Urinary Sodium Values Research Articles

Relationship between GDF-15, urinary sodium and markers of renal function in patients with chronic heart failure

Abstract Background Patients with heart failure (HF) often have altered renal function. Urinary sodium is a marker of diuretic resistance and is associated with a worse prognosis in HF. Growth differentiation factor-15 (GDF-15) is a marker of oxidative stress and inflammation and is a prognostic predictor in HF. Objectives We sought to assess the relationship of GDF-15 with renal function parameters and with urinary sodium in patients with chronic HF. Methods We undertook a cross-sectional study of patients with HF from specialized outpatient clinic. Patients with signs and symptoms of HF and LVEF <50% were included. An echocardiogram was performed and blood samples were collected, which were frozen for the final study, where the performance of GDF-15 in the prediction of renal outcomes in HF will be evaluated. The dosage of NT-proBNP was performed using the Elecsys® system (Roche, Basel, Switzerland) and GDF-15 by the sandwich immunoassay method with monoclonal antibodies (Elecsys®, Roche, Basel, Switzerland). Analysis of the relationship between GDF-15 and baseline renal parameters was performed. Correlation analysis was performed between GDF-15 and continuous variables, using the Spearman method. Results Sixty-seven patients were included. The etiologies of HF were hypertension, diabetes mellitus, alcoholic cardiomyopathy and idiopathic cardiomyopathy. Forty-one (61.2%) individuals were male, with a mean age of 61±13 years. Median GDF-15 values were 1413 pg/mL (interquartile range 1044–2554). Patients with GDF-15 values above the median had lower urinary sodium values (88 mEq/L [53–121] vs 112 [76–171], p=0.06), lower glomerular filtration rate (GFR) (63.9±29.1 vs 91.2±25 mL/min/1.73 m2, p=0.001) and higher creatinine levels (1.32 mg/dL [0.85–1.71] vs 0.91 [0.78–1.08], p<0.001). There was no significant difference in relation to urinary albumin (21 mg/L [7–126] vs 15.1 [5.8–41], p=0.30). The urinary albumin/creatinine ratio was higher in the group above the median, but did not reach statistical significance (38 mg/g [11–110] vs 12.5 [4.9–29], p=0.13). There was a direct correlation between GDF-15 and creatinine (r=0.56, p<0.001) and an inverse correlation with urinary sodium (r=−0.39, p=0.005) and with GFR (r=−0.55, p<0.001). Conclusion GDF-15 correlated with lower urinary sodium levels and worse kidney function in patients with chronic HF. Future studies should address whether GDF-15 is a predictor of worsening renal function overtime. Funding Acknowledgement Type of funding sources: None.

Quantification of urinary sodium concentrations in term infants.

Infants with gastrointestinal conditions and poor weight gain are administered sodium supplementation based on urinary sodium concentrations. However, the reference range of urinary electrolytes is unknown. The aim of this study was to ascertain the normal values of urinary electrolytes in healthy, term infants. Secondary aims were to establish the relationship between urinary electrolytes with weight velocity and feeding practices. Healthy, term (≥37 weeks' gestation) infants were recruited. Parental questionnaires were completed before discharge and at six weeks. Electrolytes were quantified from a urine sample at six weeks. t-Tests and Mann-Whitney U tests were conducted for parametric and non-parametric electrolytes, respectively. A total of 200 infants were recruited before discharge. Twenty-nine follow-up questionnaires and urine samples were returned (nine female; mean gestational age 39 + 6 weeks [SD 9.9 days]; mean birthweight 3350 g [SD 483 g]; 17 breastfed, nine formula and three mixed; mean change in Z score for weight -0.914 [SD 0.814]). Majority (25/29) of infants had urinary sodium <20 mmo/L. Change in Z score for weight was similar between infants with sodium <20 mmol/L and >20 mmol/L ( P = 0.78). All exclusively breastfed infants had sodium <20 mmol/L, however, not statistically dissimilar to formula-fed infants ( P = 0.27). Most term infants in this study had urinary sodium values <20 mmol/L with no identified relationship to weight velocity. Lower concentrations of sodium could be not quantified reliably because of the limitations of the analytical method that were used. More evidence is required to identify candidates for sodium supplementation.

Deaths and life expectancy losses attributable to diet high in sodium in China

Objective: To quantitatively estimate the deaths and life expectancy losses attributable to diet high in sodium in China, and examine the gains and shifts under different control scenarios of sodium consumption. Methods: Based on data from the cause-of-death through the National Mortality Surveillance System, and 24 hours urinary sodium values from Global Burden of Disease study on Chinese's estimates, population attributable fractions with the framework of comparative risk assessment were used to analyze the deaths and life expectancy losses due to diet high in sodium. The same methods were followed to examine the gains and shifts under different control scenarios of sodium consumption. Results: In 2013, 1 430 (940 for men and 490 for women) thousand deaths were attributable to diet high in sodium, accounting for 15.6% (17.4% for men and 13.0% for women) of all-cause deaths in China, which causing 2.17 (2.49 for men and 1.71 for women) years of life expectancy loss. Diet with high sodium in 2013 caused 1 200, 50 and 180 thousand deaths from cardiovascular disease, chronic kidney disease and stomach cancer respectively, accounting for 31.5%, 30.8% and 64.8% of those specific causes. Comparing to the baseline in 2013, if the targets of 10% decrease of sodium consumption by 2020 and 15% by 2030 for Chinese chronic disease prevention and treatment planning, and 30% decrease by 2030 for WHO non-communicable disease monitoring framework are achieved, 220, 340 and 730 thousand deaths will be averted, which may gain 0.30, 0.45 and 0.95 years of life expectancy, respectively. Conclusions: As one of the leading risk factors, diet high in sodium had caused heavy burden of disease from cardiovascular disease, chronic kidney disease and stomach cancer on Chinese residents. Intervention programs on sodium-reduction are urgently needed in China and related cost-effectiveness is highly expected.

The effectiveness of an educational intervention for sodium restriction in patients with hypertension: study protocol for a randomized controlled trial

BackgroundThe effectiveness of nonpharmacological interventions in blood pressure reduction has been evidenced by several studies. Nevertheless, as adherence to a low-sodium diet is poor, interventions regarding habit changing should be of a motivational nature in order to develop the ability of overcoming obstacles regarding sodium-restriction behavior.The present study aims to describe the protocol and randomization of a clinical trial design in order to evaluate the effectiveness of an educational intervention based on Dietary Sodium Restriction Questionnaire (DSRQ) scores. The effectiveness measures are the DSRQ score variation and reduction in urinary sodium values from baseline to after 2 and 6 months.Methods/designThis parallel, randomized clinical trial will include 120 participants, recruited and randomized as follows: 60 of them to be allocated to a sodium-restriction educational intervention group whose results are based on the DSRQ application; and the other 60 allocated to a control group with usual care. Educational orientation and usual care sessions will be conducted once a month for a period of 6 months. Both spot urine collection – estimating sodium intake – and the DSRQ will be applied at the baseline, in the eighth week and at the end of the follow-up. There will also be blood collection and 24-h ambulatory blood pressure monitoring (ABPM) at the beginning and end of the follow-up. Anthropometric measurements, blood pressure measurement and 24-h food recall will be collected during follow-up.DiscussionThe study “The effectiveness of an educational intervention to sodium restriction in patients with hypertension” is based on the results of the DSRQ application, whose objective is to evaluate aspects related to nonadherence to the recommendation of a low-sodium diet, identifying adherence barriers and facilitators, contributing to the planning of interventions for improving the adoption of a low-sodium diet and, consequently, hypertension control.Trial registration numberClinicalTrials.gov, Identifier: NCT02848690. Registered retrospectively on 27 July 2016.

Urinary Neutrophil Gelatinase Associated Lipocalcin—A Novel Diagnostic and Prognostic Biomarker of Hours in Acute Kidney Injury in Cirrhosis

Background and Aim: Acute kidney injury (AKI) is prone to increase mortality in patients with cirrhosis. Identification of kidney failure etiology and recognition of those at the highest mortality risk remains a challenge. We aimed to determine an accuracy of uNGAL for diagnosing HRS in cirrhosis and association in predicting mortality at 30 days in AKI in cirrhosis. Methods: We Prospectively enrolled patients with cirrhosis at single institute from western India. Patients were investigated for uNGAL by CMIA method upon hospital admission (within 24 h or after development of AKI). FeNa calculated from urine and serum creatinine and urinary sodium values. Patients with urinary tract infection and anuria were excluded. Kidney failure type was determined blinded to NGAL measurements. Patients were followed for 30 days and 90 days. Results: We enrolled 45 patients of cirrhosis. Four (8.6%) patients had normal kidney function, 5 (12%) stable chronic kidney disease, 14 (33.33%) prerenal azotemia, 16(38.09%) HRS and 6 (14.2%) intrinsic acute kidney injury (iAKI). Patients with HRS had mean uNGAL levels of 432.45 ng/ml intermediate between prerenal azotemia mean 256 ng/ml, and iAKI [1389 ng/ml]. 12 patients died at 30 days. Patients with intrinsic AKI had highest uNGAl level. Level of uNGAL correlated with MELD levels. Eleven patients had hepatic encephalopathy and 6 had SBP. Patients with SBP had higher mean NGAL values (1234 ng/ml) than patients with hepatic encephalopathy (552 ng/ml).though serum creatine values were same in HRS or prerenal AKI, uNGAL can differentiate early between two conditions. FeNa levels does not differentiate between prerenal and HRS group. Conclusion: uNGAL level and Fe Na can serve as early marker in differentiating HRS and prerenal AKI early than serum creatinine. Patients with higher urinary NGAL level has higher transplant free mortality at 30 days. The authors have none to declare.

Dietary Sodium and Blood Pressure in Older Adults

Given the proportion of older adults who are hypertensive and the population of older adults who are at risk for hypertension, the U.S. must mobilize public health efforts aimed at prevention. Scientific evidence has demonstrated the efficacy of sodium reduction to lower blood pressure. Translating this evidence into practice involves knowledge about the food sources of sodium so effective interventions can be designed and implemented. The purpose of this essay was to examine major food group sources of sodium in a cohort of older adults, with and without high blood pressure, in an urban community in Southwestern Pennsylvania. The University of Pittsburgh's "Center for Healthy Aging" promotes healthy aging in the community with the "10 Keys to Healthy Aging" campaign. One of the keys aims to lower systolic blood pressure to ≤140 mmHg. A low sodium intervention was implemented by the CHA project in hypertensive individuals. The sodium intake of the 521 community volunteers, mean age 74.5 years, 60% male, 94.1% white, who completed a FFQ, was compared to a sub-sample of hypertensives (n=214) who, in addition, collected one 24-hour urinary sodium. Mean baseline dietary sodium for the entire cohort was 1,796 mg per day compared to 1,821 mg per day in hypertensives. Urinary sodium was 1.8 times higher (141 mmol/24 hrs [3,240 mg]) than self-reported intake and decreased to 130 mmol/24 hrs (2,990 mg) at 6-months. The correlation between dietary and urinary sodium at baseline was weak (r=0.16) and remained weak (0.23) at 6-months. Major food sources of sodium were soups, breads, tomato sauce, salad dressings, and prepared cereals. Data indicate that the sodium intake of the group exceeds the 2005 Dietary Guidelines of ≤1500 mg per day by approximately 200% for individuals at increased risk using urinary sodium values. Even the most successful dietary interventions to reduce sodium intake to the recommended levels would be ineffective without the food industry’s help in reducing sodium added to foods during processing. This prevention strategy, in combination with stronger public health messages, would help to reduce the sodium intake in the population and help to achieve reductions in blood pressures.

Ethnic differences in intake and excretion of sodium, potassium, calcium and magnesium in South Africans

To determine any differences in the urinary excretion and dietary intake of sodium, potassium, magnesium and calcium intake in three South African ethnic groups, and to assess whether the blood pressure-cation association varies according to ethnic status. A cross-sectional study of 325 black, white and mixed-ancestry men and women, conveniently sampled in Cape Town. Twenty-four-hour urine samples were collected on three separate occasions for assessment of urinary electrolytes, and three 24-h dietary recalls for the corresponding urine collection times were administered by two trained fieldworkers. Para-amino benzoic acid was used as a marker of the completeness of urine collection. Mean urinary sodium values equate to a daily salt (sodium chloride) intake of 7.8, 8.5 and 9.5 g in black, mixed-ancestry and white individuals, respectively. In normotensive individuals, black and mixed-ancestry subjects had significantly lower median urinary sodium concentrations than white subjects, but these differences were not evident between black and white hypertensive subjects. No ethnic differences were found for urinary potassium, except for mixed-ancestry normotensive individuals having a lower excretion than white normotensive individuals. Urinary magnesium excretion did not differ across ethnic groups. In both normotensive and hypertensive individuals, urinary calcium concentrations differed between all three groups, with black subjects having the lowest values, approximately less than half those of white subjects. White normotensive subjects in Cape Town have higher habitual intakes of sodium, but also higher calcium intakes than their black and mixed-ancestry counterparts. Dietary differences may contribute to ethnic-related differences in blood pressure.

Renal effects on a solitary kidney of specific inhibition of cyclooxygenease-2 after 24 h of complete ureteric obstruction in rats.

The purpose of this study is to show whether selective (celecoxib) and non-selective (piroxicam) inhibitors of COX-2 can alter the morphological and functional changes after the release of a 24 h complete ureteric obstruction in tissue from solitary rat kidney. Forty male Sprague-Dawley rats weighing 225-250 g were used. The animals were divided into four groups. In group 1 rats (control, n=10), only right nephrectomy was performed. Group 2 rats (untreated, n=10) underwent right nephrectomy and the left ureter was completely obstructed. In group 3 rats (celecoxib), the same operation was performed as described for group 2 and than celecoxib was administered by gavage for a period of 24 h. Group 4 rats (piroxicam) underwent the same operation as described for group 2, then piroxicam was administered intramuscularly at least 1 h before the release of the for 24 h complete ureteric obstruction. All animals were then prepared for functional and histopathological studies. The administration of celecoxib produced a significant decrease in blood urea nitrogen levels when compared to the animals receiving piroxicam and the animals with no treatment. Moreover, celecoxib caused a significant decreased in creatinine levels when compared to the untreated group. Urine volume and the urinary sodium values were increased in the celecoxib group when compared with the other groups. The administration of celecoxib and piroxicam caused a significant decrease in the number of interstitial macrophages when compared to the untreated group. The Bowman space was significantly increased in the untreated group when compared with the celecoxib and the piroxicam groups. These studies indicate that celecoxib may be an important factor affecting renal morphological and functional changes after the release of a 24 h complete ureteric obstruction.

Apparent racial difference in response to angiotensin I infusion

Angiotensin I was infused into 16 healthy volunteers, 8 blacks and 8 whites with diastolic blood pressures below 75 mm Hg and the infusion rate increased at 3 min intervals until a diastolic blood pressure of equal to or greater than 95 mm Hg was achieved. Blacks exhibited a significantly greater angiotensin I sensitivity needing 1.8 micrograms/min as opposed to 3.9 micrograms/min in whites to achieve the target blood pressure. Plasma renin activities were similar in the two groups, but blacks had significantly higher urinary sodium values than whites, 223 mmol per 24 h as compared to 121 mmol per 24 h. It is concluded that the differences in response could be largely due to differences in dietary sodium intake. These factors need to be carefully considered when using angiotensin I infusion as a pharmacodynamic model for studying the effects of ACE inhibitors.

Obstructive Uropathy Mimicking Volume Depletion

WHEN volume depletion, heart failure, or other salt-retaining states occur, the reabsorption of sodium in the proximal and distal renal tubules is enhanced. 1,2 As a result, the urine is usually hyperosmotic to plasma, with a sodium concentration equal to or less than 10 to 15 mEq/liter. 3 Based on these facts, one laboratory criterion for volume depletion, or other prerenal factors, in the etiogenesis of acute oliguria is a low urinary sodium concentration. 3 The physicians managing two patients with acute urinary tract obstruction and low urinary sodium values were misled by laboratory values to an initial diagnosis of volume depletion. Report of Cases Case 1.— An 82-year-old man who, during December 1970, fell and sustained a comminuted fracture of the left hip. A pin was inserted in the femur several days after the accident. At that time, a Foley catheter was inserted. On Jan 12,1971, the Foley catheter

Inappropriate values of the juxtaglomerular index during changes in rat serum sodium levels.

Extreme variations of dietary sodium are reflected in serum and urinary sodium levels. In rats fed a high-sodium diet and then abruptly switched to a low-sodium diet or fed a low-sodium diet and then switched to a high-sodium diet, the juxtaglomerular index was dissociated from both serum and urinary sodium values.