Low Water Intake Research Articles

Abstract P018: Periodic Water Intake Exacerbates Hypertension, Decreases Renal Function and Increases Renal Inflammation in Spontaneously Hypertensive Rats

Water is essential for life. The kidneys are major regulators of fluid balance but also appear susceptible to adverse effects of periodic water intake since epidemiological studies have linked low water intake to chronic kidney disease. However, the impact of periodic water intake on renal health has largely been ignored. This study investigated the chronic effects of periodic drinking on blood pressure, kidney function, and immune cell infiltration in rats with pre-existing hypertension. Mean arterial pressure (MAP) was measured continuously in spontaneously hypertensive rats (SHR) that were only given access to water for 2 hours per day versus control rats given free access to water over a 4-week period (n=>8 per group). Glomerular filtration rate (GFR) was measured via transcutaneous FITC-sinistrin clearance at baseline and at the end of the 4-week protocol. Renal immune cell infiltration and cytokine production was assessed by flow cytometry. Basal MAP and renal function were similar between the control and water-restricted (WR) groups. Water restriction led to a significant increase in MAP from baseline (8.8±4.5mmHg versus 0.6±5.5mmHg in WR and control SHR, respectively; P<0.05). Moreover, GFR decreased from baseline by 29±6% in the WR SHR (P<0.001). In comparison, GFR did not change significantly over time in the control SHR (-5.3±2.6% from baseline; P>0.05). The increase in MAP and reduction in renal function in the WR-SHR was associated with periodic increases in urine osmolality (69±26% versus baseline, P<0.05), indicative of cycles of dehydration and replenishment. Renal immune cell infiltration was similar between the groups. However, cytokine analyses revealed a phenotypic shift towards a pro-inflammatory Th1 phenotype in kidney T cell infiltrate from WR versus control SHR. This was indicated by a greater proportion of T cells producing IFN-γ in SHR subjected to water restriction than control SHR (9.5±3.3% versus 2.9±0.9%, respectively; P<0.05). In conclusion, recurrent dehydration associated with periodic drinking exacerbates hypertension, renal dysfunction and inflammation in male SHR. This highlights the importance of regular water intake for the maintenance of kidney health, particularly in populations with existing disease.

Patterns of drinking and eating across the European Union: implications for hydration status.

Appropriate hydration is essential for health and well-being. In Europe, water consumption patterns vary despite the unlimited availability of this resource. Water constitutes the largest proportion of total fluid intake in most countries. According to the 2008 European Food Safety Authority's Concise Food Consumption Database, tap water consumption was highest in the northern European countries and in Austria. While Germany had a particularly low intake of tap water, it led in consumption of fruit and vegetable juices, soft drinks, and especially bottled water. European nutrition surveys generally report an average fluid intake within the recommended range of 1500-2000 mL/day, with higher intake levels corresponding with increasing frequency of intake. However, some population groups consume less than others, e.g., the elderly who are at higher risk for dehydration due to age-related increased urinary fluid losses. In turn, physical activity is associated with higher beverage consumption as is adherence to a health-conscious diet. While water constitutes the most commonly consumed beverage throughout Europe, drinking patterns and quantities vary and are influenced by a variety of factors, including age, gender, diet, and physical activity level.

Elevated sodium and dehydration stimulate inflammatory signaling in endothelial cells and promote atherosclerosis.

Cardiovascular diseases (CVDs) are a leading health problem worldwide. Epidemiologic studies link high salt intake and conditions predisposing to dehydration such as low water intake, diabetes and old age to increased risk of CVD. Previously, we demonstrated that elevation of extracellular sodium, which is a common consequence of these conditions, stimulates production by endothelial cells of clotting initiator, von Willebrand Factor, increases its level in blood and promotes thrombogenesis. In present study, by PCR array, using human umbilical vein endothelial cells (HUVECs), we analyzed the effect of high NaCl on 84 genes related to endothelial cell biology. The analysis showed that the affected genes regulate many aspects of endothelial cell biology including cell adhesion, proliferation, leukocyte and lymphocyte activation, coagulation, angiogenesis and inflammatory response. The genes whose expression increased the most were adhesion molecules VCAM1 and E-selectin and the chemoattractant MCP-1. These are key participants in the leukocyte adhesion and transmigration that play a major role in the inflammation and pathophysiology of CVD, including atherosclerosis. Indeed, high NaCl increased adhesion of mononuclear cells and their transmigration through HUVECs monolayers. In mice, mild water restriction that elevates serum sodium by 5 mmol/l, increased VCAM1, E-selectin and MCP-1 expression in mouse tissues, accelerated atherosclerotic plaque formation in aortic root and caused thickening or walls of coronary arteries. Multivariable linear regression analysis of clinical data from the Atherosclerosis Risk in Communities Study (n=12779) demonstrated that serum sodium is a significant predictor of 10 Years Risk of coronary heart disease. These findings indicate that elevation of extracellular sodium within the physiological range is accompanied by vascular changes that facilitate development of CVD. The findings bring attention to serum sodium as a risk factor for CVDs and give additional support to recommendations for dietary salt restriction and adequate water intake as preventives of CVD.

Water intake: validity of population assessment and recommendations.

Good hydration is vital for good health and well-being. Until recently, there was little interest in collecting data on water and drink and beverage intake. However, there is increasing evidence that a low water intake or mild dehydration may be linked with the risk of chronic diseases. Accurate estimates of intake in populations are essential to explore these relationships. This will enable the identification of specific populations at the risk of low water intake and allow exposure assessment of potential contaminates and specific nutrients present in drinks and beverages. In addition, data from these population studies are used as the basis of national and international recommendations on water intake and to set and evaluate national health policies. For example, EFSA based their recommendations on data from population studies from 13 European countries. The range of intakes varied from 720 to 2621 mL/day; this diversity cannot be explained by environmental differences alone. However, this variability may, at least partially, be explained by the inconsistency in methodologies used as none of surveys used a dietary assessment tool validated for total water intake or beverage and drink intake. It is reasonable to suggest that this may result in incomplete data collection and it raises questions on the validity of the recommendations. The relationship between water consumption and health warrants further investigation, and robust methodologies are essential to ensure that these data are accurate and useful for setting public health priorities and policies.

A pilot study on how do elite surfski padllers manage their effort and hydration pattern in the heat.

To investigate thermal response, hydration behaviour and performance over flatwater kayaking races in tropical conditions (36.8°C and 68% rh). Five internationally-ranked subjects participated in the 2012 Surfski Ocean Racing World Cup in Guadeloupe to the “Ze Caribbean Race 2012” [i.e., a 35-km downwind race]. Core temperature (T°C) and heart rate (HR) were measured using portable telemetry units whereas water intake was deduced from backpacks absorption. The kayakers were asked to rate both their comfort sensation and thermal sensation on a scale before and after the race. The performance was related to an increase in T°C, high HR and low water intake (WI); and (2) high values of final T°C were related to high pre T°C and greater increases in T°C being obtained with low pre T°C and (3) WI being related to high pre T°C. The present study demonstrated that the fastest kayakers were those able to paddle at the highest intensities, increasing their T°C and drinking little water without any interference from thermal sensations. Water intake was positively related to pre-race T°C, which reinforces the importance of beginning surfski races with a low T°C. This study demonstrated that well-trained kayakers drinking ad libitum were able to anticipate their intensity/heat storage ratio to prevent heat illness and severe dehydration and maintain high performance.

Physicochemical analysis of urinary stones from Dharmapuri district

Nephrolithiasis is a common disease caused by the multifactorial components such as geographical location, bacterial infection, low urine volume, and low intake of water. This disease induces severe metabolic abnormalities in the human body. As the prevalence of this disease was high in Dharmapuri district located in Tamil Nadu, urinary stones removed from the patients pertaining to this district were collected and to identify the toxic elements present in the stones. The presence of functional groups and phases of the stones were analyzed using X-ray diffraction (XRD), Fourier transform Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR). The majority of stones were found to be calcium oxalate monohydrate (COM) and mixed stones having minor existence of struvite and uric acid. Hexagonal shaped COM crystals, needle shaped uric acid crystals and layered arrangement of struvite crystals in the core region were revealed by Scanning Electron Microscopy (SEM). Thermo Gravimetric Analysis (TGA) was used to determine the thermal stability and the hardness of the stone which was measured using Vickers hardness (HV). The presence of toxic elements in stones such as zirconium and mercury was identified using Energy Dispersive X-ray Spectroscopy (EDS). The EDS analysis showed higher concentration of zirconium in the core region compared to the periphery. The percentage of zirconium was relatively high compared to other toxic elements in the stones. The Vickers hardness results indicated that high HV values in the core region than the periphery and this might be due to the presence of zirconium.

Perturbed energy balance and hydration status in ultra-endurance runners during a 24 h ultra-marathon.

The present study aimed to assess the adequacy of energy, macronutrients and water intakes of ultra-endurance runners (UER) competing in a 24 h ultra-marathon (distance range: 122-208 km). The ad libitum food and fluid intakes of the UER (n 25) were recorded throughout the competition and analysed using dietary analysis software. Body mass (BM), urinary ketone presence, plasma osmolality (POsmol) and volume change were determined at pre- and post-competition time points. Data were analysed using appropriate t tests, with significance set at P <0·05. The total energy intake and expenditure of the UER were 20 (sd 12) and 55 (sd 11) MJ, respectively (control (CON) (n 17): 12 (sd 1) and 14 (sd 5) MJ, respectively). The protein, carbohydrate and fat intakes of the UER were 1·1 (sd 0·4), 11·3 (sd 7·0) and 1·5 (sd 0·7) g/kg BM, respectively. The rate of carbohydrate intake during the competition was 37 (sd 24) g/h. The total water intake of the UER was 9·1 (sd 4·0) litres (CON: 2·1 (sd 1·0) litres), while the rate of water intake was 378 (sd 164) ml/h. Significant BM loss occurred at pre- to post-competition time points (P =0·001) in the UER (1·6 (sd 2·0) %). No significant changes in POsmol values were observed at pre- (285 (sd 11) mOsmol/kg) to post-competition (287 (sd 10) mOsmol/kg) time points in the UER and were lower than those recorded in the CON group (P <0·05). However, plasma volume (PV) increased at post-competition time points in the UER (10·2 (sd 9·7) %; P <0·001). Urinary ketones were evident in the post-competition samples of 90 % of the UER. Energy deficit was observed in all the UER, with only one UER achieving the benchmark recommendations for carbohydrate intake during endurance exercise. Despite the relatively low water intake rates recorded in the UER, hypohydration does not appear to be an issue, considering increases in PV values observed in the majority (80 %) of the UER. Population-specific dietary recommendations may be beneficial and warranted.

Optimal Hydration Biomarkers: Consideration of Daily Activities

Water intake and hydration status have recently gained attention as one of the many, and potentially manipulable, factors associated with disease development and wellbeing [1–7] . Researchers have explored a variety of physiological dysfunctions implicated with chronic low water intake and hypohydration, but particular interest resides in the study of obesity and related disease states due to overwhelming prevalence. However, the current lack of a hydration assessment gold standard greatly impedes our attempts to link water intake and negative health outcomes as well as to make public dietary guidelines. Current hydration biomarkers include blood, saliva, and urine sampling subjected to a variety of quantification methods (osmolality, specific gravity, volume, etc.). Recent work from our laboratory [8] contributed to the ongoing quest to identify optimal selection of hydration biomarkers, but through consideration of the context under which body water loss occurs. We present two scenarios when selecting optimal hydration biomarkers: i) active versus passive body water loss, and ii) single versus serial measurements.

Low intake of water is the main cause of urinary stone forming in Iran areas that have reserves of heavy water

Low intake of water is the main cause of urinary stone forming in Iran areas that have reserves of heavy water

Low intake of water is the main cause of urinary stone forming in Iran areas that have reserves of heavy water

Low intake of water is the main cause of urinary stone forming in Iran areas that have reserves of heavy water

Production aspects of broiler breeders submitted to different drinker types

The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37- to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers) with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p 0.05) of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p<0.05) under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p<0.05) between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.

Drinking preferences in chinchillas (Chinchilla laniger), degus (Octodon degu) and guinea pigs (Cavia porcellus)

Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi-arid habitat with varying, species-specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species-specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.

Factors associated with low water intake among South Korean adolescents - Korea National Health and Nutrition Examination Survey, 2007-2010

Water is essential for life and plain water instead of sugar-sweetened beverages is one approach for decreasing energy intake. Due to limited data on characteristics associated with water intake among Korean adolescents, this study examined associations of demographic and behavioral characteristics with plain water intake by using nationally representative sample of South Korean adolescents. The data (2007-2010 Korea National Health and Nutrition Examination Survey) for 1,288 high school-aged adolescents (15-18 years) were used. Multivariable logistic regression was used to calculate adjusted odds ratios (OR) for factors associated with low water intake (< 4 cups/day) and very low water intake (< 2.5 cups/day). Nationwide, 38.4% and 19.0% of adolescents reported drinking water < 4.0 cups/day and < 2.5 cups/day, respectively. The mean plain water intake was 5.7 cups/day for males and 4.1 cups/day for females. Females had significantly higher odds for drinking water < 2.5 cups/day (OR = 2.2) than males, whereas adolescents with low milk consumption had significantly lower odds for drinking water < 2.5 cups/day (OR = 0.7). Factors significantly associated with a greater odds for drinking water < 4 cups/daywere being female (OR = 2.8) and not meeting physical activity recommendations (≥ 20 min/day on < 3 days/week) (OR = 1.6). Being underweight, overweight, and obese were significantly associated with reduced odds for drinking water < 4 cups/day (OR = 0.7, 0.4 and 0.5, respectively). However, intake of soda, coffee drinks, fruits, vegetables, and sodium and eating out were not significantly associated with low or very low water intake. These findings may be used to target intervention efforts to increase plain water intake as part of a healty lifestyle.

Physiological basis of dietary prevention of perimenopausal disorders in the context of dietary habits associated with the consumption of water and beverages by women aged 45-65.

IntroductionThis study aimed to evaluate the amount of water and type of beverages consumed by women of perimenopausal age against a background of dietary prevention of perimenopausal disorders.Material and methodsThis study was conducted in autumn 2012, in Wielkopolska Province (Poland), on 100 women aged from 45 to 65 years, employed as office workers. Information on the diet, beverages consumption and anthropometric data were collected.ResultsAnalysis of the nutritional status of the surveyed women showed that over 50% of them had excess body weight. Analysis of the survey results indicated that the amount of water in the diet of the examined women was appropriate, although the type of drinks consumed was inadequate. The women consumed too much coffee and tea, and simultaneously had a low intake of potable water. More than a half of the surveyed women sweetened coffee and tea. Women with excess body weight did so statistically significantly quite often, and they also used larger amounts of sugar for sweetening. Nearly 60% of the surveyed women added milk, or less frequently cream, to coffee. Milk was statistically significantly more frequently chosen by women with normal body weight, and cream by women with excess body weight. There was a positive correlation between body mass index and the energy value of the consumed fluids.ConclusionsThe dietary irregularities identified in this study may intensify perimenopausal symptoms and contribute to the development of diet-related chronic diseases. Taking into account the observed irregularities, it seems appropriate to provide perimenopausal women with nutrition education and diet correction, including the amount and type of fluids consumed.

Influence of polymerisation conditions on the properties of polymer/clay nanocomposite hydrogels

Free-radical polymerisation of acrylamide derivatives in the presence of exfoliated clay platelets has recently emerged as a new technique for the synthesis of strong and tough nanocomposite hydrogels (NCHs) with a unique hybrid organic/inorganic network structure. The central intent of many research studies in the field of NCHs conducted so far was to change hydrogel properties with the introduction of various clays and variation of the clay content. Here, we demonstrate that the properties of NCHs significantly vary depending on initiating conditions used for hydrogel synthesis via in situ polymerisation in solutions of high monomer concentrations (above 1 mol L(-1)). A unique, complementary combination of real-time dynamic rheology and pulsed NMR/MRI has been used to study the influence of the composition of a redox initiating system on the gelation process and hydrogel properties. The molar ratio of the persulphate initiator to tertiary amine activator affects the polymerisation kinetics, morphology and mechanical properties of the hydrogels. We further show that activator-dominated systems tend to produce hydrogels with higher storage modulus and lower water intake. This trend is attributed to the increase in the cross-linking degree. From the analysis of the water state in NCH and hydrogels prepared with and without an organic cross-linker, it was concluded that clay platelets did not form covalent bonds with polymer molecules but contributed to the formation of a physical network. There is evidence of self-crosslinking of polymer chains during acrylamide polymerisation at high monomer concentration. The composition of the initiating system influences the number of formed self-crosslinks.

Estimations of water balance after validating and administering the water balance questionnaire in pregnant women

Dehydration during pregnancy may be harmful for the mother and fetus; thus our objective was to understand whether pregnant women balance water intake and loss. The Water Balance Questionnaire (WBQ) was modified to reflect pregnancy (WBQ-P). Validation was performed using 3-day diaries (n = 60) and hydration indices in urine (osmolality, specific gravity, pH and color, n = 40). The WBQ-P was found valid according to Kedhal τ-b coefficient agreement. The WBQ-P was administered to 95, 100 and 97 women per trimester, in Greece. Median (IQR) water balance, intake and loss were, respectively, 203 (−577, 971), 2917 (2187, 3544) and 2658 (2078, 3391) ml/day; these did not differ among the trimesters or between pregnant and non-pregnant women. However, more pregnant women were falling in the higher quartiles of water balance distribution. No differences in sources of water intake were identified except that women in the third trimester had lower water intake from beverages.

Fluid Replacement Strategy during a 27-Km Trail Run in Hot and Humid Conditions

We evaluated the effects of the fluid replacement strategy on core temperature, heart rate and urine osmolality during a 27-km trail run in tropical climate. 20 well-trained runners completed a 27-km trail race in tropical conditions. They were acclimatized to these conditions. Heart rate was monitored every 5 s, while core temperature and perceived thermal and comfort sensations were recorded before, at the 11(th) km, and just after the end of the race. Water intake, urine osmolality and body mass were measured before and after the race. Core temperature and the scores of perceived thermal and comfort sensations were significantly higher at the 11(th) km and at the end of the race compared to before the race, but not at the 11(th) km compared to the end of the race [corrected]. No participant exhibited dehydration as assessed by urine osmolality. The less the trail runners weighed, the greater the heat retention was. The less hot they felt at the end of the race, the more they lost water, and the better the performance was. The fastest runners were able to tolerate a greater variation in core temperature between the beginning and the end of the trail race with lower water intake.

Short-term Physiological Effects of Increased Water Intake in a Clinical Setting

Low water intake is associated with long-term adverse health outcomes. Despite this, few studies had examined hydration physiology in the general population, where adequate intake, and not excessive loss, is the primary determinant of hydration. This study sought to evaluate the responsiveness of hydration biomarkers in urine and blood to acute changes in water intake. Key findings were that markers of urine concentration and urine volume change rapidly in response to a change in water intake, whereas plasma osmolality is maintained. Moreover, urine concentration varies as a function of the time of day, with nighttime and morning urine samples being more concentrated than afternoon samples. These results suggest that short, well-timed urine samples, such as those taken in the afternoon, may provide values comparable with 24-hour collections, which are more time-consuming and less convenient.

P202 Risk factors for recurrent cystitis following acute cystitis in female patients

We conducted a retrospective analysis of acute cystitis (AC) patients to evaluate the risk factors of recurrent cystitis (RC) patients following AC. The clinical records of 254 subjects with a confirmed diagnosis of AC and 90 healthy subjects who visited the Health Promotion Center between 2008 and 2012 were reviewed. A patient was diagnosed with RC if she was treated for three or more symptomatic episodes of cystitis over a 12-month period. Results were analyzed according to three groups: normal control (group A, n = 90), AC (group B, n = 121), and RC (group C, n = 133). Women in the cystitis groups (groups B and C) were more likely to have diabetes, be menopausal, have a history of catheterization or sexually transmitted infections (STI), have a low daily water intake, have frequent sexual intercourse, and to use contraception more frequently than the normal control group (P < 0.05). In groups B and C, Escherichia coli was the most common uropathogen, followed by Staphylococcus saprophyticus, Enterococcus species, and Klebsiella species. There were no differences between groups in the detection rates of these uropathogens. Factors that affected progression to RC were diabetes, catheterization history, STI history, sexual intercourse more than four times per month, sexual intercourse in the last month, and the use of contraceptives (P < 0.05). The identification of these factors may help develop preventive, diagnostic, and therapeutic strategies for treating RC that has progressed from AC.

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 m² 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 m²) and self-reported CVD. Results: Of 3,427 adults (mean age 46 (range 20-84); mean eGFR 95 ml/min/1.73 m² (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.