Effect of a low-salt diet on chronic kidney disease outcomes: a systematic review and meta-analysis

Dietary salt intake and kidney function in rural Senegalese populations: a cross-sectional study

INTRODUCTION

High salt intake is a major risk factor for hypertension and its complications such as chronic kidney disease (CKD) and cardiovascular diseases. The present study aimed to determine level of sodium consumption and its relation with kidney function in the rural populations of Ferlo (centre of Senegal).

SUBJECTS AND METHODS

We performed a cross-sectional study including 400 volunteers aged > 18 years. Clinical, biological and dietary data were collected during household visits. Daily sodium intake was measured in the 24 h-urine outpout and CKD was defined as eGFR < 60 ml/min. Linear regression analysis was used to assess association between sodium intake and covariates.

RESULTS

Mean age was 46.42 ± 15.60 and sex-ratio was 1.05. Prevalence of hypertension, CKD and overweight were 21.5, 11.7 and 20.5%, respectively. The median daily salt intake was 11.7 g with interquartile range of 14.8 g. Only 11.25% of participants consumed less than 5 g/day. After multivariate analysis, high salt intake was associated with age > 60 years, overweight and CKD. However, gender and hypertension were not significantly associated with salt intake. Industrial broths (91.5%) and bread (85%) represented the main sources of dietary salt.

CONCLUSION

This study revealed high levels of daily salt intake contrasting with low potassium intakes in the majority of participants. Participants with CKD, overweight and age > 60 years presented higher salt consumption. Stategies to reduce salt consumption are urgently needed to reduce burden of CKD in rural Senegalese populations.

Sodium and water dynamics in the progression of chronic kidney disease: mechanisms and clinical significance

AIM

Lifestyle modifications can postpone the progression of chronic kidney disease toward its terminal stage. This mini-review aims to explore the impact of salt and water intake on the progression of chronic kidney disease (CKD) and provide insights into the optimal consumption levels to preserve the glomerular filtration rate.

METHODS

We reviewed relevant literature to examine the association between salt and water consumption and CKD progression. Our analysis includes discussions on the pathophysiology, findings from clinical trials, and recommended intake guidelines.

RESULTS

Sodium intake, often linked to cardiovascular risk and CKD progression, has shown a complex J-shaped association in some studies, leading to uncertainty about the ideal salt intake level. Sodium and fluid retention are key factors contributing to hypertension, a well-established risk factor for CKD progression. Low-sodium diets have demonstrated promise in reducing blood pressure and enhancing the effects of renin-angiotensin-aldosterone system inhibitors in non-dialysis CKD patients. However, a debate persists regarding the independent effect of salt restriction on CKD progression. Despite medical recommendations, salt consumption remains high among CKD patients. Additionally, the role of water consumption in CKD remains controversial despite its established benefits for CKD prevention in the general population.

CONCLUSION

Lifestyle modifications involving salt and water intake can influence the progression of CKD. While low-sodium diets have shown potential for mitigating hypertension and proteinuria in non-dialysis CKD patients, their independent impact on CKD progression warrants further investigation. The role of water consumption in CKD remains uncertain, and there is a need for additional research in this area. Clinicians should consider individualized dietary recommendations for CKD patients to help preserve the glomerular filtration rate and improve overall outcomes.

Risk Factors of Chronic Kidney Disease Progression: Between Old and New Concepts

Chronic kidney disease (CKD) is a condition characterized by the gradual loss of kidney function over time and it is a worldwide health issue. The estimated frequency of CKD is 10% of the world's population, but it varies greatly on a global scale. In absolute terms, the staggering number of subjects affected by various degrees of CKD is 850,000,000, and 85% of them are in low- to middle-income countries. The most important risk factors for chronic kidney disease are age, arterial hypertension, diabetes, obesity, proteinuria, dyslipidemia, and environmental risk factors such as dietary salt intake and a more recently investigated agent: pollution. In this narrative review, we will focus by choice just on some risk factors such as age, which is the most important non-modifiable risk factor, and among modifiable risk factors, we will focus on hypertension, salt intake, obesity, and sympathetic overactivity.

Vegetarian Nutrition in Chronic Kidney Disease

There is rising interest globally with respect to the health implications of vegetarian or plant-based diets. A growing body of evidence has demonstrated that higher consumption of plant-based foods and the nutrients found in vegetarian and plant-based diets are associated with numerous health benefits, including improved blood pressure, glycemic control, lipid levels, body mass index, and acid-base parameters. Furthermore, there has been increasing recognition that vegetarian and plant-based diets may have potential salutary benefits in preventing the development and progression of chronic kidney disease (CKD). While increasing evidence shows that vegetarian and plant-based diets have nephroprotective effects, there remains some degree of uncertainty about their nutritional adequacy and safety in CKD (with respect to protein-energy wasting, hyperkalemia, etc.). In this review, we focus on the potential roles of and existing data on the efficacy/effectiveness and safety of various vegetarian and plant-based diets in CKD, as well as their practical application in CKD management.

Better Life's Essential 8 Is Associated With Lower Risk of Diabetic Kidney Disease: A Community-Based Study

Background Diabetic kidney disease (DKD) is a common diabetic complication and increases the complexity of diabetes management. No prospective study has focused on the association between DKD and Life's Essential 8 (LE8). Our study aims to examine the association between LE8 and DKD risk. Methods and Results A total of 7605 participants, aged 54.32±9.77 years, and 4688 participants, aged 56.11±10.38 years, were included in the longitudinal and trajectory analyses, respectively, from 2006 to 2020. The DKD was confirmed using data collected during each follow-up. LE8 was based on 4 health behaviors and 4 health factors. The range of each metric was 0 to 100, and the overall LE8 score was calculated as the unweighted average of all 8 component metric scores. The trajectories of LE8 during 2006 to 2010 were classified using latent mixture models. Cox models and restricted cubic splines were applied. After a median follow-up of 12.41 and 6.71 years in longitudinal and trajectory analyses, respectively, the DKD incidence decreased, with the LE8 level increasing (P-trend<0.05), and the linearity assumption for this relationship (P-nonlinear=0.685) had been satisfied. Adjusted hazard ratios (HRs) for the highest tertile were 0.77 (95% CI, 0.69-0.87) and 0.70 (95% CI, 0.62-0.78) in baseline and time-updated LE8 scores, respectively, compared with the lowest tertile. Adjusted HR was 0.53 (95% CI, 0.41-0.69) for the stable-high pattern compared with the stable-low pattern. Conclusions Although LE8 is an indicator of cardiovascular health, the beneficial impact of a high LE8 score is also evident in the protection of renal health among patients with diabetes.

Tissue Sodium Accumulation Induces Organ Inflammation and Injury in Chronic Kidney Disease

High salt intake is a primary cause of over-hydration in chronic kidney disease (CKD) patients. Inflammatory markers are predictors of CKD mortality; however, the pathogenesis of inflammation remains unclear. Sodium storage in tissues has recently emerged as an issue of concern. The binding of sodium to tissue glycosaminoglycans and its subsequent release regulates local tonicity. Many cell types express tonicity-responsive enhancer-binding protein (TonEBP), which is activated in a tonicity-dependent or tonicity-independent manner. Macrophage infiltration was observed in the heart, peritoneal wall, and para-aortic tissues in salt-loading subtotal nephrectomized mice, whereas macrophages were not prominent in tap water-loaded subtotal nephrectomized mice. TonEBP was increased in the heart and peritoneal wall, leading to the upregulation of inflammatory mediators associated with cardiac fibrosis and peritoneal membrane dysfunction, respectively. Reducing salt loading by a diuretic treatment or changing to tap water attenuated macrophage infiltration, TonEBP expression, and inflammatory marker expression. The role of TonEBP may be crucial during the cardiac fibrosis and peritoneal deterioration processes induced by sodium overload. Anti-interleukin-6 therapy improved cardiac inflammation and fibrosis and peritoneal membrane dysfunction. Further studies are necessary to establish a strategy to regulate organ dysfunction induced by TonEBP activation in CKD patients.

Uncovering culinary medicine research themes: Current status and future direction

Background: Culinary medicine (CM), an emerging discipline, is a novel approach that focuses on the art of food and cooking to prevent or improve health outcomes among chronic patients suffering from lifestyle diseases. The concept originated in the USA, gaining interest from scholars in medicine, nutrition, nursing, and the gastronomic discipline. Notably, in the last five years, there has been exponential growth in CM literature. In this regard, this study sought to examine the growth, performance and distinct research themes of CM literature over time. Methods: To achieve the study's objectives, this study employs descriptive, performance and bibliometric analysis. The descriptive analysis was applied to examine the growth of the CM literature since its emergence. The performance analysis was used to identify the most influential journals, articles, and authors in the CM domain. The bibliographic coupling analysis was adopted to discover the various research themes of the CM knowledge base. Results: This study identifies three stages of literature development: Early stage, modest growth stage, and emerging stage. Further, the results indicate that most of the studies on CM had been conducted in developed countries. Our findings reveal a clear interest in integrating the CM curriculum into medical/nutrition education programs in recent years. Additionally, the study discovers four distinct main research themes: knowledge assessment, impact measurement, acceptance and efficacy, and implementation of CM. Conclusions: These findings are helpful for scholars in medicine, nutrition, nursing, and gastronomy as they provide an overview of CM's development and research focus. Future studies could focus on expanding the geographical distribution of research on CM and further exploring the identified research themes to gain a deeper understanding of the potential of this approach for improving health outcomes among chronic disease patients.

Lifestyle Modifications and Nutritional and Therapeutic Interventions in Delaying the Progression of Chronic Kidney Disease: A Review

Chronic kidney disease (CKD) is a debilitating progressive illness that affects more than 10% of the world's population. In this literature review, we discussed the roles of nutritional interventions, lifestyle modifications, hypertension (HTN) and diabetes mellitus (DM) control, and medications in delaying the progression of CKD. Walking, weight loss, low-protein diet (LPD), adherence to the alternate Mediterranean (aMed) diet, and Alternative Healthy Eating Index (AHEI)-2010 slow the progression of CKD. However, smoking and binge alcohol drinking increase the risk of CKD progression. In addition, hyperglycemia, altered lipid metabolism, low-grade inflammation, over-activation of the renin-angiotensin-aldosterone system (RAAS), and overhydration (OH) increase diabetic CKD progression. The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend blood pressure (BP) control of <140/90 mmHg in patients without albuminuria and <130/80 mmHg in patients with albuminuria to prevent CKD progression. Medical therapies aim to target epigenetic alterations, fibrosis, and inflammation. Currently, RAAS blockade, sodium-glucose cotransporter-2 (SGLT2) inhibitors, pentoxifylline, and finerenone are approved for managing CKD. In addition, according to the completed Study of Diabetic Nephropathy with Atrasentan (SONAR), atrasentan, an endothelin receptor antagonist (ERA), decreased the risk of renal events in diabetic CKD patients. However, ongoing trials are studying the role of other agents in slowing the progression of CKD.

Exploiting the Crithmum maritimum L. Aqueous Extracts and Essential Oil as Potential Preservatives in Food, Feed, Pharmaceutical and Cosmetic Industries

Chritmum maritimum, sea fennel, is a facultative halophyte used in salads, soups, and sauces, as well as used to prepare medicinal juices and aqueous extracts (AE) to treat several ailments. Its essential oil (EO) is used as a spice and aromatizing. In this work, the nutritional (crude protein, fiber, lipids, and ashes content) and HPLC-PDA phenolic profiles were determined. Furthermore, the antioxidant potential of the infusion and of the decoction, as well as the antibacterial activity of both, the AE and EO, were assessed against food-contaminating bacteria. The composition of the EO was also established. Sea fennel exhibited considerable fiber (34.3 ± 1.92%) and mineral content (23.6 ± 4.8%). AE contains chlorogenic acid as the major phenolic compound, 49.7 ± 0.8 mg/g in the infusion dry extract and (26.8 ± 0.9 mg/g in the decoction dry extract). EO contains high amounts of monoterpene hydrocarbons, namely γ-terpinene and sabinene. In regards to the antioxidant activity, IC₅₀ values for the infusion and decoction were, respectively: 36.5 ± 1.4 μg/mL and 44.7 ± 4.4 μg/mL in the DPPH assay; 37.3 ± 2.6 μg/mL and 38.4 ± 1.8 μg/mL, in the ABTS assay. EO is particularly active against Bacillus cereus and Lactobacillus plantarum. The results support the use of sea fennel AE and EO as a potential alternative preservative ingredient for feeds, foods, pharmaceutical, and cosmetic industries, due to the antioxidant activity of infusion and decoction, and antibacterial properties of essential oil.