Higher Sodium Intake Assessed by 24 Hour Urinary Sodium Excretion Is Associated with Non-Alcoholic Fatty Liver Disease: The PREVEND Cohort Study

24-Hour Urinary Sodium Excretion Is Associated With Increased Risk of Pancreatic Cancer: A Prospective Cohort Study

INTRODUCTION

This study builds on previous research and its limitations, which indicate the need for further investigation in prospective cohorts. Our aim was to explore the association between estimated 24-hour urinary sodium excretion (indicative of daily sodium consumption) and the occurrence of pancreatic cancer in the UK Biobank's large prospective cohort.

METHODS

Using the INTERSALT equation, the study computed estimated 24-hour urinary sodium excretion by analyzing the baseline spot urine sodium measurements of 434,372 individuals enrolled in the UK Biobank. Pancreatic cancer cases were identified through UK cancer registries. Adjusted Cox proportional hazards models were used to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between estimated 24-hour urinary sodium excretion and the risk of pancreatic cancer.

RESULTS

Over a median follow-up period of 13.8 years, 1,765 cases of pancreatic cancer were detected. The multivariable adjusted Cox model showed that each 1-gram rise in estimated 24-hour urinary sodium excretion corresponded to a 1.12 HR for incident pancreatic cancer (95% CI: 1.03, 1.22). The estimated HR for 24-hour urinary sodium excretion in binary form was 1.23 (95% CI: 1.05, 1.44). Compared with the lowest group, the group with the highest estimated 24-hour urinary sodium excretion exhibited an HR of 1.38 (95% CI: 1.21, 1.58).

DISCUSSION

These results propose an association between elevated sodium consumption and a heightened risk of pancreatic cancer. Further validation and exploration of potential mechanisms are warranted.

Sex-Specific Association between Sodium Intake Estimated by 24-Hour Urinary Sodium Excretion and Nonalcoholic Fatty Liver Disease: The Community-Based Prospective Cohort Study

Evidence for the association between high sodium intake and the onset of nonalcoholic fatty liver disease (NAFLD) is insufficient. This study examined the sex-specific association between sodium intake and the risk of NAFLD. This study included 2582 adults (aged 40-69 years; 1011 males and 1571 females). The total sodium excreted over 24 h was estimated from spot urine specimens using Tanaka's equation. Based on these estimates, participants were categorized into three groups according to their 24-h urinary sodium excretion levels: lowest (T1), middle (T2), and highest (T3). In addition, the participants were divided into non-NAFLD (≤36) and NAFLD (>36) groups based on the hepatic steatosis index. During the follow-up period (14 years), NAFLD was observed in 551 participants. The estimated 24-h urinary sodium excretion levels were positively associated with the incidence of NAFLD in all subjects. Upon sex stratification, females in the T2 and T3 groups exhibited adjusted hazard ratios of 1.35 and 1.51, respectively, compared with the T1 group. However, a significant relationship was not observed in males. High intake of sodium, especially among females, may be an important factor contributing to the development of NAFLD. Individuals with high sodium intake should be appropriately counselled and monitored for the risk of NAFLD.

Fatty liver index (FLI): more than a marker of hepatic steatosis

Fatty liver index (FLI) was developed as a simple and accurate marker of hepatic steatosis. FLI is derived from an algorithm based on body mass index, waist circumference, and levels of triglycerides and gamma-glutamyltransferase, and it is widely used in clinical and epidemiological studies as a screening tool for discriminating between healthy and nonalcoholic fatty liver disease (NAFLD) subjects. However, a systematic review of the literature regarding FLI revealed that this index has more extensive relationships with biochemical and physiological parameters. FLI is associated with key parameters of lipid, protein and carbohydrate metabolism, hormones, vitamins and markers of inflammation, or oxidative stress. FLI can be a predictor or risk factor for a number of metabolic and nonmetabolic diseases and mortality. FLI is also used as an indicator for determining the effects of health-related prevention interventions, medications, and toxic substances on humans. Although in most cases, the exact mechanisms underlying these associations have not been fully elucidated, they are most often assumed to be mediated by insulin resistance, inflammation, and oxidative stress. Thus, FLI may be a promising marker of metabolic health due to its multiple associations with parameters of physiological and pathological processes. In this context, the present review summarizes the data from currently available literature on the associations between FLI and biochemical variables and physiological functions. We believe that this review will be of interest to researchers working in this area and can provide new perspectives and directions for future studies on FLI.

Hepatic Transcriptomics Reveals Reduced Lipogenesis in High-Salt Diet Mice

It has been demonstrated that a high salt diet (HSD) increases the risk of cardiovascular disease and metabolic dysfunction. In particular, the impact and molecular mechanisms of long-term HSD on hepatic metabolism remain largely unknown. To identify differentially expressed genes (DEGs) affecting the metabolism of liver tissues from HSD and control groups, a transcriptome analysis of liver tissues was performed in this study. As a result of the transcriptome analysis, the expression of genes related to lipid and steroid biosynthesis (such as Fasn, Scd1, and Cyp7a1) was significantly reduced in the livers of HSD mice. Additionally, several gene ontology (GO) terms have been identified as associated with metabolic processes in the liver, including the lipid metabolic process (GO: 0006629) and the steroid metabolic process (GO: 0008202). An additional quantitative RT-qPCR analysis was conducted to confirm six down-regulated genes and two up-regulated genes. Our findings provide a theoretical basis for further investigation of HSD-induced metabolic disorders.

Dietary Sodium and Nonalcoholic Fatty Liver Disease: A Systematic Review

(1) Introduction: Restriction in sodium intake is an important strategy for reducing cardiovascular morbidity and mortality, considering the direct influence of high-sodium diet consumption on the development of hypertension and cardiovascular diseases. There are only a few studies dealing with the influence of dietary sodium on the development of nonalcoholic fatty liver disease (NAFLD). In this systematic review, evidence in humans and animal models was compiled in a critical view of the influence of dietary sodium intake patterns on NAFLD markers; (2) Methods: Systematic review of PubMed data. Clinical outcomes included the prevalence/incidence of NAFLD for human studies, and NAFLD markers (hepatic lipogenesis, and markers of steatosis, fibrosis, and inflammation) for animal studies. The protocol was registered at the International Prospective Register of Systematic Review (PROSPERO; CRD42023390447); (3) Results and Conclusion: Seven studies in humans and eight in animals were included. All studies in humans were observational and associated high-sodium intake with NAFLD. However, in animals, both the increased and reduced consumption of sodium negatively influenced markers of liver steatosis, inflammation, and fibrosis.

Interaction between the PNPLA3 Gene and Nutritional Factors on NAFLD Development: The Korean Genome and Epidemiology Study

Genetic and nutritional factors contribute to the development of non-alcoholic fatty liver disease (NAFLD); however, gene-diet interactions in NAFLD development are poorly understood. In this case-control study, a large dataset from the Korean Genome and Epidemiology Study cohort (n = 72,299) comprising genomic data, medical records, social history, and dietary data was used. We investigated the interactions between the PNPLA3 rs738409 genotype and nutritional factors and their possible effect on the risk of NAFLD development in 2950 patients with NAFLD and 12,907 controls. In the PNPLA3 risk allele group, high protein, fat, sodium, phosphorus, niacin, and vitamin B6 intakes were associated with a decreased risk of NAFLD. In the non-risk allele group, only high fat intake was associated with a decreased risk of NAFLD. Among these nutrients, high sodium intake had a significant protective interaction with the PNPLA3 genotype against NAFLD (p = 0.002). Among salty foods, only kimchi had a significant protective effect against the PNPLA3 genotype (p = 0.012). Thus, the PNPLA3 genotype is differentially associated with nutritional factors. In particular, it interacts with kimchi, a fermented vegetable dish. Therefore, fermented vegetables may serve as a tailored therapeutic food for people with the PNPLA3 risk allele.

The World Hypertension League Science of Salt: a regularly updated systematic review of salt and health outcomes studies (Sept 2019 to Dec 2020)

The World Hypertension League Science of Salt health outcomes review series highlights high-quality publications relating to salt intake and health outcomes. This review uses a standardised method, outlined in previous reviews and based on methods developed by WHO, to identify and critically appraise published articles on dietary salt intake and health outcomes. We identified 41 articles published between September 2019 to December 2020. Amongst these, two studies met the pre-specified methodological quality criteria for critical appraisal. They were prospective cohort studies and examined physical performance and composite renal outcomes as health outcomes. Both found an association between increased/higher sodium intake and poorer health outcomes. Few studies meet criteria for high-quality methods. This review adds further evidence that dietary salt reduction has health benefits and strengthens evidence relating to health outcomes other than blood pressure and cardiovascular disease. We observe that most studies on dietary sodium do not have adequate methodology to reliably assess sodium intake and its association with health outcomes.

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.

Role of high-salt diet in non-alcoholic fatty liver disease: a mini-review of the evidence

With the rising incidence of both obesity and diabetes, non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. However, lifestyle intervention remains to be an effective approach for NAFLD due to lack of therapeutic medication. Recently, salt, an essential micronutrient free of calories, has raised a global concern owing to its wide-range healthy relevance. Accumulated evidence has suggested that a long-term high-salt diet (HSD) independently increases the risk of NAFLD. In the past decades, a number of studies have been reported regarding the mechanism of much investigation concerning HSD-induced NAFLD. Here, we review the updates in epidemiology and molecular mechanism of HSD-induced NAFLD and provide a novel insight into the role of HSD in the regulation of lipid metabolism.

Association of Non-alcoholic Fatty Liver Disease With Salt Intake and Dietary Diversity in Chinese Medical Examination Adults Aged 18-59 Years: A Cross-Sectional Study

Objectives

Given the significance of dietary factors in the development of non-alcoholic fatty liver disease (NAFLD). We conducted a cross-sectional study to investigate the association of NAFLD with salt intake and dietary diversity in a medical examination population aged 18–59 years.

Methods

Data from two Chinese health management centers were utilized between January 2017 and December 2019. The general information, laboratory tests, lifestyle habits, and diet of the participants were all evaluated. Based on alcohol consumption and abdominal ultrasound results, a total of 23,867 participants were divided into the NAFLD (n = 7,753) and control (n = 16,114) groups. Salt intake and dietary diversity were calculated separately for study participants using the spot urine method and dietary diversity scores (DDS). The multilevel logistic model and subgroup analysis were used to analyze the relationship between salt intake, dietary diversity, and NAFLD.

Results

We found that the prevalence of NAFLD was 32.48%. Salt intake was associated with increased NAFLD (Q2 vs. Q1: OR = 1.201, 95% CI 1.094-1.317, P < 0.001; Q3 vs. Q1: OR = 1.442, 95% CI 1.316-1.580, P < 0.001; Q4 vs. Q1: OR = 1.604, 95% CI 1.465-1.757, P < 0.001), whereas sufficient dietary diversity was a protective factor for NAFLD (Sufficient DDS vs. Insufficient DDS: OR: 0.706, 95% CI 0.517-0.965, P < 0.05). The effects of salt intake and dietary diversity on NAFLD were equally stable in the subgroup analysis.

Conclusions

We can conclude that NAFLD is highly prevalent in medical examination adults aged 18-59 years in China. Furthermore, the risk of salt intake for NAFLD and the protective effect of dietary diversity on NAFLD should be taken into account in the management of NAFLD.

Sodium in relation with nonalcoholic fatty liver disease: A systematic review and meta-analysis of observational studies

Findings on the association of sodium with nonalcoholic fatty liver disease (NAFLD) are conflicting. The present systematic review and meta‐analysis study aimed to assess the association between salt or sodium intake or serum sodium levels and NAFLD risk. Relevant articles were identified by searching PubMed, Web of Knowledge, Scopus, Proquest, and Embase databases through May 1, 2021, without language restriction. The pooled odds ratio (OR) and 95% confidence interval (CI) were estimated using Der‐Simonian and Laird method and random‐effects meta‐analysis. The certainty of the evidence was rated using the GRADE method. Out of 6470 documents, 7 epidemiological/observational (1 cohort, 1 case–control, and 5 cross‐sectional) studies on the relationship between dietary salt/sodium intakes and NAFLD risk met our inclusion criteria. The meta‐analysis of all studies showed a significant positive association between the highest salt/sodium intake and NALFD risk (OR = 1.60, 95% CI: 1.19–2.15) with a meaningful heterogeneity among studies (I² = 96.70%, p‐value <.001). The NAFLD risk was greater in the studies with higher quality (OR = 1.81, 95% CI: 1.24–2.65) or using the equation‐based methods for NAFLD ascertainment (OR = 2.02, 95% CI: 1.29–3.17) or urinary sodium collection as a sodium intake assessment (OR = 2.48, 95% CI: 1.52–4.06). The overall certainty of the evidence was very low. In conclusion, high sodium intake seems to be related to increased NAFLD risk. Further well‐designed studies are needed to clarify this association and shed light on the underlying mechanisms.

Mineralocorticoid receptor modulation by dietary sodium influences NAFLD development in mice

INTRODUCTION AND OBJECTIVES

Nonalcoholic-fatty-liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome (MetS). Mineralocorticoid receptor (MR) activation is associated with increased risk of MetS but few studies have assessed the role of liver MR on NAFLD. We aimed to evaluate the effect of MR modulation by sodium intake in liver injury in experimental models of NAFLD.

MATERIALS AND METHODS

C57BL/6J mice were fed either a high-fat-diet (HFD) or a choline/methionine deficient (MCD) diet with different sodium concentrations. Hepatic concentration of lipid species, serum aldosterone levels, expression of MR, proinflammatory and profibrotic markers and liver histology were assessed.

RESULTS

Mice fed with High-Na⁺/HFD showed a lower MR expression in liver (p = 0.01) and less steatosis on histology (p = 0.04). Consistently, animals from this group exhibited lower levels of serum aldosterone (p = 0.028) and lower hepatic triglyceride content (p = 0.008). This associated to a reduced expression of lipogenic genes, significant changes in lipid subspecies, lower HOMA-IR (p < 0.05), and lower expression of pro-inflammatory and profibrotic markers compared to those mice fed a Low-Na⁺/HFD. Additionally, mice fed a High-Na⁺/HFD showed higher expression of salt-inducible kinase (SIK)-1 and lower expression of serum-and-glucocorticoid-inducible kinase (SGK)-1. Similar results were observed with the MCD diet model.

CONCLUSION

We identified in two experimental models of NAFLD that High-Na⁺ diet content is associated to lower serum aldosterone levels and hepatic MR downregulation, associated to decreased steatosis and reduced de novo hepatic lipogenesis, proinflammatory and profibrotic markers. Decreased activation of hepatic MR seems to generate beneficial downstream inhibition of lipogenesis in experimental NAFLD.

Aerobic Exercise Training Prevents Insulin Resistance and Hepatic Lipid Accumulation in LDL Receptor Knockout Mice Chronically Fed a Low-Sodium Diet

Background: A low-sodium (LS) diet reduces blood pressure, contributing to the prevention of cardiovascular diseases. However, intense dietary sodium restriction impairs insulin sensitivity and worsens lipid profile. Considering the benefits of aerobic exercise training (AET), the effect of LS diet and AET in hepatic lipid content and gene expression was investigated in LDL receptor knockout (LDLr-KO) mice. Methods: Twelve-week-old male LDLr-KO mice fed a normal sodium (NS) or LS diet were kept sedentary (S) or trained (T) for 90 days. Body mass, plasma lipids, insulin tolerance testing, hepatic triglyceride (TG) content, gene expression, and citrate synthase (CS) activity were determined. Results were compared by 2-way ANOVA and Tukey’s post-test. Results: Compared to NS, LS increased body mass and plasma TG, and impaired insulin sensitivity, which was prevented by AET. The LS-S group, but not the LS-T group, presented greater hepatic TG than the NS-S group. The LS diet increased the expression of genes related to insulin resistance (ApocIII, G6pc, Pck1) and reduced those involved in oxidative capacity (Prkaa1, Prkaa2, Ppara, Lipe) and lipoprotein assembly (Mttp). Conclusion: AET prevented the LS-diet-induced TG accumulation in the liver by improving insulin sensitivity and the expression of insulin-regulated genes and oxidative capacity.

The Activity of N-acetyl-β-hexosaminidase in the Blood, Urine, Cerebrospinal Fluid and Vitreous Humor Died People Due to Alcohol Intoxication

BACKGROUND

The article aimed to assess the activity of the hexosaminidase (HEX) and its HEX A and HEX B isoenzymes in persons who suddenly died due to ethanol poisoning and explain the cause of their death.

METHODS

The research involved two groups of the deceased group A-22 people (20 males, 2 females; the average age 46 years) who died due to alcohol intoxication (with the blood alcohol content of 4‱ and above in all biological materials at the time of death-blood, urine, cerebrospinal fluid, and vitreous humor), and group B-30 people (22 males, 8 females; the average age 54 years), who died suddenly due to other reasons than alcohol.

RESULTS

The highest activity of the HEX was found in the serum of A and B groups. A significantly lower activity of HEX, HEX A, and HEX B was observed in the urine of group A in comparison to the sober decedents.

CONCLUSION

The lower activity of HEX and its isoenzymes in the dead's urine due to ethanol poisoning may suggest its usefulness as a potential marker of harmful alcohol drinking. Damage done to the kidneys by ethanol poisoning may be one of the possible mechanisms leading to death. Kidneys may be damaged intravitally via the inflammatory agent. Thus, it is necessary to conduct further research to evaluate the diagnostic usefulness of exoglycosidases while determining the death mechanisms of people who lost their lives due to ethanol poisoning.

Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019

As the science surrounding population sodium reduction evolves, monitoring and evaluating new studies on intake and health can help increase our understanding of the associated benefits and risks. Here we describe a systematic review of recent studies on sodium intake and health, examine the risk of bias (ROB) of selected studies, and provide direction for future research. Seven online databases were searched monthly from January 2015 to December 2019. We selected human studies that met specified population, intervention, comparison, outcome, time, setting/study design (PICOTS) criteria and abstracted attributes related to the study population, design, intervention, exposure, and outcomes, and evaluated ROB for the subset of studies on sodium intake and cardiovascular disease risks or indicators. Of 41,601 abstracts reviewed, 231 studies were identified that met the PICOTS criteria and ROB was assessed for 54 studies. One hundred and fifty-seven (68%) studies were observational and 161 (70%) focused on the general population. Five types of sodium interventions and a variety of urinary and dietary measurement methods were used to establish and quantify sodium intake. Five observational studies used multiple 24-h urine collections to assess sodium intake. Evidence mainly focused on cardiovascular-related indicators (48%) but encompassed an assortment of outcomes. Studies varied in ROB domains and 87% of studies evaluated were missing information on ≥1 domains. Two or more studies on each of 12 outcomes (e.g., cognition) not previously included in systematic reviews and 9 new studies at low ROB suggest the need for ongoing or updated systematic reviews of evidence on sodium intake and health. Summarizing evidence from assessments on sodium and health outcomes was limited by the various methods used to measure sodium intake and outcomes, as well as lack of details related to study design and conduct. In line with research recommendations identified by the National Academies of Science, future research is needed to identify and standardize methods for measuring sodium intake.