Personalized Hydration Strategy to Improve Fluid Balance and Intermittent Exercise Performance in the Heat.

Sweat rate and electrolyte losses have a large inter-individual variability. A personalized approach to hydration can overcome this issue to meet an individual's needs. This study aimed to investigate the effects of a personalized hydration strategy (PHS) on fluid balance and intermittent exercise performance. Twelve participants conducted 11 laboratory visits including a VO2max test and two 5-day trial arms under normothermic (NOR) or hyperthermic (HYP) environmental conditions. Each arm began with three days of familiarization exercise followed by two random exercise trials with either a PHS or a control (CON). Then, participants crossed over to the second arm for: NOR+PHS, NOR+CON, HYP+PHS, or HYP+CON. The PHS was prescribed according to the participants' fluid and sweat sodium losses. CON drank ad libitum of commercially-available electrolyte solution. Exercise trials consisted of two phases: (1) 45 min constant workload; (2) high-intensity intermittent exercise (HIIT) until exhaustion. Fluids were only provided in phase 1. PHS had a significantly greater fluid intake (HYP+PHS: 831.7 ± 166.4 g; NOR+PHS: 734.2 ± 144.9 g) compared to CON (HYP+CON: 369.8 ± 221.7 g; NOR+CON: 272.3 ± 143.0 g), regardless of environmental conditions (p < 0.001). HYP+CON produced the lowest sweat sodium concentration (56.2 ± 9.0 mmol/L) compared to other trials (p < 0.001). HYP+PHS had a slower elevated thirst perception and a longer HIIT (765 ± 452 s) compared to HYP+CON (548 ± 283 s, p = 0.04). Thus, PHS reinforces fluid intake and successfully optimizes hydration status, regardless of environmental conditions. PHS may be or is an important factor in preventing negative physiological consequences during high-intensity exercise in the heat.

Cannabinoids regulate an insula circuit controlling water intake.

The insular cortex, or insula, is a large brain region involved in the detection of thirst and the regulation of water intake. However, our understanding of the topographical, circuit, and molecular mechanisms for controlling water intake within the insula remains parcellated. We found that type-1 cannabinoid (CB1) receptors in the insular cortex cells participate in the regulation of water intake and deconstructed the circuit mechanisms of this control. Topographically, we revealed that the activity of excitatory neurons in both the anterior insula (aIC) and posterior insula (pIC) increases in response to water intake, yet only the specific removal of CB1 receptors in the pIC decreases water intake. Interestingly, we found that CB1 receptors are highly expressed in insula projections to the basolateral amygdala (BLA), while undetectable in the neighboring central part of the amygdala. Thus, we recorded the neurons of the aIC or pIC targeting the BLA (aIC-BLA and pIC-BLA) and found that they decreased their activity upon water drinking. Additionally, chemogenetic activation of pIC-BLA projection neurons decreased water intake. Finally, we uncovered CB1-dependent short-term synaptic plasticity (depolarization-induced suppression of excitation [DSE]) selectively in pIC-BLA, compared with aIC-BLA synapses. Altogether, our results support a model where CB1 receptor signaling promotes water intake by inhibiting the pIC-BLA pathway, thereby contributing to the fine top-down control of thirst responses.

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.

Water Intake and Adiposity Outcomes among Overweight and Obese Individuals: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Water consumption is believed to be a key factor in weight management strategies, yet the existing literature on the subject yields inconsistent findings. To systematically assess the scientific evidence regarding the effect of water intake on adiposity, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) among overweight and obese populations. METHODS: PubMed and Embase were searched for relevant articles published up to December 2023. The summary weighted mean difference (WMD) and 95% confidence interval (CI) were estimated using the DerSimonian-Laird random-effects model. RESULTS: In this meta-analysis of eight RCTs, interventions to promote water intake or to substitute water for other beverages as compared to the control group resulted in a summary WMD of -0.33 kg (95% CI = -1.75-1.08, I2 = 78%) for body weight, -0.23 kg/m2 (95% CI = -0.55-0.09, I2 = 0%) for body mass index (BMI), and 0.05 cm (95% CI = -1.20-1.30, I2 = 40%) for waist circumference (WC). Among RCTs substituting water for artificially sweetened beverages, summary WMD was 1.82 kg (95% CI = 0.97-2.67, I2 = 0%) for body weight and 1.23 cm (95% CI = -0.03-2.48, I2 = 0%) for WC. Conversely, among RCTs substituting water for sugar-sweetened beverages, summary WMD was -0.81 kg (95% CI = -1.66-0.03, I2 = 2%) for body weight and -0.96 cm (95% CI = -2.06-0.13, I2 = 0%) for WC. CONCLUSIONS: In conclusion, water intake may not significantly impact adiposity among overweight and obese individuals. However, replacing sugar-sweetened beverages with water might offer a modest benefit in inducing weight loss.

Water intake and obesity: By amount, timing, and perceived temperature of drinking water.

Water intake has been suggested to be associated with weight control, but evidence for optimal water intake in terms of amount, timing, and temperature is sparse. Additionally, genetic predisposition to obesity, which affects satiety and energy expenditure, might interact with water intake in regulating individual adiposity risk. We conducted a cross-sectional study recruiting 172 Korean adults. Information on water intake and lifestyle factors was collected through self-reported questionnaires, and height, weight, and waist circumference (WC) were measured by researchers. The oral buccal swab was performed for genotyping of FTO rs9939609, MC4R rs17782313, BDNF rs6265 and genetic risk of obesity was calculated. Linear regression was performed to estimate mean difference in body mass index (BMI) and WC by water intake and its 95% confidence interval (95% CI). As a sensitivity analysis, logistic regression was performed to estimate odds ratio (OR) of obesity/overweight (BMI of ≥23kg/m2; WC of ≥90cm for men and of ≥80cm for women) and its 95% CI. Drinking >1L/day was significantly associated with higher BMI (mean difference: 0.90, 95% CI 0.09, 1.72) and WC (mean difference: 3.01, 95% CI 0.62, 5.41) compared with drinking ≤1L/day. Independent of total water intake, drinking before bedtime was significantly associated with lower BMI (mean difference: -0.98, 95% CI -1.91, -0.05). The results remained consistent when continuous BMI and WC were analyzed as categorical outcomes. By perceived temperature, drinking >1L/day of cold water was associated with higher BMI and WC compared with drinking ≤1L/day of water at room-temperature. By genetic predisposition to obesity, a positive association between water intake and WC was confined to participants with low genetic risk of obesity (P interaction = 0.04). In conclusion, amount, timing, and perceived temperature of water intake may be associated with adiposity risk and the associations might vary according to genetic predisposition to obesity.

Timing of early water intake post-general anaesthesia: a systematic review and meta-analysis.

BACKGROUND: Early water intake has gained widespread attention considering enhanced recovery after surgery (ERAS). In the present systematic evaluation and meta-analysis, we assessed the effects of early water intake on the incidence of vomiting and aspiration in adult patients who received general anaesthesia on regaining consciousness during the resuscitation period. OBJECTIVE: To systematically analyse the results of randomised controlled trials on early postoperative water intake in patients who underwent different types of surgery under general anaesthesia, both at home and abroad, to further explore the safety and application of early water intake and provide an evidence-based foundation for clinical application. DESIGN: Systematic review and meta-analysis. METHODS: To perform the systematic evaluation and meta-analysis, we searched the Web of Science, CINAHL, Embase, PubMed, Cochrane Library, Sinomed, China National Knowledge Infrastructure (CNKI), Wanfang, and Vipshop databases to identify randomised controlled trial studies on early water intake in adult patients who received general anaesthesia. RESULTS: Herein, we included 10 publications with a total sample size of 5131 patients. Based on statistical analysis, there was no statistically significant difference in the incidence of vomiting (odds ratio [OR] = 0.81; 95% confidence interval [CI] [0.58-1.12]; p = 0.20; I-squared [I2] = 0%) and aspiration (OR = 0.78; 95%CI [0.45-1.37]; p = 0.40; I2 = 0%) between the two groups of patients on regaining consciousness post-general anaesthesia. CONCLUSION: Based on the available evidence, early water intake after regaining consciousness post-anaesthesia did not increase the incidence of adverse complications when compared with traditional postoperative water abstinence. Early water intake could effectively improve patient thirst and facilitate the recovery of gastrointestinal function.

The protective role of water intake in age-related eye diseases: insights from a Mendelian randomization study.

Age-related eye diseases (AREDs), including age-related cataracts (ARCs), age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma, are a leading cause of visual loss globally. This study aimed to explore the effects of dietary water intake on AREDs using Mendelian randomization. In the European population, genome-wide association study (GWAS) summary statistics of water intake and AREDs were obtained from the UK Biobank database and the FinnGen Consortium, respectively. The causal associations between water intake and ARED risks were explored by univariable and multivariable MR analyses, followed by sensitivity analyses to test the robustness of the results and detect potential pleiotropy bias. Water intake was associated with reduced risks of ARCs (odds ratio [OR]: 0.61; 95% confidence interval [CI]: 0.46-0.83; P = 1.44 × 10-3) and DR (OR: 0.52; 95% CI: 0.36-0.76; P = 5.47 × 10-4), and a suggestive reduced risk of AMD (OR: 0.42; 95% CI: 0.20-0.88; P = 2.18 × 10-2). Water intake had no effect on glaucoma (OR: 1.16; 95% CI: 0.72-1.88; P = 0.549). After adjusting confounders, the causal effects of water intake on ARCs and DR persisted. Our study provides evidence of the preventive role of water intake in ARCs and DR from a genetic perspective.

Drinking Large Volume of Hot Water May Cause Increased 18 F-FDG Uptake in Esophagus.

ABSTRACT: We present 2 cases of diffuse FDG accumulation in the esophagus due to drinking hot water before an 18 F-FDG PET/CT scan. Drinking large volume of hot water immediately before the FDG PET/CT study may lead to challenges in the interpretation of the hypermetabolic esophagus.

Effects of adaptive duration to salinity in drinking water on behavior, weight gain and blood biochemical parameters in growing goats.

This experiment aimed to determine the effect of adaptive duration to saline water on behaviors, weight gain and blood biochemical parameters in growing goats. The experiment was arranged in a completely randomized design, which included four treatments with five animals per group. The goats were administered either fresh water (control) or seawater with a salinity of 1.5%, with varying durations of adaptation to seawater. The adaptive durations included an abrupt change (A0) from fresh water to seawater with a salinity of 1.5% or stepwise adaptation either 4 (A4) or 7 (A7) days of increasing saline concentrations. The results showed that dry matter intake in the non-adapted goats (A0 group) was lower than that of the control group or the adapted goats throughout the experiment (p<0.05). In contrast, water intake from drinking saline water was greater than that in the control group (p<0.05). Body weigh did not differ among the treatments; however, non-adapted goats exhibited a lower weight gain than the adapted goats (p<0.05). The goats in the A0 and A4 groups exhibited increased plasma levels of urea, AST, and ALT compared with the control and A7 groups. However, blood electrolyte levels remained unchanged and were within the normal range for goats. Therefore, it is concluded that the stepwise adaptation to seawater with a salinity of 1.5% for 21 days has no influence on productivity and health status of goats.

The effect of hydrogen-rich water consumption on premenstrual symptoms and quality of life: a randomized controlled trial.

BACKGROUND: Premenstrual syndrome (PMS) consists of psychiatric or somatic symptoms negatively affecting the daily life. PMS treatment can involve the use of complementary-alternative approaches. Hydrogen-rich water (HRW) has antioxidant and anti-inflammatory properties that may treat PMS. This study aimed to investigate the effect of drinking HRW on the severity of premenstrual symptoms and the quality of life of women who suffer from PMS. METHODS: This study is a randomized controlled trial. Participants were randomized into two groups (intervention group=33, control group=32) using the block randomization method. Participants were requested to consume 1500-2000 mL of HRW daily in the intervention group and drink water in the placebo group. Participants began drinking either HRW or placebo water from day 16 of their menstrual cycle until day 2 of the following cycle for three menstrual cycles. The research data were collected using a Demographic Information Form, Premenstrual Syndrome Scale (PMSS), and Short form of the World Health Organization Quality of Life Questionnaire (WHOQOL- BREF). RESULTS: The intervention group had significantly lower mean scores than the control group in both the first and second follow-ups on the PMSS (P<0.05). In the first follow-up, the intervention group had significantly higher mean scores in the Physical Health and Psychological domains of the WHOQOL-BREF compared to the control group (P<0.05). Group × time interaction was significant for PMSS (F = 10.54, P<0.001). Group × time interaction was insignificant for WHOQOL- BREF (P>0.05). CONCLUSIONS: The consumption of HRW reduces the severity of premenstrual symptoms and improves individuals' quality of life in physical and psychological domains.

Low-sodium diet with adequate water intake improved the clinical efficacy in Ménière's disease.

BACKGROUND: Ménière's disease (MD) is a common idiopathic inner ear disorder in otorhinolaryngology characterized by recurrent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus and ear fullness. OBJECTIVE: To study the effects of low-sodium diet with adequate water intake on the clinical efficacy in MD. METHODS: Fifty patients diagnosed with stage-3 unilateral MD were randomly divided into control group(n = 25) and experimental group(n = 25). The control group was given routine medication therapy, and the experimental group was restricted to an sodium intake of 1500 mg/d and a water intake of 35 ml/kg/d based in addition to the routine medication therapy. The two groups were assessed using pure tone audiometry, electrocochleography, Tinnitus Handicap Inventory (THI), and Dizziness Handicap Inventory (DHI). RESULTS: The pure tone audiometry and electrocochleography showed better improvements after treatment in the experimental group than the control group (p < 0.05). The THI improved values in the experimental group were significantly higher than the control group (p < 0.001). The DHI improved values in the experimental group were significantly higher than the control group (p = 0.004). CONCLUSIONS AND SIGNIFICANCE: Low-sodium diet with adequate water intake improved the hearing and alleviated vertigo and tinnitus in MD patients.

The estrogenic reduction in water intake stimulated by dehydration involves estrogen receptor alpha and a potential role for GLP-1.

It is well documented that estrogens inhibit fluid intake. Most of this research, however, has focused on fluid intake in response to dipsogenic hormone and/or drug treatments in euhydrated rats. Additional research is needed to fully characterize the fluid intake effects of estradiol in response to true hypovolemia. As such, the goals of this series of experiments were to provide a detailed analysis of water intake in response to water deprivation in ovariectomized female rats treated with estradiol. In addition, these experiments also tested if activation of estrogen receptor alpha is sufficient to reduce water intake stimulated by water deprivation and tested for a role of glucagon like peptide-1 in the estrogenic control of water intake. As expected, estradiol reduced water intake in response to 24 and 48 h of water deprivation. The reduction in water intake was associated with a reduction in drinking burst number, with no change in drinking burst size. Pharmacological activation of estrogen receptor alpha reduced intake. Finally, estradiol-treatment caused a leftward shift in the behavioral dose response curve of exendin-4, the glucagon like peptide-1 agonist. While the highest dose of exendin-4 reduced 10 min intake in both oil and estradiol-treated rats, the intermediate dose only reduced intake in rats treated with estradiol. Together, this series of experiments extends previous research by providing a more thorough behavioral analysis of the anti-dipsogenic effect of estradiol in dehydrated rats, in addition to identifying the glucagon like peptide-1 system as a potential bioregulator involved in the underlying mechanisms by which estradiol reduces water intake in the female rat.

Effect of water sulfate and dietary bismuth subsalicylate on feed and water intake, ruminal hydrogen sulfide concentration, and trace-mineral status of growing beef heifers.

In the Northern Great Plains, cattle may be exposed to water with an elevated sulfate concentration resulting in ruminal hydrogen sulfide (H2S) production and risk of copper deficiency. There are currently few strategies available to help mitigate effects arising from high-sulfate water (HS). The objective of this study was to evaluate the effects of feeding a moderate-forage diet with or without bismuth subsalicylate (BSS; 0.0% vs. 0.4% DM basis) when provided water with a low- (LS; 346 ±â€…13) or HS (4,778 ±â€…263 mg/L) concentration on feed and water intake, ruminal H2S concentration, and liver and serum trace-mineral concentrations. Twenty-four Limousin × Simmental cross beef heifers (221 ±â€…41 kg) were stratified based on initial liver Cu into a completely randomized block design with a 2 × 2 factorial treatment arrangement. Feed and water intake (measured weekly), ruminal H2S concentration (measured on days 42 and 91), liver (measured on days -13 and 91), and serum trace-mineral concentrations (measured on days 1, 28, 56, and 91) were evaluated. Initial liver trace-mineral concentrations were used as a covariate in the statistical model. Water intake tended to be reduced with the inclusion of BSS (P = 0.095) but was not affected by water sulfate (P = 0.40). Water sulfate and BSS did not affect dry matter intake (DMI; P ≥ 0.89). Heifers consuming HS had a ruminal H2S concentration that was 1.58 mg/L more (P < 0.001) than LS. The inclusion of BSS reduced (P = 0.035) ruminal H2S concentration by more than 44% (1.35 vs. 0.75 mg/L). Regardless of the water sulfate concentration, heifers fed BSS had lesser liver Cu concentration (average of 4.08 mg/kg) than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS (42.2 vs. 58.3; sulfate × BSS, P = 0.019). The serum concentration of Cu did not differ over time for heifers not provided BSS; whereas, heifers provided BSS had lesser serum Cu concentration on day 91 than on days 28 and 55 (BSS × time, P < 0.001). The liver concentration of selenium was reduced (P < 0.001) with BSS inclusion but the selenium concentration in serum was not affected by sulfate, BSS, or time (P ≥ 0.16). BSS reduced ruminal H2S concentration, but depleted liver Cu and Se. Moreover, sulfate concentration in water did not appear to affect DMI, water intake, or growth, but increased ruminal H2S and reduced liver Cu concentration.

Water containing a high concentration of sulfate increases the risk of hydrogen sulfide production in the rumen and consequently of polioencephalomalacia. In addition, water with a high-sulfate concentration may induce copper deficiency indicated by depleted liver copper concentration. Bismuth subsalicylate (BSS) can bind to sulfides and may reduce the risk of hydrogen sulfide production and therefore may mitigate risks associated with high-sulfate water. In this study, the effects of water sulfate concentrations (346 ±â€…13 vs. 4,778 ±â€…263 mg/L) were tested along with 0.0% vs. 0.4% of dietary BSS. Water intake tended to be reduced with the inclusion of BSS but was not affected by water sulfate. Water sulfate concentration and BSS did not affect dry matter intake (DMI). Heifers consuming high-sulfate water (HS) had a ruminal H2S concentration that was 1.58 mg/L more than low-sulfate water (LS). The inclusion of BSS reduced ruminal H2S concentration by 44% (1.35 vs. 0.75 mg/L). Regardless of the water sulfate concentration, heifers fed BSS had lesser liver Cu concentration than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS. BSS reduced ruminal hydrogen sulfide concentration but depleted liver Cu. Sulfate concentration in water did not affect DMI, water intake, or growth, but increased ruminal hydrogen sulfide concentration and reduced liver Cu concentration.

H2OAthletes study protocol: effects of hydration changes on neuromuscular function in athletes.

We aim to understand the effects of hydration changes on athletes' neuromuscular performance, on body water compartments, fat-free mass hydration and hydration biomarkers and to test the effects of the intervention on the response of acute dehydration in the hydration indexes. The H2OAthletes study (clinicaltrials.gov ID: NCT05380089) is a randomised controlled trial in thirty-eight national/international athletes of both sexes with low total water intake (WI) (i.e. < 35·0 ml/kg/d). In the intervention, participants will be randomly assigned to the control (CG, n 19) or experimental group (EG, n 19). During the 4-day intervention, WI will be maintained in the CG and increased in the EG (i.e. > 45·0 ml/kg/d). Exercise-induced dehydration protocols with thermal stress will be performed before and after the intervention. Neuromuscular performance (knee extension/flexion with electromyography and handgrip), hydration indexes (serum, urine and saliva osmolality), body water compartments and water flux (dilution techniques, body composition (four-compartment model) and biochemical parameters (vasopressin and Na) will be evaluated. This trial will provide novel evidence about the effects of hydration changes on neuromuscular function and hydration status in athletes with low WI, providing useful information for athletes and sports-related professionals aiming to improve athletic performance.

Schedule risk model of water intake tunnel construction considering mood factors and its application.

The mood index [Formula: see text] was used to describe evaluator attitudes regarding the progress of a project that formed the basis of a construction period prediction model. The degrees of pessimism [Formula: see text] and optimism [Formula: see text] were introduced, and an analysis model was established using [Formula: see text] and [Formula: see text] to predict the construction period and completion probability Firstly, the absolute construction period of each process of tunnel No. 2 can be obtained according to the measured daily average footage of each process of tunnel No. 1. Secondly, the probability of the stoppage caused by different factors can be obtained after the statistical analysis of the factors responsible for the stoppage of tunnel No. 1. Finally, the expected construction period and completion probability of tunnel No. 2 under different pessimism and optimism conditions are obtained by using the progress risk analysis theory of emotional models and the program evaluation and review technique method. An engineering application showed that the expected construction period increased, and the completion probability decreased considerably with increasing pessimism; the opposite trend occurred as optimism increased. During the process of risk management and control, the prediction model can be used to perform precise quantitative analysis of the expected construction period and completion probability, reduce the blindness of construction management, control decisions of complex giant tunnel projects, and provide a more accurate basis for decision makers to judge risks. The findings of this study can be applied to hydraulic tunnels and can provide a reference for traffic tunnels, railway tunnels, and other similar projects.

Water intake, baseline biopsy, and graft function after living donor kidney transplantation.

Increased water intake is recommended for kidney transplant recipients; however, its efficacy remains controversial. We hypothesized that pre-existing histological findings of the allograft might modulate the impact of water intake. We retrospectively analyzed 167 adults with living-donor kidney transplants (April 2011-May 2020; median observation period, 77 months) whose baseline biopsy data were available. We compared the chronic-change group (n = 38) with the control group (n = 129) to assess the impact of self-reported daily water intake on the estimated glomerular filtration rate (eGFR). The range distribution of water intake was as follows: - 1000 ml (n = 4), 1000-1500 ml (n = 23), 1500-2000 ml (n = 64), 2000-2500 ml (n = 57), 2500-3000 ml (n = 16), and 3000 - ml (n = 3). Donor age was significantly higher in the chronic-change group. In the control group, the ΔeGFR/year increase was correlated with water intake. However, the increase in the water intake of the chronic-change group significantly decreased ΔeGFR/year (1000-1500 ml: + 1.95 ml/min/1.73 m2 and > 2000 ml: - 1.92 ml/min/1.73 m2, p = 0.014). This study suggested a potential influence of increased water intake on recipients with marginal grafts in living donor kidney transplantation.

Sodium and water dynamics in the progression of chronic kidney disease: mechanisms and clinical significance.

AIM: Lifestyle modifications can postpone the progression of chronic kidney disease toward its terminal stage. This mini-review aims to explore the impact of salt and water intake on the progression of chronic kidney disease (CKD) and provide insights into the optimal consumption levels to preserve the glomerular filtration rate. METHODS: We reviewed relevant literature to examine the association between salt and water consumption and CKD progression. Our analysis includes discussions on the pathophysiology, findings from clinical trials, and recommended intake guidelines. RESULTS: Sodium intake, often linked to cardiovascular risk and CKD progression, has shown a complex J-shaped association in some studies, leading to uncertainty about the ideal salt intake level. Sodium and fluid retention are key factors contributing to hypertension, a well-established risk factor for CKD progression. Low-sodium diets have demonstrated promise in reducing blood pressure and enhancing the effects of renin-angiotensin-aldosterone system inhibitors in non-dialysis CKD patients. However, a debate persists regarding the independent effect of salt restriction on CKD progression. Despite medical recommendations, salt consumption remains high among CKD patients. Additionally, the role of water consumption in CKD remains controversial despite its established benefits for CKD prevention in the general population. CONCLUSION: Lifestyle modifications involving salt and water intake can influence the progression of CKD. While low-sodium diets have shown potential for mitigating hypertension and proteinuria in non-dialysis CKD patients, their independent impact on CKD progression warrants further investigation. The role of water consumption in CKD remains uncertain, and there is a need for additional research in this area. Clinicians should consider individualized dietary recommendations for CKD patients to help preserve the glomerular filtration rate and improve overall outcomes.

Association of plain water intake with self-reported depression and suicidality among Korean adolescents.

OBJECTIVES: Adolescent depression and suicidality are serious health problems worldwide. Lower plain water intake has been proposed as a risk factor for depression in adults. This study investigated the association of daily plain water intake with self-reported depression and suicidality among Korean adolescents. METHODS: We used nationwide data from 112,250 students aged 12-18 years who participated in the Korean Youth Risk Behavior Web-based Surveys in 2019 and 2020. Daily plain water intake was categorized as <1 glass, 1-2 glasses, and ≥3 glasses. The adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for self-reported depression and suicidality were calculated using multiple regression analyses. RESULTS: The weighted prevalence rates of self-reported depression, suicidal ideation, suicide planning, and suicide attempts were 26.7%, 12.0%, 3.8%, and 2.5%, respectively. Of the participants, 3.9%, 18.5%, and 77.7% were categorized into the <1 glass/day, 1-2 glass/day, and ≥3 glass/day groups, respectively. Compared to the reference group (≥3 glass/day), the lowest level of water intake (<1 glass/day) was associated with higher odds of self-reported depression (aOR, 1.30; 95% CI, 1.20 to 1.39), suicidal ideation (aOR, 1.39; 95% CI, 1.27 to 1.55), suicide planning (aOR, 1.46; 95% CI, 1.25 to 1.69), and suicide attempts (aOR, 1.38; 95% CI, 1.15 to 1.67). Moderately lower water intake (1-2 glass/day) showed slightly increased odds of self-reported depression (aOR, 1.05; 95% CI, 1.01 to 1.10) and suicidal ideation (aOR, 1.08; 95% CI, 1.03 to 1.14). CONCLUSIONS: Lower plain water intake was significantly associated with a higher risk of self-reported depression and suicidality among Korean adolescents. Since this cross-sectional study is unable to establish a causal relationship, it underscores the need for additional longitudinal research.

Promoting fluid intake to increase urine volume for kidney stone prevention: Protocol for a randomized controlled efficacy trial of the sipIT intervention.

BACKGROUND: Risk of kidney stone recurrence can be reduced by increasing fluid intake and urine production but most patients fail to adhere to recommended clinical guidelines. Patients have indicated that common barriers to fluid intake include a lack of thirst, forgetting to drink, and not having access to water. We developed the sipIT intervention to support patients' fluid intake with semi-automated tracking (via a mobile app, connected water bottle and a smartwatch clockface that detects drinking gestures) and provision of just-in-time text message reminders to drink when they do not meet the hourly fluid intake goal needed to achieve the recommended volume. This trial evaluates the efficacy of sipIT for increasing urine output in patients at risk for recurrence of kidney stones. METHOD/DESIGN: Adults with a history of kidney stones and lab-verified low urine production (<2 L/day) will be randomly assigned to receive either usual care (education and encouragement to meet fluid intake guidelines) or usual care plus the sipIT intervention. The primary outcome is 24-h urine volume; secondary outcomes include urinary supersaturations, past week fluid intake, and experienced automaticity of fluid intake. Outcomes will be assessed at baseline, 1 month, 3 months, and 12 months. CONCLUSIONS: The sipIT intervention is the first to prompt periodic fluid intake through integration of just-in-time notifications and semi-automated tracking. If sipIT is more efficacious than usual care, this intervention provides an innovative treatment option for patients needing support in meeting fluid intake guidelines for kidney stone prevention.