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Afsar B, Afsar RE. The role of glycosaminoglycans in blood pressure regulation. Microcirculation 2023; 30:e12832. [PMID: 37794746 DOI: 10.1111/micc.12832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/06/2023] [Accepted: 09/23/2023] [Indexed: 10/06/2023]
Abstract
Essential hypertension (HT) is the global health problem and is a major risk factor for the development of cardiovascular and kidney disease. High salt intake has been associated with HT and impaired kidney sodium excretion is considered to be a major mechanism for the development of HT. Although kidney has a very important role in regulation of BP, this traditional view of BP regulation was challenged by recent findings suggesting that nonosmotic tissue sodium deposition is very important for BP regulation. This new paradigm indicates that sodium can be stored and deposited nonosmotically in the interstitium without water retention and without increased BP. One of the major determinants of this deposition is glycosaminoglycans (GAGs). By binding to GAGs found in the endothelial surface layer (ESL) which contains glycocalyx, sodium is osmotically inactivated and not induce concurrent water retention. Thus, GAGs has important function for homeostatic BP and sodium regulation. In the current review, we summarized the role of GAGs in ESL and BP regulation.
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Affiliation(s)
- Baris Afsar
- School of Medicine, Department of Nephrology, Suleyman Demirel University, Isparta, Turkey
| | - Rengin Elsurer Afsar
- School of Medicine, Department of Nephrology, Suleyman Demirel University, Isparta, Turkey
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2
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Oppelaar JJ, Vuurboom MD, Wenstedt EFE, van Ittersum FJ, Vogt L, Olde Engberink RHG. Reconsidering the Edelman equation: impact of plasma sodium concentration, edema and body weight. Eur J Intern Med 2022; 100:94-101. [PMID: 35393237 DOI: 10.1016/j.ejim.2022.03.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND Guidelines recommend treatment of dysnatremias to be guided by formulas based on the Edelman equation. This equation describes the relation between plasma sodium concentration and exchangeable cations. However, this formula does not take into account clinical parameters that have recently been associated with local tissue sodium accumulation, which occurs without concurrent water retention. We investigated to what extent such clinical factors affect the Edelman equation and dysnatremia treatment. METHODS We performed a post-hoc analysis with original data of the Edelman study. Linear regression was used to examine the effect of age, sex, weight, edema, total body water (TBW) and heart and kidney failure on the Edelman equation. With attenuated correction, we corrected for measurement errors of both variables. Using piecewise regression, we analyzed whether the Edelman association differs for different plasma sodium concentrations. RESULTS Data was available for 82 patients; 57 males and 25 females with a mean (SD) age of 57 (15) years. The slope of the Edelman equation was significantly affected by weight (p=0.01) and edema (p=0.03). Also, below and above plasma sodium levels of 133 mmol/L the slope of the Edelman equation was significantly different (1.25 x0025vs 0.58x0025, p<0.01). CONCLUSION Edelman's equation's coefficients are significantly affected by weight, edema and plasma sodium, possibly reflecting differences in tissue sodium accumulation capacity. The performance of Edelman-based formulas in clinical settings may be improved by taking these clinical characteristics into account.
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Affiliation(s)
- Jetta J Oppelaar
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands
| | - Mart D Vuurboom
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands
| | - Eliane F E Wenstedt
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands
| | - Frans J van Ittersum
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Internal Medicine, Section of Nephrology, Boelelaan 1117, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, The Netherlands
| | - L Vogt
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands
| | - Rik H G Olde Engberink
- Amsterdam UMC location University of Amsterdam, Department of Internal Medicine, Section of Nephrology, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, The Netherlands.
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Effect of sodium administration on fluid balance and sodium balance in health and the perioperative setting. Extended summary with additional insights from the MIHMoSA and TOPMAST studies. J Crit Care 2021; 67:157-165. [PMID: 34798374 DOI: 10.1016/j.jcrc.2021.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE We aimed to provide an extended analysis of the physiological handling of of the sodium burden induced by maintenance fluids. MATERIALS AND METHODS We revisited two studies that demonstrated, in healthy volunteers and in surgical patients, that maintenance fluids with 154 mmol/L of sodium lead to a more positive fluid balance than a regimen containing 54 mmol/L. We report different unpublished data on the renal handling of the imposed sodium burdens with specific attention to the resulting fluid and sodium balances. RESULTS The kidneys adapt to the sodium-rich fluids not only by altering sodium excretion, but also by retaining extra free water by concentrating urine. Realigning urinary sodium excretion with an increased administration takes around one day in health and much longer in the clinical setting. This difference may be explained by the presence of hypovolemia-induced aldosterone secretion in the latter group. Non-osmotic storage of sodium limits an unrestrained fluid retention even when very high amounts of sodium are administered but fluid accumulation will inevitably be further prolonged. CONCLUSIONS Sodium administration induced by sodium-rich maintenance fluids leads, especially in the clinical setting, to prolonged fluid retention when compared with a regimen that resembles a healthy dietary sodium intake, even when kidney function is normal.
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4
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Luft FC. Did you know? Fluid-and-electrolyte replacement and the uncertainty principle. Acta Physiol (Oxf) 2020; 230:e13511. [PMID: 32445605 DOI: 10.1111/apha.13511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 05/17/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Friedrich C. Luft
- Experimental and Clinical Research Center Max‐Delbrück Center and Charité Medical Faculty Berlin Germany
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5
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Le bilan du sodium : nouveaux aspects. NUTR CLIN METAB 2020. [DOI: 10.1016/j.nupar.2020.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Carranza-León DA, Oeser A, Marton A, Wang P, Gore JC, Titze J, Stein CM, Chung CP, Ormseth MJ. Tissue sodium content in patients with systemic lupus erythematosus: association with disease activity and markers of inflammation. Lupus 2020; 29:455-462. [PMID: 32070186 DOI: 10.1177/0961203320908934] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Sodium (Na+) is stored in the skin and muscle and plays an important role in immune regulation. In animal models, increased tissue Na+ is associated with activation of the immune system, and high salt intake exacerbates autoimmune disease and worsens hypertension. However, there is no information about tissue Na+ and human autoimmune disease. We hypothesized that muscle and skin Na+ content is (a) higher in patients with systemic lupus erythematosus (SLE) than in control subjects, and (b) associated with blood pressure, disease activity, and inflammation markers (interleukin (IL)-6, IL-10 and IL-17 A) in SLE. METHODS Lower-leg skin and muscle Na+ content was measured in 23 patients with SLE and in 28 control subjects using 23Na+ magnetic resonance imaging. Demographic and clinical information was collected from interviews and chart review, and blood pressure was measured. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Plasma inflammation markers were measured by multiplex immunoassay. RESULTS Muscle Na+ content was higher in patients with SLE (18.8 (16.7-18.3) mmol/L) than in control subjects (15.8 (14.7-18.3) mmol/L; p < 0.001). Skin Na+ content was also higher in SLE patients than in controls, but this difference was not statistically significant. Among patients with SLE, muscle Na+ was associated with SLEDAI and higher concentrations of IL-10 after adjusting for age, race, and sex. Skin Na+ was significantly associated with systolic blood pressure, but this was attenuated after covariate adjustment. CONCLUSION Patients with SLE had higher muscle Na+ content than control subjects. In patients with SLE, higher muscle Na+ content was associated with higher disease activity and IL-10 concentrations.
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Affiliation(s)
| | - A Oeser
- Department of Medicine, Vanderbilt University Medical Center, USA
| | - A Marton
- Department of Medicine, Duke-NUS Medical School, Singapore
| | - P Wang
- Department of Radiology, Vanderbilt University Medical Center, USA
| | - J C Gore
- Department of Radiology, Vanderbilt University Medical Center, USA
| | - J Titze
- Department of Medicine, Duke-NUS Medical School, Singapore
| | - C M Stein
- Department of Medicine, Vanderbilt University Medical Center, USA.,Department of Pharmacology, Vanderbilt University Medical Center, USA
| | - C P Chung
- Department of Medicine, Vanderbilt University Medical Center, USA.,Tennessee Valley Healthcare System, US Department of Veterans Affairs, USA
| | - M J Ormseth
- Department of Medicine, Vanderbilt University Medical Center, USA.,Tennessee Valley Healthcare System, US Department of Veterans Affairs, USA
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7
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Canaud B, Kooman J, Selby NM, Taal M, Francis S, Kopperschmidt P, Maierhofer A, Kotanko P, Titze J. Sodium and water handling during hemodialysis: new pathophysiologic insights and management approaches for improving outcomes in end-stage kidney disease. Kidney Int 2020; 95:296-309. [PMID: 30665570 DOI: 10.1016/j.kint.2018.09.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/22/2018] [Accepted: 09/24/2018] [Indexed: 02/07/2023]
Abstract
Space medicine and new technology such as magnetic resonance imaging of tissue sodium stores (23NaMRI) have changed our understanding of human sodium homeostasis and pathophysiology. It has become evident that body sodium comprises 3 main components. Two compartments have been traditionally recognized, namely one that is circulating and systemically active via its osmotic action, and one slowly exchangeable pool located in the bones. The third, recently described pool represents sodium stored in skin and muscle interstitium, and it is implicated in cell and biologic activities via local hypertonicity and sodium clearance mechanisms. This in-depth review provides a comprehensive view on the pathophysiology and existing knowledge gaps of systemic hemodynamic and tissue sodium accumulation in dialysis patients. Furthermore, we discuss how the combination of novel technologies to quantitate tissue salt accumulation (e.g., 23NaMRI) with devices to facilitate the precise attainment of a prescribed hemodialytic sodium mass balance (e.g., sodium and water balancing modules) will improve our therapeutic approach to sodium management in dialysis patients. While prospective studies are required, we think that these new diagnostic and sodium balancing tools will enhance our ability to pursue more personalized therapeutic interventions on sodium and water management, with the eventual goal of improving dialysis patient outcomes.
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Affiliation(s)
- Bernard Canaud
- Centre for Medical Excellence, Fresenius Medical Care Deutschland, Bad Homburg, Germany; Montpellier University, Montpellier, France.
| | - Jeroen Kooman
- Maastricht Universitair Medisch Centrum - Maastricht, Netherlands
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Derby, UK
| | - Maarten Taal
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Derby, UK
| | - Susan Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, UK
| | | | | | - Peter Kotanko
- Renal Research Institute, New York, New York, USA; Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jens Titze
- Division of Cardiovascular and Metabolic Disease, Duke-NUS, Singapore; Division of Nephrology, Duke University Medical Center, Durham, North Carolina, USA; Division of Nephrology and Hypertension, University Clinic Erlangen, Germany
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8
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Olde Engberink RHG, Selvarajah V, Vogt L. Clinical impact of tissue sodium storage. Pediatr Nephrol 2020; 35:1373-1380. [PMID: 31363839 PMCID: PMC7316850 DOI: 10.1007/s00467-019-04305-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 03/18/2019] [Accepted: 04/18/2019] [Indexed: 12/20/2022]
Abstract
In recent times, the traditional nephrocentric, two-compartment model of body sodium has been challenged by long-term sodium balance studies and experimental work on the dermal interstitium and endothelial surface layer. In the new paradigm, sodium can be stored without commensurate water retention in the interstitium and endothelial surface layer, forming a dynamic third compartment for sodium. This has important implications for sodium homeostasis, osmoregulation and the hemodynamic response to salt intake. Sodium storage in the skin and endothelial surface layer may function as a buffer during periods of dietary depletion and excess, representing an extra-renal mechanism regulating body sodium and water. Interstitial sodium storage may also serve as a biomarker for sodium sensitivity and cardiovascular risk, as well as a target for hypertension treatment. Furthermore, sodium storage may explain the limitations of traditional techniques used to quantify sodium intake and determine infusion strategies for dysnatraemias. This review is aimed at outlining these new insights into sodium homeostasis, exploring their implications for clinical practice and potential areas for further research for paediatric and adult populations.
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Affiliation(s)
- Rik H. G. Olde Engberink
- grid.7177.60000000084992262Location AMC, Department of Internal Medicine, Section Nephrology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Viknesh Selvarajah
- grid.5335.00000000121885934Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, UK
| | - Liffert Vogt
- grid.7177.60000000084992262Location AMC, Department of Internal Medicine, Section Nephrology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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9
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Christa M, Weng AM, Geier B, Wörmann C, Scheffler A, Lehmann L, Oberberger J, Kraus BJ, Hahner S, Störk S, Klink T, Bauer WR, Hammer F, Köstler H. Increased myocardial sodium signal intensity in Conn's syndrome detected by 23Na magnetic resonance imaging. Eur Heart J Cardiovasc Imaging 2019; 20:263-270. [PMID: 30307545 PMCID: PMC6383057 DOI: 10.1093/ehjci/jey134] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/11/2018] [Accepted: 08/29/2018] [Indexed: 11/12/2022] Open
Abstract
AIMS Sodium intake has been linked to left ventricular hypertrophy independently of blood pressure, but the underlying mechanisms remain unclear. Primary hyperaldosteronism (PHA), a condition characterized by tissue sodium overload due to aldosterone excess, causes accelerated left ventricular hypertrophy compared to blood pressure matched patients with essential hypertension. We therefore hypothesized that the myocardium constitutes a novel site capable of sodium storage explaining the missing link between sodium and left ventricular hypertrophy. METHODS AND RESULTS Using 23Na magnetic resonance imaging, we investigated relative sodium signal intensities (rSSI) in the heart, calf muscle, and skin in 8 PHA patients (6 male, median age 55 years) and 12 normotensive healthy controls (HC) (8 male, median age 61 years). PHA patients had a higher mean systolic 24 h ambulatory blood pressure [152 (140; 163) vs. 125 (122; 130) mmHg, P < 0.001] and higher left ventricular mass index [71.0 (63.5; 106.8) vs. 55.0 (50.3; 66.8) g/m2, P = 0.037] than HC. Compared to HC, PHA patients exhibited significantly higher rSSI in the myocardium [0.31 (0.26; 0.34) vs. 0.24 (0.20; 0.27); P = 0.007], calf muscle [0.19 (0.16; 0.22) vs. 0.14 (0.13; 0.15); P = 0.001] and skin [0.28 (0.25; 0.33) vs. 0.19 (0.17; 0.26); P = 0.014], reflecting a difference of +27%, +38%, and +39%, respectively. Treatment of PHA resulted in significant reductions of the rSSI in the myocardium, calf muscle and skin by -13%, -27%, and -29%, respectively. CONCLUSION Myocardial tissue rSSI is increased in PHA patients and treatment of aldosterone excess effectively reduces rSSI, thus establishing the myocardium as a novel site of sodium storage in addition to skeletal muscle and skin.
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Affiliation(s)
- Martin Christa
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Andreas M Weng
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Bettina Geier
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Caroline Wörmann
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Anne Scheffler
- Institute of Pharmacy and Food Chemistry, Chair of Food Chemistry, University of Würzburg, Würzburg, Germany
| | - Leane Lehmann
- Institute of Pharmacy and Food Chemistry, Chair of Food Chemistry, University of Würzburg, Würzburg, Germany
| | - Johannes Oberberger
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Bettina J Kraus
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Stefanie Hahner
- Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Stefan Störk
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Thorsten Klink
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Wolfgang R Bauer
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Fabian Hammer
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Internal Medicine, University Greifswald, Greifswald, Germany
| | - Herbert Köstler
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.,Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
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Hammon M, Grossmann S, Linz P, Seuss H, Hammon R, Rosenhauer D, Janka R, Cavallaro A, Luft FC, Titze J, Uder M, Dahlmann A. 3 Tesla 23Na Magnetic Resonance Imaging During Acute Kidney Injury. Acad Radiol 2017; 24:1086-1093. [PMID: 28495210 DOI: 10.1016/j.acra.2017.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 10/19/2022]
Abstract
RATIONALE AND OBJECTIVES Sodium and proton magnetic resonance imaging (23Na/1H-MRI) have shown that muscle and skin can store Na+ without water. In chronic renal failure and in heart failure, Na+ mobilization occurs, but is variable depending on age, dialysis vintage, and other features. Na+ storage depots have not been studied in patients with acute kidney injury (AKI). MATERIALS AND METHODS We studied 7 patients with AKI (mean age: 51.7 years; range: 25-84) and 14 age-matched and gender-matched healthy controls. All underwent 23Na/1H-MRI at the calf. Patients were studied before and after acute hemodialysis therapy within 5-6 days. The 23Na-MRI produced grayscale images containing Na+ phantoms, which served to quantify Na+ contents. A fat-suppressed inversion recovery sequence was used to quantify H2O content. RESULTS Plasma Na+ levels did not change. Mean Na+ contents in muscle and skin did not significantly change following four to five cycles of hemodialysis treatment (before therapy: 32.7 ± 6.9 and 44.2 ± 13.5 mmol/L, respectively; after dialysis: 31.7 ± 10.2 and 42.8 ± 11.8 mmol/L, respectively; P > .05). Water content measurements did not differ significantly before and after hemodialysis in muscle and skin (P > .05). Na+ contents in calf muscle and skin of patients before hemodialysis were significantly higher than in healthy subjects (16.6 ± 2.1 and 17.9 ± 3.2) and remained significantly elevated after hemodialysis. CONCLUSIONS Na+ in muscle and skin accumulates in patients with AKI and, in contrast to patients receiving chronic hemodialysis and those with acute heart failure, is not mobilized with hemodialysis within 5-6 days.
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11
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The Authors Reply. Kidney Int 2017; 92:514-515. [DOI: 10.1016/j.kint.2017.04.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 04/06/2017] [Indexed: 11/22/2022]
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12
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Rakova N, Kitada K, Lerchl K, Dahlmann A, Birukov A, Daub S, Kopp C, Pedchenko T, Zhang Y, Beck L, Johannes B, Marton A, Müller DN, Rauh M, Luft FC, Titze J. Increased salt consumption induces body water conservation and decreases fluid intake. J Clin Invest 2017; 127:1932-1943. [PMID: 28414302 DOI: 10.1172/jci88530] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 02/17/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions. METHODS Over the course of 2 separate space flight simulation studies of 105 and 205 days' duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance. RESULTS A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion. CONCLUSION Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion. FUNDING Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO, Coppenrath und Wiese, ENERVIT, HIPP, Katadyn, Kellogg, Molda, and Unilever.
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13
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Olde Engberink RH, Rorije NM, van den Born BJH, Vogt L. Quantification of nonosmotic sodium storage capacity following acute hypertonic saline infusion in healthy individuals. Kidney Int 2017; 91:738-745. [DOI: 10.1016/j.kint.2016.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 11/17/2016] [Accepted: 12/01/2016] [Indexed: 10/20/2022]
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Quantitative assessment of muscle injury by (23)Na magnetic resonance imaging. SPRINGERPLUS 2016; 5:661. [PMID: 27347460 PMCID: PMC4899351 DOI: 10.1186/s40064-016-2193-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/20/2016] [Indexed: 11/23/2022]
Abstract
Background 23Na magnetic resonance imaging (23Na-MRI) is able to measure Na+ in vivo in humans and allows quantification of tissue sodium distribution. We now tested the utility of 23Na-MRI technique in detecting and assessing sports-related acute muscular injury. Case presentation We assessed tissue Na+ of both lower legs with a 3T MRI scanner using a customized 23Na knee coil. The affected left calf muscle in an injured volleyball player showed a hyperintense Na+ signal. Follow-up measurements revealed persistently increased muscle Na+ content despite complete clinical recovery. Conclusions Our findings suggest that 23Na-MRI could have utility in detecting subtle muscular injury and might indicate when complete healing has occurred. Furthermore, 23Na-MRI suggests the presence of substantial injury-related muscle electrolyte shifts that warrant more detailed investigation.
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15
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Titze J, Rakova N, Kopp C, Dahlmann A, Jantsch J, Luft FC. Balancing wobbles in the body sodium. Nephrol Dial Transplant 2015; 31:1078-81. [PMID: 26410883 DOI: 10.1093/ndt/gfv343] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 11/13/2022] Open
Abstract
Sodium balance is achieved within a matter of days and everything that enters should come out; sodium stores are of questionable relevance and sodium accumulation is accompanied by weight gain. Careful balance studies oftentimes conflicted with this view, and long-term studies suggested that total body sodium (TBNa) fluctuates independent of intake or body weight. We recently performed the opposite experiment in that we fixed sodium intake for 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 related to cortisol. TBNa was not dependent on sodium intake, but instead exhibited far longer (greater than or equal to monthly) infradian rhythms independent of extracellular water, body weight or blood pressure. To discern the mechanisms further, we delved into sodium magnetic resonance imaging (Na-MRI) to identify sodium storage clinically. We found that sodium stores are greater in men than in women, increase with age and are higher in hypertensive than normotensive persons. We have suggestive evidence that these sodium stores can be mobilized, also in dialysis patients. The observations are in accordance with our findings that immune cells regulate a hypertonic interface in the skin interstitium that could serve as a protective barrier. Returning to our balance studies, we found that due to biological variability in 24-h sodium excretion, collecting urine for a day could not separate 12, 9 or 6 g/day sodium intakes with the precision of tossing a coin. Every other daily urine sampling correctly classified a 3-g difference in salt intake less than half the time, making the gold standard 24-h urine collection of little value in predicting salt intake. We suggest that wobbles in expected outcomes can lead to novel clinical insights even with respect to banal salt questions.
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Affiliation(s)
- Jens Titze
- Interdisciplinary Center for Clinical Research and Department for Nephrology and Hypertension, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Natalia Rakova
- Interdisciplinary Center for Clinical Research and Department for Nephrology and Hypertension, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany Experimental and Clinical Research Center, an institutional cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Christoph Kopp
- Interdisciplinary Center for Clinical Research and Department for Nephrology and Hypertension, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany
| | - Anke Dahlmann
- Interdisciplinary Center for Clinical Research and Department for Nephrology and Hypertension, Nikolaus-Fiebiger Center for Molecular Medicine, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, Universitätsklinikum Regensburg and Universität Regensburg, Regensburg, Germany
| | - Friedrich C Luft
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA Experimental and Clinical Research Center, an institutional cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
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Dahlmann A, Dörfelt K, Eicher F, Linz P, Kopp C, Mössinger I, Horn S, Büschges-Seraphin B, Wabel P, Hammon M, Cavallaro A, Eckardt KU, Kotanko P, Levin NW, Johannes B, Uder M, Luft FC, Müller DN, Titze JM. Magnetic resonance-determined sodium removal from tissue stores in hemodialysis patients. Kidney Int 2015; 87:434-41. [PMID: 25100048 PMCID: PMC4932096 DOI: 10.1038/ki.2014.269] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 01/31/2023]
Abstract
We have previously reported that sodium is stored in skin and muscle. The amounts stored in hemodialysis (HD) patients are unknown. We determined whether (23)Na magnetic resonance imaging (sodium-MRI) allows assessment of tissue sodium and its removal in 24 HD patients and 27 age-matched healthy controls. We also studied 20 HD patients before and shortly after HD with a batch dialysis system with direct measurement of sodium in dialysate and ultrafiltrate. Age was associated with higher tissue sodium content in controls. This increase was paralleled by an age-dependent decrease of circulating levels of vascular endothelial growth factor-C (VEGF-C). Older (>60 years) HD patients showed increased sodium and water in skin and muscle and lower VEGF-C levels compared with age-matched controls. After HD, patients with low VEGF-C levels had significantly higher skin sodium content compared with patients with high VEGF-C levels (low VEGF-C: 2.3 ng/ml and skin sodium: 24.3 mmol/l; high VEGF-C: 4.1 ng/ml and skin sodium: 18.2 mmol/l). Thus, sodium-MRI quantitatively detects sodium stored in skin and muscle in humans and allows studying sodium storage reduction in ESRD patients. Age and VEGF-C-related local tissue-specific clearance mechanisms may determine the efficacy of tissue sodium removal with HD. Prospective trials on the relationship between tissue sodium content and hard end points could provide new insights into sodium homeostasis, and clarify whether increased sodium storage is a cardiovascular risk factor.
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Affiliation(s)
- Anke Dahlmann
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Kathrin Dörfelt
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Florian Eicher
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Peter Linz
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Christoph Kopp
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Irina Mössinger
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stephan Horn
- Kuratorium für Heimdialyse und Nierentransplantation e.V., Erlangen, Germany
| | | | - Peter Wabel
- Fresenius Medical Care, Bad Homburg, Germany
| | - Matthias Hammon
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Alexander Cavallaro
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Kai-Uwe Eckardt
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Bernd Johannes
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Michael Uder
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Friedrich C Luft
- 1] Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine (MDC), Berlin, Germany [2] Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Dominik N Müller
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Jens M Titze
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Jantsch J, Binger KJ, Müller DN, Titze J. Macrophages in homeostatic immune function. Front Physiol 2014; 5:146. [PMID: 24847274 PMCID: PMC4017126 DOI: 10.3389/fphys.2014.00146] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/27/2014] [Indexed: 01/20/2023] Open
Abstract
Macrophages are not only involved in inflammatory and anti-infective processes, but also play an important role in maintaining tissue homeostasis. In this review, we summarize recent evidence investigating the role of macrophages in controlling angiogenesis, metabolism as well as salt and water balance. Particularly, we summarize the importance of macrophage tonicity enhancer binding protein (TonEBP, also termed nuclear factor of activated T-cells 5 [NFAT5]) expression in the regulation of salt and water homeostasis. Further understanding of homeostatic macrophage function may lead to new therapeutic approaches to treat ischemia, hypertension and metabolic disorders.
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Affiliation(s)
- Jonathan Jantsch
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen, Germany
| | - Katrina J Binger
- Experimental and Clinical Research Center (ECRC), Max-Delbrück Center for Molecular Medicine, Charité Medical Faculty Berlin, Germany
| | - Dominik N Müller
- Experimental and Clinical Research Center (ECRC), Max-Delbrück Center for Molecular Medicine, Charité Medical Faculty Berlin, Germany
| | - Jens Titze
- Interdisciplinary Center for Clinical Research and Department of Nephrology and Hypertension, Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen, Germany ; Divison of Clinical Pharmacology, Vanderbilt University School of Medicine Nashville, TN, USA
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Titze J, Dahlmann A, Lerchl K, Kopp C, Rakova N, Schröder A, Luft FC. Spooky sodium balance. Kidney Int 2014; 85:759-67. [DOI: 10.1038/ki.2013.367] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 11/09/2022]
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Abstract
PURPOSE OF REVIEW The equilibration theory of extracellular body fluids is tightly linked to sodium (Na) metabolism. It is accepted that with changes in salt intake, renal sodium elimination will prevent any change in interstitial Na content and concentration. This review summarizes recent anomalous findings regarding salt and water homeostasis that are inconsistent with current assumptions. RECENT FINDINGS Recent findings from chemical analysis studies of laboratory animals, as well as noninvasive quantitative Na MRI (Na-MRI) studies in patients, have shown that remarkable amounts of Na are stored in muscle and in skin without commensurate water retention. Furthermore, an ultra-long Na balance study in humans suggests the presence of endogenous clocks that generate weekly and monthly infradian rhythmicity of Na storage independent of salt intake. Animal experiments suggest that fluids in the skin interstitium are hypertonic compared with plasma, and that interstitial osmotic stress induces local extrarenal immune cell and lymph-capillary driven mechanisms for electrolyte clearance and maintenance of the internal environment. SUMMARY Recent quantitative evidence challenges current ideas on salt and water homeostasis, and suggests that Na homeostasis cannot be maintained without additional previously unappreciated extrarenal regulatory mechanisms.
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Affiliation(s)
- Jens Titze
- Interdisciplinary Center for Clinical Research and Department of Nephrology and Hypertension, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Wiig H, Schröder A, Neuhofer W, Jantsch J, Kopp C, Karlsen TV, Boschmann M, Goss J, Bry M, Rakova N, Dahlmann A, Brenner S, Tenstad O, Nurmi H, Mervaala E, Wagner H, Beck FX, Müller DN, Kerjaschki D, Luft FC, Harrison DG, Alitalo K, Titze J. Immune cells control skin lymphatic electrolyte homeostasis and blood pressure. J Clin Invest 2013; 123:2803-15. [PMID: 23722907 DOI: 10.1172/jci60113] [Citation(s) in RCA: 294] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 04/05/2013] [Indexed: 11/17/2022] Open
Abstract
The skin interstitium sequesters excess Na+ and Cl- in salt-sensitive hypertension. Mononuclear phagocyte system (MPS) cells are recruited to the skin, sense the hypertonic electrolyte accumulation in skin, and activate the tonicity-responsive enhancer-binding protein (TONEBP, also known as NFAT5) to initiate expression and secretion of VEGFC, which enhances electrolyte clearance via cutaneous lymph vessels and increases eNOS expression in blood vessels. It is unclear whether this local MPS response to osmotic stress is important to systemic blood pressure control. Herein, we show that deletion of TonEBP in mouse MPS cells prevents the VEGFC response to a high-salt diet (HSD) and increases blood pressure. Additionally, an antibody that blocks the lymph-endothelial VEGFC receptor, VEGFR3, selectively inhibited MPS-driven increases in cutaneous lymphatic capillary density, led to skin Cl- accumulation, and induced salt-sensitive hypertension. Mice overexpressing soluble VEGFR3 in epidermal keratinocytes exhibited hypoplastic cutaneous lymph capillaries and increased Na+, Cl-, and water retention in skin and salt-sensitive hypertension. Further, we found that HSD elevated skin osmolality above plasma levels. These results suggest that the skin contains a hypertonic interstitial fluid compartment in which MPS cells exert homeostatic and blood pressure-regulatory control by local organization of interstitial electrolyte clearance via TONEBP and VEGFC/VEGFR3-mediated modification of cutaneous lymphatic capillary function.
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Affiliation(s)
- Helge Wiig
- Department of Biomedicine, University of Bergen, Bergen, Norway
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Kopp C, Linz P, Dahlmann A, Hammon M, Jantsch J, Müller DN, Schmieder RE, Cavallaro A, Eckardt KU, Uder M, Luft FC, Titze J. 23Na magnetic resonance imaging-determined tissue sodium in healthy subjects and hypertensive patients. Hypertension 2013; 61:635-40. [PMID: 23339169 DOI: 10.1161/hypertensionaha.111.00566] [Citation(s) in RCA: 287] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High dietary salt intake is associated with hypertension; the prevalence of salt-sensitive hypertension increases with age. We hypothesized that tissue Na(+) might accumulate in hypertensive patients and that aging might be accompanied by Na(+) deposition in tissue. We implemented (23)Na magnetic resonance imaging to measure Na(+) content of soft tissues in vivo earlier, but had not studied essential hypertension. We report on a cohort of 56 healthy control men and women, and 57 men and women with essential hypertension. The ages ranged from 22 to 90 years. (23)Na magnetic resonance imaging measurements were made at the level of the calf. We observed age-dependent increases in Na(+) content in muscle in men, whereas muscle Na(+) content did not change with age in women. We estimated water content with conventional MRI and found no age-related increases in muscle water in men, despite remarkable Na(+) accumulation, indicating water-free Na(+) storage in muscle. With increasing age, there was Na(+) deposition in the skin in both women and men; however, skin Na(+) content remained lower in women. Similarly, this sex difference was found in skin water content, which was lower in women than in men. In contrast to muscle, increasing Na(+) content was paralleled with increasing skin water content. When controlled for age, we found that patients with refractory hypertension had increased tissue Na(+) content, compared with normotensive controls. These observations suggest that (23)Na magnetic resonance imaging could have utility in assessing the role of tissue Na(+) storage for cardiovascular morbidity and mortality in longitudinal studies.
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Affiliation(s)
- Christoph Kopp
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, TN 37232, USA
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