Urinary Sodium Concentration Research Articles

Renal profiling based on estimated glomerular filtration rate and spot urine sodium identifies high-risk acute heart failure patients.

In acute heart failure (AHF), assessment of renal function comprises estimation of glomerular filtration rate (eGFR), which does not provide any information about renal sodium/water handling. We describe the interactions between urinary sodium concentration and eGFR to better characterize AHF patients. In 219 patients with AHF, spot urine sodium (UNa+ ) and eGFR were assessed on admission, day 1 and day 2 of hospitalization. We found no correlation between UNa+ and eGFR (calculated on each consecutive day, as an average of all three values, and as changes from baseline; all P> 0.05). The population was subsequently divided into four profiles based on eGFR (preserved vs. impaired; cutoff of 60 mL/min/1.73 m2 ) and UNa+ (sodium excreter vs. non-excreter; cutoff of 60 mmol/L). At day 1, there were 70 (31.9%) patients classified as preserved eGFR/sodium excreter, 37 (16.8%) as impaired eGFR/sodium non-excreter, 72 (32.9%) as impaired eGFR/sodium excreter, and 40 (18%) as preserved eGFR/sodium non-excreter. Both sodium non-excreter profiles were associated with an increased risk of in-hospital heart failure worsening [odds ratio (OR) 2.8, 95% confidence interval (CI) 1.3-6.4], inotrope use (OR 2.6, 95% CI 1.1-6.7) and rehospitalization due to AHF (OR 3.2, 95% CI 1.6-6.2; all P< 0.05). The preserved eGFR/sodium non-excreter profile was associated with highest 1-year mortality (52.5%) and remained an independent prognosticator after adjustment for other prognosticators (hazard ratio 2.9, 95% CI 1.7-5.2; P< 0.0005). In AHF, values of spot UNa+ and eGFR are not interrelated. Concomitant assessment of eGFR and spot UNa+ may be useful for better clinical and therapeutic profiling of patients.

Discrepant acute effect of saline loading on blood pressure, urinary sodium and potassium according to salt intake level: EpiSS study.

Acute dietary salt intake may cause an elevation in blood pressure (BP). The study aimed to assess the acute effect of saline loading on BP in subjects with different levels of salt intake. This study is based on the baseline survey of systemic epidemiology of salt sensitivity study. The sodium excretion in the 24‐hour urine was calculated for estimating the level of salt intake. Subjects were performed an acute oral saline loading test (1 L), and data of 2019 participants were included for analyses. Multivariate linear regression and stratified analyses were performed to identify associations between 24‐hour urinary sodium (24hUNa) with BP changes. Due to saline loading, systolic BP (SBP), pulse pressure, and urinary sodium concentration were significantly increased, while diastolic BP, heart rate, and urinary potassium concentration were significantly decreased. The SBP increments were more significant in subjects with lower salt intake, normotensives, elders, males, smokers, and drinkers. There was a significant linear negative dose‐response association between SBP increment with 24hUNa (β = −0.901, 95% CI: −1.253, −0.548), especially in lower salt intake individuals (β = −1.297, 95% CI: −2.338, −0.205) and hypertensive patients (β = −1.502, 95% CI: −2.037, −0.967). After excluding patients who received antidiabetic or antihypertensive medicines, the effects of negative associations weakened but remained significantly. In conclusion, acute salt loading leads to an increment in SBP, and the increased SBP was negatively related with 24hUNa. This study indicated avoiding acute salt loading was important for escaping acute BP changes, especially in lower salt intake populations.

Degree of Portal and Systemic Hemodynamic Alterations Predict Recurrent AKI and Chronic Kidney Disease in Patients With Cirrhosis.

The relevance of hemodynamic derangements on the incidence of recurrent acute kidney injury (AKI) and chronic kidney disease (CKD) in patients with cirrhosis is largely unknown. Consecutive patients with cirrhosis with a complete record of baseline hemodynamics were followed for identifying risk factors for the development of recurrent AKI and CKD by using negative binomial regression and competing risk analysis, respectively. Consecutive patients with cirrhosis (n = 2013, age 50.1 ± 11.8 years, 80% male, Child A:B:C percentage 13.7:52.9:33.4, and mean Child‐Turcotte‐Pugh score 8.6 ± 1.8) were enrolled, 893 (44.3%) of whom received beta‐blockers, with 44.2% responders. Prior AKI was noted in 12.4% at enrollment. At a median follow‐up of 379 (interquartile range: 68‐869) days, AKI developed at a rate of 0.37 episodes per person‐year, and 26% patients developed CKD. A lower mean number of AKI episodes (0.05 ± 0.25 vs. 0.42 ± 0.868; P < 0.001), CKD (subdistribution hazard ratio 0.74 [0.54‐1.02]), and mortality (hazard ratio 0.21 [0.06‐0.73]) were observed in beta‐blocker responders. Albuminuria was an independent risk factor for recurrent AKI, CKD, and mortality (P < 0.05). Lower systemic vascular resistance index predicted hemodynamic response (odds ratio 2.04 [1.29‐3.22]), cumulative AKI episodes (ratio of means 0.10 [0.08‐0.14]), and development of CKD (subdistribution hazard ratio 0.70 [0.58‐0.83]). Higher hepatic venous pressure gradient (≥17 mm Hg) predicted AKI episodes (ratio of means 1.76 [1.32‐2.35]) but not CKD. Conclusion: High portal pressure and severe vasodilatation predispose patients with cirrhosis to repeated AKI episodes and development of CKD. Response to beta‐blockers and therapies targeting the vasodilatory state could prevent frequent AKI and the risk of CKD development. Albuminuria could serve as an early marker of renal dysfunction in patients with cirrhosis.

Hemorrhagic Cerebral Vascular Accident with Breakdown of Salt-Wasting Cerebral Syndrome in Acute Lymphoblastic Leukemia: Case Report

Introduction:Cerebral Salt Losing Syndrome (SCLS) is defined as a renal loss of sodium during intracranial disease, leading to hyponatremia and decreased volume of extravascular fluid. Studies show the existence of an association with hemorrhagic stroke (HCV) and SCLS as a complication that significantly contributes to the morbidity and mortality of patients with acute lymphoid leukemia (ALL).Objective:To report a case of a patient with ALL who presented HCV with neurological lesion, showing repercussions in the nervous system through SCPS.Case Description:A 33-year-old female patient was referred to the specialized hematology service, complaining of petechiae spread in the trunk and limbs, high fever, progressive asthenia, generalized pain in addition to nausea and vomiting. Laboratory data showed pancytopenia and IgM and IgG serology reagent for dengue. Cytomorphological examination of peripheral blood showed the presence of 68% of lymphoid blast cells, later confirming by bone marrow aspirate immunophenotyping as a CD10 negative pre-B ALL (pro-B ALL). After the start of chemotherapy treatment, the patient presented episodes of generalized tonic-clonic seizure crisis that were repeated in the two days that followed, in addition to referring to intense paresthesia in the upper limbs and headache and referred to the Intensive Care Unit (ICU). Imaging exams showed heterogeneous right frontal hemorrhage compatible with HCV, and sagittal sinus thrombosis, with an increase in frontal hematoma with deviation of centro medial structures. Subsequently, he presented high urinary output (6,500 mL / 24 hours) with severe polydipsia, in addition to hyponatremia (129), hypouricemia (20) and decreased creatinine (0.3), urinary sodium concentration and urinary osmolarity, evolving with dehydration (+++ / 4+) and hemodynamic instability, establishing the diagnosis of SCPS. After intervention with flourcortisone and hydroelectrolytic replacement, the patient presented an improvement in the condition of SCLS and, with significant clinical improvement, the patient continues on specific cancer treatment, and without neurological sequelae.Conclusion:The correct clinical and laboratory diagnosis allows an early and safe intervention. Knowledge of this clinical entity enables specific treatment and a favorable outcome for the patient. Disclosures No relevant conflicts of interest to declare.

Electrolyte-based calculation of fluid shifts after infusing 0.9% saline in severe hyperglycemia

BackgroundEarly treatment of severe hyperglycemia involves large shifts of body fluids that entail a risk of hemodynamic instability. We studied the feasibility of applying a new electrolyte equation that estimates the degree of volume depletion and the distribution of infused 0.9% saline in this setting.MethodsThe new equation was applied to plasma and urinary concentrations of sodium and chloride measured before and 30 min after a 30-min infusion of 1 L of 0.9% saline on two consecutive days in 14 patients with severe hyperglycemia (mean age 50 years). The extracellular fluid (ECF) volume was also estimated based on the volume dilution kinetics of chloride.ResultsOn day 1, the baseline ECF volume amounted to 11.5 L. The saline infusion expanded the ECF space by 160 mL and the intracellular fluid space by 375 mL. On day 2, the ECF volume was 15.5 L, and twice as much of the infused fluid remained in the ECF space. The chloride dilution kinetics yielded baseline ECF volumes of 11.6 and 15.2 L on day 1 and day 2, respectively. No net uptake of glucose to the cells occurred during the two 1-h measurement periods despite insulin administration in the intervening time period.ConclusionsThe electrolyte equation was feasible to apply in a group of hyperglycemic patients. The ECF space was 3 L smaller than expected on admission but normal on the second day. Almost half of the infused fluid was distributed intracellularly.

Urinary sodium and iodine concentrations among Belgian adults: results from the first national Health Examination Survey.

Iodine deficiency and excessive salt intakes have adverse health consequences. The objective was to measure sodium and iodine concentrations in urine spot samples among a representative sample of Belgian adults and compare those to World Health Organization (WHO) recommendations. Spot urine samples were collected in 2018 from participants of the Belgian Health Examination Survey. Iodine and sodium concentrations were measured by inductively coupled plasma mass spectrometry and ion selective electrodes respectively. Tanaka and INTERSALT equations were used to predict 24-h urinary sodium excretion using sodium and creatinine concentration in spot samples, sex, and measured height and weight. Median urinary iodine concentration (UIC) among adults (n = 1092) was 93.6 µg/L, indicating mild iodine deficiency according to WHO thresholds. Median UIC among participants who reported thyroid problems over the last year was significantly higher than among those who did not report thyroid problems (104.1 µg/L versus UIC = 92.2 µg/L, p < 0.001). There were no significant differences in median UIC between sexes, age groups, and regions. The average salt intake among Belgian adults (n = 1120) was 8.3 ± 0.1 g/day using the Tanaka equation and 9.4 ± 0.1 g/day using the INTERSALT equation. For both equations, <5% of the population met the recommended WHO upper salt intake level of 5 g/day. Iodine nutrition in the Belgian adult, nonpregnant population likely indicates mild iodine deficiency as the median UIC was below the WHO threshold for iodine sufficiency. Salt intake was substantially higher than the WHO recommendations. Further policy efforts are needed to optimize iodine and reduce salt intake in Belgium.

Aldosterone-Mediated Sodium Retention Is Reflected by the Serum Sodium to Urinary Sodium to (Serum Potassium)2 to Urinary Potassium (SUSPPUP) Index.

The serum sodium to urinary sodium ratio divided by the (serum potassium)2 to urinary potassium ratio (SUSPPUP formula) reflects aldosterone action. We here prospectively investigated into the usefulness of the SUSPPUP ratio as a diagnostic tool in primary hyperaldosteronism. Parallel measurements of serum and urinary sodium and potassium concentrations (given in mmol/L) in the fasting state were done in 225 patients. Of them, 69 were diagnosed with primary aldosteronism (PA), 102 with essential hypertension (EH), 26 with adrenal insufficiency (AI) and 28 did not suffer from the above-mentioned disorders and were assigned to the reference group (REF). The result of the SUSPPUP formula was highest in the PA group (7.4, 4.2–12.3 L/mmol), followed by EH (3.2, 2.3–4.3 L/mmol), PA after surgery (3.9, 3.0–6.0 L/mmol), REF (3.4 ± 1.4 L/mmol) and AI (2.9 +/− 1.2 L/mmol). The best sensitivity in distinguishing PA from EH was reached by multiplication of the aldosterone to renin-ratio (ARR) with the SUSPPUP formula (92.7% at a cut off > 110 L/mmol), highest specificity was reached by the SUSPPUP determinations (87.2%). The integration of the SUSPPUP ratio into the ARR helps to improve the diagnosis of hyperaldosteronism substantially.

Estimated 24-Hour Urinary Sodium Excretion and Incident Cardiovascular Disease and Mortality Among 398 628 Individuals in UK Biobank.

We report on an analysis to explore the association between estimated 24-hour urinary sodium excretion (surrogate for sodium intake) and incident cardiovascular disease (CVD) and mortality. Data were obtained from 398 628 UK Biobank prospective cohort study participants (40-69 years) recruited between 2006 and 2010, with no history of CVD, renal disease, diabetes mellitus or cancer, and cardiovascular events and mortality recorded during follow-up. Hazard ratios between 24-hour sodium excretion were estimated from spot urinary sodium concentrations across incident CVD and its components and all-cause and cause-specific mortality. In restricted cubic splines analyses, there was little evidence for an association between estimated 24-hour sodium excretion and CVD, coronary heart disease, or stroke; hazard ratios for CVD (95% CIs) for the 15th and 85th percentiles (2.5 and 4.2 g/day, respectively) compared with the 50th percentile of estimated sodium excretion (3.2 g/day) were 1.05 (1.01-1.10) and 0.96 (0.92-1.00), respectively. An inverse association was observed with heart failure, but that was no longer apparent in sensitivity analysis. A J-shaped association was observed between estimated sodium excretion and mortality. Our findings do not support a J-shaped association of estimated sodium excretion with CVD, although such an association was apparent for all-cause and cause-specific mortality across a wide range of diseases. Reasons for these differences are unclear; methodological limitations, including the use of estimating equations based on spot urinary data, need to be considered in interpreting our findings.

High Dietary Salt Intake in Pediatric Patients with Type 1 Diabetes Mellitus Not Related to Overweight and Obesity

Aim: People around the world are consuming much more sodium than is physiologically necessary. A number of studies suggest that dietary sodium intake is related to weight gain. The aim of our study was to evaluate in a population of children and adolescents with type 1 diabetes mellitus, possible correlations between the urinary sodium excretion (UNa24h), indirect marker of sodium intake, and both duration of diabetes and BMI z-score. Moreover, we also evaluated the correlation between UNa24h and duration of diabetes according with the presence/absence of overweight/obesity. Research Design and Methods: Children and adolescents aged between 4 and 18 years with type 1 diabetes were consecutively enrolled from Regional Center for Pediatric Diabetes in Naples. Urinary sodium concentrations were tested in three 24 h urine samples of 68 individuals (204 tests). Results: Mean UNa24h was 141.3±68.2 mmol/24h corresponding to 8.1±3.9 gr of NaCl intake. Seventyfive percent of subjects aged between 4 and 6 years, 95% of subjects aged between 7 and 10 years and 79.5% of subjects aged between 11 and 18 years consume more salt of the LARN’s advice. Urinary sodium excretion increased in relation to the increase of duration, in years, of diabetes (p=0.0027). No statistically significant relationship is between UNa24h (mmol/24h) and zBMI (p=0.705). Conclusions: This study shows that young patients with type 1 diabetes have high levels of UNa24h. Given the close correlation between the UNa24h and salt intake we can conclude that they take more salt with their diet. High salt intake is not related to overweight but to diabetes duration.

Obstructive Sleep Apnea Syndrome as a Potential Cause of Nocturia in Younger Adults

To investigate the impact of age on the relationship between obstructive sleep apnea syndrome (OSAS), nocturia, and other lower urinary tract symptoms (LUTSs). This was a secondary analysis study based on data derived from a previously conducted prospective observational cohort study on OSAS and nocturia. We analyzed 90 subjects who were suspected of having OSAS. Prior to polysomnography, we assessed International Prostate Symptom Score-Quality of Life scores, Overactive Bladder Symptom Scores, and International Consultation on Incontinence Modular Questionnaire-Nocturia Quality of Life scores to evaluate LUTSs. Nocturnal urine volume, night-time frequency, and night-time urine electrolyte content were measured during polysomnography. Patients were divided into groups according to age and OSAS severity determined using apnea-hypopnea index (AHI) scores. Young patients were those aged <65 years and elderly patients, ≥65 years. A multiple linear regression with multiple imputations was performed to examine the association of night-time frequency with demographic, polysomnographic, and clinical characteristics. In young patients, night-time frequency was significantly associated with nocturnal urine volume, AHI score, and total IPSS. However, night-time frequency in elderly subjects was not associated with demographic and polysomnographic characteristics. In order to compare the severity of OSAS, night-time frequency and urinary sodium content significantly increased only in young patients (P=.007 and .004, respectively). OSAS is a strong candidate of causative factor for nocturia in younger individuals. When a younger patient complains nocturia without any urological disorders, OSAS should be kept in mind as a potential cause of nocturia.

Spironolactone-furosemide combination therapy and acid-base disorders in liver cirrhosis patients .

Respiratory alkalosis (RA) and dilutional hyperchloremic acidosis (DHA) are the most common acid-base balance (ABB) disorders in patients with liver cirrhosis. The aims of this study were to clarify whether RA develops in relation to DHA via respiratory compensation of metabolic acidosis and whether spironolactone in combination with low-dose furosemide - diuretics known to ameliorate DHA - positively affects RA in liver cirrhosis patients. 59 patients with advanced cirrhosis were divided into two groups. Group D consisted of individuals (urine sodium concentration (UNa+) > 20 mmol/L) who responded to combination therapy consisting of spironolactone and low-dose furosemide. The non-D group consisted of individuals (UNa+ ≤ 20 mmol/L) who either did not respond to the treatment or who were not administered it. In both groups, we examined serum and urine concentrations of electrolytes and ABB parameters, including SNa+-SCl- and SNa+/SCl- values. In group D, we found a statistically significant relationship between pCO2 and SHCO3-: r = 0.756 (p < 0.001) and between pCO2 and SNa+-SCl-: r = 0.522 (p = 0.001). Neither Salb nor the corrected anion gap were associated with changes in SHCO3- or pCO2 values. Although SHCO3- values were normal, abnormal pCO2 values were observed in one third of group D patients. Based on multivariable analysis, SHCO3- proved to be a statistically significant influencing factor on pCO2 values. DHA contributes to the development of RA in individuals with liver cirrhosis. Reducing DHA by means of effective diuretic therapy comprising spironolactone and furosemide has a beneficial effect on RA in such patients.

Evolution and evolving resolution of controversy over existence and prevalence of cerebral/renal salt wasting.

The topic of hyponatremia is in a state of flux. We review a new approach to diagnosis that is superior to previous methods. It simplifies identifying the causes of hyponatremia, the most important issue being the differentiation of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) from cerebral/renal salt wasting (RSW). We also report on the high prevalence of RSW without cerebral disease in the general wards of the hospital. We applied our new approach to hyponatremia by utilizing sound pathophysiologic criteria in 62 hyponatremic patients. Seventeen (27%) had SIADH, 19 (31%) had a reset osmostat, 24 (38%) had RSW with 21 having no evidence of cerebral disease, 1 had Addison's disease, and 1 was because of hydrochlorothiazide. Many had urine sodium concentrations (UNa) less than 30 mmol/l. RSW is much more common than perceived in the general wards of the hospital. It is important to change the terminology from cerebral to RSW and to differentiate SIADH from RSW. These changes will improve clinical outcomes because of divergent therapeutic goals of water-restricting in SIADH and administering salt and water to a dehydrated patient with RSW. The present review will hopefully spur others to reflect and act on the new findings and different approaches to hyponatremia.

Urinary Fractional Clearance of Sodium in 8 Healthy Beagle Dogs Fed Normal, Low, or Ultralow Sodium Diets.

The purpose of this study was to investigate in healthy adult dogs if there was a daily fluctuation in the FCNa, the role that dietary sodium intake played on the FCNa, and the role that feeding played on the obtained value for FCNa. Three different diets were used in a group of 8 healthy beagle dogs in a crossover design. The sodium content of the diets was normal (0.26%), low (0.18%), and ultralow (0.06%). Spot urine and blood samples were collected from which the urine and serum sodium and creatinine concentration were determined, and the FCNa was calculated. The median FCNa for the normal, low, and ultralow sodium diets was 0.5, 0.77, and 0.15, respectively. Individual dogs showed a daily variation in FCNa, and samples which were collected shortly after eating showed the greatest variation. This study showed that in a group of healthy beagle dogs without obvious renal disease, the FCNa could exceed 1 and that there was both an individual and daily variation in the FCNa. The greatest variation was seen whilst the dogs were fed the low and ultralow sodium diets and when the samples were collected shortly after eating. This study concluded that an FCNa > 1% may not be indicative of acute tubular dysfunction in young dogs, and use of the FCNa for assessing renal function in clinical cases should take into account the animal's diet, as well as the time the samples were taken in relation to feeding.

Enhancement of the serum chloride concentration by administration of sodium\u2013glucose cotransporter-2 inhibitor and its mechanisms and clinical significance in type 2 diabetic patients: a pilot study

BackgroundChloride is a key electrolyte that regulates the body fluid distribution. Accordingly, manipulating chloride kinetics by selecting a suitable diuretic could be an attractive strategy for correcting body fluid dysregulation. Therefore, this study examined the effects and contributing factors of a sodium–glucose cotransporter-2 inhibitor (SGLT2i) on the serum chloride concentration in type 2 diabetic (T2DM) patients without heart failure (HF).MethodsThis study was a retrospective single-center observational study that enrolled 10 T2DM/non-HF outpatients for whom the SGLT2i empagliflozin (daily oral dose of 10 mg) was prescribed. Among these 10 patients, 6 underwent detailed clinical testing that included hormonal and metabolic blood tests.ResultsEmpagliflozin treatment for 1–2 months decreased body weight (− 2.69 ± 1.9 kg; p = 0.002) and HbA1c (− 0.88 ± 0.55%; p = 0.0007). The hemoglobin (+ 0.27 ± 0.36 g/dL; p = 0.04) and hematocrit (+ 1.34 ± 1.38%; p = 0.014) values increased, but the serum creatinine concentration remained unchanged. The serum chloride concentration increased from 104 ± 3.23 to 106 ± 2.80 mEq/L (p = 0.004), but the sodium and potassium concentrations did not change. The spot urinary sodium concentration decreased from 159 ± 43 to 98 ± 35 mEq/L (p < 0.02) and the spot urinary chloride tended to decrease (from 162 ± 59 to 104 ± 36 mEq/L, p < 0.08). Both renin and aldosterone tended to be activated (5/6, 83%). The strong organic acid metabolite concentrations of serum acetoacetate (from 42 ± 25 to 100 ± 45 μmol/L, p < 0.02) and total ketone bodies (from 112 ± 64 to 300 ± 177 μmol/L, p < 0.04) increased, but the actual HCO3− concentration decreased (from 27 ± 2.5 to 24 ± 1.6 mEq/L, p < 0.008).ConclusionsThe present study demonstrated that SGLT2i enhances the serum chloride concentration in T2DM patients and suggests that the effect is mediated by the possible following mechanisms: (1) enhanced reabsorption of urinary chloride by aldosterone activation due to blood pressure lowering and blood vessel contraction effects, (2) reciprocal increase in the serum chloride concentration by reducing the serum HCO3− concentration via a buffering effect of strong organic acid metabolites, and (3) reduced NaHCO3 reabsorption and concurrently enhanced chloride reabsorption in the urinary tubules by inhibiting Na+–H+ exchanger 3 in the renal proximal tubules. Thus, the diuretic SGLT2i induces excessive extravascular fluid to drain into the vascular space by the enhanced vascular “tonicity” caused by the elevated serum chloride concentration.

Analysis of food and fluid intake in elite ultra-endurance runners during a 24-h world championship

BackgroundProperly replacing energy and fluids is a challenge for 24-h ultramarathoners because such unusually high intake may induce adverse effects (gastrointestinal symptoms [GIS] and exercise-associated hyponatremia [EAH]). We analyzed such intake for 12 twelve elite athletes (6 males and 6 females; age: 46 ± 7 years, height: 170 ± 9 cm, weight: 61.1 ± 9.6 kg, total distance run: 193–272 km) during the 2019 24-h World Championships and compared it to the latest nutritional recommendations described by the International Society of Sports Nutrition in 2019. We hypothesized that these elite athletes would easily comply these recommendations without exhibiting detrimental adverse symptoms.MethodsAd libitum food and fluid intake was recorded in real-time and energy, macronutrient, sodium, and caffeine intake then calculated using a spreadsheet in which the nutritional composition of each item was previously recorded. GIS, markers of dehydration (body mass modifications, plasma and urine osmolality, and plasma volume; samples obtained 26 h before and just after the race) and EAH (plasma and urine sodium concentrations) were also assessed.ResultsFluid, energy, and carbohydrate intake of the 11 finishers was 16.4 ± 6.9 L, 35.1 ± 15.7 MJ, and 1.49 ± 0.71 kg, respectively. Individual analyses showed that all but one (for fluid intake) or two (for energy and carbohydrate intake) consumed more than the minimum recommendations. The calculated energy balance remained, however, largely negative (− 29.5 ± 16.1 MJ). Such unusually high intake was not accompanied by detrimental GIS (recorded in 75%, but only transiently [3.0 ± 0.9 h]) or EAH (0%). The athletes were not dehydrated, shown by the absence of significant body mass loss (− 0.92 ± 2.13%) and modifications of plasma osmolality and an increase in plasma volume (+ 19.5 ± 15.8%). Performance (distance ran) positively correlated with energy intake (ρ = 0.674, p = 0.023) and negatively (ρ = − 0.776, p = 0.005) with fluid intake.ConclusionsOverall, almost all of these elite 24-h ultramarathoners surpassed the nutritional recommendations without encountering significant or the usual adverse effects.

Utility of Urine Biomarkers and Electrolytes for the Management of Heart Failure.

To provide insight into the role of urine biomarkers and electrolytes for the management of heart failure. The age-dependent decrease in glomerular filtration rate due to loss of functional nephrons occurs at a faster pace in heart failure, potentially exacerbated by episodes of acute kidney injury. Urine biomarkers have not convincingly demonstrated to improve detection of irreversible renal damage and predict long-term renal trajectories, compared with serial creatinine measurements. Recent data show that natriuresis and diuretic response track poorly with glomerular filtration, but strongly with prognosis. Urine sodium concentration > 50-70mmol/L was recently put forward through expert consensus as an adequate diuretic response. The value of urine biomarkers to detect structural renal damage in heart failure remains unsure and the latter is probably uncommon, especially over short-term follow-up. Urine electrolytes on the other hand predict diuretic response accurately and may allow better diuretic titration.

Lower urine sodium predicts longer length of stay in acute heart failure patients: Insights from the ROSE AHF trial.

BackgroundIn patients hospitalized with acute heart failure (AHF), low urine sodium concentration (U Na) after diuretic treatment may identify patients at risk for longer length of stay (LOS) and adverse events. We investigated the prognostic significance of 24‐hour cumulative postdiuretic urine sodium concentration in a multicenter clinical trial population.MethodsThe Renal Optimization Strategies Evaluation AHF (ROSE AHF) trial randomized 360 patients with AHF and renal dysfunction receiving intravenous diuretic to dopamine, nesiritide, or placebo. Sodium concentration was measured in cumulative urine sample collected during the first 24 hours after randomization in 298 patients. Based on prior studies, lower U Na was defined as ≤60 mmol/L.ResultsLower U Na was present in 142 (48%) patients, who had longer LOS (7 days vs 5 days, P < .001) and less 72‐hour weight loss (5.7 lb vs 9.0 lb, P < .001). These associations persisted after controlling for baseline estimated glomerular filtration rate and outpatient furosemide dose. Lower U Na did not modify the null effects of dopamine or nesiritide on clinical outcomes. Results were similar for spot rather than cumulative 24‐hour U Na concentration.ConclusionIn patients hospitalized for AHF and renal dysfunction, U Na ≤ 60 mmol/L during the first 24 hours of diuresis identifies patients at risk for prolonged hospitalization but does not provide an indication for adjunctive dopamine or nesiritide.

P5007Acute natriuretic activity of sodium-glucose cotransporter 2 inhibitor in heart failure patients with type 2 diabetes mellitus

Abstract Background Sodium-glucose cotransporter 2 (SGLT2) inhibitor promotes diuresis and reduces the risk of hospitalization for heart failure (HF). However, the mechanisms of diuretic effects of SGLT2 inhibitor in HF patients with type 2 diabetes mellitus (T2DM) remain under investigation. Purpose The purpose of this study was to investigate the mechanisms of acute diuretic effects of SGLT2 inhibitor and to identify its predictor in HF patients with T2DM. Methods We prospectively enrolled 40 hospitalized HF patients with T2DM (68±13 years, 63% male, and hemoglobin A1c 7.1±0.9%) between July 2014 and June 2018. All patients received ipragliflozin at a dose of 50 mg once daily after breakfast. They underwent 24-hour urine test and first-morning blood and urine tests before and after ipragliflozin therapy. Results Urine volume significantly increased from 1,365±511 ml/day on day 0 to 1,698±595 ml/day on day 3 (p&lt;0.001). Multivariate linear regression analyses showed that the increase of 24-hour urine sodium but not urine sugarwas significantlyand independently associated with the increase of 24-hour urine volume (β-Coefficient=0.80; P&lt;0.001). Univariate and multivariate logistic regression analyses showed that higher dosage of furosemide-equivalent loop diuretics and lower level of first-morning urine sodium concentration (per 1 mEq/L) at baseline were significantly associated with the diuretic effect of ipragliflozin therapy, and the latter independently predicted increase of 24-hour urine volume (Table). Predictors for increase of urine volume Univariate Multivariate Odds ratio (95% CI) P value Odds ratio (95% CI) P value Dosage of furosemide, mg 1.09 (1.01–1.18) 0.04 – – HbA1c, % 1.45 (0.56–3.78) 0.44 Fasting blood glucose, mg/dL 1.02 (0.99–1.04) 0.24 eGFR, mL/min/1.73m2 1.01 (0.97–1.05) 0.65 Plasma BNP, pg/mL 1.00 (0.99–1.01) 0.12 Left ventricular ejection fraction, % 0.98 (0.94–1.02) 0.24 First-morning urine sugar, mg/dL 1.20 (0.96–1.50) 0.12 First-morning urine sodium, mEq/L 0.96 (0.93–0.99) 0.02 0.96 (0.93–0.99) 0.02 24-hour urine sugar, g/day 3.49 (0.13–93.40) 0.46 24-hour urine sodium, mEq/day 0.98 (0.96–1.01) 0.20 eGFR, estimated glomerular filtration rate; BNP, brain natriuretic peptide. Conclusion SGLT2 inhibitor has acute natriuretic activity and may restore loop-diuretic resistance in HF patients with T2DM. Acknowledgement/Funding None

Hyponatraemia and Syndrome of Inappropriate Antidiuretic Hormone Secretion in Non-azotaemic Dogs with Babesiosis Associated with Decreased Arterial Blood Pressure.

IntroductionA previous study on canine babesiosis showed low serum tonicity in affected dogs, which may result from syndrome of inappropriate antidiuretic hormone secretion (SIADH). This endocrine disorder was recognised in human malaria which is considered a disease with similar pathogenesis to canine babesiosis. The aim of this study was to investigate the occurrence of SIADH in babesiosis-afflicted dogs.Material and MethodsSerum and urinary sodium and urine specific gravity (USG) were determined in dogs with babesiosis. Mean arterial pressure (MAP) was measured at the beginning of the clinical examination. Serum tonicity and osmolality were calculated. Correlations were calculated between MAP and serum and urinary sodium concentrations, USG, serum tonicity, and calculated serum osmolality.ResultsStatistically significant correlations were observed between MAP and tonicity, calculated osmolality, USG, and serum and urinary sodium concentrations in non-azotaemic dogs. In three non-azotaemic dogs SIADH was recognised.ConclusionSIADH develops in non-azotaemic dogs with babesiosis. It is probably associated with decreased blood pressure in infected dogs. Thus, it seems that in fact it may be appropriate vasopressin secretion in canine babesiosis as a protective mechanism in hypotension which leads to hypoxia and renal failure in affected dogs.

The Short-Term Effects of Roux-en-Y Gastric Bypass on Renal Excretion of Sodium and Its Association with Blood Pressure

Bariatric surgery has been shown to be effective in reducing weight and has benefits, such as lowering blood pressure. An increase in urinary sodium excretion has been suggested as a possible mechanism. This study explored changes in sodium excretion and their correlation with blood pressure after Roux-en-Y gastric bypass. This study was conducted on 28 obese participants with body mass index (BMI) of 44.54 ± 7.81kg/m2 who underwent gastric bypass. Before surgery and at the third and sixth months after gastric bypass, blood pressure, urinary sodium concentration, 24-hour (24-h) urinary sodium excretion, and fractional excretion of sodium were evaluated. In addition, serum sodium and potassium levels were determined. Nonparametric tests were used to analyze the data. Blood pressure decreased after surgery and remained at low levels over the 3- and 6-month periods. The urinary sodium concentration increased at 3months after surgery; however, the 24-h urinary sodium excretion and urine volume decreased. Interestingly, although some associations between variables were observed, significant correlations between the 24-h urinary sodium excretion and the systolic, diastolic, and mean blood pressures were found. In addition, the urine volume was higher in the sixth month than in the third month following surgery. In the months immediately following surgery, a low-salt and low-volume diet favors decreases in urine volume and 24-h urinary sodium excretion. In addition, in the sixth month after surgery, an association between blood pressure and 24-h urinary sodium excretion was observed.