High sodium intake adversely affects oxidative-inflammatory response, cardiac remodelling and mortality after myocardial infarction

Potential role of inflammation in relation to dietary sodium and β-carotene with non-alcoholic fatty liver disease: a mediation analysis

Background

High sodium intake has been linked to the prevalence of non-alcoholic fatty liver disease (NAFLD), but underlying mechanism remains unclear. This study aims to explore the role of chronic inflammation in the association between sodium and NAFLD. We also observed whether β-carotene, which had a strong anti-inflammatory effect, lowers the odds of NAFLD.

Methods

We performed mediation analyses to assess the mediating effects of C-reactive protein (CRP) and red cell distribution width (RDW) on the relationship between dietary sodium and NAFLD defined by the hepatic steatosis index (HSI) and the fatty liver index (FLI), respectively.

Results

A total of 6725 participants were included in this study. Compared with the high sodium-low carotene group, participants in the high sodium-high carotene group had 16% and 26% lower odds for HSI and FLI-defined NAFLD, respectively. There were positive indirect effects of dietary sodium intake on the HSI-defined NAFLD (indirect effect: 0.0057, 95% CI: 0.0021–0.0091, P < 0.0001), as well as the FLI defined NAFLD (indirect effect: 0.0081, 95% CI: 0.0024–0.0162, P < 0.0001) when C-reactive protein (CRP) was considered as a mediator. The mediating effects were somewhat attenuated after further adjusting for dietary β-carotene intake. Similar results were found when RDW was considered as a mediator in the HSI-defined NAFLD analysis.

Conclusions

Higher sodium intake increases the odds of NAFLD by upregulating inflammation. Dietary β-carotene may attenuate this association by down regulating inflammation.

High-salt intake reduces renal tissue levels of inflammatory cytokines in mice

High salt (HS) intake is usually considered as an aggravating factor to induce inflammatory renal injury. However, the changes in the renal levels of inflammatory cytokines during HS intake is not yet clearly defined. We hypothesize that HS increases renal levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) but decreases interleukin-10 (IL-10; anti-inflammatory cytokine) and these responses exacerbate in NO deficient conditions. Both wild-type (WT) and endothelial NO synthase knockout (eNOSKO) mice (~8 weeks old, n = 6 in each group) were given normal-salt (NS; 0.3% NaCl) and HS (4% NaCl) containing diets for 2 weeks. Systolic blood pressure (SBP) was determined by tail-cuff plethysmography and urine collections were made using metabolic cages. Basal SBP was higher in eNOSKO than WT mice (131 ± 7 vs 117 ± 3 mmHg; p < .05). HS intake for 2 weeks increased SBP in eNOSKO (161 ± 5 mmHg) but not in WT mice. In NS groups, the cytokine levels in renal tissues (measured using ELISA kits and expressed in pg/mg protein) were significantly higher in eNOSKO than WT mice (TNF-α, 624 ± 67 vs. 325 ± 73; IL-6, 619 ± 106 vs. 166 ± 61; IL-10, 6,087 ± 567 vs. 3,929 ± 378). Interestingly, these cytokine levels in HS groups were significantly less both in WT (TNF-α, 114 ± 17; IL-6, 81 ± 14; IL-10, 865 ± 130) and eNOSKO (TNF-α, 115 ± 18; IL-6, 56 ± 7; IL-10, 882 ± 141) mice. These findings indicate that HS induces downregulation of cytokines in the kidney. Such HS-induced reduction in cytokines, particularly TNF-α (a natriuretic agent), would facilitate more salt-retention, and thus, leading to salt-sensitive hypertension in NO deficient conditions.

Short-Term High-NaCl Dietary Intake Changes Leukocyte Expression of VLA-4, LFA-1, and Mac-1 Integrins in Both Healthy Humans and Sprague-Dawley Rats: A Comparative Study

This study is aimed at assessing the effects of a short-term high-salt (HS) diet on the peripheral blood leukocyte (PBL) activation status in healthy rats and young human individuals. Distribution of PBL subpopulations and surface expression of integrins were determined using flow cytometry in 36 men and women on a 7-day low-salt diet (<3.2 g salt/day) immediately followed by a 7-day HS diet (~14 g salt/day) or in Sprague-Dawley (SD) rats (n = 24) on a 0.4% NaCl diet (aLS group) or a 4% NaCl diet (aHS group) for 7 days. The aHS group presented with an increased frequency of granulocytes, while the frequency of lymphocytes was reduced. Although in humans HS diet reduced the expression of CD11b(act) integrin on lymphocytes, the frequency of CD11b(act)-bearing cells among all PBL subsets was increased. The aHS group of rats exhibited increased expression of total CD11b/c in granulocytes and CD3 lymphocytes. The expression of CD11a was significantly reduced in all PBL subsets from human subjects and increased in the aHS group. CD49d expression on all PBL subsets was significantly decreased in both humans and rats. In human subjects, we found reduced frequencies of intermediate monocytes accompanied by a reciprocal increase in classical monocytes. Present results suggest that a short-term HS diet can alter leukocytes' activation status and promote vascular low-grade inflammation.

Dose-response association of dietary sodium intake with all-cause and cardiovascular mortality: a systematic review and meta-analysis of prospective studies

OBJECTIVE

High Na intake has been associated with different health problems. However, serious controversies exist over studies investigating associations of Na intake with mortality from all-causes and CVD. The present systematic review and meta-analysis was done to investigate, for the first time, the dose-response association of dietary Na intake with all-cause and CVD mortality among prospective studies.

DESIGN

Relevant papers published up to August 2017 were searched in MEDLINE, EMBASE and Google Scholar databases. Prospective cohort studies on the association of dietary Na intake with all-cause or/and CVD mortality were included. Linear and non-linear dose-response associations between Na intake and CVD and all-cause mortality were examined.

RESULTS

Overall, twenty publications met inclusion criteria. A significant non-linear association (P&lt;0·001) was found between Na intake and CVD mortality risk among studies assessing urinary Na excretion, with a relatively steep slope at Na intakes above 2400mg/d. However, the association was not significant in studies using dietary Na intake (P=0·61). Additionally, the non-linear association of Na intake with all-cause mortality was also non-significant. No linear association (effect size; 95 % CI; I 2) was seen between 100mg/d increment in Na intake and CVD mortality (1·01; 0·97, 1·05; 98·4 %) or all-cause mortality (1·01; 1·00, 1·02; 89·2 %). Following subgroup analyses, the association between Na intake and CVD mortality was observed only among studies conducted in the USA (0·99; 0·99, 1·00; 20·0 %).

CONCLUSIONS

The study showed a direct association between urinary Na excretion and CVD mortality which was more considerable at intakes above 2400mg/d. In contrast, no significant association was found between Na intake and all-cause mortality. Further long-term prospective studies on different populations are required to confirm these findings.

A Nexus model of cellular transition in cancer

The exact cause of cancer is one of the most immutable medical questions of the century. Cancer as an evolutionary disease must have a purpose and understanding the purpose is more important than decoding the cause. The model of cancer proposed herein, provides a link between the cellular biochemistry and cellular genetics of cancer evolution. We thus call this model as the “Nexus model” of cancer. The Nexus model is an effort to identify the most apparent route to the disease. We have tried to utilize existing cancer literature to identify the most plausible causes of cellular transition in cancer, where the primary cancer-causing agents (physical, chemical or biological) act as inducing factors to produce cellular impeders. These cellular impeders are further linked to the Nexus. The Nexus then generates codes for epigenetics and genetics in cancer development.

Urinary potassium is a potential biomarker of disease activity in Ulcerative colitis and displays in vitro immunotolerant role

We evaluated the in-vitro effect of potassium on CD4⁺ T cells and the role of urinary potassium as a potential biomarker of disease activity in patients with ulcerative colitis (UC). This prospective observational cohort study included healthy controls (n = 18) and UC patients [n = 30, median age: 40 (IQR: 28–46) years, 17 males)] with active disease(assessed by Mayo score) from September 2015–May 2016. Twenty-four hours urinary potassium along with fecal calprotectin (FCP) were estimated in UC patients (at baseline and follow-up after 3–6 months) and controls. In healthy volunteers, we also assessed the effect of potassium on CD4⁺ T cells differentiated in the presence of Th17 polarizing condition. UC patients had significantly higher FCP (368.2 ± 443.04 vs 12.44 ± 27.51, p < 0.001) and significantly lower urinary potassium (26.6 ± 16.9 vs 46.89 ± 35.91, p = 0.01) levels than controls. At follow-up, a significant increase in urinary potassium among patients who had clinical response [n = 22, 21.4 (14.4–39.7) to 36.5 (20.5–61.6), p = 0.04] and remission [n = 12, 18.7 (9.1–34.3) to 36.5 (23.4–70.5), p = 0.05] was accompanied with a parallel decline in FCP. On in-vitro analysis, potassium under Th17 polarizing conditions significantly inhibited IL-17 and interferon-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\gamma $$\end{document}γ expression while favoring the induction of FoxP3⁺ T cells. Therefore, urinary potassium levels are inversely associated with disease activity in UC with in-vitro data supporting an immune-tolerant role of potassium.

Cholinergic Stimulation Improves Oxidative Stress and Inflammation in Experimental Myocardial Infarction

We previously reported that cholinergic stimulation with pyridostigmine (PY) induces anti-inflammatory cell recruitment soon after myocardial infarction (MI). In this study, we evaluated the anti-inflammatory effects of PY during the proliferative phase of cardiac repair by analyzing the infiltration of macrophages, Treg lymphocytes, oxidative stress and inflammatory cytokines. Wistar rats underwent control sham surgery or ligation of the left coronary artery and were randomly allocated to remain untreated (untreated infarcted group, I) or to receive PY (30 mg·kg(−1)·day(−1)) in the supplied water (infarcted treated group, I + PY). Blood pressure and heart rate variability were registered at day 5 post-MI. The animals were euthanized 7 days after thoracotomy, when the hearts were removed and processed for immunohistochemistry (CD68, CD206, FOXP3), cytokines (IL-1β, IL-6, IL-10, TNF-α) and oxidative stress (superoxide dismutase, catalase, glutathione peroxidase, lipidic and protein peroxidation). PY treatment increased parasympathetic modulation, M2 macrophages and the anti-oxidant enzyme activity but reduced protein oxidation (carbonyls) and the concentration of IL-1β, IL-6, TNF-α and IL-10. Cholinergic stimulation induces parasympathetic neuro-immune modulation and anti-inflammatory cell enrollment as well as prevents oxidative stress and cytokine production after MI.

Association between 24-h urinary sodium excretion and obesity in Korean adults: A multicenter study

OBJECTIVE

The aim of this study was to explore the association between sodium intake, as assessed by 24-h urinary sodium excretion, and various obesity parameters among South Korean adults. The associations of 24-h urinary sodium excretion and sodium intake calculated from the dietary questionnaire with obesity parameters also were compared.

METHODS

This multicenter, cross-sectional study analyzed data of 640 healthy adults from eight provinces in South Korea. Obesity was assessed by body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Mean 24-h urinary sodium excretion was calculated from repeatedly collected 24-h urine samples. Participants' dietary intake was assessed by 24-h dietary recall interview on the days before 24-h urine collection.

RESULTS

In both sexes, the means of all anthropometric measurements tended to increase proportionally with 24-h urinary sodium excretion quartiles, regardless of adjustment. Men in the highest quartile (Q4) of 24-h urinary sodium excretion had increased odds of obesity (as assessed by BMI, WC, WHR, and WHtR) compared with men in the three lower quartiles (Q1-Q3) of 24-h urinary sodium excretion. Women in Q4 of 24-h urinary sodium excretion exhibited a higher chance of general obesity and abdominal obesity. Sodium intake calculated from the dietary questionnaire was not significantly associated with obesity in either sex.

CONCLUSIONS

In Korean adults, there was a positive association between higher sodium intake as assessed by 24-h urinary sodium excretion and obesity independent of energy intake.

Neuronal circuits involved in osmotic challenges

The maintenance of plasma sodium concentration within a narrow limit is crucial to life. When it differs from normal physiological patterns, several mechanisms are activated in order to restore body fluid homeostasis. Such mechanisms may be vegetative and/or behavioral, and several regions of the central nervous system (CNS) are involved in their triggering. Some of these are responsible for sensory pathways that perceive a disturbance of the body fluid homeostasis and transmit information to other regions. These regions, in turn, initiate adequate adjustments in order to restore homeostasis. The main cardiovascular and autonomic responses to a change in plasma sodium concentration are: i) changes in arterial blood pressure and heart rate; ii) changes in sympathetic activity to the renal system in order to ensure adequate renal sodium excretion/absorption, and iii) the secretion of compounds involved in sodium ion homeostasis (ANP, Ang-II, and ADH, for example). Due to their cardiovascular effects, hypertonic saline solutions have been used to promote resuscitation in hemorrhagic patients, thereby increasing survival rates following trauma. In the present review, we expose and discuss the role of several CNS regions involved in body fluid homeostasis and the effects of acute and chronic hyperosmotic challenges.

Low zinc levels is associated with increased inflammatory activity but not with atherosclerosis, arteriosclerosis or endothelial dysfunction among the very elderly

BACKGROUND

Reduced zinc intake has been related to atherogenesis and arteriosclerosis. We verified this assumption in very old individuals, which are particularly prone to both zinc deficiency and structural and functional changes in the arterial wall.

METHODS

Subjects (n = 201, 80-102 years) with uneventful cardiovascular history and who were not in use of anti-inflammatory treatments in the last 30-days were enrolled. Daily intake of zinc, lipid profile, plasma C-reactive protein (CRP), plasma zinc, flow-mediated dilation (FMD), carotid ultrasonography and cardiac computed tomography were obtained. Young's Elastic Modulus, Stiffness Index and Artery Compliance were calculated.

RESULTS

There was no significant difference in clinical or laboratorial data between subjects grouped according to plasma zinc tertile, except for CRP (p = 0.01) and blood leukocytes (p = 0.002), of which levels were higher in the upper tertiles. The average daily intake of zinc was not significantly correlated with zinc or CRP plasma levels. The plasma zinc/zinc intake ratio was inversely correlated with plasma CRP levels (- 0.18; p = 0.01). There was no significant difference between the plasma zinc tertiles and FMD, carotid intima-media thickness, coronary calcium score, carotid plaque presence, remodeled noncalcified coronary plaques, or low-attenuation noncalcified coronary plaques.

CONCLUSION

Although plasma zinc level is inversely related to systemic inflammatory activity, its plasma levels of daily intake are not associated to alterations in structure or function of the arterial wall.

GENERAL SIGNIFICANCE

In the very elderly plasma concentrations or daily intake of zinc is not related to endothelial dysfunction, arteriosclerosis or atherosclerotic burden at coronary or carotid arteries.

Compared with usual sodium intake, low- and excessive-sodium diets are associated with increased mortality: a meta-analysis

BACKGROUND

The effect of sodium intake on population health remains controversial. The objective was to investigate the incidence of all-cause mortality (ACM) and cardiovascular disease events (CVDEs) in populations exposed to dietary intakes of low sodium (<115 mmol), usual sodium (low usual sodium: 115-165 mmol; high usual sodium: 166-215 mmol), and high sodium (>215 mmol).

METHODS

The relationship between individual measures of dietary sodium intake vs. outcome in cohort studies and randomized controlled trials (RCTs) measured as hazard ratios (HRs) were integrated in meta-analyses.

RESULTS

No RCTs in healthy population samples were identified. Data from 23 cohort studies and 2 follow-up studies of RCTs (n = 274,683) showed that the risks of ACM and CVDEs were decreased in usual sodium vs. low sodium intake (ACM: HR = 0.91, 95% confidence interval (CI) = 0.82-0.99; CVDEs: HR = 0.90, 95% CI = 0.82-0.99) and increased in high sodium vs. usual sodium intake (ACM: HR = 1.16, 95% CI = 1.03-1.30; CVDEs: HR = 1.12, 95% CI = 1.02-1.24). In population representative samples adjusted for multiple confounders, the HR for ACM was consistently decreased in usual sodium vs. low sodium intake (HR = 0.86; 95% CI = 0.81-0.92), but not increased in high sodium vs. usual sodium intake (HR = 1.04; 95% CI = 0.91-1.18). Within the usual sodium intake range, the number of events was stable (high usual sodium vs. low usual sodium: HR = 0.98; 95% CI = 0.92-1.03).

CONCLUSIONS

Both low sodium intakes and high sodium intakes are associated with increased mortality, consistent with a U-shaped association between sodium intake and health outcomes.

Plasma 8-isoprostane levels are associated with endothelial dysfunction in resistant hypertension

BACKGROUND

Impaired endothelial function and arterial stiffness are associated with hypertension and are important risk factors for cardiovascular events. Reactive oxygen species reduce nitric oxide bioavailability and have a pivotal role in endothelial function. Resistant hypertension (RHTN) is characterized by blood pressure (BP) above goal (140/90mmHg) in spite of the concurrent use of ≥3 antihypertensive drugs of different classes. This study evaluated the association between 8-isoprostane levels, an oxidative stress marker, endothelial function and arterial stiffness, in RHTN.

METHODS

Ninety-four RHTN and 55 well-controlled hypertensive (HT) patients were included. Plasma 8-isoprostane levels were determined by ELISA. Also, flow-mediated dilation (FMD) and pulse wave velocity (PWV) were evaluated to determine endothelial function and arterial stiffness, respectively.

RESULTS

Levels of 8-isoprostane were markedly higher in RHTN compared to HT patients (22.5±11.2 vs. 17.3±9.8pg/ml, p<0.05, respectively). A significant inverse correlation was observed between FMD and 8-isoprostane (r=-0.35, p=0.001) in RHTN. Finally, multiple logistic regression revealed that 8-isoprostane was a significant predictor of endothelial dysfunction (FMD≤median) in RHTN group.

CONCLUSION

RHTN showed markedly higher oxidative stress measured by 8-isoprostane, compared to HT patients. Taken together, our findings suggest the involvement of oxidative stress in endothelial function in RHTN.

Effect of left atrium volume on patients' prognosis following acute myocardial infarction

Evaluating left atrium volume is a good way to estimate prognosis in acute myocardial infarction patients because it indicates to time and severity of diastolic dysfunction and longer-term results of acute myocardial infarction. The present study aims at evaluating the effect of left atrium volume on patients' prognosis following acute myocardial infarction. This is a cohort study conducted on 100 patients who were admitted with acute myocardial infarction. They were studied for 9 months and their one-month mortality rate was evaluated. The patients were studied considering demographic factors, risk factors, mechanical and arrhythmic complications and echocardiography indexes such as systolic and diastolic functions and left atrium volume. It was seen that mortality (27.3%, 6.22) in patients with atrium index > 32 mL m(-2) is more than cases with lower atrium index (1.3%, 1.78) (p = 0.001). There was not any meaningful difference in mortality rate of the patients considering age and gender (p > 0.05). This study indicated to lack of any meaningful difference in patients' mortality rate in terms of hypertension, diabetes, smoking and dyslipidemia. But, mortality rate was significantly higher in MI as a result of elevated-ST, diastolic dysfunction, restrictive pattern, ejection fraction of left atrium < 40%, left atrium volume index > 32 mL m(-2). High volume left atrium independently refers to bad prognosis in patients with acute myocardial infarction which is confirmed with outcome clinical predictors and common echocardiography indexes even following modification.

Dietary sodium, adiposity, and inflammation in healthy adolescents

OBJECTIVES

To determine the relationships of sodium intake with adiposity and inflammation in healthy adolescents.

METHODS

A cross-sectional study involved 766 healthy white and African American adolescents aged 14 to 18 years. Dietary sodium intake was estimated by 7-day 24-hour dietary recall. Percent body fat was measured by dual-energy x-ray absorptiometry. Subcutaneous abdominal adipose tissue and visceral adipose tissue were assessed using magnetic resonance imaging. Fasting blood samples were measured for leptin, adiponectin, C-reactive protein, tumor necrosis factor-α, and intercellular adhesion molecule-1.

RESULTS

The average sodium intake was 3280 mg/day. Ninety-seven percent of our adolescents exceeded the American Heart Association recommendation for sodium intake. Multiple linear regressions revealed that dietary sodium intake was independently associated with body weight (β = 0.23), BMI (β = 0.23), waist circumference (β = 0.23), percent body fat (β = 0.17), fat mass (β = 0.23), subcutaneous abdominal adipose tissue (β = 0.25), leptin (β = 0.20), and tumor necrosis factor-α (β = 0.61; all Ps < .05). No relation was found between dietary sodium intake and visceral adipose tissue, skinfold thickness, adiponectin, C-reactive protein, or intercellular adhesion molecule-1. All the significant associations persisted after correction for multiple testing (all false discovery rates < 0.05).

CONCLUSIONS

The mean sodium consumption of our adolescents is as high as that of adults and more than twice the daily intake recommended by the American Heart Association. High sodium intake is positively associated with adiposity and inflammation independent of total energy intake and sugar-sweetened soft drink consumption.