Development and Validation of an Instrument to Evaluate Perceived Wellbeing Associated with the Ingestion of Water: The Water Ingestion-Related Wellbeing Instrument (WIRWI).

BACKGROUND: Ingestion of water has been associated with general wellbeing. When water intake is insufficient, symptoms such as thirst, fatigue and impaired memory result. Currently there are no instruments to assess water consumption associated with wellbeing. The objective of our study was to develop and validate such an instrument in urban, low socioeconomic, adult Mexican population. METHODS: To construct the Water Ingestion-Related Wellbeing Instrument (WIRWI), a qualitative study in which wellbeing related to everyday practices and experiences in water consumption were investigated. To validate the WIRWI a formal, five-process procedure was used. Face and content validation were addressed, consistency was assessed by exploratory and confirmatory psychometric factor analyses, repeatability, reproducibility and concurrent validity were assessed by conducting correlation tests with other measures of wellbeing such as a quality of life instrument, the SF-36, and objective parameters such as urine osmolality, 24-hour urine total volume and others. RESULTS: The final WIRWI is composed of 17 items assessing physical and mental dimensions. Items were selected based on their content and face validity. Exploratory and confirmatory factor analyses yielded Cronbach's alpha of 0.87 and 0.86, respectively. The final confirmatory factor analysis demonstrated that the model estimates were satisfactory for the constructs. Statistically significant correlations with the SF-36, total liquid consumption and simple water consumption were observed. CONCLUSION: The resulting WIRWI is a reliable tool for assessing wellbeing associated with consumption of plain water in Mexican adults and could be useful for similar groups.

Effect of Increased Water Intake on Urinary DNA Adduct Levels and Mutagenicity in Smokers: A Randomized Study.

UNLABELLED: The association between fluid intake and bladder cancer risk remains controversial. Very little is known about to which extent the amount of water intake influences the action of excreting toxics upon the urinary system. This proof of concept trial investigates the effect of water intake on mutagenesis in smokers, a high risk population for bladder cancer. METHODS: Monocentric randomized controlled trial. Inclusion Criteria. Male subjects aged 2045-45 y/o, smokers, and small drinkers (24-hour urinary volume <1 L and osmolality >700 mOsmol/kg). OUTCOMES: 4-ABP DNA adducts formation in exfoliated bladder cells in 24-hour urine collection and urinary mutagenicity in 24-hour urine. TEST GROUP: Subjects consumed 1.5 L daily of the study product (EVIAN) on top of their usual water intake for 50 days. CONTROL GROUP: Subjects continued their usual lifestyle habits. RESULTS: 65 subjects were randomized. Mean age was 30 y/o and mean cigarettes per day were 20. A slight decrease in adducts formation was observed between baseline and last visit but no statistically significant difference was demonstrated between the groups. Urinary mutagenicity significantly decreased. The study shows that increasing water intake decreases urinary mutagenicity. It is not confirmed by urinary adducts formation. Further research would be necessary.

Twenty-four-hour urine osmolality as a physiological index of adequate water intake.

While associations exist between water, hydration, and disease risk, research quantifying the dose-response effect of water on health is limited. Thus, the water intake necessary to maintain optimal hydration from a physiological and health standpoint remains unclear. The aim of this analysis was to derive a 24 h urine osmolality (U(Osm)) threshold that would provide an index of "optimal hydration," sufficient to compensate water losses and also be biologically significant relative to the risk of disease. Ninety-five adults (31.5 ± 4.3 years, 23.2 ± 2.7 kg·m(-2)) collected 24 h urine, provided morning blood samples, and completed food and fluid intake diaries over 3 consecutive weekdays. A U(Osm) threshold was derived using 3 approaches, taking into account European dietary reference values for water; total fluid intake, and urine volumes associated with reduced risk for lithiasis and chronic kidney disease and plasma vasopressin concentration. The aggregate of these approaches suggest that a 24 h urine osmolality ≤500 mOsm·kg(-1) may be a simple indicator of optimal hydration, representing a total daily fluid intake adequate to compensate for daily losses, ensure urinary output sufficient to reduce the risk of urolithiasis and renal function decline, and avoid elevated plasma vasopressin concentrations mediating the increased antidiuretic effort.

Association between water intake, chronic kidney disease, and cardiovascular disease: a cross-sectional analysis of NHANES data.

BACKGROUND: Evidence from animal and human studies suggests a protective effect of higher water intake on kidney function and cardiovascular disease (CVD). Here the associations between water intake, chronic kidney disease (CKD) and CVD were examined in the general population. METHODS: We conducted a cross-sectional analysis of the 2005-2006 National Health and Nutrition Examination Survey. Non-pregnant adults with an estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m(2) who were not taking diuretics were included. Total water intake from foods and beverages was categorized as low (<2.0 l/day), moderate (2.0-4.3 l/day) and high (>4.3 l/day). We examined associations between low total water intake and CKD (eGFR 30-60 ml/min/1.73 m(2)) and self-reported CVD. RESULTS: Of 3,427 adults (mean age 46 (range 20-84); mean eGFR 95 ml/min/1.73 m(2) (range 30-161)), 13% had CKD and 18% had CVD. CKD was higher among those with the lowest (<2.0 l/day) vs. highest total water intake (>4.3 l/day) (adjusted odds ratio (OR) 2.52; 95% confidence interval (CI) 0.91-6.96). When stratified by intake of (1) plain water and (2) other beverages, CKD was associated with low intake of plain water: adjusted OR 2.36 (95% CI 1.10-5.06), but not other beverages: adjusted OR 0.87 (95% CI 0.30-2.50). There was no association between low water intake and CVD (adjusted OR 0.76; 95% CI 0.37-1.59). CONCLUSIONS: Our results provide additional evidence suggesting a potentially protective effect of higher total water intake, particularly plain water, on the kidney.

Primary prevention of nephrolithiasis is cost-effective for a national healthcare system.

UNLABELLED: Study Type--Therapy (cost-effectiveness meeting) Level of Evidence 2b. What's known on the subject? and What does the study add? One of the major problems with nephrolithiasis is the high rate of recurrence, which can effect up to 50% of patients over a 5-year period. Patients with recurrent stones are recommended to increase fluid intake based on prospective studies that show a reduction in recurrence rates in patients who intake a high volume of water. Strategies to reduce stones in recurrent stone formers are quite effective with a >50% risk reduction with increased fluid intake alone. Unfortunately, despite a high societal cost and morbidity, there are no prospective studies evaluating the benefit of fluid intake to prevent stone disease in subjects without a prior history of stone but at risk for stones. The budget impact analyses show that prevention of nephrolithiasis can have a significant cost savings for a payer in a healthcare system and reduce the stone burden significantly. Future studies will need to assess the feasibility and effectiveness of such an approach in a population. OBJECTIVE: • To evaluate the impact of primary prevention of stones using a strategy of increased fluid intake. SUBJECTS AND METHODS: • A Markov model was constructed and analysed using Excel to calculate and compare the costs and outcomes for a virtual cohort of subjects with low vs high water intake. • A literature search was used to formulate assumptions for the model including an annual incidence of urolithiasis of 0.032%, annual risk of stone recurrence of 14.4% and 40% risk reduction in subjects with high water intake. • Costs were based on resource utilisation from the Delphi panel and official price lists in France. • Outcomes were based on payer perspective and included direct and indirect costs and loss of work. RESULTS: • The base-case analysis found total cost of urolithiasis is €4267 with direct costs of €2767, including cost of treatment and complications. The annual budget impact for stone disease based on 65 million inhabitants is €590 million for the payer. • The use of high water intake by 100% of the population results in annual cost savings of €273 million and 9265 fewer stones. Even if only 25% of the population is compliant, there is still a cost saving of €68 million and 2316 stones. • The model was evaluated to determine the impact of varying the assumptions by ±10%. For example, when the incidence of stone disease is increased or decreased by 10% then the mean (range) baseline cost will change by €59(531-649) million for the payer and savings will either increase or decrease by €27 (246-300) million. • The largest impact on cost savings occurs when varying risk reduction of water by 10% resulting in either a mean (range) increase or decrease by €35 (238-308) million. • Varying cost of stone management by 10% has an impact of ±€17 million. Varying other factors such as stone recurrence by 10% has only an impact of ±€9 million and varying risk of chronic kidney disease ±€1 million, as they affect only a portion of the population. CONCLUSIONS: • The budget impact analyses show that prevention of nephrolithiasis can have a significant cost savings for a payer in a healthcare system and reduce the stone burden significantly. • Future studies will need to assess the feasibility and effectiveness of such an approach in a population.