Dietary Sodium Intake and Outcomes: a Secondary Analysis From Sodium-HF.

OBJECTIVES: This post hoc analysis of SODIUM-HF (Study of Dietary Intervention under 100 mmol in Heart Failure) assessed the association between baseline dietary sodium intake and change at 6 months with a composite of cardiovascular (CV) hospitalizations, emergency department visits and all-cause death at 12 and 24 months. BACKGROUND: Dietary sodium restriction is common advice for patients with heart failure (HF). Randomized clinical trials have not shown a beneficial effect of dietary sodium restriction on clinical outcomes. METHODS: A multivariable Cox proportional hazard regression model was used to assess the association of dietary sodium intake measured at randomization with primary and secondary endpoints. RESULTS: The study included 792 participants. Baseline sodium intake was ≤ 1500 mg/day in 19.9% (n = 158), 1501-3000 mg/day in 56.5% (n = 448) and > 3000 mg/day in 23.4% (n = 186) of participants. The factors associated with higher baseline sodium intake were higher calorie consumption, higher body mass index and recruitment from Canada. Multivariable analyses showed no association between baseline sodium intake nor magnitude of 6-month change or 12- or 24-month outcomes. In a responder analysis, participants achieving a sodium intake < 1500 mg at 6 months showed an association with a decreased risk for the composite outcome (adjusted HR 0.52 [95% CI 0.25, 1.07] P = 0.08) and CV hospitalization (adjusted HR 0.51 [95% CI 0.24, 1.09] P = 0.08) at 12 months. CONCLUSION: There was no association between dietary sodium intake and clinical outcomes over 24 months in patients with HF. Responder analyses suggest the need for further investigation of the effects of sodium reduction in those who achieve the targeted dietary sodium-reduction level.

Inadequate Dietary Education and Poor Adherence to a High Protein, Low Sodium Diet in Cirrhosis: Mixed Methods Approach.

BACKGROUND: Malnutrition in cirrhosis is associated with poor outcomes, leading to guidelines for a high protein, low sodium diet; however, there is no guidance regarding the implementation of diet education in clinical practice. METHODS: A mixed methods study enrolled 21 patients with cirrhosis and their caregivers. Semi-structured interviews on barriers and facilitators of dietary education and adherence were conducted. Demographic and clinical data were obtained, along with quantitative measures of dietary adherence, including 24-h food recall and spot urine sodium. Combined deductive and inductive coding was used to identify qualitative themes, along with a quantitative assessment of interviews. Quantitative data was reported using descriptive statistics with frequencies, mean and confidence intervals. RESULTS: Participants were mostly male (16/21) with a mean age 57.8 years (SE 2.8) and MELD-Na 9 (SE 1.2). 4 themes emerged: 1. More than 50% of participants and caregivers endorsed no or inadequate diet education 2. They reported mostly negative experiences with dietary adherence with largest impact on social life 3. Facilitators of adherence included the presence of household support and fear of complications of cirrhosis 4. Overwhelmingly desired non-generic handouts and information. Dietary adherence was poor with only one participant meeting protein and sodium requirements based on food recall. Four participants who adhered to < 2000 mg sodium had inadequate daily caloric intake. CONCLUSIONS: Dietary education is inadequate, and adherence to dietary recommendations is poor in patients with cirrhosis. Future studies should use these barriers and facilitators for intervention development.

Blood Pressure Effects of Sodium Reduction: Dose-Response Meta-Analysis of Experimental Studies.

BACKGROUND: The relationship between dietary sodium intake and blood pressure (BP) has been tested in clinical trials and nonexperimental human studies, indicating a direct association. The exact shape of the dose-response relationship has been difficult to assess in clinical trials because of the lack of random-effects dose-response statistical models that can include 2-arm comparisons. METHODS: After performing a comprehensive literature search for experimental studies that investigated the BP effects of changes in dietary sodium intake, we conducted a dose-response meta-analysis using the new 1-stage cubic spline mixed-effects model. We included trials with at least 4 weeks of follow-up; 24-hour urinary sodium excretion measurements; sodium manipulation through dietary change or supplementation, or both; and measurements of systolic and diastolic BP at the beginning and end of treatment. RESULTS: We identified 85 eligible trials with sodium intake ranging from 0.4 to 7.6 g/d and follow-up from 4 weeks to 36 months. The trials were conducted in participants with hypertension (n=65), without hypertension (n=11), or a combination (n=9). Overall, the pooled data were compatible with an approximately linear relationship between achieved sodium intake and mean systolic as well as diastolic BP, with no indication of a flattening of the curve at either the lowest or highest levels of sodium exposure. Results were similar for participants with or without hypertension, but the former group showed a steeper decrease in BP after sodium reduction. Intervention duration (≥12 weeks versus 4 to 11 weeks), type of study design (parallel or crossover), use of antihypertensive medication, and participants' sex had little influence on the BP effects of sodium reduction. Additional analyses based on the BP effect of difference in sodium exposure between study arms at the end of the trial confirmed the results on the basis of achieved sodium intake. CONCLUSIONS: In this dose-response analysis of sodium reduction in clinical trials, we identified an approximately linear relationship between sodium intake and reduction in both systolic and diastolic BP across the entire range of dietary sodium exposure. Although this occurred independently of baseline BP, the effect of sodium reduction on level of BP was more pronounced in participants with a higher BP level.

Cleavage state of γENaC in mouse and rat kidneys.

Extracellular proteases can activate the epithelial Na channel (ENaC) by cleavage of the γ subunit. Here, we investigated the cleavage state of the channel in the kidneys of mice and rats on a low-salt diet. We identified the cleaved species of channels expressed in Fisher rat thyroid cells by coexpressing the apical membrane-bound protease channel-activating protease 1 (CAP1; prostasin). To compare the peptides produced in the heterologous system with those in the mouse kidney, we treated both lysates with PNGaseF to remove N-linked glycosylation. The apparent molecular mass of the smallest COOH-terminal fragment of γENaC (52 kDa) was indistinguishable from that of the CAP1-induced species in Fisher rat thyroid cells. Similar cleaved peptides were observed in total and cell surface fractions of the rat kidney. This outcome suggests that most of the subunits at the surface have been processed by extracellular proteases. This was confirmed using nonreducing gels, in which the NH2- and COOH-terminal fragments of γENaC are linked by a disulfide bond. Under these conditions, the major cleaved form in the rat kidney had an apparent molecular mass of 56 kDa, ∼4 kDa lower than that of the full-length form, consistent with excision of a short peptide by two proteolytic events. We conclude that the most abundant γENaC species in the apical membrane of rat and mouse kidneys on a low-Na diet is the twice-cleaved, presumably activated form.NEW & NOTEWORTHY We have identified the major aldosterone-dependent cleaved form of the epithelial Na channel (ENaC) γ subunit in the kidney as a twice-cleaved peptide. This form appears to be identical in size with a subunit cleaved in vitro by the extracellular protease channel-activating protease 1 (prostasin). In the absence of reducing agents, it has an overall molecular mass less than that of the intact subunit, consistent with the excision of an inhibitory domain.

A Randomized Trial of Distal Diuretics versus Dietary Sodium Restriction for Hypertension in Chronic Kidney Disease.

BACKGROUND: Distal diuretics are considered less effective than loop diuretics in CKD. However, data to support this perception are limited. METHODS: To investigate whether distal diuretics are noninferior to dietary sodium restriction in reducing BP in patients with CKD stage G3 or G4 and hypertension, we conducted a 6-week, randomized, open-label crossover trial comparing amiloride/hydrochlorothiazide (5 mg/50 mg daily) with dietary sodium restriction (60 mmol per day). Antihypertension medication was discontinued for a 2-week period before randomization. We analyzed effects on BP, kidney function, and fluid balance and related this to renal clearance of diuretics. RESULTS: A total of 26 patients (with a mean eGFR of 39 ml/min per 1.73 m2) completed both treatments. Dietary sodium restriction reduced sodium excretion from 160 to 64 mmol per day. Diuretics produced a greater reduction in 24-hour systolic BP (SBP; from 138 to 124 mm Hg) compared with sodium restriction (from 134 to 129 mm Hg), as well as a significantly greater effect on extracellular water, eGFR, plasma renin, and aldosterone. Both interventions resulted in a similar decrease in body weight and NT-proBNP. Neither approaches decreased albuminuria significantly, whereas diuretics did significantly reduce urinary angiotensinogen and ß2-microglobulin excretion. Although lower eGFR and higher plasma indoxyl sulfate correlated with lower diuretic clearance, the diuretic effects on body weight and BP at lower eGFR were maintained. During diuretic treatment, higher PGE2 excretion correlated with lower free water clearance, and four patients developed mild hyponatremia. CONCLUSIONS: Distal diuretics are noninferior to dietary sodium restriction in reducing BP and extracellular volume in CKD. Diuretic sensitivity in CKD is maintained despite lower diuretic clearance. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: DD-study: Diet or Diuretics for Salt-sensitivity in Chronic Kidney Disease (DD), NCT02875886.

Sodium Intake and Related Diseases.

Moderation in the use of salt (sodium chloride) in food and food preparations prevents the tendency of blood pressure to increase with age, and this is documented by many studies in current literature [...].

Effect of Mineral-Balanced Deep-Sea Water on Kidney Function and Renal Oxidative Stress Markers in Rats Fed a High-Salt Diet.

This study investigated the effect of mineral-balanced deep-sea water (DSW) on kidney health using an animal model of kidney injury due to a high-sodium diet. High magnesium/low sodium (HMLS) and high magnesium/high calcium (HMHC) DSW samples with different mineral contents were prepared. Sprague-Dawley rats were fed an 8% sodium chloride (NaCl) diet for four weeks to induce kidney injury, and each group was supplied with purified water or mineral water. Kidney injury was observed in the NaCl group according to increased kidney injury markers and malondialdehydes, providing evidence of oxidative stress. However, the kidney injury was repaired by the intake of mineral-balanced DSW. It was confirmed that the HMLS and HMHC groups showed improved Na+ excretion through the urine. Kidney injury markers in urine decreased and upregulation of low-density lipoprotein receptor-related protein2 mRNA expression was observed in the HMLS and HMHC groups. In addition, superoxide dismutase activity was increased in the HMHC groups. The gene expression patterns of the RNA sequencing were similar between the CON and HMLS groups. These results suggest that DSW has beneficial effects on kidney health due to the balanced magnesium and calcium levels in models of kidney injury caused by excessive sodium intake.

Sodium Reduction: How Big Might the Risks and Benefits Be?

Cardiovascular diseases are the leading cause of death worldwide and raised blood pressure is the leading risk for these conditions. Excess sodium intake clearly elevates blood pressure though the association of sodium intake with cardiovascular outcomes has been disputed. Nonetheless, it was estimated that in 2017 excess dietary sodium caused between 1.4 and 5.4 million deaths. Key underlying assumptions for those estimates were that the association between sodium intake and cardiovascular disease is direct and linear, and that a daily consumption level of 2.0 g of sodium minimised risk. Recent data indicating that reported U-shaped associations of sodium with risk are the result of confounding provide strong support for the first assumption. Cardiovascular risks may, however, continue to decline below intake levels of 2.0 g per day. Further, because excess sodium intake appears to drive a progressive rise in blood pressure with age, the magnitude of the disease burden avoidable by sodium reduction may have been under-estimated. Regardless, health benefits will only be achieved if safe, effective and scalable interventions can be defined and none have been identified to date. Salt substitution, which switches regular salt for a reduced-sodium, added-potassium alternative offers a significant opportunity. Falls in blood pressure with salt substitution are comparable to single-drug therapy and salt substitutes are low cost, simple to use, well-tolerated and could be applied community-wide. Data that prove clinical benefits and exclude risks will be required to support widespread use. An ongoing large-scale randomised trial of the effects of salt substitution on stroke, major cardiovascular events and death will complete soon and define the role of salt substitutes in public health.

Interim effects of salt substitution on urinary electrolytes and blood pressure in the China Salt Substitute and Stroke Study (SSaSS).

The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched salt substitute compared to usual salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of salt substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of salt substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.

Impact of salt substitute and stepwise reduction of salt supply on blood pressure in residents in senior residential facilities: Design and rationale of the DECIDE-Salt trial.

BACKGROUND: High sodium intake has been considered as the leading dietary risk factor for deaths and disability-adjusted life-years among older adults. High-quality randomized trials to evaluate the effects of practical sodium reduction strategies are needed. METHODS: The study is a cluster randomized trial with a 2 × 2 factorial design conducted in 48 senior residential facilities in northern China. These facilities are randomly assigned (1:1:1:1) to 1 of 4 groups: stepwise salt supply control (SSSC) in which 5%-10% of the study salt supply in the institutional kitchens will be reduced every 3 months, replacing normal salt with salt substitute (SS); SSSC only; SS only; or neither SSSC nor SS. The interventions last for 2 years with follow-up every 6 months. The primary outcome is the change in systolic blood pressure from baseline to 24 months. Secondary outcomes include the incidence of hyperkalemia, hyponatremia, cardiovascular events, and death. CURRENT STATUS: The study has recruited and randomized 48 senior residential facilities with 1,606 participants. Mean age at baseline was 71 years, and 76% are male. Both types of salt intervention were initiated in the study facilities between January and April 2018. CONCLUSION: The study is well placed to define the effects of 2 practical and scalable sodium reduction strategies for blood pressure reduction and will provide important new data about safety of these strategies among older adults in China.

A Self-management Approach for Dietary Sodium Restriction in Patients With CKD: A Randomized Controlled Trial.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD) are particularly sensitive to dietary sodium. We evaluated a self-management approach for dietary sodium restriction in patients with CKD. STUDY DESIGN: Randomized controlled trial. SETTING & PARTICIPANTS: Nephrology outpatient clinics in 4 Dutch hospitals. 99 adults with CKD stages 1 to 4 or a functioning (estimated glomerular filtration rate≥25mL/min/1.73m2) kidney transplant, hypertension, and sodium intake>130mmol/d. INTERVENTION: Routine care was compared with routine care plus a web-based self-management intervention including individual e-coaching and group meetings implemented over a 3-month intervention period, followed by e-coaching over a 6-month maintenance period. OUTCOMES: Primary outcomes were sodium excretion after the 3-month intervention and after the 6-month maintenance period. Secondary outcomes were blood pressure, proteinuria, costs, quality of life, self-management skills, and barriers and facilitators for implementation. RESULTS: Baseline estimated glomerular filtration rate was 55.0±22.0mL/min/1.73m2. During the intervention period, sodium excretion decreased in the intervention group from 188±8 (SE) to 148±8mmol/d (P<0.001), but did not change significantly in the control group. At 3 months, mean sodium excretion was 24.8 (95% CI, 0.1-49.6) mmol/d lower in the intervention group (P=0.049). At 3 months, systolic blood pressure (SBP) decreased in the intervention group from 140±3 to 132±3mm Hg (P<0.001), but was unchanged in the control group. Mean difference in SBP across groups was-4.7 (95% CI, -10.7 to 1.3) mm Hg (P=0.1). During the maintenance phase, sodium excretion increased in the intervention group, but remained lower than at baseline at 160±8mmol/d (P=0.01), while it decreased in the control group from 174±9 at the end of the intervention period to 154±9mmol/d (P=0.001). Consequently, no difference in sodium excretion between groups was observed after the maintenance phase. There was no difference in SBP between groups after the maintenance phase. LIMITATIONS: Limited power, postrandomization loss to follow-up, Hawthorne effect, lack of dietary data, short-term follow-up. CONCLUSIONS: A coaching intervention reduced sodium intake at 3 months. Efficacy during the maintenance phase was diminished, possibly due to inadvertent adoption of the intervention by the control group. FUNDING: Grant funding from the Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT02132013.

Salt restriction lowers blood pressure at rest and during exercise without altering peripheral hemodynamics in hypertensive individuals.

Dietary salt restriction is a well-established approach to lower blood pressure and reduce cardiovascular disease risk in hypertensive individuals. However, little is currently known regarding the effects of salt restriction on central and peripheral hemodynamic responses to exercise in those with hypertension. Therefore, this study sought to determine the impact of salt restriction on the central and peripheral hemodynamic responses to static-intermittent handgrip (HG) and dynamic single-leg knee extension (KE) exercise in individuals with hypertension. Twenty-two subjects (14 men and 8 women, 51 ± 10 yr, 173 ± 11 cm, 99 ± 23 kg) forewent their antihypertensive medication use for at least 2 wk before embarking on a 5-day liberal salt (LS: 200 mmol/day) diet followed by a 5-day restricted salt (RS: 10 mmol/day) diet. Subjects were studied at rest and during static intermittent HG exercise at 15, 30, and 45% of maximal voluntary contraction and KE exercise at 40, 60, and 80% of maximum KE work rate. Salt restriction lowered resting systolic blood pressure (supine: -12 ± 12 mmHg, seated: -17 ± 12 mmHg) and diastolic blood pressure (supine: -3 ± 9 mmHg, seated: -5 ± 7 mmHg, P < 0.05). Despite an ~8 mmHg lower mean arterial blood pressure during both HG and KE exercise following salt restriction, neither central nor peripheral hemodynamics were altered. Therefore, salt restriction can lower blood pressure during exercise in subjects with hypertension, reducing the risk of cardiovascular events, without impacting central and peripheral hemodynamics during either arm or leg exercise.NEW & NOTEWORTHY This is the first study to examine the potential blood pressure-lowering benefit of a salt-restrictive diet in individuals with hypertension without any deleterious effects of exercising blood flow. While mean arterial pressure decreased by ~8 mmHg following salt restriction, these findings provide evidence for salt restriction to provide protective effects of reducing blood pressure without inhibiting central or peripheral hemodynamics required to sustain arm or leg exercise in subjects with hypertension.

Effects of the DASH Diet and Sodium Intake on Bloating: Results From the DASH-Sodium Trial.

INTRODUCTION: Bloating is one of the most common gastrointestinal complaints. Evidence has linked fiber and sodium to bloating; however, randomized trials examining these diet components are lacking. Here, we used a randomized trial to examine the effects of the high-fiber DASH diet and dietary sodium intake on abdominal bloating. We hypothesized that both the high-fiber DASH diet and higher sodium intake would increase bloating. METHODS: The DASH-Sodium trial (1998-1999) randomized healthy adults to a high-fiber (32 g/d) DASH or low-fiber (11 g/d) Western diet (control). On their assigned diet, participants ate 3 sodium levels (50, 100, and 150 mmol/d at 2100 kcal) in 30-day periods in random order, with 5-day breaks between each period. The participants reported the presence of bloating at baseline and after each feeding period. Statistical analyses included log-binomial models to evaluate the risk of bloating. RESULTS: Of 412 participants (mean age 48 years; 57% women; 57% black), 36.7% reported bloating at baseline. Regardless of the diet, high sodium intake increased the risk of bloating (risk ratio = 1.27; 95% confidence interval: 1.06-1.52; P = 0.01). The high-fiber DASH diet also increased the risk of bloating over all sodium levels (risk ratio = 1.41; 95% confidence interval: 1.22-1.64; P < 0.001). The effect of high-fiber DASH on bloating was greater in men than in women (P for interaction = 0.001). DISCUSSION: Higher dietary sodium increased bloating, as did the high-fiber DASH diet. Although healthful high-fiber diets may increase bloating, these effects may be partially mitigated by decreasing dietary sodium intake. Future research is needed to explore mechanisms by which sodium intake and diet can influence bloating.

Long-Term Effects of Intensive Low-Salt Diet Education on Deterioration of Glomerular Filtration Rate among Non-Diabetic Hypertensive Patients with Chronic Kidney Disease.

BACKGROUND: Diet modification, especially a decrease in salt intake, might be an important non-pharmacological strategy to improve chronic kidney disease (CKD) prognosis. OBJECTIVES: We conducted a prospective cohort study to investigate whether an intensive low-salt diet education program effectively attenuated the rate of renal function decline in hypertensive patients with CKD. METHODS: This cohort study recruited 171 participants from a previous open-labelled, case-controlled, randomized clinical trial that originally consisted of 245 hypertensive CKD patients who were assigned to two groups, intensive low-salt diet or conventional education. We evaluated the renal outcomes, which included the rate of change in estimated glomerular filtration rate (eGFR) per year, the increase in serum creatinine ≥50%, the decrease in eGFR ≥30%, and the percent change in albuminuria throughout the entire study period. RESULTS: The baseline characteristics of the cohort participants between the two groups were similar at the time of trial phase randomization. During the whole study period, the rate of renal function decline was significantly faster in the conventional group (0.11 ± 4.63 vs. -1.53 ± 3.04 mL/min/1.73 m2/year, p = 0.01). The percent of incremental change in serum creatinine ≥50% was 1.1% in the intensive group and 8.2% in the conventional group (p = 0.025), and the percent of decremental change in eGFR ≥30% was 3.3% in the intensive group and 11.1% in the conventional group (p= 0.048). With logistic regression analysis adjusted for related factors, we found that the conventional group showed a higher risk for deterioration in serum creatinine and eGFR during the entire study period. Especially, we found that the intensive education program preserved eGFR in participants with one, several, or all of the following characteristics at the time of randomization: older age, female, obese, had higher protein intake, higher amounts of albuminuria, higher salt intake. CONCLUSION: This cohort study demonstrated that an intensive low-salt diet education program attenuated the rate of renal function decline in hypertensive CKD patients independent of its effect on lowering salt intake or albuminuria during the 36 months of follow-up.

Feasibility of Assessing Sodium-Associated Body Fluid Composition in End-Stage Renal Disease.

BACKGROUND: Cardiovascular disease accounts for more than half of all deaths in the hemodialysis (HD) population. Although much of this mortality is associated with fluid overload (FO), FO is difficult to measure, and many HD patients have significant pulmonary congestion despite the absence of clinical presentation. Cohort studies have observed that FO, as measured by bioimpedance spectroscopy (BIS), correlates with mortality. Other studies have observed that lower sodium intake is associated with less fluid-related weight gain, improved hypertension, and survival. Whether sodium intake influences FO in HD patients as measured by BIS is not known. OBJECTIVE: The aims of the study were to determine the feasibility of assessing the impact of sodium restriction on body fluid composition as measured by BIS among patients with three levels of sodium intake and to determine if there are statistical and/or clinical differences in BIS measures across sodium intake groups. METHODS: We used a double-blinded randomized controlled trial design with three levels of sodium restriction, 2,400 mg per day, 1,500 mg per day, and unrestricted (control group), to test our aims. Forty-two HD patients from a tertiary acute care academic institution associated with three urban DaVita dialysis centers were enrolled. Participants remained in the inpatient center for 5 days and 4 nights and were randomly assigned to sodium intake groups. Body fluid composition was measured with BIS. RESULTS: Recruitment, enrollment, and retention statistics supported the feasibility of the study design. Regression analyses showed that there were no statistically significant differences among sodium intake groups on any of the outcomes. DISCUSSION: Our data suggest the need for additional research into the effects of sodium restriction on body fluid composition.

Long-term low salt diet increases blood pressure by activation of the renin-angiotensin and sympathetic nervous systems.

Background The aim of this study was to investigate the effect of long-term low salt diet on blood pressure and its underlying mechanisms.Methods Male Sprague-Dawley (SD) rats were divided into normal salt diet group (0.4%) and low salt diet group (0.04%). Blood pressure was measured with the non-invasive tail-cuff method. The contractile response of isolated mesenteric arteries was measured using a small vessel myograph. The effects on renal function of the intrarenal arterial infusion of candesartan (10 µg/kg/min), an angiotensin II receptor type 1 (AT1R) antagonist, were also measured. The expressions of renal AT1R and mesenteric arterial α1A, α1B, and α1D adrenergic receptors were quantified by immunoblotting. Plasma levels of angiotensin II were also measured.Results Systolic blood pressure was significantly increased after 8 weeks of low salt diet. There were no obvious differences in the renal structure between the low and normal salt diet groups. However, the plasma angiotensin II levels and renal AT1R expression were higher in low than normal salt diet group. The intrarenal arterial infusion of candesartan increased urine flow and sodium excretion to a greater extent in the low than normal salt diet group. The expressions of α1A and α1D, but not α1B, adrenergic receptors, and phenylephrine-induced contraction were increased in mesenteric arteries from the low salt, relative to the normal salt diet group.Conclusion Activation of the renin-angiotensin and sympathetic nervous systems may be involved in the pathogenesis of long-term low salt diet-induced hypertension.

Therapeutic strategies in the treatment of Menière's disease: the Italian experience.

PURPOSE: Ménière's disease (MD) is an inner ear disorder of unknown etiology, whose pathological substrate is the endolymphatic hydrops. Different treatments have been proposed; however, evidence of their effectiveness is lacking. The aim of this study was to evaluate by a questionnaire which medical and surgical treatments are used in Italy for the treatment of MD and to compare them with those proposed in other countries. METHODS: An electronic questionnaire of 40 questions was formulated and sent to Italian otolaryngologist (ENT) divided into two groups: Group 1 ("generalists" 60.8%) and Group 2 ("neurotologist- NO" 39.2%). RESULTS: One hundred and twenty five ENT replied. Treatment of the acute phase, apart from symptomatics, was based on diuretics that are prescribed by 83.5% of respondents, steroids, prescribed by 66.7%, and vasodilators, prescribed by 22%. In the intercritical phase, 87.2% of respondents recommended low-salt diet, 78.4% of respondents prescribed betahistine, and 52.8% diuretics. Statistical analysis did not show correlation neither with the declared specialization nor with the number of patients treated. In case of failure of medical treatment, IT gentamicin was suggested by 48.8% of the respondents and IT steroids by 40.8%. Statistical analysis showed that generalists prefer IT steroids and NO IT gentamicin (p 0.019). In case of failure of both medical treatment and IT treatment, vestibular neurectomy was indicated by 58.4% of the respondents, 6.4% indicated endolymphatic sac surgery, and 2.4% surgical labyrinthectomy. CONCLUSION: In Italy, the treatment of MD stand on a gradual approach that starts from the dietary-behavioral changes and a pharmacological therapy based on betahistine. In refractory cases, IT treatment initially with steroids and, therefore, with gentamicin allows the control in vertigo in the majority of cases. In case of failure of IT treatment, VNS is the surgery of choice.

Rationale and design of the Study of Dietary Intervention Under 100 MMOL in Heart Failure (SODIUM-HF).

BACKGROUND: Patients with heart failure (HF) remain at high risk for future events despite medical and device therapy. Dietary sodium reduction is often recommended based on limited evidence. However, it is not known whether dietary sodium reduction reduces the morbidity or mortality associated with HF. METHODS: The SODIUM study is a pragmatic, randomized, open-label trial assessing the efficacy of dietary sodium reduction to <1500 mg daily counseling compared to usual care for patients with chronic HF. The intervention is provided by trained personnel at the site and uses 3-day food records for directing counseling. The primary outcome is an intention-to-treat analysis on the time to first cardiovascular event or death measured at 12 months. Secondary end points include the change in quality of life (using the Kansas City Cardiomyopathy Questionnaire), change in New York Heart Association class, and change in 6-minute walk test. The first patient was enrolled in March 2014, and subsequently, 27 sites in 6 countries enrolled patients. CONCLUSIONS: The SODIUM-HF trial will provide a robust evaluation of the effects of dietary sodium reduction in patients with HF. Results are expected in 2020.