5%), fish and seafood (61.3%), and water intake (67.9%). However, most participants reported an adequate ability to understand the connection between nutrition and health (89.1%), to distinguish between healthy and less healthy options (84.4%), and to acquire nutrition information (75.6%). Non-adherence to dietary recommendations and low food literacy abilities were more prevalent in disadvantaged groups (older age, rural settings, retirement or social welfare, low educational attainment, formerly married). Health literacy was negatively associated with not adhering to dietary recommendations and poor self-rated food literacy abilities. The study suggests that low socioeconomic status negatively impacts food literacy and adherence to dietary recommendations among Romanian adults. Identifying target populations to improve food-related abilities and health literacy can aid public health services in improving health outcomes.

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.

Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality

BACKGROUND

It is known that some people age faster than others, some people live into old age disease-free, while others develop age-related chronic diseases. With a rapidly aging population and an emerging chronic diseases epidemic, finding mechanisms and implementing preventive measures that could slow down the aging process has become a new challenge for biomedical research and public health. In mice, lifelong water restriction shortens the lifespan and promotes degenerative changes. Here, we test the hypothesis that optimal hydration may slow down the aging process in humans.

METHODS

We performed a cohort analysis of data from the Atherosclerosis Risk in Communities study with middle-age enrollment (45-66 years, n = 15,752) and 25 years follow-up. We used serum sodium, as a proxy for hydration habits. To estimate the relative speed of aging, we calculated the biological age (BA) from age-dependent biomarkers and assessed risks of chronic diseases and premature mortality.

FINDINGS

The analysis showed that middle age serum sodium >142 mmol/l is associated with a 39% increased risk to develop chronic diseases (hazard ratio [HR] = 1.39, 95% confidence interval [CI]:1.18-1.63) and >144 mmol/l with 21% elevated risk of premature mortality (HR = 1.21, 95% CI:1.02-1.45). People with serum sodium >142 mmol/l had up to 50% higher odds to be older than their chronological age (OR = 1.50, 95% CI:1.14-1.96). A higher BA was associated with an increased risk of chronic diseases (HR = 1.70, 95% CI:1.50-1.93) and premature mortality (HR = 1.59, 95% CI 1.39-1.83).

INTERPRETATION

People whose middle-age serum sodium exceeds 142 mmol/l have increased risk to be biologically older, develop chronic diseases and die at younger age. Intervention studies are needed to confirm the link between hydration and aging.

FUNDING

This work was funded by Intramural Research program of the National Heart, Lung, and Blood Institute (NHLBI). The ARIC study has been funded in whole or in part with federal funds from the NHLBI; the National Institutes of Health (NIH); and the Department of Health and Human Services.

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.

Influence of “Sneznik-1/79” Mineral Water on Anthropometric, Functional and Biochemical Parameters of Professional Basketball Players: Role of Oxidative Stress

Adequate hydration represents the balance between the water intake and loss and has an unambiguous significance for public health and it is essential to sustain life. The changes in electrolyte balance which occur during and after training affect on athletes health and performance. Therefore, fluid replacement with adequate mineral composition is of utmost importance. The aim of the present study was to examine the influence of low mineral water from the well Sneznik-1/79 on anthropometric, functional, biochemical parameters and redox status of professional basketball players. In total, 17 male basketball players were included, during the pre-competitive mesocycle, and after the initial testing, they were randomly divided into two groups: group 1 - consumed the commercial drinking water for four weeks (n=7), and group 2 - consumed water from the well Sneznik-1/79 for four weeks (n=10). Determination of the anthropometric, functional, biochemical parameters and redox status was performed. Our results pointed out that consumption of mineral water from the well Sneznik is completely safe from the aspect of affecting various anthropometric, functional and biochemical parameters as well as systemic oxidative stress of professional athletes. In addition, existence of discretely better effects over commercial drinking water indicates that a long period of monitoring may certainly be of interest for further investigation.

Seasonal effects on urinary iodine concentrations in women of reproductive age: An observational study in Tanzania and South Africa

BACKGROUND

Iodine intake in populations is usually assessed by measuring urinary iodine concentrations (UICs) in spot samples. Hot climate conditions may reduce urine volume, thus leading to overestimations of UIC and thereby masking inadequate iodine intake.

OBJECTIVES

We investigated the effects of season on UICs in 2 populations exposed to high-temperature climates.

METHODS

In this observational study, we examined women (18-49 years) in Tanzania (ncold = 206; nhot = 179) and South Africa (ncold = 157; nhot = 126) during cold and hot seasons. From each woman in both seasons, we obtained two 24-hour urine collections and 2 spot urine samples, as well as salt, water, and cow's milk samples. We measured the urine volume, UIC, and urinary creatinine concentration (UCC). The 24-hour urinary iodine excretion (UIE) was calculated and used to estimate the iodine intake. We used linear mixed-effects models to test for differences between seasons.

RESULTS

In Tanzanian women, we observed no seasonal effect on the urine volume, 24-hour UIE, 24-hour UIC, spot UIC, spot UIC:UCC ratio, or salt iodine concentration. In South African women, the median 24-hour urine volume was 1.40 L (IQR, 0.96-2.05 L) in the winter and 15% lower in the summer (P < 0.001). The median 24-hour UIE was 184 µg/day (IQR, 109-267 µg/day) in the winter and 34% lower in the summer (P < 0.001), indicating a lower iodine intake. As a result, UICs did not significantly differ between seasons in 24-hour collections and spot samples, whereas the spot UIC:UCC ratio differed by 21% (P < 0.001) and reflected the lower iodine intake. In both study populations, the within- and between-person variabilities in urine volume, 24-hour UICs, and spot UICs were higher than the variability between seasons.

CONCLUSIONS

Spot UIC may slightly overestimate the iodine intake in hot temperatures due to concentrated urine, and methods to correct for urine volume may be considered. Local seasonal differences in iodine intakes may also occur in some populations. This trial was registered at http://www.clinicaltrials.gov as NCT03215680.

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 dehydration during pregnancy on birth weight and length in West Jakarta

Nutrition and maternal behavior are critical factors in fetal development. Maternal water intake is necessary to regulate metabolism and may influence fetal growth. This study aims to determine the effect of dehydration during pregnancy on birth weight and length. This cohort-prospective study took place in the area of Kebon Jeruk District Health Centre. A total of 38 subjects of pregnant women in their second trimester were examined. Subject characteristics were collected through direct measurements and interviews. Urine and blood samples were collected at the sixth trimester (32–34 and 35–37 weeks) to determine hydration status. Nutritional status was collected through food recall, while birth weight and length were obtained from the anthropometric measurements 30 min after birth. From a total of 38 subjects, 20 were dehydrated, and 18 were well hydrated. There was a significant relationship between hydration status and water intake, birth weight and length, head circumference, and chest circumference. After being corrected to the level of water intake, the difference in birth weight and length between the two groups were 500⋅6 g and 0⋅4 cm, and 0⋅8 cm and 1⋅4 cm for the head circumference and chest circumference (P < 0⋅05). It is recommended for mothers to monitor their weight and ensure fluid intake of 3⋅0 l per day. Further research requires more subjects to observe the effects of chronic maternal dehydration on pregnancy output and a cohort study that monitors infant development in the first six months of life.

Evaluation of hydration status during the COVID-19 pandemic: a study of Turkish young adults

Adequate hydration is an essential component of health at every stage of life. Although many factors such as age, gender, physical activity, drug use, and illness affect hydration status, it is vital to maintain water balance, especially in infectious diseases. This study was conducted to estimate the hydration status of young adults living in Turkey during the COVID-19 pandemic. The total water intake (TWI) and total water loss of the individuals were determined using the Water Balance Questionnaire (WBQ), which consists of questions about physical activity status, frequency of food and beverage consumption, water consumption, and water loss with urine and feces. The TWI of men and women was found to be 4,776.1 and 4,777.3 mL/day, respectively (p > 0.05). It was determined that 29% of the total water was obtained from drinking water, 49% from other beverages, and 22% from food. A positive net water balance was found in all body mass index (BMI) groups, men, and women. The net water balance was statistically lower in men (2,230.6 mL) than women (2,783.8 mL) (p < 0.05). As the COVID-19 pandemic continues, studies should be done on hydration status in the more balanced populations in terms of BMI and age groups.

Total water intake by kilogram of body weight: Analysis of the Australian 2011 to 2013 National Nutrition and Physical Activity Survey

AIM

Water is critical for human survival, yet water intake equations may not reflect contemporary populations. This research aims to determine the total water intake of a representative Australian population, per kilogram of body weight (mL/kg) and stratified by age and sex.

METHODS

A secondary analysis of the 2011 to 2013 National Nutrition and Physical Activity Survey (n = 10 146) was conducted. Dietary intake from food and beverages was assessed by a 24-hour recall, with respondent's weight objectively measured. Data were descriptively analysed, with multiple linear regressions used to identify the impact of demographic and physiologic factors on total water intake (mL/kg).

RESULTS

The median (interquartile range) daily total water intake per kilogram of body weight for children (2-8 years), adolescents (9-18 years) and adults (19+ years) were 77.1 (57.4-100) mL/kg, 40.4 (29.3-53.4) mL/kg and 35.5 mL/kg (26.1-47.8), respectively. Increasing height and waist circumference were associated with reduced total water intake, with a change of -1.03 mL/kg (-1.43, -0.618) [coefficient (95% confidence interval)] in children for height and -0.448 mL/kg (-0.484, -0.412) in adults for waist circumference. Similarly, seasonality decreased intake, with greatest reductions in winter [adolescents: -4.11 mL/kg (-6.83, -1.40)]. In comparison, being male, living in rural areas and having a physical occupation were associated with greater intake, by 1.73 mL/kg (0.347, 3.10), 4.74 mL/kg (3.47, 6.00) and 2.82 (trade workers: 1.08, 4.59) in adults, respectively.

CONCLUSIONS

Total water intake (mL/kg) decreased with age in both sexes. The results highlight possibilities to incorporate other factors into water intake equations to improve their accuracy.

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.

The comparison of water intake patterns and hydration biomarkers among young adults with different hydration statuses in Hebei, China

Background

Water is essential for maintaining the functions of human body properly. Studies have shown that the amounts and contributions of fluids were associated with health and hydration status. The objectives of the study was that to explore the differences of water intake pattern and hydration biomarkers among young males and females in different hydration statuses.

Methods

A cross-sectional study was implemented 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 questionnaire and duplicate portion method, respectively. The osmolality and electrolyte concentrations of the 24 h urine and plasma were tested. Differences in optimal hydration (OH), middle hydration (MH) and hypohydration (HH) groups, divided by the osmolality of 24 h urine, were compared.

Results

Totally, 156 participants (80 males and 76 females) completed the study. OH group had highest proportions of participants met the recommendations of total water intake (TWI) and total drinking fluids of China (34.5%, 36.2%), while HH group had lowest (7.7%, 0.0%). OH group had higher amounts of TWI, total drinking fluids, water and lower amounts of sugar-sweetened-beverages (SSBs) (P < 0.05). The percentage of total drinking fluids in TWI decreased from 54.1% in OH group to 42.6% in HH group (P < 0.05). OH group had higher and lower contributions of water and SSBs to total drinking fluids (P < 0.05); produced 551–950 mL more, excreted significantly less quantity of solutes of urine (P < 0.05). No significant differences were found in plasma osmolality among the three groups (P > 0.05). Among both males and females, the amounts of TWI and water were higher in OH group than others (P < 0.05). Males had 4.3% lower, 5.4% and 1.1% higher contributions of milk and milk products, SSBs and alcohol to total drinking fluids than females (P < 0.05); males had higher volume of urine than females only in MH group (P < 0.05). There were no significant differences of plasma osmolality between males and females in the same group (P > 0.05).

Conclusions

Young adults with optimal hydration status had better water intake pattern and less concentrated urine. Females maybe have better water intake pattern than males.

Trial registration Chinese clinical trial registry. Name of the registry: Relationship of drinking water and urination. Trial registration number: ChiCTR-ROC-17010320. Date of registration: 01/04/2017. URL of trial registry record: http://www.chictr.org.cn/edit.aspx?pid=17601&htm=4.

Pain Across the Menstrual Cycle: Considerations of Hydration

Chronic pain – pain that persists for more than 3 months – is a global health problem and is associated with tremendous social and economic cost. Yet, current pain treatments are often ineffective, as pain is complex and influenced by numerous factors. Hypohydration was recently shown to increase ratings of pain in men, but studies in this area are limited (n = 3). Moreover, whether hypohydration also affects pain in women has not been examined. In women, changes in the concentrations of reproductive hormones across menstrual phases may affect pain, as well as the regulation of body water. This indicates potential interactions between the menstrual phase and hypohydration on pain, but this hypothesis has yet to be tested. This review examined the literature concerning the effects of the menstrual phase and hypohydration on pain, to explore how these factors may interact to influence pain. Future research investigating the combined effects of hypohydration and menstrual phase on pain is warranted, as the findings could have important implications for the treatment of pain in women, interpretation of previous research and the design of future studies.

Nocturnal Urine Production in Women With Global Polyuria

PURPOSE

Low nocturnal urine production (NUP) may be sufficient to rule out global polyuria (GP) in men. This study determines the sensitivity of indices for nocturnal polyuria (NP), defined as nocturnal polyuria index (NPi; nocturnal urine volume/24-hour urine volume) ≥0.33 or NUP ≥90 mL/hr, for detecting GP in women.

METHODS

Data were analyzed from 2 prospective protocols involving subjects recruited from a urology ambulatory care unit and a continence clinic. Women ≥18 years with nocturia were included if they met either of 2 common criteria for GP: (1) ≥40 mL/kg/24 hr or (2) ≥3,000 mL/24 hr.

RESULTS

Thirty-one women were included (NPi, 28.6 [21.3-40.7]; NUP, 100.8 [68.3-135.8] mL/hr). At the ≥40 mL/kg/24-hr cutoff, 40% and 63% of women reporting ≥1 nocturnal void(s) (n=30) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. Additionally, 53% and 71% of subjects reporting ≥2 nocturnal voids (n=17) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. At the ≥3,000 mL/24-hr cutoff, 38% and 69% of women reporting ≥1 nocturnal void(s) (n=13) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively, and 63% and 88% of subjects reporting ≥2 nocturnal voids (n=8) had NPi ≥0.33 and NUP ≥90 mL/hr, respectively. By extension, 37%-62% of women with nocturia and GP did not have NP by NPi ≥0.33 criteria, and 12%-37% did not have NP by NUP ≥90 mL/hr criteria.

CONCLUSION

Indices of excess nighttime urination do not reliably predict GP in women. A full-length voiding diary may be particularly important in the evaluation of women with nocturia. Nocturia in women merits further consideration as a distinct entity.

A Novel Urinary Biomarker Approach Reveals Widespread Exposure to Multiple Low-Calorie Sweeteners in Adults

BACKGROUND

Observational investigations into the health impacts of low-calorie sweeteners (LCSs) in humans fail to adequately identify or fully characterize LCS consumption.

OBJECTIVES

We aimed to utilize a novel biomarker approach to investigate exposure to 5 LCSs and to test whether reported low-calorie sweetened beverage (LCSB) consumption effectively identifies exposure to LCSs in adults.

METHODS

In this cross-sectional analysis, 2 population studies were conducted in adults. Urinary excretions of 5 LCSs, namely acesulfame-K, saccharin, cyclamate, sucralose, and steviol glycosides, were simultaneously determined using LC tandem-MS. In Study 1, previously collected 24-h urine samples (n = 357) were analyzed. In Study 2, previously collected 24-h urine samples (n = 79) were analyzed to compare urinary excretions of LCSs with self-reported LCSB consumption for identifying LCS exposure. Exposure to LCSs was characterized using descriptive statistics and chi-square tests were performed to assess associations between age-groups and LCS excretion, and to assess the proportion of individuals identified as LCS consumers using biomarker data or reported LCSB consumption.

RESULTS

A total of 341 adults (45% men) and 79 adults (39% men) were included in the final analysis of Studies 1 and 2, respectively. In Study 1, >96% of samples contained ≥1 LCS and almost 60% contained ≥3 LCSs. A greater proportion of younger adults (<40 y old) excreted ≥3 LCSs than older adults (>40 y old) (P < 0.001). In Study 2, a much higher prevalence of LCS consumption was observed using biomarker data (92%) than reported LCSB consumption (6%) (P < 0.001).

CONCLUSIONS

This work indicates widespread exposure to LCSs, suggesting that population-based research to date into LCS exposure and health may be flawed. Therefore, a urinary biomarker approach offers considerable potential for more robust investigations in this area.

Influence of “Sneznik-1/79” Mineral Water on Anthropometric, Functional and Biochemical Parameters of Professional Basketball Players: Role of Oxidative Stress

Adequate hydration represents the balance between the water intake and loss and has an unambiguous significance for public health and it is essential to sustain life. The changes in electrolyte balance which occur during and after training affect on athletes health and performance. Therefore, fluid replacement with adequate mineral composition is of utmost importance. The aim of the present study was to examine the influence of low mineral water from the well Sneznik-1/79 on anthropometric, functional, biochemical parameters and redox status of professional basketball players. In total, 17 male basketball players were included, during the pre-competitive mesocycle, and after the initial testing, they were randomly divided into two groups: group 1 – consumed the commercial drinking water for four weeks (n = 7), and group 2 – consumed water from the well Sneznik-1/79 for four weeks (n = 10).

Determination of the anthropometric, functional, biochemical parameters and redox status was performed. Our results pointed out that consumption of mineral water from the well Sneznik is completely safe from the aspect of affecting various anthropometric, functional and biochemical parameters as well as systemic oxidative stress of professional athletes. In addition, existence of discretely better effects over commercial drinking water indicates that a long period of monitoring may certainly be of interest for further investigation.

The Validity of Urine Color as a Hydration Biomarker within the General Adult Population and Athletes: A Systematic Review

Frequent monitoring of hydration status may help to avoid the adverse effects of dehydration. Other than urine color assessment, hydration assessment methods are largely impractical for the general population and athletes to implement on a routine basis. Despite its widespread use, the validity of urine color as an indicator of hydration status has not been systematically evaluated. The objective of this systematic review is to determine the validity of urine color evaluation as a hydration status assessment method in the general adult population, older adults, and athletes. Using the PRISMA guidelines, electronic databases were searched to identify original research articles of all study design types for inclusion. Of the 424 articles screened, 10 met inclusion criteria. Most studies compared urine color to either urinary specific gravity or urine osmolality, and reported significant associations (r) ranging from 0.40 to 0.93. Lower correlations were noted in studies of adults aged >60 years. Studies generally reported a high sensitivity of urine color as a diagnostic tool for detecting dehydration and supported the ability of this method to distinguish across categories of hydration status. Research is needed to determine if clinicians, patients, and clients can accurately utilize this method in clinical and real-world settings. Future research is also needed to extend these findings to other populations, such as children.Key teaching pointsInadequate hydration can lead to impairments in physical performance and cognitive function.Methods used to assess hydration status include plasma/serum osmolality, urinary specific gravity (USG), urine osmolality (Uosm), change in body weight, urine volume, and urine color.Urine color assessment is a practical method that is routinely used in clinical, athletic, and other settings. The validity of this method has not been systemically evaluated.Available research was limited to 10 articles.Validity of this method was generally supported; however, research has not investigated the validity of this method by clinicians, patients and clients.

Water and Beverage Consumption among a Nationally Representative Sample of Children and Adolescents in the United Arab Emirates

There are limited studies examining water consumption among individuals in hot climates. We assessed the daily total water intake from plain water, other beverages, and food in a nationally representative sample of children and adolescents aged 6-18 years in the United Arab Emirates. Total water intake was compared against the recommendations of the Institute of Medicine and the European Food Safety Authority. Sociodemographic information, 24 h dietary recall, physical activity levels, and anthropometric data were collected from 527 participants. The mean ± SE of total water intake was 1778.4 ± 33.8 mL/day. Plain drinking water was the largest contributor to total water intake (51.6%), followed by food (27.3%). Sugar-sweetened beverages constituted 13.9% of water intake. The proportion of participants who met the Institute of Medicine recommendations ranged from 15% (males aged 14-18) to 25% (children aged 6-8). The proportion of participants who met the European Food Safety Authority recommendations ranged from 31% (females aged 14-18) to 36% (males aged 14-18). The water-to-energy ratio was 1.0-1.15 L/1000 kcal, meeting recommendations. The majority of participants failed to meet water intake recommendations, highlighting the need for targeted interventions to promote increased water consumption among children and adolescents.

Influence of Water Intake and Balance on Body Composition in Healthy Young Adults from Spain

The increasing prevalence of overweight and obesity has become an epidemic public health problem worldwide. In the last years, several investigations have suggested that water intake and retention could have important implications for both weight management and body composition. However, there is a lack of information about this issue globally, and mainly specifically in Spain. Thus, the aim of this study was to analyze the association between hydration status and body composition in a sample of healthy Spanish adults. The study involved 358 subjects, aged 18-39 years. The recently validated "hydration status questionnaire" was used to assess their water intake, elimination, and balance. Anthropometric measurements were performed according to the recommendations of the International Standards for Anthropometric Assessment (ISAK). Body composition variables were acquired by bioelectrical impedance analysis. Differences in anthropometric and body composition variables were assessed through the ANOVA test and considered significant at p < 0.05. Fluid intake was correlated with body water content. Inverse associations between water consumption, normalized by weight, with body weight, body fat mass, and waist circumference were found. Moreover, according to water balance, significant differences in body water content in females were observed. In conclusion, higher fluid intake seems to be related with a healthier body composition. Therefore, the improvement of water intake and water balance could be useful for overweight and obesity prevention, although further studies are needed to confirm the present findings.

Fluctuation of Water Intake and of Hydration Indices during the Day in a Sample of Healthy Greek Adults

Mild dehydration may occur during specific periods of the day because of poor hydration habits and/or limited access to a variety of beverages or foods, for example, in work environments. Measurement of hydration indices in spot or in 24 h urine samples may mask mild dehydration in specific periods of the day. Healthy subjects (n = 164; 74 females; age 38 ± 12 years) living in Athens, Greece were enrolled in the study. Subjects recorded their solid food and drink intakes and recorded and collected all urinations for three consecutive days. Water intake was analyzed in 24 h and 6 h periods from wake-up time and scored for variety. Urine hydration indices (osmolality, volume, color, specific gravity) were analyzed in 24 h samples, in morning urine samples and in samples collected in 6 h periods from wake-up time. Fluctuations during the day were significant for the intake of drinking water, hot beverages, milk, fruit and vegetable juices, and alcoholic drinks and for urine osmolality, volume, color, and specific gravity. The urine volume of the first 6 h period after wake-up time (557 ± 231 mL/day) reflects by 76% the 24 h urine collection (1331 ± 144 mL/day). Water intake from all beverages, with the exception of alcoholic beverages, was greater in the first 6h period (morning period) and decreased throughout the day. Hydration indices changed accordingly. The 6 h timed urine sample collected reflects indices in samples collected over 24 h better than any spot urine sample.

Hydration status, total water intake and subjective feelings of adolescents living in a hot environment, during a typical school day

AIM

Individuals living in a hot environment appear to face increased risk of dehydration. Currently there is not extensive literature on the adolescent population in relation to hydration. The aim of the present study was to assess hydration status and total water intake (TWI) at school, of adolescents living in a hot environment, and to investigate the association of hydration and TWI with various subjective feelings.

METHODS

The hydration status of 141 adolescents (boys n = 102), age 15-17 years, was assessed via urine specific gravity (USG), at the beginning (07:30 am) and at the end (1:30 pm) of one school day. TWI from fluids and solid food was assessed via detailed food and fluid records. Subjective feelings (i.e. thirst, alertness, ability to concentrate) were recorded by specific scales.

RESULTS

Ninety percent of the students arrived dehydrated at school (USG >1.020). Thirteen students were hydrated (USG <1.020), 67 students were slightly dehydrated (USG 1.021-1.029), and 50 students were seriously dehydrated (USG >1.030). There was no difference in TWI between the three groups (765 ± 451 mL). TWI correlated with alertness (p = 0.005) and the ability to concentrate (p = 0.015), and inversely correlated with fatigue (p = 0.015). Seriously dehydrated students felt less alert in the morning (p < 0.035) whereas the feeling of thirst was similar between all groups.

CONCLUSIONS

The prevalence of the dehydration of the adolescents during school time appeared to be extremely high, and thirst was not driving those adolescents to drink enough. Apart from health concerns, school performance could be affected by dehydration and inadequate water intake.

Differing Water Intake and Hydration Status in Three European Countries-A Day-to-Day Analysis

Adequate hydration is essential for maintaining health and functionality of the human body. Studies assessing both daily water intake and hydration status are lacking. This study explored data from the European Hydration Research Study (EHRS) and focused on total water intake (TWI), 24 h hydration status, and day-to-day variations in a sample of 573 healthy adults. TWI was assessed by food records and hydration status (urine osmolality and urine volume) was measured from 24 urine samples collected over seven consecutive days. On all weekdays, mean TWI was higher (p < 0.001 for all days) for the German subjects compared to the Greek and Spanish participants. In 37% of the male and 22% of the female subjects, the individual mean TWI was below the European Food Safety Authority (EFSA) recommendation, with 16% men (4% women) being below the EFSA recommendation on every testing day. Twenty-four hour urine osmolality was lower in women compared to men (595 ± 261 vs. 681 ± 237 mOsmol/kg; p < 0.001). More men (40%) showed a urine osmolality ≥800 mOsmol/kg at least on four days of the study period compared to women (26%) and more participants from Spain (46%) compared to Greece (29%) and Germany (11%). A large number of individuals showed an inadequate hydration status on several days per week, which may have a negative health and cognitive impact on daily life.

Patterns of adherence to diuretics, dietary sodium and fluid intake recommendations in adults with heart failure

BACKGROUND

Three behaviors advocated to minimize fluid-related hospitalizations in patients with heart failure (HF) are restricted sodium and fluid intake and consistent oral diuretic use. Adherence to behaviors intended to decrease risk of hospitalization is believed to vary over time, but surprisingly little research has addressed patterns of adherence in HF patients.

OBJECTIVE

To describe patterns over time of 3 recommended self-care behaviors (i.e., diet, fluid intake, and diuretic dosing) in adults with HF and to determine how time and behavior influenced adherence rates.

METHODS

We enrolled 24 adults hospitalized for a HF exacerbation and discharged on a loop diuretic into a descriptive, longitudinal pilot study. Over 3-months, diuretic use was measured using electronic event monitoring, and participants were telephoned regularly to assess sodium and fluid intake. Data were summarized for each 2-week intervals.

RESULTS

The overall adherence rates were 42.4% for low sodium diet, 96.4% for fluid restriction, and 84.7% for the diuretic regimen. Early after hospital discharge, medication adherence was the highest, and dietary adherence was the lowest, but adherence to diet and diuretic use decreased significantly over time.

CONCLUSION

Although participants were just discharged from the hospital after an acute exacerbation of HF, all three behavioral patterns decreased markedly over the 3-month follow-up period.

Mild dehydration in dyspeptic athletes is able to increase gastrointestinal symptoms: Protective effects of an appropriate hydration

BACKGROUND

Water balance influences gastrointestinal (GI) activity. Our aim was to evaluate how dehydration and rehydration with different types of water are able to affect GI activity in healthy and dyspeptic athletes.

METHODS

Twenty non-competitive athletes, respectively 10 healthy and 10 dyspeptic subjects, were enrolled. All subjects underwent three test sessions (0, A, B) of 6 hours. Dehydration was achieved with a walking/jogging exercise test on a treadmill. After exercising, 500 mL of calcium-bicarbonate (Test A) or soft water (Test B) were administered, while no rehydration was provided during Test 0; thereafter, all subjects consumed a light lunch. GI symptoms were evaluated during each test and an electrocardiogram (ECG) Holter recording was performed at the end of the exercise.

KEY RESULTS

Dyspeptic subjects exhibited higher overall symptoms during Test 0 (VAS: 30.8 ± 0.8 mm) compared to Test A (18.4 ± 1.1, P < 0.001) and Test B (24.4 ± 1.3, P < 0.001). However, analyzing GI symptoms, only subjects receiving calcium-bicarbonate water (Test A) showed significantly lower symptomatic scores compared to Test 0 or Test B. Moreover, heart rate variability analyses revealed that only in Test A dyspeptic patients exhibit a trend to a decrease in the post-prandial low/high frequency (LF/HF) ratio, similarly to healthy subjects, while in Test 0 and Test B, post-prandial LF/HF ratio was increased compared to the pre-prandial phase.

CONCLUSIONS AND INFERENCES

Our results show that mild dehydration in dyspeptic athletes is able to increase GI symptoms but an adequate rehydration, with calcium-bicarbonate water, is able to improve post-exercise disturbances restoring sympathovagal imbalance.

Development and relative validity of a self-administered semi-quantitative drinks frequency questionnaire, validated in a population of university students

AIM

Drinks can contribute to energy as well as micro- and macro-nutrient intake. Drink-specific, validated, quick and easy to administer questionnaires are needed to monitor secular trends in beverage consumption for different populations. The aim of the present cross-sectional study was to develop and validate a drink-specific questionnaire for the Greek population.

METHODS

A 41-item semi-quantitative drinks frequency questionnaire (DFQ) was developed and validated against 7-day weighed food records, among young Greek adults. Wilcoxon ranks tests, Kendall tau-b correlations and Bland-Altman plot were used to compare the two methods. Fifty-nine Greek University students (28 males, 31 females) completed both methods.

RESULTS

No difference was observed in total drinks intake between the two methods. The Bland-Altman plot showed that the two methods are likely to agree concerning the total drinks intake. Wilcoxon's rank test showed no significant differences between the two methods, except for the 'whiskey/vodka/gin' intake (P < 0.001). 'Good' agreement (tau-b > 0.61) was observed for most DFQ items, including low-fat and chocolate milk, hot chocolate, Greek/espresso coffee, commercial tea, packaged fruit juices, wine, alcohol-free beer, light cola-type drinks and water (tap/bottled/sparkling). 'Low' agreement (<0.30) was noted for filtered/instant/iced coffee, freshly squeezed orange juice and some alcoholic drinks (beer/whiskey/vodka/gin).

CONCLUSIONS

The DFQ appears to be an overall valid means of estimating the habitual intake of drinks in large-scale epidemiological surveys. The study supports the use of DFQ for assessing drinks consumption patterns and secular trends.

Is the default of 2 liters for daily per-capita water consumption appropriate? A nationwide survey reveals water intake in Japan

Two liters per day is generally applied as the default drinking water intake rate for risk assessments, although evidence supporting this value is insufficient. This study aimed to reveal actual water intakes from tap water and other types of drinks, and to explore the relationships between these intakes. For this purpose, we conducted a nationwide Internet questionnaire survey. Tap water intake negatively correlated with bottled water and soft drink intakes, suggesting a mutually complementary relationship. We propose an index, potential Tap Water Intake (pTWI), calculated by adding soft drinks and bottled water to tap water intake. Mean per-capita tap water intake across the entire Japanese population was estimated at 1.28 L/d, whereas mean pTWI was estimated at 1.65 L/d. Two liters per day corresponds to the 88th percentile of tap water intake and to the 76th percentile of pTWI, and covers the intake of the majority of the population in Japan. This rate should continue being used as the default in the Japanese population, but the rate to cover the tap water intake of almost the entire population would be higher: it was >2.5 L/d.

Sodium and Potassium Intake from Food Diaries and 24-h Urine Collections from 7 Days in a Sample of Healthy Greek Adults

Objective

The main objective of the present study was to evaluate sodium and potassium intake, employing 24 h and spot urine samples and food diaries for seven consecutive days.

Methods

For seven consecutive days subjects recorded their food and drink intakes, and recorded and collected all urinations. Food sodium and potassium intake were analyzed in 24- and 6-h intervals from wake-up time. Urine indices were analyzed in first morning, 24- and 6-h intervals samples over the day from wake-up time. The study took place in Agricultural University of Athens, Greece. In total, 163 healthy subjects (age 39 ± 12 years; 74 females) were enrolled in the study.

Results

Mean urine sodium excretion was 2,803.3 ± 1,249.0 mg/day (121.9 ± 54.3 mmol/day) and mean urine potassium excretion was 2,152.2 ± 913.3 mg/day (55.2 ± 23.4 mmol/day). The highest potassium concentration was measured in the afternoon, while the lowest sodium concentration was measured in the overnight 6-h interval. Food sodium intake was 1,983.2 ± 814.1 mg/day and food potassium was 2,264.5 ± 653.3 mg/day. The sources that contribute most in food sodium intake are dairy products 24%, breads 22%, and savory snacks 17%.

Conclusion

Strategies should encourage the Greek population to moderate sodium intake and promote potassium intake, thus adopting a healthier dietary and lifestyle pattern.

Hydration status, drug interactions, and determinants in a Spanish elderly population: a pilot study

Proper hydration is essential to maintain optimal health and well-being at all stages of life, especially for the elderly. Side effects of certain drugs that affect hydration status may compromise the health of the ancients, who also constitute the most vulnerable group. No studies have been carried out, to our knowledge, at the intersection of drugs and hydration status. Our study aimed to evaluate the effects of chronic use of certain drugs (diuretics, corticoids and metformin) in the hydration status of the elderly. Results were obtained from a cross-sectional study with 96 volunteers (65-93 years) selected based on their pharmacological treatment. It included a validated food and drink frequency questionnaire and water removal, dehydration signs and symptoms assessment and urine analysis. All data were analysed by age and sex. Water balance decreased with advanced age, especially in men's group. Results were confirmed by means of the evaluation of dehydration signs and symptoms and colorimetric and chemical analysis of urine. Correlations between consumption of corticoids and hydration status were found, with different signs depending on the administration route (Rho = 0.522 and Rho = - 0,522 for oral and pulmonary corticoids, respectively). Furthermore, correlations between diuretics (Rho = - 0.343, p < 0.05) and metformin (Rho = - 0.802, p < 0.01) consumption and different urine markers were determined. In conclusion, the predominant dehydration state of the volunteers of the study is affected by drugs consumption and their route of administration. Hence, there is an urgent need for monitorization of hydration status based on drugs consumption.

Racial/Ethnic and Socioeconomic Disparities in Hydration Status Among US Adults and the Role of Tap Water and Other Beverage Intake

OBJECTIVES

To evaluate whether differences in tap water and other beverage intake explain differences in inadequate hydration among US adults by race/ethnicity and income.

METHODS

We estimated the prevalence of inadequate hydration (urine osmolality ≥ 800 mOsm/kg) by race/ethnicity and income of 8258 participants aged 20 to 74 years in the 2009 to 2012 National Health and Nutrition Examination Survey. Using multivariable regression models, we estimated associations between demographic variables, tap water intake, and inadequate hydration.

RESULTS

The prevalence of inadequate hydration among US adults was 29.5%. Non-Hispanic Blacks (adjusted odds ratio [AOR] = 1.44; 95% confidence interval [CI] = 1.17, 1.76) and Hispanics (AOR = 1.42; 95% CI = 1.21, 1.67) had a higher risk of inadequate hydration than did non-Hispanic Whites. Lower-income adults had a higher risk of inadequate hydration than did higher-income adults (AOR = 1.23; 95% CI = 1.04, 1.45). Differences in tap water intake partially attenuated racial/ethnic differences in hydration status. Differences in total beverage and other fluid intake further attenuated sociodemographic disparities.

CONCLUSIONS

Racial/ethnic and socioeconomic disparities in inadequate hydration among US adults are related to differences in tap water and other beverage intake. Policy action is needed to ensure equitable access to healthy beverages.

Characteristics of Beverage Consumption Habits among a Large Sample of French Adults: Associations with Total Water and Energy Intakes

BACKGROUND

Adequate hydration is a key factor for correct functioning of both cognitive and physical processes. In France, public health recommendations about adequate total water intake (TWI) only state that fluid intake should be sufficient, with particular attention paid to hydration for seniors, especially during heatwave periods. The objective of this study was to calculate the total amount of water coming from food and beverages and to analyse characteristics of consumption in participants from a large French national cohort.

METHODS

TWI, as well as contribution of food and beverages to TWI was assessed among 94,939 adult participants in the Nutrinet-Santé cohort (78% women, mean age 42.9 (SE 0.04)) using three 24-h dietary records at baseline. Statistical differences in water intakes across age groups, seasons and day of the week were assessed.

RESULTS

The mean TWI was 2.3 L (Standard Error SE 4.7) for men and 2.1 L (SE 2.4) for women. A majority of the sample did comply with the European Food Safety Authority (EFSA) adequate intake recommendation, especially women. Mean total energy intake (EI) was 1884 kcal/day (SE 1.5) (2250 kcal/day (SE 3.6) for men and 1783 kcal/day (SE 1.5) for women). The contribution to the total EI from beverages was 8.3%. Water was the most consumed beverage, followed by hot beverages. The variety score, defined as the number of different categories of beverages consumed during the three 24-h records out of a maximum of 8, was positively correlated with TWI (r = 0.4); and with EI (r = 0.2), suggesting that beverage variety is an indicator of higher consumption of food and drinks. We found differences in beverage consumptions and water intakes according to age and seasonality.

CONCLUSIONS

The present study gives an overview of the water intake characteristics in a large population of French adults. TWI was found to be globally in line with public health recommendations.

Water Intake in a Sample of Greek Adults Evaluated with the Water Balance Questionnaire (WBQ) and a Seven-Day Diary

Awareness on the importance of hydration in health has created an unequivocal need to enrich knowledge on water intake of the general population and on the contribution of beverages to total water intake. We evaluated in the past water intake in a sample of Greek adults using two approaches. In study A, volunteers completed the Water Balance Questionnaire (WBQ), a food frequency questionnaire, designed to evaluate water intake (n = 1092; 48.1% males; 43 ± 18 years). In study B, a different population of volunteers recorded water, beverage, and food intake in seven-day diaries (n = 178; 51.1% males; 37 ± 12 years). Herein, data were reanalyzed with the objective to reveal the contribution of beverages in total water intake with these different methodologies. Beverage recording was grouped in the following categories: Hot beverages; milk; fruit and vegetable juices; caloric soft drinks; diet soft drinks; alcoholic drinks; other beverages; and water. Total water intake and water intake from beverages was 3254 (SE 43) mL/day and 2551 (SE 39) mL/day in study A; and 2349 (SE 59) mL/day and 1832 (SE 56) mL/day in study B. In both studies water had the highest contribution to total water intake, approximately 50% of total water intake, followed by hot beverages (10% of total water intake) and milk (5% of total water intake). These two approaches contribute information on water intake in Greece and highlight the contribution of different beverages; moreover, they point out differences in results obtained from different methodologies attributed to limitations in their use.

Fatigue and fluid hydration status in multiple sclerosis: A hypothesis

BACKGROUND

Fatigue is a prevalent and functionally disabling symptom for individuals living with multiple sclerosis (MS) which is poorly understood and multifactorial in etiology. Bladder dysfunction is another common MS symptom which limits social engagement and quality of life. To manage bladder issues, individuals with MS tend to limit their fluid intake, which may contribute to a low-hydration (LoH) state and fatigue.

OBJECTIVE

To evaluate the relationship between patient-reported MS fatigue, bladder dysfunction, and hydration status.

METHODS

We performed a prospective cross-sectional study in 50 women with MS. Participants submitted a random urine sample and completed several fatigue-related surveys. Using a urine specific gravity (USG) threshold of 1.015, we classified MS subjects into two groups: high-hydration (HiH) and LoH states.

RESULTS

LoH status was more common in MS subjects with bladder dysfunction. Statistically significant differences in self-reported Fatigue Performance Scale were observed between HiH and LoH subjects (p = 0.022). USG was significantly correlated with fatigue as measured by the MS Fatigue Severity Scale (FSS) score (r = 0.328, p = 0.020).

CONCLUSION

Hydration status correlates with self-reported fatigue, with lower fatigue scores found in those with HiH status (USG < 1.015).