The Influence of Salt Sensitivity Phenotype on Sodium Excretion and Diuresis: A Chrononutrition Pilot Study.

Background: Chrononutrition studies on interaction of diet/nutrients on endogenous circadian clocks and meal timing on metabolic homeostasis may be of importance in the management of nocturnal polyuria (NP), owing to loss of circadian rhythm in nighttime urination. Dietary salt restriction is an increasingly popular lifestyle recommendation for NP patients. Aim: This study aims to evaluate the effect of an acute salt load on diuresis and to study the phenomenon of salt sensitivity. Methodology. Young, healthy men (n = 21, fasted and sober) ingested 500 ml of water on the control day and 8 g and 12 g of salt with water (500 ml) on two other days. Blood and urine samples were collected at 0 hrs, 2 hrs, and 4 hrs and voided volumes were recorded. Diuresis, serum and urine osmolality, sodium, potassium, urea, and creatinine were measured. Salt sensitivity was determined based on the rate of sodium excretion. Results: Compared to 8 g, ingestion of 12 g of salt significantly increased diuresis after 4 hrs. Pure water load induced fast diuresis, whereas salt and water load initially reduced diuresis and promoted late increase in diuresis. The total voided volume was significantly lower in the salt sensitive individuals. Conclusion: Taken together, salt sensitivity profile and type and time of fluid intake are important considerations to build effective personalized lifestyle recommendations for NP patients, which needs further investigation.

Observing the water handling in humans to resolve the role of the interstitium: preliminary results of the usability of deuterium oxide and bio-impedance analysis - a pilot analysis.

The aim of this research was to evaluate the relevance of using deuterium oxide (2H2O) and bio-impedance analysis (BIA) to assess size and function of the interstitium for urological research. Nineteen volunteers were recruited to this prospective trial combining ingestion of 2H2O and BIA. Blood samples were obtained every 10 min after ingestion of 2H2O. Urine was collected before and after the experiment. BIA was performed every 5 min. Body position was alternated to study the effect on fluid distribution. First order kinetics were assumed for the uptake of 2H2O from the gastrointestinal tract to the blood. Sex seemed to have an influence with a significantly slower exchange for women (p = 0.041, men: 0.052 min-1, women: 0.038 min-1). Impedance measured in legs (men: p = 0.012, women: p = 0.008) and trunk (both p < 0.001) decreased significantly with posture change. These changes probably reflect the orthostatic redistribution of fluid with an increase of fluid in both trunk and legs. Both methods were tested and found to be useful for further urological research. Significant gender differences in 2H2O uptake dynamics from the gastrointestinal pool were observed. An impact of posture changes on the electrical impedance measured was observed.

Nocturnal bladder emptying and Quality of Life in patients with spinal cord injury.

BACKGROUND: Little is known about the relationship between sleep disruption due to nocturnal bladder emptying and Quality of Life in patients with spinal cord injury. AIM: The aim of this study was to evaluate the possible influence of number of nocturnal bladder emptying, bladder emptying method and nocturnal incontinence on the Quality of Life of patients with spinal cord injury. DESIGN: The design of this paper is a cross-sectional descriptive study. SETTING: The setting is in- and outpatient. POPULATION: Seventy-nine patients aged between 18 and 77 years with SCI in a first rehabilitation period or follow-up. METHODS: Patients were asked to complete Short Form-36 and Incontinence Quality of Life questionnaires and a medical information form. Independent samples t-tests and ANOVA were used to compare scores between groups. RESULTS: The response rate was 71 out of 79 (89%; 51 males and 20 females). 16 paraplegic and 4 tetraplegic patients were chronic, 29 paraplegic and 22 tetraplegic patients were in rehabilitation therapy or had finished this treatment recently. The paraplegic group had a significantly better Short Form-36 total score and emotional function score, while the tetraplegic group had a significantly better Incontinence Quality of Life total score and avoidance and limiting behavior score. The paraplegic patients with 0-1 nocturnal bladder emptying had better Short Form-36-derived Quality of Life than those with ≥2 emptying. Quality of Life score was not associated with gender, leg oedema, incontinence, or acute/chronic group. Incontinence Quality of Life score was significantly better for patients with incomplete spinal cord injury. Fully completed questionnaires were returned by 36 patients; at least 1 item was missing for 35 participants. CONCLUSIONS: General Short Form-36-derived Quality of Life was better for the paraplegic population. Incontinence-related Quality of Life was better in tetraplegic patients, most of whom used suprapubic catheterization. Paraplegic patients had compromised sleep and Quality of Life when the patient had to wake up two or more times at night to empty the bladder by voiding or intermittent catheterization. The high number of incomplete responders indicates the shortcomings of Quality-of-Life questionnaires for wheelchair-bound patients with spinal cord injury. CLINICAL REHABILITATION IMPACT: The use of suprapubic catheterization should be considered to improve Quality of Life for tetraplegic patients. For paraplegic patients, we must focus urological policy on aiming to reduce the number of nighttime bladder emptying to one or none.

Could Evening Dietary Protein Intake Play a Role in Nocturnal Polyuria?

Urea is the most abundant and the largest contributing factor for urine osmolality. Urinary urea excretion is highly interrelated with dietary protein intake. Accordingly, an increase of urinary urea excretion due to high protein diet may lead to urea-induced osmotic diuresis. This study aims to explore the association between nocturnal polyuria (NP) and urea. This is a post hoc analysis of a prospective observational study of subjects who completed a renal function profile between October 2011 and February 2015 (n = 170). Each subject underwent a 24 h urine collection, which included 8 urine samples collected at 3 h intervals. Urine volume, osmolality, creatinine, urea and sodium were determined. Urinary urea excretion was used to estimate dietary protein intake. Compared to the control group, subjects with NP exhibited significantly higher nighttime urea and sodium excretion. Estimated evening dietary protein intake was correspondingly significantly higher amongst the NP subgroup. Nighttime diuresis rate was positively associated with age and nighttime free water clearance, creatinine clearance, sodium excretion, and urea excretion in NP subjects. Therefore, increased nocturnal urinary urea excretion may reflect an additional important mediator of nocturia owing to excess nocturnal urine production.

Nocturia in patients with cognitive dysfunction: a systematic review of the literature.

BACKGROUND: The objective of this study is to evaluate current literature on the association between cognitive dysfunction and nocturia. METHODS: A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was conducted through MEDLINE, EMBASE and COCHRANE databases and completed in November 2019. Randomized and non-randomized studies were included if they assessed the association between cognitive dysfunction and nocturia in older participants with or without neurological diseases. The quality of included studies was evaluated using the Risk of Bias Assessment tool for Non-randomized Studies (RoBANS). RESULTS: A total of 8 cross-sectional studies conducted in older patient populations met the criteria for inclusion. A statistically significant association was identified in 6 studies on univariate analysis, which persisted in 2 studies after controlling for confounding factors. The association between cognitive dysfunction and nocturia was positive for all 6 significant analyses. The overall risk of bias was unclear. CONCLUSION: A significant positive association between cognitive dysfunction and nocturia was identified. However, research has been limited to cross-sectional studies, which precludes identification of causality between cognitive dysfunction and nocturia. Heightened awareness of the complex interplay between cognition and nocturia would allow professionals involved in the care of cognitively impaired patients with concomitant nocturia to more effectively manage these symptoms.

Impact of food and drinks on urine production: A systematic review.

CONTEXT: The impact of food and drinks on body fluid metabolism is of direct clinical relevance but current evidence remains fragmented. AIM: Synthesise current evidence on the role of food and drinks in urine production. METHODS: Systematic review as per PRISMA guidelines using MEDLINE and EMBASE databases (completed October 2019). Studies reporting on the effect of food, food constituents, and drinks on urine production were included. Two authors performed an independent extraction of relevant articles using predetermined data sets and completed quality-of-study indicators. RESULTS: A total of 49 studies were included, of which 21 enroled human subjects, and 28 were clinically relevant animal studies (all of which utilised rodent models). The included studies were determined to be of variable quality. High dietary sodium, as well as wine, spirits, high-caffeine coffee, and caffeinated energy drinks, increased urine production in human studies. Decreased urine production was associated with low dietary sodium and consumption of milk, orange juice, and high-salt/high-sugar drinks. In animal models, a variety of fruits, vegetables, herbs, spices, and honey were associated with increased urine production. CONCLUSION: Current evidence suggests that although several types of food and drinks may impact body fluid metabolism, the quality of the data is variable. Urine production appears to be influenced by multiple factors including composition (ie, moisture, macronutrients, and electrolytes), metabolite load, and the presence of specific diuresis-promoting substances (eg, caffeine, alcohol) and other bioactive phytochemicals. Future research is needed to support current evidence and the physiologic mechanisms underlying these findings.

The role of lower urinary tract symptoms in fall risk assessment tools in hospitals: a review.

A large number of falls in hospitals occur on the way to the toilet. Accordingly, a literature search was conducted in Web of Science, PubMed, Embase, and the Cochrane Library to identify fall risk screening and assessment metrics published between 1980 and 2019 and to study the inclusion of lower urinary tract symptoms (LUTS) and their related parameters in these screening tools. In addition, the literature was searched to explore the relationship between toilet-related falls and LUTS. In total, 23 fall risk scales were selected, from which 11 were applicable for in-hospital patients. In nine of the 11 scales for in-hospital patients, a LUTS or LUTS-related parameter was included. In the 12 risk assessment tools for community-dwelling older people, there were no LUTS included. Frequency, urinary incontinence, and nocturia were mostly reported in the literature as a potential fall risk parameter. It is recommended to create greater awareness of nocturia and other LUTS among caregivers of hospitalized patients to prevent falls.

Dietary considerations in the evaluation and management of nocturia.

Aim: This narrative review investigates the effect of dietary intake on nocturnal voiding severity. The primary aims of this review are to provide a framework for future research and ultimately contribute to more comprehensive, lifestyle-centered guidelines for the management of nocturia. Methods: A literature search was conducted in Web of Science, PubMed, and Google Scholar databases using the keywords "nocturia", "diuresis", "natriuresis", "food", "diet", and "nutrients". Results: High fruit and vegetable consumption was negatively associated with nocturia. High intake of tea and dietary sodium showed a positive association with nocturia. Several foods have also been directly linked to changes in diuresis rate, glycemic control, and endogenous serum melatonin concentration, offering potential mechanisms for this observed effect. Overall quality of the evidence was low. Conclusion: At present, there is limited evidence to suggest that certain foods, electrolytes, and specific compounds may contribute to the pathogenesis of nocturia. A greater understanding of the impact of food and nutrients on body fluid metabolism is needed to further refine the evaluation and treatment of nocturia.

Haptoglobin 1-1 phenotype: A risk factor for 24-hours polyuria.

BACKGROUND: Haptoglobin (Hp) displays three major phenotypes (Hp 1-1, Hp 2-2 and Hp 2-1). Hp 1-1 has been implicated in high blood pressure and salt sensitivity, and thus may mediate excess urine production. AIM: To explore the relationship between Hp polymorphisms and polyuria (>40 mL/kg/24 hours). METHODOLOGY: Post hoc analysis of a prospective observational study of subjects who completed a renal function profile between October 2011 and February 2015 (n = 170). Hp phenotypes were determined by starch gel electrophoresis using haemoglobin-supplemented serum. The distribution of Hp phenotypes in subjects with and without polyuria was compared to a reference group of the same geography and ethnic composition. Diuresis rate, sodium clearance and free water clearance were compared within and between phenotypes. RESULTS: The Hp1 allele frequency was significantly overexpressed in subjects with polyuria compared to the reference group (0.500 vs 0.400, P < .05). Consistently, the Hp 1-1 phenotype was more prevalent in subjects with polyuria compared to the reference group (28% vs 16%, P < .05). In contrast to Hp 2-1/2-2, Hp 1-1 demonstrated no circadian variation in diuresis rate, sodium clearance or free water clearance. A significant association between plasma Hp concentration and 24-hours sodium clearance was observed in Hp 1-1 subjects without polyuria (ß = 0.222; 95% CI 0.003-0.441; P = .047). CONCLUSION: The Hp1 allele was more frequent in subjects with polyuria, and participants with the Hp 1-1 phenotype were at greater risk for polyuria. Hp 1-1 subjects demonstrated an altered ability to concentrate urine with a slower continuous excretion of sodium throughout the day. Plasma Hp concentration of Hp 1-1 was positively correlated with 24-hours sodium clearance in subjects without polyuria.

The effect of a multidisciplinary weight loss program on renal circadian rhythm in obese adolescents.

Adolescent obesity is a serious health problem associated with many comorbidities. Obesity-related alterations in circadian rhythm have been described for nocturnal blood pressure and for metabolic functions. We believe renal circadian rhythm is also disrupted in obesity, though this has not yet been investigated. This study aimed to examine renal circadian rhythm in obese adolescents before and after weight loss.In 34 obese adolescents (median age 15.7 years) participating in a residential weight loss program, renal function profiles and blood samples were collected at baseline, after 7 months, and again after 12 months of therapy. The program consisted of dietary restriction, increased physical activity, and psychological support. The program led to a median weight loss of 24 kg and a reduction in blood pressure. Initially, lower diurnal free water clearance (- 1.08 (- 1.40-- 0.79) mL/min) was noticed compared with nocturnal values (0.75 (- 0.89-- 0.64) mL/min). After weight loss, normalization of this inverse rhythm was observed (day - 1.24 (- 1.44-1.05) mL/min and night - 0.98 (- 1.09-- 0.83) mL/min). A clear circadian rhythm in diuresis rate and in renal clearance of creatinine, solutes, sodium, and potassium was seen at all time points. Furthermore, we observed a significant increase in sodium clearance. Before weight loss, daytime sodium clearance was 0.72 mL/min (0.59-0.77) and nighttime clearance was 0.46 mL/min (0.41-0.51). After weight loss, daytime clearance increased to 0.99 mL/min (0.85-1.17) and nighttime clearance increased to 0.78 mL/min (0.64-0.93).Conclusion: In obese adolescents, lower diurnal free water clearance was observed compared with nocturnal values. Weight loss led to a normalization of this inverse rhythm, suggesting a recovery of the anti-diuretic hormone activity. Both before and after weight loss, clear circadian rhythm of diuresis rate and renal clearance of creatinine, solutes, sodium, and potassium was observed.What is Known:• Obesity-related alterations in circadian rhythm have been described for nocturnal blood pressure and for metabolic functions. We believe renal circadian rhythm is disrupted in obesity, though this has not been investigated yet.What is New:• In obese adolescents, an inverse circadian rhythm of free water clearance was observed, with higher nighttime free water clearance compared with daytime values. Weight loss led to a normalization of this inverse rhythm, suggesting a recovery of the anti-diuretic hormone activity.• Circadian rhythm in diuresis rate and in the renal clearance of creatinine, solutes, sodium, and potassium was preserved in obese adolescents and did not change after weight loss.

Conservative treatment for leg oedema and the effect on nocturnal polyuria in patients with spinal cord injury.

OBJECTIVES: To evaluate the possible influence of non-pharmacological interventions, such as compressive bandages and intermittent pneumatic compression (IPC), on leg oedema and nocturnal polyuria (NP), and the possible interrelation between both pathologies in patients with spinal cord injury (SCI), as patients with SCI often have leg oedema and during the night the oedema decreases as a result of natural drainage mechanisms that can cause NP. PATIENTS AND METHODS: Patients with SCI who followed their first rehabilitation after their SCI with bilateral leg oedema and/or with as much or a larger urine volume at night as during the day. The patients were all wheelchair users and followed the rehabilitation programme daily for 3 weeks. In all, 24 patients, aged between 21 and 63 years, were selected for participation in the 3-week rehabilitation programme. During the first week, baseline data were collected. During the second week, IPC was executed from the moment the patient went to lie down. During the third week, the patients wore multilayer compressive bandages. Leg circumference was measured in the morning before sitting up and at the moment they went to lie down in bed. During each study week, a daily frequency-volume chart (24 h) was completed. RESULTS: The leg volume of both legs was significantly different between the morning and evening (right leg F = 103.90, P < 0.001; left leg F = 100.77, P < 0.001) and between the three treatments (right F = 9.70, P < 0.001; left F = 9.66, P < 0.001). There was a significant difference between the compressive bandages and the baseline period (right and left leg, both P < 0.001) and between the compressive bandages and IPC (right leg P = 0.009 and left leg P = 0.015). There was no significant difference between IPC and the baseline. When no treatment or IPC was used, urine production was significantly higher during the bed-rest period. The urine production was significantly lower comparing the use of compressive bandages to baseline and IPC, during bed rest (P = 0.009) and during sleep (P < 0.001). There was a significant decrease in absolute voided volume at night with the compressive bandages as treatment (P < 0.001). There was a significant positive association between the leg volume change during the day and the urine-production ratio, 100 mL increase in leg volume was associated with 8% increase in the log-transformed urine-production ratio. CONCLUSION: There are alternative treatment options for patients with SCI who have oedema or NP. Oedema formation and urine production appear to be related to each other. Therefore, the use of compressive bandages was shown to be a valuable treatment option to improve both leg oedema and NP.

Evaluation of the occurrence and diagnose definitions for nocturnal polyuria in spinal cord injured patients during rehabilitation.

BACKGROUND: Little is known about the occurrence of nocturnal polyuria (NP) in spinal cord injured (SCI) patients and the definitions which are preferable in this population. AIM: To determine the occurrence of NP in SCI patients during in-patient rehabilitation in the Ghent University Hospital. To study the influence of different time periods (daytime, bed rest and sleep) on the accuracy of the existing diagnose definitions for NP specifically for this type of patients. DESIGN: Retrospective study using patient records. SETTING: SCI patients during hospital-based rehabilitation between 2011 and 2014. POPULATION: Seventy-four SCI patients were selected and their records of frequency-volume charts (FVC) were examined, after exclusion of unreliable data, forty-seven patients were retained for the current study. METHODS: Retrospective study using data from FVC of either two or three days from patients with SCI. Nocturnal urine production (NUP) and nocturnal polyuria index (NPi) were calculated. RESULTS: There was a significant increase in diuresis, calculated as urine production, between day time and bed rest (P=0.008) and between day time and sleep (P=0.001). All patients showed NP during a 12-hour night time period (including both bed rest and sleep) and 39 patients showed NP during the 8-hour period of sleep. There was no significant difference in mean urine production between bed rest and sleep. Prevalence of NP did not significantly differ between the complete or incomplete SCI patients or between patients with higher and lower SCI levels. CONCLUSIONS: This study showed that the occurrence of NP in patients with SCI is high and that it is important to consider which definitions of NP are used for diagnosis. Increase in diuresis is observed during bed rest and sleep and the diagnose is correctly estimated when nocturnal urine production definitions are used in both time periods. In accordance with what was expected, diagnose of NP was overestimated when NP index type definitions were used. CLINICAL REHABILITATION IMPACT: It is important to be aware of the frequent-occurrence of NP in SCI patients and the impact of their daily routine to the accuracy of the diagnosis of NP. More knowledge about this topic can help to avoid incontinence caused by nocturnal polyuria.

Accumulation and detoxification of metals and arsenic in tissues of cattle (Bos taurus), and the risks for human consumption.

The aim of this study was to investigate metal accumulation and detoxification processes in cattle from polluted and unpolluted areas. Therefore dairy cows from farms and free ranging Galloway cows from nature reserves were used as study animals. The concentrations of Ag, Cd, Pb, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn and As were determined in muscle, kidney, liver and lungs of cattle from polluted and reference areas in Belgium. In kidney and liver also the metallothionein concentrations were measured. For Ag, Mn, Co, Cu, Zn and As the concentrations in the different tissues were significantly higher in the sampled Galloways than in the sampled dairy cows. On the other hand Cd and Pb were significantly higher in tissues of both cattle breeds from polluted sites. Cadmium seemed to be the most important metal for metallothionein induction in kidneys whereas Zn seemed to be the most important metal for the induction of metallothionein in the liver. This study also suggested that only for Mn and Cd a significant part of the uptake occurs via the lungs. Although in muscle none of the Cd and Pb levels exceeded the European limits for human consumption, 40% of the livers and 85% of the kidneys of all examined cows were above the European limit for cadmium. Based on the existing minimum risk levels (MRLs) for chronic oral exposure, the present results suggested that a person of 70kg should not eat more than 150g cow meat per day because of the Cr levels in the muscles.

Metal exposure and accumulation patterns in free-range cows (Bos taurus) in a contaminated natural area: Influence of spatial and social behavior.

Possible effects of spatial metal distribution, seasonal-, ecological- and ethological parameters, on the metal exposure of cows were investigated. Therefore the habitat use, vegetation selection and foraging behavior of two free ranging Galloway herds in a metal polluted nature reserve were observed. Metal concentrations in soil, vegetation, hair, blood and feces were measured. Although both herds lived in the same reserve, their metal exposure differed significantly. A high consumption of soft rush by herd 1 during winter for instance was responsible for a large increase in daily Cd intake. The results of this study suggest that the exposure and health risks of large grazers can probably not only be predicted by a general monitoring of soil and vegetation pollution. Also detailed information about the occurring vegetation types, spatial habitat use together with the social- and foraging behavior and diet selection of the species need to be studied.