Novel conservative management of chronic kidney disease via dialysis-free interventions

Plant-Dominant Low-Protein Diets: A Promising Dietary Strategy for Mitigating Disease Progression in People with Chronic Kidney Disease-A Comprehensive Review

Chronic kidney disease (CKD) is a global health crisis affecting over 10% of the population, with mortality rates increasing significantly. Current management strategies, including expensive medications and renal replacement therapies, highlight the need for cost-effective, conservative approaches. This review examines the evidence for plant-dominant low-protein diets (PLADO) in managing non-dialysis-dependent CKD. Existing guidelines for protein restriction in CKD vary considerably, with inconsistencies and a lack of personalization noted in the KDOQI and KDIGO recommendations. While traditional low-protein diet trials show limited success due to poor adherence and marginal benefits, PLADO offers a potentially more sustainable alternative. PLADO's advantages include improved nutrient density, reduced dietary acid load, anti-inflammatory effects, and beneficial modulation of the gut microbiome, potentially reducing uremic toxins and improving cardiovascular health. However, challenges remain, including adherence issues, potential nutrient deficiencies, and potassium management. Although observational studies show promise, further large-scale randomized controlled trials are necessary to validate PLADO's efficacy and establish optimal dietary composition. A personalized, multidisciplinary approach is essential for successful implementation and monitoring to maximize PLADO's benefits in improving outcomes for individuals with NDD-CKD.

Should a low-protein diet and ketoanalogue supplementation be part of the management of advanced chronic kidney disease?

The vast majority of patients with advanced chronic kidney disease (CKD) who transition to end-stage kidney disease (ESKD) are treated with dialysis. Given that dialysis does not always have the intended effects of increasing longevity and/or improving health, particularly in those with high comorbidity burden and/or older age groups, there has been increasing emphasis on interventions that delay or avert the need for renal replacement therapy. Among the multi-disciplinary approaches used to reduce CKD progression, dietary interventions are a major cornerstone. Current guidelines support the role of a low-protein diet in patients with moderate to advanced CKD who are metabolically stable. In addition to dietary protein amount, there is evidence that dietary protein sources as well as nutrients in plant-based foods have an important impact on kidney health outcomes. Clinical practice guidelines, including the 2020 National Kidney Foundation and Academy of Nutrition and Dietetics Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines for Nutrition in CKD, recommend a low protein diet for patients with moderate to advanced non-dialysis dependent (NDD)-CKD who are metabolically stable to reduce risk of ESKD and death. In addition to recommending lower protein intake, the recent 2024 Kidney Disease Improving Global Outcomes CKD Guidelines include a Practice Point advising that people with CKD eat more plant-based foods than animal-based foods. Increasing data also show that plant-based diets are associated with lower risk of progression of CKD and its complications including cardiovascular disease (cardio-kidney-metabolic syndrome), acid-base balance disorders, mineral bone disease, and dysglycemia.

Elevated TyG-BMI index predicts incidence of chronic kidney disease

Chronic kidney disease (CKD) represents a significant global public health issue, with its incidence and prevalence escalating annually. Metabolic disorders are one of the major etiological factors of CKD. This study investigates the relationship between the emerging metabolic index triglyceride-glucose body mass index (TyG-BMI) and the onset of CKD. Our study enrolled 3,485 healthy participants (1,576 men and 1,909 women), with a follow-up period of 3 years. The primary outcome was the emergence of CKD, defined by an eGFR less than 60 mL/(min × 1.73 m2) or the onset of proteinuria. To examine the TyG-BMI and CKD onset relationship, we used univariate and multivariate logistic regression analyses, stratified analyses, and receiver operating characteristic (ROC) curves. After a three-year follow-up, CKD developed in 2% (n = 70) of the participants. Subjects were divided into three equal groups based on their TyG-BMI values, from lowest to highest. After adjusting for potential confounders, the highest TyG-BMI group exhibited a multifactor-adjusted odds ratio (OR) of 4.24 (95% CI 1.30-13.78, P = 0.016) compared to the lowest group. Stratified analyses revealed that the association between TyG-BMI and CKD onset was stronger among females, individuals younger than 60 years, and those with a BMI ≥ 24 kg/m2. Furthermore, TYG-BMI was effective in predicting the incidence of CKD. Our findings indicate that TyG-BMI is an independent risk factor for the onset of CKD and that assessment of TyG-BMI may be useful for the early identification of individuals at high risk for CKD.

Clinical value of serum MMP-3 in chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is defined as the progressive deterioration of renal parenchyma and decline in renal unit function. In the early stages of CKD(G1 + G2), symptoms are usually not obvious and cannot be effectively recognized on the basis of available clinical markers. Progression to the middle and late stages of CKD results in severe kidney damage with multiple complications causing adverse outcomes, including death. Therefore, the early diagnosis and monitoring of CKD is critical. Matrix metalloproteinase-3 (MMP-3), an extracellular matrix-degrading enzyme, plays an important role in kidney diseases. However, the clinical significance of serum MMP-3 levels in CKD has rarely been reported.

METHODS

We quantified the serum MMP-3 levels of 237 patients with CKD and 96 healthy individuals by using a highly sensitive time-resolved fluorescence immunoassay and analyzed differences in MMP-3 levels among the stages of CKD and the correlations of these changes with clinical indicators.

RESULTS

The serum MMP-3 concentrations of patients with CKD (171.76 ± 165.22 ng/mL) were significantly higher than those of healthy controls (34.05 ± 22.93 ng/mL; P < 0.0001). In CKD, serum MMP-3 levels were significantly correlated with estimated glomerular filtration rate (eGFR) (r =  - 0.5804, P < 0.0001), serum creatinine (CREA) (r = 0.5823, P < 0.0001), blood urea nitrogen (BUN) (r = 0.6106, P < 0.0001), and protein-to-creatinine ratio (r = 0.4992, P < 0.0001). Randomized forest analysis finds CREA, BUN, and MMP-3 most significant influences on CKD disease severity. The critical value of MMP-3 concentration of 40.39 ng/mL combined with eGFR was effective in diagnosing positive patients in the early (G1 + G2) stage of CKD and showed a positivity rate of 73.45 %. Moreover, in the early stages of CKD, patients with CKD who had serum MMP-3 concentration > 100 ng/mL had more severe renal impairment and inflammation than those with CKD who have lower serum MMP-3 concentrations.

CONCLUSION

Elevated serum MMP-3 levels are correlated with decreased kidney function in CKD progression, and patients with concomitant inflammation may express high levels of serum MMP-3. Serum MMP-3 may assist eGFR in improving the diagnosis of patients with early CKD.

Dialysis vintage is associated with a high prevalence and severity of unpleasant symptoms in patients on hemodialysis

Background: The burden of physical and emotional symptoms caused by somatic illness is present in most dialysis patients. However, it's unclear how symptom burden varies among patients with different dialysis vintages. We sought to examine differences in the prevalence and severity of unpleasant symptoms in hemodialysis patients with diverse dialysis vintage cohorts.Methods: This cross-sectional study included patients on maintenance hemodialysis at the Second Hospital of Anhui Medical University. We used the Dialysis Symptom Index (DSI) to determine the associated unpleasant symptoms, which is a validated survey to assess symptom burden/severity (higher scores indicate more severe symptoms), over June 2022 - September 2022.Results: We studied 146 patients: 35 (24%) had a dialysis vintage of ≤12 months (group 1) and 111 (76%) had a dialysis vintage of >12 months (group 2). Concerning Group 1 patients, the prevalence and severity of unpleasant symptoms were significantly higher in Group 2, the most common individual symptoms included feeling tired or lack of energy and trouble falling asleep (i.e., 75-85% of patients in each group), with dialysis vintage being an independent influencing factor (adjusted OR, 0.19; 95% CI, 0.16 to 0.23). Lower hemoglobin levels, iron stores, and dialysis adequacy levels are correlated with longer dialysis vintage.Conclusion: We observed a high prevalence of unpleasant symptoms and symptom clusters in a diverse dialysis vintages hemodialysis cohort. Further studies are needed to accurately and routinely define the symptom burden of chronic patients with chronic kidney disease (CKD).

Nutritional and Dietary Management of Chronic Kidney Disease Under Conservative and Preservative Kidney Care Without Dialysis

While dialysis has been the prevailing treatment paradigm for patients with advanced chronic kidney disease (CKD), emphasis on conservative and preservative management in which dietary interventions are a major cornerstone have emerged. Based on high-quality evidence, international guidelines support the utilization of low-protein diets as an intervention to reduce CKD progression and mortality risk, although the precise thresholds (if any) for dietary protein intake vary across recommendations. There is also increasing evidence demonstrating that plant-dominant low-protein diets reduce the risk of developing incident CKD, CKD progression, and its related complications including cardiometabolic disease, metabolic acidosis, mineral and bone disorders, and uremic toxin generation. In this review, we discuss the premise for conservative and preservative dietary interventions, specific dietary approaches used in conservative and preservative care, potential benefits of a plant-dominant low-protein diet, and practical implementation of these nutritional strategies without dialysis.

The Role of Plant-Based Diets in Preventing and Mitigating Chronic Kidney Disease: More Light than Shadows

Chronic kidney disease (CKD) is a non-communicable disease that affects >10% of the general population worldwide; the number of patients affected by CKD is increasing due in part to the rise in risk factors such as obesity, hypertension, and diabetes mellitus. As many studies show, diet can be an important tool for preventing and mitigating the onset of non-communicable diseases. Plant-based diets (PBDs) are those that emphasize the consumption of plant foods and may or may not include small or moderate amounts of animal foods. Recently, these diets have received increasing interest because they have been associated with favourable effects on health and also appear to protect against the development and progression of CKD. PBDs, which are associated with protein restrictions, seem to offer adjunctive advantages in patients with chronic kidney disease, as compared to conventional low-protein diets that include animal proteins. The principal aims of this review are to provide a comprehensive overview of the existing literature regarding the role of plant-based diets and low-protein, plant-based diets in the context of chronic kidney disease. Moreover, we try to clarify the definition of plant-based diets, and then we analyse possible concerns about the use of PBDs in patients with chronic kidney disease (nutritional deficiency and hyperkalaemia risk). Finally, we offer some strategies to increase the nutritional value of plant-based low-protein diets. In the Materials and Methods section, many studies about plant-based diets and low-protein plant-based diets (e.g., the very-low-protein diet and vegan low-protein diet, LPD) in chronic kidney disease were considered. In the Results and Conclusion section, current data, most from observational studies, agree upon the protective effect of plant-based diets on kidney function. Moreover, in patients with advanced CKD, low-protein plant-based options, especially a very-low-protein diet supplemented with heteroanalogues (VLPDs), compared to a conventional LPD appear to offer adjunctive advances in terms of delaying dialysis and mitigating metabolic disturbances. However, further studies are necessary to better investigate the possible metabolic and cardiovascular advantages of plant-based LPDs versus conventional LPDs.

Alterations of gut microbes and their correlation with clinical features in middle and end-stages chronic kidney disease

Gut microecosystem has been shown to play an important role in human health. In recent years, the concept of the gut-kidney axis has been proposed to explain the potential association between gut microbiota and chronic kidney disease (CKD). Here, a cohort of fecal samples collected from patients with CKD (n = 13) were involved. The composition of gut microbial communities and clinical features in CKD and end-stage renal disease (ESRD) were characterized. Our study focused on the changes in gut microbiome and the correlation with clinical features in patients with CKD and ESRD by analyzing high-throughput sequencing results of collected feces. We elucidated the alterations of gut microbiota in CKD patients at different stages of disease and initially identified the gut microbiota associated with CKD progression. We also combined correlation analysis to identify clinical features closely related to the gut microbiome. Our results offered the possibility of using non-invasive gut microbiome in the early diagnosis of course from CKD to ESRD and provide new insights into the association between clinical features and gut microbiota in CKD.

Living Well With Kidney Disease and Effective Symptom Management: Consensus Conference Proceedings

Chronic kidney disease (CKD) confers a high burden of uremic symptoms that may be underrecognized, underdiagnosed, and undertreated. Unpleasant symptoms, such as CKD-associated pruritus and emotional/psychological distress, often occur within symptom clusters, and treating 1 symptom may potentially alleviate other symptoms in that cluster. The Living Well with Kidney Disease and Effective Symptom Management Consensus Conference convened health experts and leaders of kidney advocacy groups and kidney networks worldwide to discuss the effects of unpleasant symptoms related to CKD on the health and well-being of those affected, and to consider strategies for optimal symptom management. Optimizing symptom management is a cornerstone of conservative and preservative management which aim to prevent or delay dialysis initiation. In persons with kidney dysfunction requiring dialysis (KDRD), incremental transition to dialysis and home dialysis modalities offer personalized approaches. KDRD is proposed as the preferred term given the negative connotations of "failure" as a kidney descriptor, and the success stories in CKD journeys. Engaging persons with CKD to identify and prioritize their personal values and individual needs must be central to ensure their active participation in CKD management, including KDRD. Person-centered communication and care are required to ensure diversity, equity, and inclusion; education/awareness that considers the health literacy of persons with CKD; and shared decision-making among the person with CKD, care partners, and providers. By putting the needs of people with CKD, including effective symptom management, at the center of their treatment, CKD can be optimally treated in a way that aligns with their goals.

Dialysis symptom index burden and symptom clusters in a prospective cohort of dialysis patients

Background

Dialysis patients experience a high symptom burden, which may adversely impact their quality of life. Whereas other specialties emphasize routine symptom assessment, symptom burden is not well-characterized in dialysis patients. We sought to examine the prevalence and severity of unpleasant symptoms in a prospective hemodialysis cohort.

Methods

Among 122 hemodialysis patients from the prospective Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease (CKD) study, CKD-associated symptoms were ascertained by the Dialysis Symptom Index, a validated survey assessing symptom burden/severity (with higher scores indicating greater symptom severity), over 6/2020–10/2020. We examined the presence of (1) individual symptoms and symptom severity scores, and (2) symptom clusters (defined as ≥ 2 related concurrent symptoms), as well as correlations with clinical characteristics.

Results

Symptom severity scores were higher among non-Hispanic White and Hispanic patients, whereas scores were lower in Black and Asian/Pacific Islander patients. In the overall cohort, the most common individual symptoms included feeling tired/lack of energy (71.3%), dry skin (61.5%), trouble falling asleep (44.3%), muscle cramps (42.6%), and itching (42.6%), with similar patterns observed across racial/ethnic groups. The most prevalent symptom clusters included feeling tired/lack of energy + trouble falling asleep (37.7%); trouble falling asleep + trouble staying asleep (34.4%); and feeling tired/lack of energy + trouble staying asleep (32.0%). Lower hemoglobin, iron stores, and dialysis adequacy correlated with higher individual and overall symptom severity scores.

Conclusion

We observed a high prevalence of unpleasant symptoms and symptom clusters in a diverse hemodialysis cohort. Further studies are needed to identify targeted therapies that ameliorate symptom burden in CKD.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-022-01313-0.

Addressing the Ethical Challenges of Providing Kidney Failure Care for Children: A Global Stance

Children with kidney failure require kidney replacement therapy (KRT), namely maintenance dialysis and kidney transplant. Adequate kidney failure care consists of KRT or conservative treatment with palliative care. In the context of kidney failure, children depend on parents who are their surrogate decision-makers, and the pediatric nephrology team for taking decisions about KRT or conservative care. In this paper, we discuss the ethical challenges that arise relating to such decision-making, from a global perspective, using the framework of pediatric bioethics. While many ethical dilemmas in the care of children with KRT are universal, the most significant ethical dilemma is the inequitable access to KRT in low & middle income countries (LMICs) where rates of morbidity and mortality depend on the family's ability to pay. Children with kidney failure in LMICs have inadequate access to maintenance dialysis, timely kidney transplant and palliative care compared to their counterparts in high income countries. Using case vignettes, we highlight how these disparities place severe burdens on caregivers, resulting in difficult decision-making, and lead to moral distress among pediatric nephrologists. We conclude with key action points to change this status-quo, the most important being advocacy by the global pediatric nephrology community for better access to affordable kidney failure care for children.

Patient-centred approaches for the management of unpleasant symptoms in kidney disease

Patients with chronic kidney disease (CKD) frequently experience unpleasant symptoms. These can be gastrointestinal (constipation, nausea, vomiting and diarrhoea), psychological (anxiety and sadness), neurological (lightheadedness, headache and numbness), cardiopulmonary (shortness of breath and oedema), dermatological (pruritus and dry skin), painful (muscle cramps, chest pain and abdominal pain) or involve sexual dysfunction, sleep disorders and fatigue. These symptoms often occur in clusters, with one of them as the lead symptom and others as secondary symptoms. Uraemic toxins (also called uremic toxins) are often considered to be the main cause of CKD-associated symptom burden, but treatment of uraemia by dialysis often fails to resolve them and can engender additional symptoms. Indeed, symptoms can be exacerbated by comorbid conditions, pharmacotherapies, lifestyle and dietary regimens, kidney replacement therapy and ageing. Patients with kidney disease, including those who depend on dialysis or transplantation, should feel actively supported in their symptom management through the identification and targeting of unpleasant symptoms via a tailored palliative care approach. Such an approach may help minimize the burden and consequences of kidney disease, and lead to improved patient outcomes including health-related quality of life and better life participation.

Risk Factors and Management of Catheter Malfunction During Urgent-Start Peritoneal Dialysis

Background: Catheter malfunction is a common complication of peritoneal dialysis (PD). This study aimed to retrospectively analyze the risk factors and management of catheter malfunction in urgent-start PD.

Methods: Patients who underwent urgent-start PD were divided into catheter-malfunction and control groups. Baseline demographic and laboratory data of the two groups were compared, and the risk factors for catheter malfunction were analyzed. Primary outcome measure was catheter survival, and the secondary outcomes were surgical complications and malfunction treatment.

Results: Total of 700 patients was analyzed, among whom 143 (20.4%) experienced catheter malfunctions, specifically catheter migration (96, 67.1%), omental wrapping (36, 25.2%), and migration plus omental wrapping (11, 7.7%). Catheter survival time in the malfunction group (202.5 ± 479.4 days) was significantly shorter than that in the control group (1295.3 ± 637.0 days) (P < 0.001). Multivariate analysis revealed higher body mass index [hazard ratio (HR), 1.061; 95% confidence intervals (CI), 1.010–1.115; P = 0.018], lower surgeon count (HR, 1.083; 95% CI, 1.032–1.136; P = 0.001), and higher serum potassium (HR, 1.231; 95% CI, 1.041–1.494; P = 0.036) as independent risk factors for catheter malfunction, while older age (HR, 0.976, 95% CI, 0.962–0.991; P = 0.002) and colonic dialysis (HR, 0.384; 95% CI, 0.254–0.581; P < 0.001) as protective factors. Further subgroup analysis revealed a shorter catheter survival time in patients with younger age ( ≤ 40 years), higher serum potassium levels (≥5 mmol/L), while a longer catheter survival time in patients with colonic dialysis. PD tube and subcutaneous tunnel preservation was successful in 41 out of 44 patients with omental wrapping. All patients had good post-incision prognoses.

Conclusions: Urgent-start PD is safe and effective for unplanned PD patients. Adequate pre-operative colonic dialysis and serum potassium level control are conducive in preventing catheter malfunction. Conservative treatment is effective in managing catheter migration alone, while preservation of the PD tube and the subcutaneous tunnel is effective for omental wrapping.

Chronic kidney disease

Chronic kidney disease is a progressive disease with no cure and high morbidity and mortality that occurs commonly in the general adult population, especially in people with diabetes and hypertension. Preservation of kidney function can improve outcomes and can be achieved through non-pharmacological strategies (eg, dietary and lifestyle adjustments) and chronic kidney disease-targeted and kidney disease-specific pharmacological interventions. A plant-dominant, low-protein, and low-salt diet might help to mitigate glomerular hyperfiltration and preserve renal function for longer, possibly while also leading to favourable alterations in acid-base homoeostasis and in the gut microbiome. Pharmacotherapies that alter intrarenal haemodynamics (eg, renin-angiotensin-aldosterone pathway modulators and SGLT2 [SLC5A2] inhibitors) can preserve kidney function by reducing intraglomerular pressure independently of blood pressure and glucose control, whereas other novel agents (eg, non-steroidal mineralocorticoid receptor antagonists) might protect the kidney through anti-inflammatory or antifibrotic mechanisms. Some glomerular and cystic kidney diseases might benefit from disease-specific therapies. Managing chronic kidney disease-associated cardiovascular risk, minimising the risk of infection, and preventing acute kidney injury are crucial interventions for these patients, given the high burden of complications, associated morbidity and mortality, and the role of non-conventional risk factors in chronic kidney disease. When renal replacement therapy becomes inevitable, an incremental transition to dialysis can be considered and has been proposed to possibly preserve residual kidney function longer. There are similarities and distinctions between kidney-preserving care and supportive care. Additional studies of dietary and pharmacological interventions and development of innovative strategies are necessary to ensure optimal kidney-preserving care and to achieve greater longevity and better health-related quality of life for these patients.