Protein Intake and Mortality in Older Adults With Chronic Kidney Disease.

Importance: Avoiding high protein intake in older adults with chronic kidney disease (CKD) may reduce the risk of kidney function decline, but whether it can be suboptimal for survival is not well known. Objective: To estimate the associations of total, animal, and plant protein intake with all-cause mortality in older adults with mild or moderate CKD and compare the results to those of older persons without CKD. Design, Setting, and Participants: Data from 3 cohorts (Study on Cardiovascular Health, Nutrition and Frailty in Older Adults in Spain 1 and 2 and the Swedish National Study on Aging and Care in Kungsholmen [in Sweden]) composed of community-dwelling adults 60 years or older were used. Participants were recruited between March 2001 and June 2017 and followed up for mortality from December 2021 to January 2024. Those with no information on diet or mortality, with CKD stages 4 or 5, or undergoing kidney replacement therapy and kidney transplant recipients were excluded. Data were originally analyzed from June 2023 to February 2024 and reanalyzed in May 2024. Exposures: Cumulative protein intake, estimated via validated dietary histories and food frequency questionnaires. Main Outcomes and Measures: The study outcome was 10-year all-cause mortality, ascertained with national death registers. Chronic kidney disease was ascertained according to estimated glomerular filtration rates, urine albumin excretion, and diagnoses from medical records. Results: The study sample consisted of 8543 participants and 14 399 observations. Of the 4789 observations with CKD stages 1 to 3, 2726 (56.9%) corresponded to female sex, and mean (SD) age was 78.0 (7.2) years. During the follow-up period, 1468 deaths were recorded. Higher total protein intake was associated with lower mortality among participants with CKD; adjusted hazard ratio (HR) for 1.00 vs 0.80 g/kg/d was 0.88 (95% CI, 0.79-0.98); for 1.20 vs 0.80 g/kg/d, 0.79 (95% CI, 0.66-0.95); and for 1.40 vs 0.80 g/kg/d, 0.73 (95% CI, 0.57-0.92). Associations with mortality were comparable for plant and animal protein (HRs, 0.80 [95% CI, 0.65-0.98] and 0.88 [95% CI, 0.81-0.95] per 0.20-g/kg/d increment, respectively) and for total protein intake in participants younger than 75 years vs 75 years or older (HRs, 0.94 [95% CI, 0.85-1.04] and 0.91 [95% CI, 0.85-0.98] per 0.20-g/kg/d increment in total protein intake, respectively). However, the hazards were lower among participants without CKD than in those with CKD (HRs, 0.85 [95% CI, 0.79-0.92] and 0.92 [95% CI, 0.86-0.98] per 0.20-g/kg/d increment, respectively; P = .02 for interaction). Conclusions and Relevance: In this multicohort study of older adults, higher intake of total, animal, and plant protein was associated with lower mortality in participants with CKD. Associations were stronger in those without CKD, suggesting that the benefits of proteins may outweigh the downsides in older adults with mild or moderate CKD.

Plant-based diet in hyperkalemic chronic kidney disease patients receiving sodium zirconium cyclosilicate: a feasibility clinical trial.

BACKGROUND: Plant-based diets (PBD) may induce hyperkalemia in chronic kidney disease (CKD) patients. OBJECTIVES: We explored the safety and feasibility of PBD in hyperkalemic CKD patients receiving the potassium binder sodium zirconium cyclosilicate (SZC). METHODS: In the current 6-wk trial, 26 hyperkalemic patients with CKD stage 4-5 not on dialysis received a low-protein low-potassium diet plus SZC for 3 wk and then a PBD with high potassium content delivered as a weekly food basket while continuing SZC for subsequent 3 wk. Plasma potassium was monitored weekly and SZC was titrated to achieve normokalemia. The 24-h urine excretion of potassium and sodium, 24-h food records, dietary quality, nutritional status, Bristol stool scale, Quality of life (QoL), and renal treatment satisfaction were assessed at baseline (week 0), week 3, and week 6. RESULTS: Mean plasma potassium decreased from 5.5 to 4.4 mEq/L within 48-72 h after baseline, then rose to 4.7-5.0 mEq/L throughout the remaining study period following dose adjustments of SZC that matched the increased potassium intake of PBD from week 3 to week 6. Over the study period, 24-h urinary potassium excretion decreased from week 0 to week 3 and increased from week 3 to week 6. During the study, 58% of patients had fasting plasma potassium between 3.5 and 5.0 mEq/L and there was no episode of plasma potassium >6.5 mEq/L or <3.0 mEq/L during the study. P-carbon dioxide increased from baseline until week 6 (21 ± 2 to 23 ± 2 mEq/L; P = 0.002; mean ± SD), whereas remaining laboratory values remained unchanged. Fiber intake, dietary quality, the domain physical functioning from QoL, and 1 question of renal treatment satisfaction improved, whereas stool type and frequency did not change after starting PBD. CONCLUSIONS: PBD in hyperkalemia-prone CKD patients receiving SZC improved dietary quality and increased the intake of healthy foods, whereas plasma potassium concentration remained stable within normal values for most patients. TRIAL REGISTRATION NUMBER: This trial was registered at the https://clinicaltrials.gov/study/NCT04207203 as NCT04207203.

What Can the Gut Microbiota of Animals Teach Us about the Relationship between Nutrition and Burden of Lifestyle Diseases?

The gut microbiota performs several crucial roles in a holobiont with its host, including immune regulation, nutrient absorption, synthesis, and defense against external pathogens, significantly influencing host physiology. Disruption of the gut microbiota has been linked to various chronic conditions, including cardiovascular, kidney, liver, respiratory, and intestinal diseases. Studying how animals adapt their gut microbiota across their life course at different life stages and under the dynamics of extreme environmental conditions can provide valuable insights from the natural world into how the microbiota modulates host biology, with a view to translating these into treatments or preventative measures for human diseases. By modulating the gut microbiota, opportunities to address many complications associated with chronic diseases appear. Such a biomimetic approach holds promise for exploring new strategies in healthcare and disease management.

Amazonian Fruits for Treatment of Non-Communicable Diseases.

PURPOSE OF REVIEW: The Amazon region has a high biodiversity of flora, with an elevated variety of fruits, such as Camu-Camu (Myrciaria dúbia), Açaí (Euterpe oleracea Mart.), Tucumã (Astrocaryum aculeatum and Astrocaryum vulgare), Fruta-do-conde (Annona squamosa L.), Cupuaçu (Theobroma grandiflorum), Graviola (Annona muricata L.), Guarana (Paullinia cupana Kunth var. sorbilis), and Pitanga (Eugenia uniflora), among many others, that are rich in phytochemicals, minerals and vitamins with prominent antioxidant and anti-inflammatory potential. RECENT FINDINGS: Studies evaluating the chemical composition of these fruits have observed a high content of nutrients and bioactive compounds. Such components are associated with significant biological effects in treating various non-communicable diseases (NCDs) and related complications. Regular intake of these fruits from Amazonas emerges as a potential therapeutic approach to preventing and treating NCDs as a nutritional strategy to reduce the incidence or mitigate common complications in these patients, which are the leading global causes of death. As studies remain largely unexplored, this narrative review discusses the possible health-beneficial effects for patients with NCDs.

IL-6 inhibition with clazakizumab in patients receiving maintenance dialysis: a randomized phase 2b trial.

Inflammation mediated by interleukin-6 (IL-6) is strongly associated with cardiovascular risk. Here we evaluated clazakizumab, a monoclonal antibody targeting the IL-6 ligand, in a phase 2b dose-finding study. Adults with cardiovascular disease and/or diabetes receiving maintenance dialysis with high-sensitivity C-reactive protein (hs-CRP) ≥ 2 mg l-1 at baseline were randomized to receive clazakizumab (2.5 mg, 5 mg or 10 mg, n = 32 per dose group) or placebo (n = 31) every 4 weeks. The primary endpoint was the change from baseline in hs-CRP to week 12, expressed as the geometric mean ratio. Clazakizumab treatment signficantly reduced serum hs-CRP concentrations at week 12 by 86%, 90% and 92% relative to placebo in patients randomized to 2.5 mg, 5 mg or 10 mg clazakizumab, respectively (all P < 0.0001), meeting the primary outcome. With regard to secondary endpoints, clazakizumab treatment reduced serum fibrinogen, amyloid A, secretory phospholipase A2, and lipoprotein(a) concentrations, as well as increased mean serum albumin concentrations at 12 weeks, relative to placebo. The proportion of patients who achieved hs-CRP < 2.0 mg l-1 was 79%, 82% and 79% in the 2.5 mg, 5 mg and 10 mg clazakizumab groups, respectively, compared with 0% of placebo-treated patients. With regard to safety, no cases of sustained grade 3 or 4 thrombocytopenia or neutropenia were observed. Serious infections were seen with similar frequency in the placebo, clazakizumab 2.5 mg and clazakizumab 5 mg groups, but were numerically more frequent in the clazakizumab 10 mg group. The results of this trial indicate that in patients receiving maintenance dialysis, clazakizumab reduced inflammatory biomarkers associated with cardiovascular events. ClinicalTrials.gov registration: NCT05485961 .

Handgrip strength and mortality in a cohort of kidney failure patients: Comparative analysis of different normalization methods.

OBJECTIVES: Reduced handgrip strength (HGS) is associated with adverse clinical outcomes. We analyzed and compared associations of HGS with mortality risk in dialysis patients, using different normalization methods of HGS. METHODS: HGS and clinical and laboratory parameters were measured in a cohort of 446 incident dialysis patients (median age 56 y, 62% men). The area under the receiver operating characteristic curve (AUROC) was used to compare different normalization methods of HGS as predictors of mortality: absolute HGS in kilograms; HGS normalized to height, weight, or body mass index; and HGS of a reference population of sex-matched controls (percentage of the mean HGS value [HGS%]). Multivariate linear regression analysis was used to assess HGS predictors. Competing risk regression analysis was used to evaluate 5-year all-cause mortality risk. Differences in survival time between HGS% tertiles were quantitated by analyzing the restricted mean survival time. RESULTS: The AUROC for HGS% was higher than the AUROCs for absolute or normalized HGS values. Compared with the high HGS% tertile, low HGS% (subdistribution hazard ratio [sHR] = 2.36; 95% CI, 1.19-3.70) and middle HGS% (sHR = 1.79; 95% CI, 1.12-2.74) tertiles were independently associated with higher all-cause mortality and those with high HGS% tertile survived on average 7.95 mo (95% CI, 3.61-12.28) and 18.99 mo (95% CI, 14.42-23.57) longer compared with middle and low HGS% tertile, respectively. CONCLUSIONS: HGS% was a strong predictor of all-cause mortality risk in incident dialysis patients and a better discriminator of survival than absolute HGS or HGS normalized to body size dimensions.

Unlocking the Potential of Brewers' Spent Grain: A Sustainable Model to Use Beer for Better Outcome in Chronic Kidney Disease.

The rising global incidence of chronic inflammatory diseases calls for innovative and sustainable medical solutions. Brewers' spent grain (BSG), a byproduct of beer production, presents a unique opportunity in this regard. This review explores the multifaceted health benefits of BSG, with a focus on managing chronic kidney disease (CKD). BSG is identified as a potent prebiotic with potential as a therapeutic agent in CKD. We emphasize the role of gut dysbiosis in CKD and discuss how BSG could help mitigate metabolic derangements resulting from dysbiosis and CKD. Fermentation of BSG further enhances its positive impact on gut health. Incorporating fermented BSG as a key component in preventive health care could promote a more sustainable and healthier future. By optimizing the use of this typically discarded byproduct, we can align proactive health-care strategies with responsible resource management, benefiting both people and the environment.

Sweet, bloody consumption - what we eat and how it affects vascular ageing, the BBB and kidney health in CKD.

In today's industrialized society food consumption has changed immensely toward heightened red meat intake and use of artificial sweeteners instead of grains and vegetables or sugar, respectively. These dietary changes affect public health in general through an increased incidence of metabolic diseases like diabetes and obesity, with a further elevated risk for cardiorenal complications. Research shows that high red meat intake and artificial sweeteners ingestion can alter the microbial composition and further intestinal wall barrier permeability allowing increased transmission of uremic toxins like p-cresyl sulfate, indoxyl sulfate, trimethylamine n-oxide and phenylacetylglutamine into the blood stream causing an array of pathophysiological effects especially as a strain on the kidneys, since they are responsible for clearing out the toxins. In this review, we address how the burden of the Western diet affects the gut microbiome in altering the microbial composition and increasing the gut permeability for uremic toxins and the detrimental effects thereof on early vascular aging, the kidney per se and the blood-brain barrier, in addition to the potential implications for dietary changes/interventions to preserve the health issues related to chronic diseases in future.

Making the invisible visible: imaging techniques for assessing muscle mass and muscle quality in chronic kidney disease.

Muscle wasting and low muscle mass are prominent features of protein energy wasting (PEW), sarcopenia and sarcopenic obesity in patients with chronic kidney disease (CKD). In addition, muscle wasting is associated with low muscle strength, impaired muscle function and adverse clinical outcomes such as low quality of life, hospitalizations and increased mortality. While assessment of muscle mass is well justified, the assessment of skeletal muscle should go beyond quantity. Imaging techniques provide the means for non-invasive, comprehensive, in-depth assessment of the quality of the muscle such as the infiltration of ectopic fat. These techniques include computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. Dual energy X-ray absorptiometry is also an imaging technique, but one that only provides quantitative and not qualitative data on muscle. The main advantage of imaging techniques compared with other methods such as bioelectrical impedance analysis and anthropometry is that they offer higher precision and accuracy. On the other hand, the higher cost for acquiring and maintaining the imaging equipment, especially CT and MRI, makes these less-used options and available mostly for research purposes. In the field of CKD and end-stage kidney disease (ESKD), imaging techniques are gaining attention for evaluating muscle quantity and more recently muscle fat infiltration. This review describes the potential of these techniques in CKD and ESKD settings for muscle assessment beyond that of muscle quantity.

The safety of a low protein diet in older adults with advanced chronic kidney disease.

BACKGROUND: A low protein diet (LPD) is recommended to patients with advanced chronic kidney disease (CKD), whereas geriatric guidelines recommend a higher amount of protein. The aim of this study was to evaluate the safety of LPD treatment in older adults with advanced CKD. METHODS: The EQUAL study is a prospective, observational study, including patients ≥65 years, incident estimated glomerular filtration rate <20 ml/min/1.73m², in six European countries with follow-up up till six years. Nutritional status was assessed by 7-point subjective global assessment (SGA) every 3-6 months. Prescribed diet (gram protein/kilogram/bodyweight) was recorded on every study visit; measured protein intake was available in three countries. Time to death and decline in nutritional status (SGA decrease by ≥2 points) were analysed using marginal structural models with dynamic inverse probability of treatment and censoring weights. RESULTS: Out of 1738 adults (631 prescribed LPD at any point during follow-up) there were 1319 with repeated SGA measurements of which 267 (20%) declined in SGA ≥ 2 points and 565 (32.5%) died. There was no difference in survival or decline in nutritional status for patients prescribed LPD ≤0.8 g/kg ideal bodyweight (Odds Ratio (OR) for mortality 1.15 (95% Confidence interval (CI) 0.86-1.55) and OR for decline in SGA 1.11 (95% CI 0.74-1.66) in the adjusted models. In patients prescribed LPD <0.6 g/kg ideal bodyweight, the results were similar. There was a significant interaction with LPD and higher age >75 years, lower SGA, and higher comorbidity burden for both mortality and nutritional status decline. CONCLUSIONS: In older adults with CKD approaching end-stage kidney disease, a traditional LPD prescribed and monitored according to routine clinical practice in Europe appears to be safe.

Identifying individuals at risk of needing CKD associated medications in a European kidney disease cohort.

BACKGROUND: The consequences of chronic kidney disease (CKD) can be addressed with a range of pharmacotherapies primarily prescribed by nephrologists. More accurate information regarding future CKD-related pharmacotherapy requirements could guide clinical decisions including follow-up frequency. METHODS: Following assignment to derivation and validation groups (2,1), variables predicting individually future use of vitamin D receptor agonists (VDRA), phosphate binders, erythropoiesis stimulating agents (ESAs) and iron were identified using logistic regression in a prospective cohort study containing demography, comorbidity, hospitalization, laboratory, and mortality data in patients with CKD stage G4/G5 across six European countries. Discriminative ability was measured using C-statistics, and predicted probability of medication use used to inform follow-up frequency. RESULTS: A total of 2196 patients were included in the analysis. During a median follow-up of 735 days 648 initiated hemodialysis and 1548 did not. Combinations of age, diabetes status and iPTH, calcium, hemoglobin and serum albumin levels predicted the use of ESA, iron, phosphate binder or VDRA, with C-statistics of 0.70, 0.64, 0.73 and 0.63 in derivation cohorts respectively. Model performance in validation cohorts were similar. Sixteen percent of patients were predicted to have a likelihood of receiving any of these medications of less than 20%. CONCLUSIONS: In a multi-country CKD cohort, prediction of ESA and phosphate binder use over a two-year period can be made based on patient characteristics with the potential to reduce frequency of follow-up in individuals with low risk for requiring these medications.

Epigenetic clocks indicate that kidney transplantation and not dialysis mitigate the effects of renal ageing.

BACKGROUND: Chronic kidney disease (CKD) is an age-related disease that displays multiple features of accelerated ageing. It is currently unclear whether the two treatment options for end-stage kidney disease (dialysis and kidney transplantation [KT]) ameliorate the accelerated uremic ageing process. METHODS: Data on clinical variables and blood DNA methylation (DNAm) from CKD stage G3-G5 patients were used to estimate biological age based on blood biomarkers (phenotypic age [PA], n = 333), skin autofluorescence (SAF age, n = 199) and DNAm (Horvath, Hannum and PhenoAge clocks, n = 47). In the DNAm cohort, we also measured the change in biological age 1 year after the KT or initiation of dialysis. Healthy subjects recruited from the general population were included as controls. RESULTS: All three DNAm clocks indicated an increased biological age in CKD G5. However, PA and SAF age tended to produce implausibly large estimates of biological age in CKD G5. By contrast, DNAm age was 4.9 years (p = 0.005) higher in the transplantation group and 5.9 years (p = 0.001) higher in the dialysis group compared to controls. This age acceleration was significantly reduced 1 year after KT, but not after 1 year of dialysis. CONCLUSIONS: Kidney failure patients displayed an increased biological age as estimated by DNAm clocks compared to population-based controls. Our results suggest that KT, but not dialysis, partially reduces the age acceleration.

Use of Analog and Human Insulin in a European Hemodialysis Cohort With Type 2 Diabetes: Associations With Mortality, Hospitalization, MACE, and Hypoglycemia.

RATIONALE & OBJECTIVE: Poor glycemic control may contribute to the high mortality rate in patients with type 2 diabetes receiving hemodialysis. Insulin type may influence glycemic control, and its choice may be an opportunity to improve outcomes. This study assessed whether treatment with analog insulin compared with human insulin is associated with different outcomes in people with type 2 diabetes and kidney failure receiving hemodialysis. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: People in the Analyzing Data, Recognizing Excellence and Optimizing Outcomes (AROii) study with kidney failure commencing hemodialysis and type 2 diabetes being treated with insulin within 288 dialysis facilities between 2007 and 2009 across 7 European countries. Study participants were followed for 3 years. People with type 1 diabetes were excluded using an established administrative data algorithm. EXPOSURE: Treatment with an insulin analog or human insulin. OUTCOME: All-cause mortality, major adverse cardiovascular events (MACE), all-cause hospitalization, and confirmed hypoglycemia (blood glucose<3.0mmol/L sampled during hemodialysis). ANALYTICAL APPROACH: Inverse probability weighted Cox proportional hazards models to estimate hazard ratios for analog insulin compared with human insulin. RESULTS: There were 713 insulin analog and 733 human insulin users. Significant variation in insulin type by country was observed. Comparing analog with human insulin at 3 years, the percentage of patients experiencing end points and adjusted hazard ratios (AHR) were 22.0% versus 31.4% (AHR, 0.808 [95% CI, 0.66-0.99], P=0.04) for all-cause mortality, 26.8% versus 35.9% (AHR, 0.817 [95% CI, 0.68-0.98], P=0.03) for MACE, and 58.2% versus 75.0% (AHR, 0.757 [95% CI, 0.67-0.86], P<0.001) for hospitalization. Hypoglycemia was comparable between insulin types at 14.1% versus 15.0% (AHR, 1.169 [95% CI, 0.80-1.72], P=0.4). Consistent strength and direction of the associations were observed across sensitivity analyses. LIMITATIONS: Residual confounding, lack of more detailed glycemia data. CONCLUSIONS: In this large multinational cohort of people with type 2 diabetes and kidney failure receiving maintenance hemodialysis, treatment with analog insulins was associated with better clinical outcomes when compared with human insulin. PLAIN-LANGUAGE SUMMARY: People with diabetes who are receiving dialysis for kidney failure are at high risk of cardiovascular disease and death. This study uses information from 1,446 people with kidney failure from 7 European countries who are receiving dialysis, have type 2 diabetes, and are prescribed either insulin identical to that made in the body (human insulin) or insulins with engineered extra features (insulin analog). After 3 years, fewer participants receiving analog insulins had died, had been admitted to the hospital, or had a cardiovascular event (heart attack, stroke, heart failure, or peripheral vascular disease). These findings suggest that analog insulins should be further explored as a treatment leading to better outcomes for people with diabetes on dialysis.

Is Trimethylamine N-oxide (TMAO) Associated with NF-κB mRNA Expression in Patients with Coronary Artery Disease?

Abstract Background: Trimethylamine N-oxide (TMAO), a gut microbiota metabolite, is associated with cardiovascular disease (CVD) development. TMAO can trigger an inflammatory response by inducing the nuclear factor-kappa B (NF-κB) signaling cascade and increasing the expression of pro-inflammatory cytokines, contributing to the worsening of CVD. This study aimed to evaluate the association between TMAO plasma levels and inflammation in patients with coronary artery disease (CAD). Methods: A cross-sectional study was carried out including 29 patients with CAD. Peripheral blood mononuclear cells (PBMC) were isolated from fasting blood samples, and NF-κB and vascular cell adhesion protein 1 (VCAM1) mRNA expression were estimated using real-time quantitative PCR. We determined TMAO plasma levels by LC-MS/MS and TNF-α by ELISA. Routine biochemical parameters were evaluated using an automatic biochemical analyzer. Correlations were estimated by Spearman or Pearson test. Statistical significance was set at the level of p < 0.05. Results: All patients presented TMAO levels within the normal range according to EUTox (normal range: 2.83 ± 1.53 mg/L; CAD patients: 0.2 [0.1 to 0.2] ng/μL). TMAO plasma levels were positively correlated with NF-κB mRNA expression (0.555; p = 0.002). Conclusion: TMAO plasma levels may be associated with NF-κB mRNA expression in patients with CAD and may contribute to the pathogenesis of this disease.

Levels of Cell-Free DNA in Kidney Failure Patients before and after Renal Transplantation.

Circulating cell-free DNA (cfDNA) has diverse applications in oncological, prenatal, toxicological, cardiovascular, and autoimmune diseases, diagnostics, and organ transplantation. In particular, mitochondrial cfDNA (mt-cfDNA) is associated with inflammation and linked to early vascular ageing (EVA) in end-stage kidney failure (ESKF), which could be a noninvasive marker for graft rejection and organ damage. Plasma samples from 44 ESKF patients, of whom half (n = 22) underwent either conservative therapy (non-HD) or hemodialysis (HD) before kidney transplantation (KT). These samples were analyzed at baseline and two years after KT. cfDNA was extracted from plasma and quantified using the fluorometric method. qPCR was used to quantify and differentiate the fractions of mt-cfDNA and nuclear cfDNA (nc-cfDNA). mt-cfDNA levels in KT patients decreased significantly from baseline to two years post-KT (p < 0.0268), while levels of total cfDNA and nc-cfDNA did not differ. Depending on therapy modality (HD vs. non-HD) before KT, total cfDNA levels were higher in HD patients at both baseline (p = 0.0133) and two years post-KT (p = 0.0421), while nc-cfDNA levels were higher in HD only at baseline (p = 0.0079). Males showed a nonsignificant trend of higher cfDNA levels. Patients with assessed vascular fibrosis (p = 0.0068), either alone or in combination with calcification plus fibrosis, showed reduced mt-cfDNA post-KT (p = 0.0195). Changes in mt-cfDNA levels suggests the impact of KT on the inflammatory state of ESKF, as evidenced via its correlation with high sensitivity C-reactive protein after KT. Further studies are warranted to assess if cfDNA could serve as a noninvasive method for monitoring the response to organ transplantation and even for amelioration of EVA status per se.

Ultraprocessed foods and chronic kidney disease-double trouble.

High energy intake combined with low physical activity generates positive energy balance, which, when maintained, favours obesity, a highly prevalent morbidity linked to development of non-communicable chronic diseases, including chronic kidney disease (CKD). Among many factors contributing to disproportionately high energy intakes, and thereby to the obesity epidemic, the type and degree of food processing play an important role. Ultraprocessed foods (UPFs) are industrialized and quite often high-energy-dense products with added sugar, salt, unhealthy fats and food additives formulated to be palatable or hyperpalatable. UPFs can trigger an addictive eating behaviour and is typically characterized by an increase in energy intake. Furthermore, high consumption of UPFs, a hallmark of a Western diet, results in diets with poor quality. A high UPF intake is associated with higher risk for CKD. In addition, UPF consumption by patients with CKD is likely to predispose and/or to exacerbate uraemic metabolic derangements, such as insulin resistance, metabolic acidosis, hypertension, dysbiosis, hyperkalaemia and hyperphosphatemia. Global sales of UPFs per capita increased in all continents in recent decades. This is an important factor responsible for the nutrition transition, with home-made meals being replaced by ready-to-eat products. In this review we discuss the potential risk of UPFs in activating hedonic eating and their main implications for health, especially for kidney health and metabolic complications of CKD. We also present various aspects of consequences of UPFs on planetary health and discuss future directions for research to bring awareness of the harms of UPFs within the CKD scenario.

The dietary source of trimethylamine N-oxide and clinical outcomes: an unexpected liaison.

The profile of gut microbiota can vary according to host genetic and dietary characteristics, and be influenced by disease state and environmental stressors. The uremic dysbiosis results in a loss of biodiversity and overgrowth of microorganisms that may cause elevation of metabolic solutes such as trimethylamine N-oxide (TMAO), inducing pathogenic effects on its host. In patients with chronic kidney disease (CKD), TMAO levels are elevated because of a decreased clearance and an increased production from the uremic gut dysbiosis with a disrupted intestinal barrier and elevated enzymatic hepatic activity. Dietary precursors of TMAO are abundant in animal-derived foods such as red meat, egg yolk and other full-fat dietary products. TMAO is also found naturally in fish and certain types of seafood, with the TMAO content highly variable according to the depth of the sea where the fish is caught, as well as processing and storage. Although evidence points towards TMAO as being an important link to vascular damage and adverse cardiovascular outcomes, the evidence in CKD patients has not been consistent. In this review we discuss the potential dietary sources of TMAO and its actions on the intestinal microbiome as an explanation for the divergent results. We further highlight the potential of a healthy diet as one feasible therapeutic opportunity to prevent gut dysbiosis and reduce uremic toxin levels in patients with CKD.