The awareness of water intake and its correlation with BMI among students attending national and international secondary schools in Riyadh, Saudi Arabia.

Dehydration is linked to worse cognitive functions and preference for beverages that are linked to obesity and other health conditions. Saudi Arabia's hot climate can exacerbate these effects and it is important to ensure that children in the region understand the benefits of adequate water intake. To evaluate secondary school student perceptions and practices regarding water intake, investigate how water intake is related to BMI and school performance, and compare international schools to national schools. This cross-sectional study surveyed understanding and practices relating to water intake of national and international secondary school students using a questionnaire based on a random selection of schools and students. One-hundred and sixty-two students from international schools (I) and 157 from national schools (N) responded. Most were aged 16 and 17 years old (I:61.1%, N:76.5%, p = .005). The average BMI of all students was 24.9 ± 6.013 (I:23.6 ± 4.658, N:26.1 ± 6.931, p < 0.001). Students understood beverages do not replace water intake (I:80.2%, N:75.8%, p = .337) and preferred water when thirsty (I:77.8%, N:75.2%, p = .549). However, water consumption was low with more than 50% of students drinking less than 1500 ml a day (I:54.3%, N:70.7%, p = .002). A positive correlation between BMI and water intake was observed only among international school students. Students have inadequate water intake despite understanding the importance of hydration. There are some differences between international school students and national school students that can be attributed to the availability and sources of water, though other factors cannot be excluded.

Cognitive performance in relation to hydration status and water intake among older adults, NHANES 2011-2014.

PURPOSE: Risks of dehydration and cognitive decline increase with advancing age, yet the relation between dehydration, water intake, and cognitive performance among older adults remains understudied. METHODS: Using data from the 2011-2014 cycles of the Nutrition and Health Examination Survey (NHANES), we tested if calculated serum osmolarity (Sosm) and adequate intake (AI) of water among women (n = 1271) and men (n = 1235) ≥ 60 years old were associated with scores of immediate and delayed recall, verbal fluency, and attention/processing speed. Sosm was categorized as < 285 (hyperhydrated), 285-289, 290-294, 295-300, or > 300 (dehydrated) mmol/L. AI of water was defined as ≥ 2 L/day for women and ≥ 2.5 L/day for men. RESULTS: Women with Sosm between 285 and 289 mmol/L scored 3.2-5.1 points higher on the Digit Symbol Substitution test (DSST) of attention/processing speed than women in other Sosm categories (P values < 0.05). There was evidence of a curvilinear relationship between DSST scores and Sosm among women and men (P values for quadratic terms < 0.02). Meeting an alternative AI on water intake of ≥ 1 mL/kcal and ≥ 1500 mL, but not the sex-specific AI, was associated with scoring one point higher on a verbal fluency test (P = 0.02) and two points higher on the DSST (P = 0.03) among women. Significant negative associations between dehydration or inadequate water intake and test scores were not observed among men. CONCLUSION: Hydration status and water intake were moderately associated with attention/processing speed among females. Future work should consider the effects of both dehydration and overhydration on cognitive function and investigate potential sex differences in cognitive responses to hydration status.

Artificial Hydration at the End of Life.

Initiation or continuation of artificial hydration (AH) at the end of life requires unique considerations. A combination of ethical precedents and medical literature may provide clinical guidance on how to use AH at the end of life. The purpose of this review is to describe the ethical framework for and review current literature relating to the indications, benefits, and risks of AH at the end of life. Provider, patient, and family perspectives will also be discussed.

Sensitization of sodium appetite: evidence for sustained molecular changes in the lamina terminalis.

Animals with a history of sodium depletions exhibit increases in salt intake, a phenomenon described as the sensitization of sodium appetite. Using a novel experimental design, the present experiments investigated whether putative molecular markers of neural plasticity and changes in the message for components of the brain renin-angiotensin-aldosterone-system (RAAS) accompany the sensitization of sodium appetite. An initial set of experiments examined whether the glutamatergic N-methyl-d-aspartate receptor antagonist MK-801 would attenuate sodium appetite sensitization and prevent changes in mRNA expression associated with sensitization. Rats with repeated sodium depletions exhibited enhanced sodium appetite and mRNA expression for components of the RAAS in areas along the lamina terminalis (LT), a region of the brain that is important for the regulation of body fluid homeostasis, and these effects were significantly attenuated by MK-801 pretreatment. A second set of experiments investigated whether successive sodium depletions would elevate sodium intake and induce a pattern of fos-B staining consistent with the Δfos-B isoform in areas along the LT. The pattern of fos-B staining in the subfornical organ was consistent with the characteristics of Δfos-B expression. Specifically, fos-B/Δfos-B expression was increased 4 days after the last of a series of sodium depletions, fos-B/Δfos-B expression was nearly absent in control rats, and the quantity of fos-B/Δfos-B staining was directly associated with a history of sodium depletions. These findings demonstrate that the sensitization of sodium appetite is associated with sustained molecular alterations in the LT that are indicative of neural plasticity and upregulation of the central RAAS.

Predicting one and three month postoperative Somatic Concerns, Psychological Distress, and Maladaptive Eating Behaviors in bariatric surgery candidates with the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF).

BACKGROUND: Presurgical psychological screening of bariatric surgery candidates includes some form of standardized psychological assessment. However, associations between presurgical psychological screening and postoperative outcome have not been extensively studied. Here, we explore associations between presurgical Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) scores and early postoperative Somatic Concerns, Psychological Distress, and Maladaptive Eating Behaviors. METHODS: The sample consisted of male (n = 238) and female (n = 621) patients who were administered the MMPI-2-RF at their presurgical psychological evaluation and received bariatric surgery. Patients were evaluated at their 1- and 3-month postoperative appointments. RESULTS: Confirmatory factor analysis indicated that three latent constructs-somatic concerns, psychological distress, and maladaptive eating behaviors-were represented by responses to a postoperative assessment and that these constructs could be measured consistently over time. Presurgical scores on MMPI-2-RF scales measuring internalizing dysfunction were associated with more psychological distress at postoperative follow-ups, scores on scales measuring somatization were associated with more postoperative somatic concerns, and scores on scales assessing emotional/internalizing, behavioral/externalizing, cognitive complaints, and thought dysfunction prior to surgery were associated with maladaptive eating behaviors after surgery. CONCLUSIONS: In conjunction with a presurgical psychological interview, the MMPI-2-RF provides information that can assist in anticipating postoperative outcomes and inform efforts to prevent them.

Is there a role for hydration at the end of life?

PURPOSE OF REVIEW: To review current evidence on issues central to the hydration debate. RECENT FINDINGS: Worldwide, there are wide variations in hydration practice in terminally ill patients, reflecting divergent beliefs of medical providers, and the paucity in scientific evidence. This issue is particularly distressful to patients/families and nurses, yet their involvement in clinical decision-making remains insufficient. A short preliminary randomized controlled intervention trial (in advanced cancer patients) adds to the mounting evidence in support of hydration in improving neuro-cognitive symptoms associated with fluid deficits. On the other hand, majority of trials conducted in patients at the very end of life (survival days or weeks), while confirming high symptom burden, suggest no relationship to fluid status, or no significant benefit with hydration intervention. In Japan, the development of national clinical guidelines for hydration therapy in terminally ill cancer patients is a significant step forward, and brings attention to this important issue. SUMMARY: Areas of future research should include patients at various stages of the illness trajectory and involve noncancer illnesses. Appropriately powered, randomized, double-blind studies of hydration are awaited. Till then, the recommendation is to individualize hydration decisions and include participation of patient/families and other disciplines.

Palliative care professionals' perceptions of nutrition and hydration at the end of life.

The provision of medically administered nutrition and hydration (MNH) for the terminally ill patient is a controversial issue and there has been much debate in the literature concerning this sensitive subject. This article reports on a qualitative research study that explores palliative care nurses' and doctors' perceptions and attitudes to patient nutrition and hydration at the end of life. Participants were from an urban and rural palliative care service. Three main discourses were identified: carers' distress at the non-provision of MNH; palliative care doctors' and nurses' position that terminal dehydration lessened the burden of suffering for dying patients; and polarisation between the acute care setting and the palliative care setting. Overlaying these three main discourses are contesting discourses involving cure vs comfort, and acute care vs palliative care. Importantly, the findings of this study reveal that palliative doctors and nurses believe that medically assisted nutrition and hydration at the end stage of life rarely benefits patients, and as long as adequate mouth care is given, patients do not suffer. However, family members do experience emotional distress in dealing with this situation. In caring for dying people, the nurse's and doctor's role is one of education and communication, involving a team approach to manage this difficult issue.

Dehydration induced by bowel preparation in older adults does not result in cognitive dysfunction.

BACKGROUND: Postoperative cognitive dysfunction occurs in a proportion of patients after noncardiac surgery. Older patients are particularly vulnerable. We hypothesized that dehydration, a common perioperative problem in the elderly, may provoke cognitive dysfunction. We used a clinical scenario free of surgical/anesthetic intervention to determine whether dehydration caused by bowel preparation results in cognitive changes. METHODS: Thirty-eight patients of an age associated with a significant incidence of postoperative cognitive dysfunction were recruited in a prospective observational study. A further control group of 14 patients undergoing sigmoidoscopy, who did not receive any bowel preparation, were matched for age, education, and gender. RESULTS: Loss of total body weight (1.5 kg [95% CI: 0.9-2.2]; P < 0.001) occurred in patients undergoing bowel preparation (2.0 [95% CI: 1.3-2.6] percent total body weight), whereas sigmoidoscopy patients' weight did not change (0.17 kg [95% CI: -0.2-0.6 kg]; P = 0.26). Total body water, derived from foot bioimpedance, indicated dehydration in the bowel preparation group only (mean impedance change 36 [Omega] [95% CI; 25-46], P < 0.001) with a calculated decrease of 2.6% in total body water (95% CI: 1.1-4.8; P < 0.001). Hematocrit increased after bowel preparation only (prebowel prep 0.41 [0.40-0.43] versus postbowel prep 0.43 [0.42-0.45]; P = 0.003). Despite this degree of dehydration, all cognitive tests were within 1 SD of the population mean of normal values. Repeated measures analysis of variance did not reveal significant changes for within group comparisons over time for motor speed (P = 0.51), executive function (P = 0.57), Trail Making Tests and recall (P = 0.88), other than a 3 s slowing in learning ability (Rey Auditory Verbal Learning Test; P = 0.04). Hydration status did not affect learning (P = 0.42), recall (P = 0.30) motor speed (P = 0.36), or executive function tests (P = 0.26). CONCLUSION: Dehydration alone does not result in cognitive dysfunction.

Dehydration anorexia is attenuated in oxytocin-deficient mice.

Evidence in rats suggests that central oxytocin (OT) signaling pathways contribute to suppression of food intake during dehydration (i.e., dehydration anorexia). The present study examined water deprivation-induced dehydration anorexia in wild-type and OT -/- mice. Mice were deprived of food alone (fasted, euhydrated) or were deprived of both food and water (fasted, dehydrated) for 18 h overnight. Fasted wild-type mice consumed significantly less chow during a 60-min refeeding period when dehydrated compared with their intake when euhydrated. Conversely, fasting-induced food intake was slightly but not significantly suppressed by dehydration in OT -/- mice, evidence for attenuated dehydration anorexia. In a separate experiment, mice were deprived of water (but not food) overnight for 18 h; then they were anesthetized and perfused with fixative for immunocytochemical analysis of central Fos expression. Fos was elevated similarly in osmo- and volume-sensitive regions of the basal forebrain and hypothalamus in wild-type and OT -/- mice after water deprivation. OT-positive neurons expressed Fos in dehydrated wild-type mice, and vasopressin-positive neurons were activated to a similar extent in wild-type and OT -/- mice. Conversely, significantly fewer neurons within the hindbrain dorsal vagal complex were activated in OT -/- mice after water deprivation compared with activation in wild-type mice. These findings support the view that OT-containing projections from the hypothalamus to the hindbrain are necessary for the full expression of compensatory behavioral and physiological responses to dehydration.

Water: an essential but overlooked nutrient.

Water is an essential nutrient required for life. To be well hydrated, the average sedentary adult man must consume at least 2,900 mL (12 c) fluid per day, and the average sedentary adult woman at least 2,200 mL (9 c) fluid per day, in the form of noncaffeinated, nonalcoholic beverages, soups, and foods. Solid foods contribute approximately 1,000 mL (4 c) water, with an additional 250 mL (1 c) coming from the water of oxidation. The Nationwide Food Consumption Surveys indicate that a portion of the population may be chronically mildly dehydrated. Several factors may increase the likelihood of chronic, mild dehydration, including a poor thirst mechanism, dissatisfaction with the taste of water, common consumption of the natural diuretics caffeine and alcohol, participation in exercise, and environmental conditions. Dehydration of as little as 2% loss of body weight results in impaired physiological and performance responses. New research indicates that fluid consumption in general and water consumption in particular can have an effect on the risk of urinary stone disease; cancers of the breast, colon, and urinary tract; childhood and adolescent obesity; mitral valve prolapse; salivary gland function; and overall health in the elderly. Dietitians should be encouraged to promote and monitor fluid and water intake among all of their clients and patients through education and to help them design a fluid intake plan. The influence of chronic mild dehydration on health and disease merits further research.

Effects of intracerebroventricular dizocilpine (MK801) on dehydration-induced dipsogenic responses, plasma vasopressin and c-fos expression in the rat forebrain.

This study determines the interaction between glutamate receptors and dehydration-induced drinking, vasopressin (AVP) release, plasma osmolality and c-fos expression in the brain of conscious rats. The NMDA receptor antagonist dizocilpine (100 nmol infused into the cerebral ventricles) suppressed drinking following either 22 h water deprivation or intragastric injection of hypertonic saline (1.5 M), attenuated the increased plasma vasopressin induced by dehydration, but had no effects on peripheral hyperosmolality caused by either water deprivation or injections of hypertonic saline. Dizocilpine had no inhibitory effects on feeding after 24 h food deprivation. Dizocilpine also suppressed c-fos expression induced by dehydration in the median preoptic nucleus (MPN), the supraoptic and paraventricular nuclei (SON and PVN), but did not influence c-fos expression in the subfornical organ (SFO). The non-NMDA receptor antagonists CNQX (400 nmol) or DNQX (60 nmol) affected neither the animals' drinking nor c-fos expression induced by dehydration. Double staining showed that suppression of c-fos expression following dizocilpine occurred in the NMDA R1 receptor containing neurons in the hypothalamus. These results suggest that the NMDA-type glutamate receptors may be involved in dehydration induced dipsogenic and neuroendocrinological responses. They complement our earlier findings that dizocilpine also attenuates drinking and c-fos expression following intraventricular infusions of angiotensin II.

Dehydration: burden or benefit to the dying patient?

Significant numbers of patients die each year from malignant disease. The question of whether or not to administer artificial hydration therapy to the patient who is in the last few days of life has been discussed for some time. Some health care professionals contend that a reduced fluid intake, which often accompanies the dying process, may result in a potentially painful and distressing state of dehydration, requiring preventative measures of fluid replacement therapy. In contrast, other clinicians suggest that artificial hydration is often of no proven benefit in the context of the dying and may impose additional physical and psychological burdens on the patient. This paper investigates the advantages and disadvantages of artificial hydration therapies in terms of the symptom distress experienced by the terminally ill cancer patient. Its aim is to promote discussion about this vital aspect of patient care.

Dehydration in dying patients: study with physicians in French-speaking Switzerland.

We surveyed physicians in French-speaking Switzerland to assess the perception of suffering resulting from dehydration and its relation to the clinical choice between oral and artificial hydration. A questionnaire describing hypothetical cases of dehydration in an elderly terminal cancer patient in different clinical situations (conscious, demented, comatose) was sent to 978 physicians. The physicians were asked to assess the discomfort due to dehydration and the treatment they would propose in order to correct this situation (oral or artificial hydration). The return rate was 41%. The results show that there is no consensus with respect to the assessment of suffering (it gets a "low" score from 33% of replies and a "high" score from 41% of replies) or of thirst ("low": 30%, "high": 43%). Only 28% of the replies indicated artificial hydration for conscious patients while 44% chose this treatment for comatose patients. Physicians choosing artificial hydration were significantly more prone to consider suffering and thirst as "serious" than those preferring hydration by mouth. It can be concluded that two thirds of the physicians who responded think that artificial hydration is not the best way to respond to dehydration in dying patients. The choice depends partly on the assessment of the suffering and thirst resulting from terminal dehydration.