1. Sodium butyrate ameliorates deoxycorticosterone acetate/salt-induced hypertension and renal damage by inhibiting the MR/SGK1 pathway
Yuting Liu,Cailin Huang,Mokan Deng,Qing Zhu,Zhida Chen,Linlin Zhang,Yeyan Zhu,Chunying Wu,Lei Wang Hypertens Res . 2021 Feb;44(2):168-178. doi: 10.1038/s41440-020-00548-3.
Our recent work demonstrates that infusion of sodium butyrate (NaBu) into the renal medulla blunts angiotensin II-induced hypertension and improves renal injury. The present study aimed to test whether oral administration of NaBu attenuates salt-sensitive hypertension in deoxycorticosterone acetate (DOCA)/salt-treated rats. Uninephrectomized male Sprague-Dawley (SD) rats were treated with DOCA pellets (150 mg/rat) plus 1% NaCl drinking water for 2 weeks. Animals received oral administration of NaBu (1 g/kg) or vehicle once per day. Our results showed that NaBu administration significantly attenuated DOCA/salt-increased mean arterial pressure from 156 ± 4 mmHg to 136 ± 1 mmHg. DOCA/salt treatment markedly enhanced renal damage as indicated by an increased ratio of kidney weight/body weight, elevated urinary albumin, extensive fibrosis, and inflammation, whereas kidneys from NaBu-treated rats exhibited a significant reduction in these renal damage responses. Compared to the DOCA/salt group, the DOCA/salt-NaBu group had ~30% less salt water intake and decreased Na+and Cl-excretion in urine but no alteration in 24-h urine excretion. Mechanistically, NaBu inhibited the protein levels of several sodium transporters stimulated by DOCA/salt in vivo, such as βENaC, γENaC, NCC, and NKCC-2. Further examination showed that NaBu downregulated the expression of mineralocorticoid receptor (MR) and serum and glucocorticoid-dependent protein kinase 1 (SGK1) in DOCA/salt-treated rats or aldosterone-treated human renal tubular duct epithelial cells. These results provide evidence that NaBu may attenuate DOCA/salt-induced hypertension and renal damage by inhibiting the MR/SGK1 pathway.
2. High sodium food consumption pattern among Malaysian population
Graham MacGregor,Ruhaya Salleh,Fatimah Othman,Wan Nur Khairunnisa Wan Kozil,Mohamad Hasnan Ahmad,Noor Safiza Mohammad Noor,Cheong Siew Man,Tahir Aris,Feng J He J Health Popul Nutr . 2021 May 31;40(Suppl 1):4. doi: 10.1186/s41043-021-00230-5.
Background:Sodium is an essential mineral needed by the human body that must be obtained from food. An excess intake, however, can lead to many diseases. As food is the main source of sodium, this study aims to provide information on high sodium food consumption patterns in the Malaysian adult population.Methods:The Malaysian Community Salt Study (MyCoSS) was a nationwide cross-sectional study, conducted between October 2017 and March 2018. A multistage complex sample was applied to select a nationally representative sample of respondents aged 18 years and above. Face to face interview by a validated Food Frequency Questionnaire (FFQ) comprising 104 food items was used to gain information on high sodium food consumption patterns.Results:A total of 1047 respondents were involved in this study, with 1032 (98.6%) answering the FFQ. From the number, 54.1% exceed the recommendation of sodium intake <2000mg/day by FFQ assessment. The results also demonstrated that fried vegetables (86.4%) were the most common high sodium food consumed, followed by bread (85.9%) and omelet (80.3%). In urban areas, bread was the most common while fried vegetables took the lead in rural areas. By sex, bread was most commonly eaten by males and fried vegetables by females. The results also found that kolok mee/kampua mee contributed the highest sodium, 256.5mg/day in 9.0% adult population, followed by soy sauce 248.1mg/day in 33.2% adult population, and curry noodles 164.2mg/day in 18.5% adult population.Conclusion:Fried vegetables, bread, and soy sauce were the main source of sodium consumption among adult. Reducing the amount of sodium added to these foods should be the top priority to reduce population sodium intake and thereby prevent sodium-related diseases in Malaysia.
3. Availability, Formulation, Labeling, and Price of Low-sodium Salt Worldwide: Environmental Scan
Xuejun Yin,Maoyi Tian,Laura K Cobb,Sallie-Anne Pearson,Matti Marklund,Kathy Trieu,Jason H Y Wu,Bruce Neal,Mark D Huffman,J Jaime Miranda,Ka Chun Li,Hueiming Liu,Jacqui Webster JMIR Public Health Surveill . 2021 Jul 14;7(7):e27423. doi: 10.2196/27423.
Background:Regular salt is about 100% sodium chloride. Low-sodium salts have reduced sodium chloride content, most commonly through substitution with potassium chloride. Low-sodium salts have a potential role in reducing the population's sodium intake levels and blood pressure, but their availability in the global market is unknown.Objective:The aim of this study is to assess the availability, formulation, labeling, and price of low-sodium salts currently available to consumers worldwide.Methods:Low-sodium salts were identified through a systematic literature review, Google search, online shopping site searches, and inquiry of key informants. The keywords "salt substitute," "low-sodium salt," "potassium salt," "mineral salt," and "sodium reduced salt" in six official languages of the United Nations were used for the search. Information about the brand, formula, labeling, and price was extracted and analyzed.Results:A total of 87 low-sodium salts were available in 47 out of 195 (24%) countries worldwide, including 28 high-income countries, 13 upper-middle-income countries, and 6 lower-middle-income countries. The proportion of sodium chloride varied from 0% (sodium-free) to 88% (as percent of weight; regular salt is 100% sodium chloride). Potassium chloride was the most frequent component with levels ranging from 0% to 100% (potassium chloride salt). A total of 43 (49%) low-sodium salts had labels with the potential health risks, and 33 (38%) had labels with the potential health benefits. The median price of low-sodium salts in high-income, upper-middle-income, and lower-middle-income countries was US $15.00/kg (IQR 6.4-22.5), US $2.70/kg (IQR 1.7-5.5), and US $2.90/kg (IQR 0.50-22.2), respectively. The price of low-sodium salts was between 1.1 and 14.6 times that of regular salts.Conclusions:Low-sodium salts are not widely available and are commonly more expensive than regular salts. Policies that promote the availability, affordability, and labeling of low-sodium salts should increase uptake, helping populations reduce blood pressure and prevent cardiovascular diseases.International registered report identifier (irrid):RR2-10.1111/jch.14054.
4. Dietary Sodium 'Controversy'-Issues and Potential Solutions
G A MacGregor,F P Cappuccio,F J He,N R C Campbell Curr Nutr Rep . 2021 Sep;10(3):188-199. doi: 10.1007/s13668-021-00357-1.
Purpose of review:High dietary sodium is estimated to be the leading dietary risk for death attributed to 1.8 million deaths in 2019. There are uniform recommendations to reduce sodium consumption based on evidence that increased dietary sodium is responsible for approximately a third of the prevalence of hypertension, and meta-analyses of randomized controlled trials show that sodium reduction lowers blood pressure, cardiovascular disease, and total mortality. Nevertheless, there is a perception that the beneficial effect of reducing dietary sodium is controversial. We provide experiential evidence relating to some sources of the controversy and propose potential solutions.Recent findings:Inappropriate research methodology, lack of rigor in research, conflicts of interest and commercial bias, questions of professional conduct, and lack of policies to protect public interests are likely to contribute to the controversy about reducing dietary sodium. There is a failure to protect policies to reduce dietary sodium from nonscientific threats. Significant efforts need to be made to ensure the integrity of nutritional research and maintain public trust.
5. Practical Method for Salt Intake Follow-Up in Hypertensive Patients
Şahbender Koç,Sadettin Selçuk Baysal Metab Syndr Relat Disord . 2020 Oct;18(8):353-361. doi: 10.1089/met.2020.0036.
Background:Obese and hypertensive (HT) patients should restrict salt intake. In excessive salt intake, ouabain-like compounds inhibit Na/K-ATPase (Na+pump), which increases intracellular Na+and Ca2+. Ca2+has a vasotonic effect on arteries and an inotropic effect on the heart and may cause cortical opacities in the lens. To our knowledge, there is still no practical method for salt intake follow-up. This study tested whether salt intake follow-up can be performed with the help of opacity tracking.Methods:In total, 400 HT patients (age 30-69 years) with cortical lens opacities were included in the study. Changes in opacities based on biomicroscopic examination at baseline and after 3 months were recorded digitally with the help of imaging software. Salt intake at 1 and 3 months was evaluated with a 24-hr urine Na assay. Changes in opacities were compared among group 1 (~50% salt reduction), group 2 (~10% salt reduction), and group 3 (~15% salt increase).Results:Age and changes in small opacity diameter (SOD) and large opacity diameter (LOD) were the most important determinants of the 50% salt reduction in the third month. For changes in LOD, the sensitivity was 88.5% [confidence interval (95% CI) 85.2-91.7] and specificity was 95.5% (95% CI 93.1-98.7) for predicting a 50% salt restriction during the 3-month period. For SOD, the values were 85% (95% CI 82.5-87) and 95% (95% CI 92.3-97.5), respectively.Conclusions:Opacity changes are a practical method for predicting a 50% reduction in salt intake over a 3-month period in 30- to 59-year-old HT patients.
6. From salt to hypertension, what is missed?
Zhiyi Ma,Ningling Sun,Yuanyuan Chen,Scott L Hummel J Clin Hypertens (Greenwich) . 2021 Dec;23(12):2033-2041. doi: 10.1111/jch.14402.
Excess salt intake is viewed as a major contributor to hypertension and cardiovascular disease, and dietary salt restriction is broadly recommended by public health guidelines. However, individuals can have widely varying physiological responses to salt intake, and a tailored approach to evaluation and intervention may be needed. The traditional sodium related concepts are challenging to assess clinically for two reasons: (1) spot and 24-hour urine sodium are frequently used to evaluate salt intake, but are more suitable for population study, and (2) some adverse effects of salt may be blood pressure-independent. In recent years, previously unknown mechanisms of sodium absorption and storage have been discovered. This review will outline the limitations of current methods to assess sodium balance and discuss new potential evaluation methods and treatment targets.
7. Sodium Intake and Related Diseases 2.0
Alessandra Durazzo,Massimo Lucarini,Antonello Santini,Ginevra Lombardi-Boccia Int J Mol Sci . 2021 Dec 24;23(1):170. doi: 10.3390/ijms23010170.
Many statements have been reported in literature from various sources warning of the possible risk to health connected to high salt (as sodium chloride) intake in the everyday diet, and it is increasingly pressing [...].
8. Salt and cardiovascular disease: insufficient evidence to recommend low sodium intake
Lynn L Moore,David McCarron,Karen Sliwa,Jan A Staessen,Rajeev Gupta,Martin O'Donnell,Giuseppe Mancia,Rafael Diaz,Thomas F Lüscher,Jagat Narula,Suzanne Oparil,Clyde Yancy,Franz H Messerli,Milton Packer,Patricio López-Jaramillo,Friedrich C Luft,Martin McKee,Johannes F E Mann,Michael H Alderman,Andrew Mente,Alta Schutte,Salim Yusuf,Adrian J B Brady,Dorairaj Prabhakaran Eur Heart J . 2020 Sep 14;41(35):3363-3373. doi: 10.1093/eurheartj/ehaa586.
Several blood pressure guidelines recommend low sodium intake (5 g/day, while awaiting the results of large randomized controlled trials of sodium reduction on incidence of cardiovascular events and mortality.
9. Effect of dose and duration of reduction in dietary sodium on blood pressure levels: systematic review and meta-analysis of randomised trials
Graham A MacGregor,Qiang Li,Sohei Yoshimura,Alexander A Leung,Liping Huang,Norm R C Campbell,Cheryl A M Anderson,Kathy Trieu,Bruce Neal,Mark Woodward,Daniel T Lackland,Feng J He BMJ . 2020 Feb 24;368:m315. doi: 10.1136/bmj.m315.
Objective:To examine the dose-response relation between reduction in dietary sodium and blood pressure change and to explore the impact of intervention duration.Design:Systematic review and meta-analysis following PRISMA guidelines.Data sources:Ovid MEDLINE(R), EMBASE, and Cochrane Central Register of Controlled Trials (Wiley) and reference lists of relevant articles up to 21 January 2019.Inclusion criteria:Randomised trials comparing different levels of sodium intake undertaken among adult populations with estimates of intake made using 24 hour urinary sodium excretion.Data extraction and analysis:Two of three reviewers screened the records independently for eligibility. One reviewer extracted all data and the other two reviewed the data for accuracy. Reviewers performed random effects meta-analyses, subgroup analyses, and meta-regression.Results:133 studies with 12 197 participants were included. The mean reductions (reduced sodiumvusual sodium) of 24 hour urinary sodium, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 130 mmol (95% confidence interval 115 to 145, P<0.001), 4.26 mm Hg (3.62 to 4.89, P<0.001), and 2.07 mm Hg (1.67 to 2.48, P<0.001), respectively. Each 50 mmol reduction in 24 hour sodium excretion was associated with a 1.10 mm Hg (0.66 to 1.54; P<0.001) reduction in SBP and a 0.33 mm Hg (0.04 to 0.63; P=0.03) reduction in DBP. Reductions in blood pressure were observed in diverse population subsets examined, including hypertensive and non-hypertensive individuals. For the same reduction in 24 hour urinary sodium there was greater SBP reduction in older people, non-white populations, and those with higher baseline SBP levels. In trials of less than 15 days' duration, each 50 mmol reduction in 24 hour urinary sodium excretion was associated with a 1.05 mm Hg (0.40 to 1.70; P=0.002) SBP fall, less than half the effect observed in studies of longer duration (2.13 mm Hg; 0.85 to 3.40; P=0.002). Otherwise, there was no association between trial duration and SBP reduction.Conclusions:The magnitude of blood pressure lowering achieved with sodium reduction showed a dose-response relation and was greater for older populations, non-white populations, and those with higher blood pressure. Short term studies underestimate the effect of sodium reduction on blood pressure.Systematic review registration:PROSPERO CRD42019140812.
10. Sodium Intake and Heart Failure
Yash Patel,Jacob Joseph Int J Mol Sci . 2020 Dec 13;21(24):9474. doi: 10.3390/ijms21249474.
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.