Dehydration Status Aggravates Early Renal Impairment in Children: A Longitudinal Study

Dehydration is common in children for physiological and behavioral reasons. The objective of this study was to assess changes in hydration status and renal impairment across school weekdays. We conducted a longitudinal study of three repeated measures of urinalysis within one week in November 2019 in a child cohort in Beijing, China. We measured urine specific gravity (USG) to determine the dehydration status, and the concentration of β2-microglobulin (β2-MG) and microalbumin (MA) to assess renal function impairment among 1885 children with a mean age of 7.7 years old. The prevalence of dehydration was 61.9%, which was significantly higher in boys (64.3%). Using chi-square tests and linear mixed-effects regression models, we documented the trends of the renal indicators’ change over time among different hydration statuses. Compared to Mondays, there were apparent increases of β2-MG concentrations on Wednesdays (β = 0.029, p < 0.001) and Fridays (β = 0.035, p < 0.001) in the dehydrated group, but not in the euhydrated group. As for the MA concentrations, only the decrease on Fridays (β = −1.822, p = 0.01) was significant in the euhydrated group. An increased trend of elevated β2-MG concentration was shown in both the euhydrated group (Z = −3.33, p < 0.001) and the dehydrated group (Z = −8.82, p < 0.001). By contrast, there was a decreased trend of elevated MA concentrations in the euhydrated group (Z = 3.59, p < 0.001) but not in the dehydrated group. A new indicator ratio, β2-MG/MA, validated the consistent trends of renal function impairment in children with dehydration. Renal impairment trends worsened as a function of school days during the week and the dehydration status aggravated renal impairment during childhood across school weekdays, especially tubular abnormalities in children.

Young Adults with Higher Salt Intake Have Inferior Hydration Status: A Cross-Sectional Study

The body’s water and sodium balances are tightly regulated and monitored by the brain. Few studies have explored the relationship between water and salt intake, and whether sodium intake with different levels of fluid intake leads to changes in hydration status remains unknown. The aim of the present study was to determine the patterns of water intake and hydration status among young adults with different levels of daily salt intakes. Participants’ total drinking fluids and water from food were determined by a 7-day 24-h fluid intake questionnaire for 7 days (from Day 1 to Day 7) and duplicate portion method (Day 5, Day 6 and Day 7). Urine of 24 h for 3 days (Day 5, Day 6 and Day 7) was collected and tested for the osmolality, the urine-specific gravity (USG), the concentrations of electrolytes, pH, creatinine, uric acid and the urea. The fasting blood samples for 1 day (Day 6) were collected and measured for the osmolality and the concentrations of electrolytes. The salt intakes of the participants were evaluated from the concentrations of Na of 24 h urine of 3 days (Day 5, Day 6 and Day 7). Participants were divided into four groups according to the quartile of salt intake, including the low salt intake (LS1), LS2, high salt intake (HS1) and HS2 groups. In total, 156 participants (including 80 male and 76 female young adults) completed the study. The salt intakes were 7.6, 10.9, 14.7 and 22.4 g among participants in the four groups (LS1, LS2, HS1 and HS2 groups, respectively), which differed significantly in all groups (F = 252.020; all p < 0.05). Compared to the LS1 and LS2 groups, the HS2 group had 310–381, 250–358 and 382–655 mL more amounts of water from the total water intake (TWI), total drinking fluids and water from food (all p < 0.05), respectively. Participants in the HS2 group had 384–403, 129–228 and 81–114 mL more in the water, water from dishes and staple foods, respectively, than those in the groups of LS1 and LS2 (p < 0.05). The HS2 group excreted 386–793 mL more urine than those in the groups of LS1 and LS2 (p < 0.05). However, regarding urine osmolality, the percentage of participants with optimal hydration status decreased from 41.0% in LS1 and LS2 to 25.6% in the HS2 group (p < 0.05). Participants with higher salt intake had higher TWI, total drinking fluids and water from food. Nevertheless, they had inferior hydration status. A reduction in salt intake should be encouraged among young adults to maintain optimal hydration status.

Lung ultrasound as tool to evaluate fluid accumulation in dialysis patients

Background: Volume overload is the main mechanism of BP elevation in end-stage kidney disease (ESKD) patients undergoing hemodialysis or peritoneal dialysis and has been linked to adverse outcomes and increased mortality in this population. Summary: This review discusses current knowledge on lung ultrasound as a tool for detection of extracellular volume overload through evaluation of extravascular lung water content. We describe the principles of lung US, the main protocols to apply it in clinical practice, and accumulated data evidence regarding its associations with cardiovascular events and mortality. We also summarize available evidence on the effect of lung-ultrasound guided volume management strategies on BP control, echocardiographic parameters and major outcomes in patients undergoing dialysis. Key Messages: Among interventions attempting to reduce the burden of cardiovascular disease in ESKD, effective management of volume overload represents an unmet clinical need. Assessment of hydration status by lung-ultrasound is a cheap, easy to employ and real-time technique that can offer accurate dry weight assessment leading to several clinical benefits.

Environmental Factors Driving Seed Hydration Status of Soil Seed Banks and the Implications for Post-fire Recruitment

Changes in fire regimes due to climate change and fire management practices are affecting the timing, length, and distribution of vegetation fires throughout the year. Plant species responses and tolerances to fire differ from season to season and are influenced by species-specific phenological processes. The ability of seeds to tolerate extreme temperatures associated with fire is one of these processes, with survival linked to seed moisture content at the time of exposure. As fire is more often occurring outside historic dry fire seasons, the probability of fire occurring when seeds are hydrated may also be increasing. In this study, we set out to understand the seasonal dynamics of seed hydration for seeds of Banksia woodland species, and how certain seed traits interact with environmental conditions to influence survival of high temperatures associated with fire. We measured the moisture content of seeds buried to 2 cm in the soil seed bank for four common native species and one invasive species on a weekly basis throughout 2017, along with soil moisture content and environmental correlates. We determined water sorption isotherms at 20°C for seeds of each species and used these functions to model weekly variation in seed water activity and predict when seeds are most sensitive to soil heating. Using Generalised additive models (GAMs), we were able to describe approximately 67% of the weekly variance in seed water activity and explored differences in seed hydration dynamics between species. Seed water activity was sufficiently high (i.e., ≥ 0.85 aw) so as to have created an increased risk of mortality if a fire had occurred during an almost continuous period between May and November in the study period (i.e., 2017). There were brief windows when seeds may have been in a dry state during early winter and late spring, and also when they may have been in a wet state during summer and late autumn. These data, and the associated analyses, provide an opportunity to develop approaches to minimize seed mortality during fire and maximize the seed bank response.

Fluid Restriction Negatively Influences Perceived Morning Alertness and Visuomotor Ability

The purpose of this study was to assess the effect of two fluid intake protocols on alertness and reaction time before and after fluid intake. Healthy college-age males (n = 12) followed two fluid intake protocols on separate occasions: (1) prescribed fluid (PF) and fluid restricted (FR). In PF, participants were instructed to consume 500 mL of fluid the night prior to and the morning of data collection. In FR, participants were instructed to refrain from the consumption of fluid for 12 h. To assess hydration status, urine specific gravity and urine color were measured. Participants perceived level of thirst and alertness were also recorded. Participants then completed visuomotor reaction time tests using the Dynavision LED board, using both a central visuomotor test and a peripheral visuomotor test (PVRT) prior to (1) and following (2) the ingestion of 100 mL of water. Participants displayed significantly improved PVRT in PF state as compared to FR (PF1 = 1.13 ± 0.16, PF2 = 1.04 ± 0.14; FR1 = 1.27 ± 0.27, FR2 = 1.18 ± 0.20; p = 0.038, ηp2 = 0.363). Both CVRT and PVRT improved over time, following the ingestion of 100 mL of fluid. Participants in the PF state were also significantly more alert than participants in the FR state (PF = 4 ± 2, FR = 5 ± 2; p = 0.019, ES = 0.839). Collectively, perceived alertness and PVRT were negatively impacted by FR.

Gênero e hidratação como mediadores relevantes para restauração de processos inflamatórios em atletas jovens

Objetivos: Poucos estudos tem dado a devida importância ao estado de hidratação e as alterações hematológicas em menores de 18 anos. O presente estudo investigou estas alterações em menores de 18 anos na prova de 3000 metros para ambos os gêneros. Método: Foram incluídos os seis melhores participantes das Olimpíadas Nacionais do Ensino Médio (menores de 18 anos) no Brasil. Trata-se de um estudo observacional e transversal. Os atletas correram 3.000 metros em uma pista oval de 400 metros. Foi realizado leucograma total e específico, eritrograma e contagem de plaquetas em quatro diferentes tempos (jejum, pré, pós e recuperação). Os cálculos de comparação entre tempos, apresentados, foram adaptados do modelo matemático de variação percentual. Resultados: Quando comparadas as médias em relação a cada tempo, pode-se notar que os eritrócitos, hemoglobina, hematócrito, leucócitos totais e basófilos aumentaram significativamente após a corrida para ambos os gêneros. Além disso, as plaquetas também aumentaram para ambos os gêneros sem significância. O coeficiente de correlação de Pearson mostrou importante interação leucócitos-plaquetas. Os homens recuperaram seu estado de hidratação em quase metade do tempo em relação as mulheres. Em relação ao sistema imune e resposta inflamatória, as atletas do gênero feminino tiveram um aumento relativo de mais que o dobro para leucócitos e não recuperaram estes valores, além de apresentarem um aumento de eosinófilos neste mesmo tempo, enquanto os atletas do gênero masculino apresentaram diminuição. As mulheres apresentaram um aumento de quase o dobro para linfócitos, enquanto os homens tiveram este comportamento para os fagócitos. Conclusões: O exercício induz alteração do estado de hidratação e sistema imune, tendo diferenças em relação ao gênero. Quando bem conduzido, gera efeitos antiinflamatórios a longo prazo. Quando não há controle sobre o volume, intensidade e recuperação pode causar imunossupressão e promover a suceptibilidade para infecções. Foi possível observar que os atletas do gênero masculino tem um menor estresse inflamatório e recuperam o seu estado de hidratação e a resposta inflamatória mais rápido que as meninas após uma corrida de 3000 metros. Objectives: Few studies have given due importance to the hydration status and hematological alterations in children under 18 years of age. The present study investigated these alterations in children under 18 years old in the 3000 meters test for both genders. Method: The six best participants of Brazil's National High School Olympiads (under 18 years old) were included. This is an observational and cross-sectional study. Athletes ran 3,000 meters on a 400 meters oval track. Total and specific white blood cell count, erythrogram, and platelet count were performed four times (fasting, pre, post, and recovery). The time comparison calculations presented were adapted from the percentage variation mathematical model. Results: When comparing the means for each time, it can be noted that erythrocytes, hemoglobin, hematocrit, total leukocytes, and basophils increased significantly after the race for both genders. Furthermore, platelets also increased for both genders without significance. Pearson's correlation coefficient showed a significant leukocyte-platelet interaction. Men regained their hydration status in almost half the time compared to women. Regarding the immune system and inflammatory response, female athletes had a relative increase of more than double for leukocytes and did not recover these values, in addition to showing an increase in eosinophils simultaneously, while male athletes showed a decrease. Women showed an increase of almost double for lymphocytes, while men showed this behavior for phagocytes. Conclusions: Exercise induces changes in hydration status and immune system, with differences concerning gender. When done well, it generates long-term anti-inflammatory effects. When there is no control over volume, intensity, and recovery, it can cause immunosuppression and increase infection susceptibility. It was observed that male athletes have lower inflammatory stress and recover their hydration status and inflammatory response faster than girls after a 3000 meter run.

Hubungan Status Gizi dan Status Hidrasi dengan Fungsi Memori Jangka Pendek Anak Usia Sekolah

ENGLISHShort-term memory in school-age children is significant in the learning process and academic ability improvement. Adequate intake of nutrients and body fluids are needed to accelerate brain performance so that children have optimum memory function. A preliminary study on short term memory of students in SD N Gembong 2, Pati Regency showed that some students experienced a decrease in short-term memory. The objective of this study was to analyze the correlation between nutritional status and nutritional status with children's short-term memory. This study used a correlational design and involved 52 students from 4th - 6th grade in elementary school. The measurement of hydration status used urine specific gravity, while short-term memory was measured using a digit span test. Then, the Chi-Square test was applied to analyze the data. This study result showed that more than half of children had normal nutritional status, good hydration status and normal short-term memory. Furthermore, nutritional status and hydration status were associated with children's short-term memory. Parents should provide more attention to their children’s nutritional and fluid needs, by 1) the children are getting used to taking breakfast before going to school and 2) parents provide meals and drinks from home for their children. INDONESIAMemori jangka pendek pada anak usia sekolah sangat berpengaruh terhadap proses belajar dan upaya peningkatan kemampuan akademik. Asupan nutrisi dan cairan tubuh yang cukup dibutuhkan untuk meningkatkan kerja otak sehingga fungsi memori anak lebih optimal. Data awal penelitian terkait memori jangka pendek anak di SD N Gembong 2 Pati menunjukkan sebagian anak mengalami penurunan memori jangka pendek. Tujuan penelitian ini adalah menganalisis hubungan status gizi dan status nutrisi dengan memori jangka pendek anak. Metode penelitian korelasional dengan jumlah sampel 52 responden anak kelas 4-6 SD. Pengumpulan data status gizi melalui pengukuran berat badan dan tinggi badan. Pengukuran status hidrasi menggunakan pemeriksaan berat jenis urine dan memori jangka pendek menggunakan test digit span. Analisa menggunakan chi square. Hasil penelitian menunjukkan sebagian besar anak mempunyai status gizi normal, status hidrasi baik dan memori jangka pendek yang normal. Terdapat hubungan antara status gizi dan status hidrasi dengan memori jangka pendek anak. Orang tua sebaiknya lebih memperhatikan kebutuhan nutrisi dan cairan anak dengan cara: 1) membiasakan sarapan sebelum berangkat sekolah; dan 2) pada saat anak ke sekolah lebih baik dibawakan bekal makanan dan minuman.

Bio-electric impedance as a tool to assess hydration in critically ill patients: an integrative review

Introduction: Assessing the hydration status of critically ill patients has been a difficult task over the decades. Determining how much fluid overload a patient has often helped in choosing a therapy. Methods such as bioelectrical impedance have been approached as a useful tool for this purpose. Objective: This study proposes to verify, through research in the literature, what is the real importance of the clinical use of bioelectrical impedance in the diagnosis of fluid overload in critically ill patients hospitalized in intensive care units. Methods: bibliographic search in the main scientific information databases: Scielo, PubMed, Cochrane, and Lilacs from January 2000 to July 2018. The selected languages were Spanish, Portuguese, and English. The keywords used were bioelectrical impedance, hydration, Intensive Care Unit, Intensive Care, bioelectrical impedance analysis, fluid balance, hydration overload. Results and Conclusion: The analysis of fluid overload in critically ill patients can be performed using multifrequency bioelectrical impedance. It is a useful tool in the diagnosis as well as in the quantification of water overload and, therefore, a corroborative method for clinical decision-making.

Effect of Intermittent Fasting (18/6) on Energy Expenditure, Nutritional Status, and Body Composition in Healthy Adults

Objective. This study was aimed at evaluating the effect of intermittent fasting of Ramadan on resting energy expenditure (REE), body composition, and nutritional status. Methods. The study was conducted on a total of 27 adults (16 females, 11 males) who were fasting (18 h) in the Ramadan month (May 6–June 3) of 2019. REE was measured using the indirect calorimeter. Dietary energy and nutrient intakes were evaluated by 3-day food records in baseline and post-Ramadan. Body composition and some metabolic parameters were analyzed simultaneously with REE measurements. All measurements were performed two times at baseline, and post-Ramadan. Results. Body weight (−2.9% vs. −1.4%), body mass index (BMI) (−3.1% vs. −2.1%), fat-free mass (−2.7% vs. −1.4%), and hydration status were decreased in both males and females after the Ramadan fasting ( p < 0.05 ). REEs (kcal/d) of the participants were 1708.1 ± 262.50 kcal/d and 1596.5 ± 302.27 kcal/d at baseline and post-Ramadan, respectively (6.5%) ( p < 0.05 ). This decrease in REE (kcal/d) in females was greater than that in males (−8.1% vs. −4.6%). However, no statistically significant difference was found in sleep duration (h), physical activity levels, dietary energy and nutrient intakes, and blood pressures (mm Hg) of both genders compared to baseline ( p > 0.05 ). Conclusion. Intermittent circadian fasting may lead to a decreased energy expenditure and a change in fat-free mass in healthy individuals, and this effect is interpreted as gender-dependent.