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International Journal of Molecular... Dec 2020Sodium is an essential mineral and nutrient used in dietary practices across the world and is important to maintain proper blood volume and blood pressure. A high sodium... (Review)
Review
Sodium is an essential mineral and nutrient used in dietary practices across the world and is important to maintain proper blood volume and blood pressure. A high sodium diet is associated with increased expression of β-myosin heavy chain, decreased expression of α/β-myosin heavy chain, increased myocyte enhancer factor 2/nuclear factor of activated T cell transcriptional activity, and increased salt-inducible kinase 1 expression, which leads to alteration in myocardial mechanical performance. A high sodium diet is also associated with alterations in various proteins responsible for calcium homeostasis and myocardial contractility. Excessive sodium intake is associated with the development of a variety of comorbidities including hypertension, chronic kidney disease, stroke, and cardiovascular diseases. While the American College of Cardiology/American Heart Association/Heart Failure Society of America guidelines recommend limiting sodium intake to both prevent and manage heart failure, the evidence behind such recommendations is unclear. Our review article highlights evidence and underlying mechanisms favoring and contradicting limiting sodium intake in heart failure.
Topics: Cardiovascular Diseases; Diet, Sodium-Restricted; Evidence-Based Medicine; Heart Failure; Humans; Hypertension; Nutrition Policy; Sodium; Sodium Chloride, Dietary; United States
PubMed: 33322108
DOI: 10.3390/ijms21249474 -
Proceedings of the Japan Academy.... 2022Extracellular fluids, including blood, lymphatic fluid, and cerebrospinal fluid, are collectively called body fluids. The Na concentration ([Na]) in body fluids is... (Review)
Review
Extracellular fluids, including blood, lymphatic fluid, and cerebrospinal fluid, are collectively called body fluids. The Na concentration ([Na]) in body fluids is maintained at 135-145 mM and is broadly conserved among terrestrial animals. Homeostatic osmoregulation by Na is vital for life because severe hyper- or hypotonicity elicits irreversible organ damage and lethal neurological trauma. To achieve "body fluid homeostasis" or "Na homeostasis", the brain continuously monitors [Na] in body fluids and controls water/salt intake and water/salt excretion by the kidneys. These physiological functions are primarily regulated based on information on [Na] and relevant circulating hormones, such as angiotensin II, aldosterone, and vasopressin. In this review, we discuss sensing mechanisms for [Na] and hormones in the brain that control water/salt intake behaviors, together with the responsible sensors (receptors) and relevant neural pathways. We also describe mechanisms in the brain by which [Na] increases in body fluids activate the sympathetic neural activity leading to hypertension.
Topics: Animals; Body Fluids; Homeostasis; Hormones; Sodium; Sodium Chloride, Dietary; Water
PubMed: 35908954
DOI: 10.2183/pjab.98.016 -
Nutrients Sep 2020Dietary sodium intake has received considerable attention as a potential risk factor of cardiovascular disease. However, evidence on the dose-response association... (Meta-Analysis)
Meta-Analysis
Dietary sodium intake has received considerable attention as a potential risk factor of cardiovascular disease. However, evidence on the dose-response association between dietary sodium intake and cardiovascular disease risk is unclear. Embase and PubMed were searched from their inception to 17 August 2020 and studies that examined the association between sodium intake and cardiovascular disease in adolescents were not included in this review. We conducted a meta-analysis to estimate the effect of high sodium intake using a random effects model. The Newcastle-Ottawa Scale assessment was performed. A random-effects dose-response model was used to estimate the linear and nonlinear dose-response relationships. Subgroup analyses and meta-regression were conducted to explain the observed heterogeneity. We identified 36 reports, which included a total of 616,905 participants, and 20 of these reports were also used for a dose-response meta-analysis. Compared with individuals with low sodium intake, individuals with high sodium intake had a higher adjusted risk of cardiovascular disease (Rate ratio: 1.19, 95% confidence intervals = 1.08-1.30). Our findings suggest that there is a significant linear relationship between dietary sodium intake and cardiovascular disease risk. The risk of cardiovascular disease increased up to 6% for every 1 g increase in dietary sodium intake. A low-sodium diet should be encouraged and education regarding reduced sodium intake should be provided.
Topics: Adolescent; Cardiovascular Diseases; Databases, Factual; Diet, Sodium-Restricted; Humans; Risk Factors; Sodium; Sodium, Dietary
PubMed: 32992705
DOI: 10.3390/nu12102934 -
Kidney International Apr 2014Current teaching states that when sodium intake is increased from low to high levels, total-body sodium (TBNa) and water increase until daily sodium excretion again... (Review)
Review
Current teaching states that when sodium intake is increased from low to high levels, total-body sodium (TBNa) and water increase until daily sodium excretion again equals intake. When sodium intake is reduced, sodium excretion briefly exceeds intake until the excess TBNa and water are eliminated, at which point sodium excretion again equals intake. However, careful balance studies oftentimes conflict with this view and long-term studies suggest that TBNa fluctuates independent of intake or body weight. We recently performed the opposite experiment in that we fixed sodium intake for several weeks at three levels of sodium intake and collected all urine made. We found weekly (circaseptan) patterns in sodium excretion that were inversely related to aldosterone and directly to cortisol. TBNa was not dependent on sodium intake but instead exhibited far longer (≥ monthly) infradian rhythms independent of extracellular water, body weight, or blood pressure. The findings are consistent with our ideas on tissue sodium storage and its regulation that we developed on the basis of animal research. We are implementing (23)Na-magnetic resonance imaging (MRI) to pursue open questions on sodium balance in patients. Our findings could be relevant to therapeutic strategies for hypertension and target-organ damage.
Topics: Animals; Humans; Sodium; Water-Electrolyte Balance
PubMed: 24107854
DOI: 10.1038/ki.2013.367 -
Function (Oxford, England) 2024
Topics: Humans; Sodium; Animals
PubMed: 38711930
DOI: 10.1093/function/zqae018 -
Structure (London, England : 1993) May 2013At synapses, sodium-coupled transporters remove released neurotransmitters, thereby recycling them and maintaining a low extracellular concentration of the... (Review)
Review
At synapses, sodium-coupled transporters remove released neurotransmitters, thereby recycling them and maintaining a low extracellular concentration of the neurotransmitter. The molecular mechanism underlying sodium-coupled neurotransmitter uptake is not completely understood. Several structures of homologs of human neurotransmitter transporters have been solved with X-ray crystallography. These crystal structures have spurred a plethora of computational and experimental work to elucidate the molecular mechanism underlying sodium-coupled transport. Here, we compare the structures of GltPh, a glutamate transporter homolog, and LeuT, a homolog of neurotransmitter transporters for the biogenic amines and inhibitory molecules GABA and glycine. We relate these structures to data obtained from experiments and computational simulations, to draw conclusions about the mechanism of uptake by sodium-coupled neurotransmitter transporters. Here, we propose how sodium and substrate binding is coupled and how binding of sodium and substrate opens and closes the gates in these transporters, thereby leading to an efficient coupled transport.
Topics: Animals; Binding Sites; Crystallography, X-Ray; Humans; Models, Biological; Models, Molecular; Neurotransmitter Transport Proteins; Sodium; Structure-Activity Relationship
PubMed: 23664361
DOI: 10.1016/j.str.2013.03.002 -
NMR in Biomedicine Feb 2016Multiple sclerosis (MS) is the most common cause of non-traumatic disability in young adults. The mechanisms underlying neurodegeneration and disease progression are... (Review)
Review
Multiple sclerosis (MS) is the most common cause of non-traumatic disability in young adults. The mechanisms underlying neurodegeneration and disease progression are poorly understood, in part as a result of the lack of non-invasive methods to measure and monitor neurodegeneration in vivo. Sodium MRI is a topic of increasing interest in MS research as it allows the metabolic characterization of brain tissue in vivo, and integration with the structural information provided by (1)H MRI, helping in the exploration of pathogenetic mechanisms and possibly offering insights into disease progression and monitoring of treatment outcomes. We present an up-to-date review of the sodium MRI application in MS organized into four main sections: (i) biological and pathogenetic role of sodium; (ii) brief overview of sodium imaging techniques; (iii) results of sodium MRI application in clinical studies; and (iv) future perspectives.
Topics: Brain Mapping; Humans; Magnetic Resonance Imaging; Multiple Sclerosis; Sodium; Sodium Isotopes
PubMed: 25851455
DOI: 10.1002/nbm.3289 -
Journal of Veterinary Diagnostic... Mar 2021Fatal sodium intoxication can occur in many species, including cattle, and postmortem confirmation often includes brain sodium concentration determination. Published...
Fatal sodium intoxication can occur in many species, including cattle, and postmortem confirmation often includes brain sodium concentration determination. Published information regarding brain sodium distribution in cattle was not found in a literature review. Our study was designed to determine whether sodium is uniformly distributed throughout the bovine brain. Eight whole bovine brains were collected from adult cattle with no neurologic signs or history suggestive of sodium intoxication, and with a non-neurologic cause of death diagnosed on gross examination. Brains were divided mid-sagittally. One hemisphere of each brain was homogenized. Subsamples were obtained from the remaining hemisphere (rostral, caudal, and dorsal cerebral cortices; brainstem, thalamus, and cerebellum). Sodium concentrations of regions and homogenates were measured by inductively coupled plasma-mass spectrometry. Data were analyzed using repeated measures ANOVA with a pairwise post-test to compare mean sodium concentration of each region to mean homogenate sodium concentration. Brain sodium was not uniformly distributed; sodium concentrations in different regions of the same brain varied somewhat unpredictably. Homogenization of an entire brain hemisphere appears to be the ideal method of sample preparation to ensure accurate brain sodium concentration measurement in adult cattle.
Topics: Animals; Brain; Cattle; Cattle Diseases; Sodium
PubMed: 33357005
DOI: 10.1177/1040638720982989 -
Seminars in Dialysis Mar 2014Oligo-anuric patients with end-stage kidney disease are dependent on hemodialysis to achieve and maintain the desired goal of euvolemia. The dialysis prescription, in... (Review)
Review
Oligo-anuric patients with end-stage kidney disease are dependent on hemodialysis to achieve and maintain the desired goal of euvolemia. The dialysis prescription, in addition to sodium and fluid restriction, is therefore a critically important factor in the care of hemodialysis patients. Various dialysate sodium concentrations have been favored throughout the history of dialysis, but the "optimal" concentration remains unclear. In this manuscript, we examine the historical context of changes to the dialysate sodium prescription, review the evidence of its associated effects, discuss 'individualization' of dialysate sodium, and highlight the need for definitive trials that are powered for important clinical outcomes.
Topics: Algorithms; Dialysis Solutions; Humans; Renal Dialysis; Sodium
PubMed: 24450281
DOI: 10.1111/sdi.12182 -
Blood Purification 2018Hypertension affects almost all chronic kidney disease patients and is related to poor outcomes. Sodium intake is closely related to blood pressure (BP) levels in this... (Review)
Review
BACKGROUND
Hypertension affects almost all chronic kidney disease patients and is related to poor outcomes. Sodium intake is closely related to blood pressure (BP) levels in this population and decreasing its intake consistently improves the BP control particularly in short-term controlled trials. However, most patients struggle in following a controlled diet on sodium according to the guidelines recommendation due to several factors and barriers discussed in this article.
SUMMARY
This review article summarizes the current knowledge related to the associations between sodium consumption, BP, and the risk of cardiovascular disease and chronic kidney disease (CKD); it also provides recommendations of how to achieve sodium intake lowering. Key Messages: Evidences support the benefits in decreasing sodium intake on markers of cardiovascular and renal outcomes in CKD. Trials had shorter follow-up and to maintain long-term sodium intake control is a major challenge. Larger studies with longer follow-up looking at hard endpoints will be important to drive future recommendations.
Topics: Blood Pressure; Humans; Hypertension; Renal Insufficiency, Chronic; Sodium
PubMed: 29478050
DOI: 10.1159/000485154