Digital Physical Activity and Exercise Interventions for People Living with Chronic Kidney Disease: A Systematic Review of Health Outcomes and Feasibility.

Physical activity is essential to interrupt the cycle of deconditioning associated with chronic kidney disease (CKD). However, access to targeted physical activity interventions remain under-supported due to limited funding and specialised staff. Digital interventions may address some of these factors. This systematic review sought to examine the evidence base of digital interventions focused on promoting physical activity or exercise and their effect on health outcomes for people living with CKD. Electronic databases (PubMed, CINAHL, Embase, Cochrane) were searched from 1 January 2000 to 1 December 2023. Interventions (smartphone applications, activity trackers, websites) for adults with CKD (any stage, including transplant) which promoted physical activity or exercise were included. Study quality was assessed, and a narrative synthesis was conducted. Of the 4057 records identified, eight studies (five randomised controlled trials, three single-arm studies) were included, comprising 550 participants. Duration ranged from 12-weeks to 1-year. The findings indicated acceptability and feasibility were high, with small cohort numbers and high risk of bias. There were inconsistent measures of physical activity levels, self-efficacy, body composition, physical function, and psychological outcomes which resulted in no apparent effects of digital interventions on these domains. Data were insufficient for meta-analysis. The evidence for digital interventions to promote physical activity and exercise for people living with CKD is limited. Despite popularity, there is little evidence that current digital interventions yield the effects expected from traditional face-to-face interventions. However, 14 registered trials were identified which may strengthen the evidence-base.

Estimated small dense low-density lipoprotein-cholesterol and the risk of kidney and cardiovascular outcomes in diabetic kidney disease.

AIMS: This study aimed to investigate the correlations between estimated small dense low-density lipoprotein-cholesterol (esd-LDL-c) and the development of end-stage kidney disease (ESKD), cardiovascular mortality, and all-cause mortality in individuals with diabetic kidney disease (DKD) or diabetes mellitus (DM) concomitant chronic kidney disease (CKD). METHODS: We analyzed the data from a biopsy-proven DKD cohort conducted at West China Hospital of Sichuan University between 2009 and 2021 (the DKD cohort) and participants with DM and CKD in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 (the NHANES DM-CKD cohort). Cox regression analysis was also used to estimate associations between esd-LDL-c and the incidence of ESKD, cardiovascular mortality, and all-cause mortality. RESULTS: There were 175 ESKD events among 338 participants in the DKD cohort. Patients were divided into three groups based on esd-LDL-c tertiles (T1 < 33.7 mg/dL, T2 ≥ 33.7 mg/dL to <45.9 mg/dL, T3 ≥ 45.9 mg/dL). The highest tertile of esd-LDL-c was associated with ESKD (adjusted HR 2.016, 95% CI 1.144-3.554, p = .015). Furthermore, there were 99 deaths (39 cardiovascular) among 293 participants in the NHANES DM-CKD cohort. Participants were classified into three groups in line with the tertile values of esd-LDL-c in the DKD cohort. The highest tertile of esd-LDL-c was associated with cardiovascular mortality (adjusted HR 3.95, 95% CI 1.3-12, p = .016) and all-cause mortality (adjusted HR 2.37, 95% CI 1.06-5.32, p = .036). CONCLUSIONS: Higher esd-LDL-c was associated with increased risk of ESKD in people with biopsy-proven DKD, and higher cardiovascular and all-cause mortality risk among those with DM-CKD.

Associations of accelerometer-measured physical activity and sedentary time with renal function and chronic kidney disease: a national population-based study.

Introduction: There is limited information about the relationship between physical activity (PA) and sedentary behaviors in chronic kidney disease (CKD). Therefore, this study aims to explore the associations of accelerometer-measured PA and sedentary behaviors with CKD. Methods: A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey in the 2003-2004 and 2005-2006 survey cycles. A uniaxial accelerometer measured physical activity (PA) and sedentary time (ST). The associations of PA and ST with estimated glomerular filtration rate (eGFR) and odds of CKD adopted the generalized linear regression, multivariable logistic regression, and isotemporal substitution models. Results: A total of 5,990 adults with 605 CKD patients were included in this study. Compared with the individuals in the first quartile group, participants in the fourth quartile of low-intensity physical activity (LIPA), moderate to vigorous physical activity (MVPA), and ST were associated with 52% (35%, 65%) and 42% (14%, 62%) lower odds of CKD and 64% (17%, 131%) higher odds of CKD, respectively. Substituting 30 min/day of ST with equivalent LIPA/MVPA contributed to risk reduction in CKD. Discussion: The findings suggest that increased LIPA and MVPA and reduced ST were associated with a lower risk of CKD and that replacing ST with LIPA may decrease the risk of CKD.

SGLT-2 inhibitors in heart failure and chronic kidney disease: A review for internists.

Despite current therapies, heart failure and chronic kidney disease continue to be major causes of morbidity and mortality. Sodium-glucose cotransporter 2 (SGLT-2) inhibitors have recently become standard-of-care therapy for these conditions. This review summarizes important randomized controlled trials of SGLT-2 inhibitors and guidelines for using these agents in patients with heart failure and chronic kidney disease in both clinic and hospital settings.

Trends in antidiabetes medication use among hospitalised patients with type 2 diabetes: a retrospective single-centre cohort study.

OBJECTIVES: Novel antidiabetes medications with proven cardiovascular or renal benefit, such as sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RA), have been introduced to the market. This study explored the 4-year trends of antidiabetes medication use among medical hospitalisations with type 2 diabetes (T2D). DESIGN: Retrospective cohort study. SETTING: Tertiary care hospital in Switzerland. PARTICIPANTS: 4695 adult hospitalisations with T2D and prevalent or incident use of one of the following antidiabetes medications (metformin, dipeptidyl peptidase-4 inhibitors (DPP-4i), sulfonylureas, GLP-1 RA, SGLT-2i, short-acting insulin or long-acting insulin), identified using electronic health record data. Quarterly trends in use of antidiabetes medications were plotted overall and stratified by cardiovascular disease (CVD) and chronic kidney disease (CKD). RESULTS: We observed a stable trend in the proportion of hospitalisations with T2D who received any antidiabetes medication (from 77.6% during 2019 to 78% in 2022; p for trend=0.97). In prevalent users, the largest increase in use was found for SGLT-2i (from 7.4% in 2019 to 21.8% in 2022; p for trend <0.01), the strongest decrease was observed for sulfonylureas (from 11.4% in 2019 to 7.2% in 2022; p for trend <0.01). Among incident users, SGLT-2i were the most frequently newly prescribed antidiabetes medication with an increase from 26% in 2019 to 56.1% in 2022 (p for trend <0.01). Between hospital admission and discharge, SGLT-2i also accounted for the largest increase in prescriptions (+5.1%; p<0.01). CONCLUSIONS: These real-world data from 2019 to 2022 demonstrate a significant shift in antidiabetes medications within the in-hospital setting, with decreased use of sulfonylureas and increased prescriptions of SGLT-2i, especially in hospitalisations with CVD or CKD. This trend aligns with international guidelines and indicates swift adaptation by healthcare providers, signalling a move towards more effective diabetes management.

Perspectives of Chronic Kidney Disease Patients on Readiness for Advance Care Planning at Komfo Anokye Teaching Hospital, Ghana.

This study examined the impact of advance care planning (ACP) on the quality of life for patients with chronic kidney disease (CKD) at Komfo Anokye Teaching Hospital in Ghana. It specifically investigated patients' perspectives on their readiness for ACP. Utilizing a qualitative descriptive design, one-on-one interviews were conducted with CKD patients at the renal clinic, employing a semi-structured interview guide for thematic analysis of audio data. The findings revealed a gap in understanding among CKD patients, with participants acknowledging their vulnerability to renal failure, often linked to a medical history of diabetes and hypertension. Despite recognizing potential outcomes such as dialysis dependency or death, some patients retained hope for a cure, relying on faith. The initial kidney failure diagnosis induced shock and distress, leading many patients to prefer the comfort and familiarity of home-based care, including dialysis. Meanwhile, a minority favored hospital care to protect their children from psychological trauma. Most patients deemed legal preparations unnecessary, citing limited assets or a lack of concern for posthumous estate execution. These insights emphasize the necessity for targeted education and support in ACP to enhance patient outcomes in chronic kidney disease care and end-of-life planning.

Kidney Aging and Chronic Kidney Disease.

The process of aging inevitably leads to an increase in age-related comorbidities, including chronic kidney disease (CKD). In many aspects, CKD can be considered a state of accelerated and premature aging. Aging kidney and CKD have numerous common characteristic features, ranging from pathological presentation and clinical manifestation to underlying mechanisms. The shared mechanisms underlying the process of kidney aging and the development of CKD include the increase in cellular senescence, the decrease in autophagy, mitochondrial dysfunction, and the alterations of epigenetic regulation, suggesting the existence of potential therapeutic targets that are applicable to both conditions. In this review, we provide a comprehensive overview of the common characteristics between aging kidney and CKD, encompassing morphological changes, functional alterations, and recent advancements in understanding the underlying mechanisms. Moreover, we discuss potential therapeutic strategies for targeting senescent cells in both the aging process and CKD.

Role of Histone Modifications in Kidney Fibrosis.

Chronic kidney disease (CKD) is characterized by persistent kidney dysfunction, ultimately resulting in end-stage renal disease (ESRD). Renal fibrosis is a crucial pathological feature of CKD and ESRD. However, there is no effective treatment for this condition. Despite the complex molecular mechanisms involved in renal fibrosis, increasing evidence highlights the crucial role of histone modification in its regulation. The reversibility of histone modifications offers promising avenues for therapeutic strategies to block or reverse renal fibrosis. Therefore, a comprehensive understanding of the regulatory implications of histone modifications in fibrosis may provide novel insights into more effective and safer therapeutic approaches. This review highlights the regulatory mechanisms and recent advances in histone modifications in renal fibrosis, particularly histone methylation and histone acetylation. The aim is to explore the potential of histone modifications as targets for treating renal fibrosis.

Advanced Interatrial Block across the Spectrum of Renal Function.

Background and Objective: Interatrial block (IAB) is defined as a conduction delay between the right and left atria. No data are available about the prevalence of both partial IAB and advanced IAB among the different stages of chronic kidney disease. The aim of this study was to describe the prevalence and type of advanced IAB across the spectrum of renal function, including patients on dialysis and the clinical characteristics associated with advanced IAB. Materials and Methods: Retrospective, single-center study of 151 patients consecutively admitted to the Nephrology and Ophthalmology Unit for 3 months. The study population was divided into three groups according to stages of chronic kidney disease. We evaluated the prevalence and pattern of IAB among the groups and the clinical characteristics associated with advanced IAB. Results: The prevalence of partial IAB was significantly lower in end-stage kidney disease (ESKD) group compared to control group (36.7% vs. 59.6%; p = 0.02); in contrast the prevalence of advanced IAB was significantly higher in both chronic kidney disease (CKD) (17.8% vs. 5.3%, p = 0.04) and ESKD group (24.5% vs. 5.3%, p = 0.005) compared to control group. The atypical pattern of advanced IAB was more frequent in both the ESKD and CKD group than in the control group (100% and 75% vs. 33.3%; p = 0.02). Overall, among patients that showed advanced IAB, 17 (73.9%) showed an atypical pattern by morphology and 2 (8.7%) showed an atypical pattern by duration of advanced IAB. The ESKD group was younger than the control group (65.7 ± 12.3 years vs. 71.3 ± 9.9 years; p = 0.01) and showed a higher prevalence of beta blockers (42.9% vs. 19.3%; p = 0.009), as in the CKD group (37.8% vs. 19.3%; p= 0.04). Conclusions: The progressive worsening of renal function was associated with an increasing prevalence of advanced IAB. Advanced IAB may be a sign of uremic cardiomyopathy and may suggest further evaluation with long-term follow-up to investigate its prognostic significance in chronic kidney disease.

Emerging therapeutic landscape: Incretin agonists in chronic kidney disease management.

The increasing incidence of chronic kidney disease (CKD) poses a significant public health concern, prompting heightened attention to its treatment. Incretins, including glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide, are intestinal peptides released after nutrient intake, known for their hypoglycemic effects in diabetes management. Recent advancements highlight the promising outcomes of GLP-1 receptor agonists in reducing CKD risk factors and improving renal outcomes. The multifaceted functions of GLP-1, such as its anti-obesity, anti-hypertensive, anti-hyperglycemic, anti-lipid, anti-inflammatory, and endothelial function protective properties, contribute to its potential as a therapeutic agent for CKD. Although experiments suggest the potential benefits of incretin in CKD, a comprehensive understanding of its specific mechanisms is still lacking. This review aims to provide a detailed examination of current evidence and potential future directions, emphasizing the promising yet evolving landscape of incretin agonists in the context of CKD.

Multi-omics analysis of kidney tissue metabolome and proteome reveals the protective effect of sheep milk against adenine-induced chronic kidney disease in mice.

Chronic kidney disease (CKD) is characterized by impaired renal function and is associated with inflammation, oxidative stress, and fibrosis. Sheep milk contains several bioactive molecules with protective effects against inflammation and oxidative stress. In the current study, we investigated the potential renoprotective effects of sheep milk and the associated mechanisms of action in an adenine-induced CKD murine model. Sheep milk delayed renal chronic inflammation (e.g., significant reduction in levels of inflammatory factors Vcam1, Icam1, Il6, and Tnfa), fibrosis (significant reduction in levels of fibrosis factors Col1a1, Fn1, and Tgfb), oxidative stress (significant increase in levels of antioxidants and decrease in oxidative markers), mineral disorders, and renal injury in adenine-treated mice (e.g. reduced levels of kidney injury markers NGAL and KIM-1). The combined proteomics and metabolomics analyses showed that sheep milk may affect the metabolic processes of several compounds, including proteins, lipids, minerals, and hormones in mice with adenine-induced chronic kidney disease. In addition, it may regulate the expression of fibrosis-related factors and inflammatory factors through the JAK1/STAT3/HIF-1α signaling pathway, thus exerting its renoprotective effects. Therefore, sheep milk may be beneficial for patients with CKD and should be evaluated in preclinical and clinical studies.

Proteomic analysis of endothelial cells and extracellular vesicles in response to indoxyl sulfate: Mechanisms of endothelial dysfunction in chronic kidney disease.

AIMS: Cardiovascular pathology is the main cause of death in chronic kidney disease (CKD) patients. CKD is associated with the accumulation of uremic toxins in the bloodstream, and indoxyl sulfate (IS) is one of the most abundant uremic toxins found in the blood of CKD patients. We conducted an in vitro study to assess the mechanisms underlying the IS-induced endothelial dysfunction that could lead to cardiovascular diseases. We also studied their extracellular vesicles (EVs) owing to their capacity to act as messengers that transmit signals through their cargo. MAIN METHODS: EVs were characterized by nanoparticle tracking analysis, transmission electron microscopy, flow cytometry, and tetraspanin expression. Cell lysates and isolated EVs were analyzed using liquid chromatography coupled with mass spectrometry, followed by Gene Set Enrichment Analysis to identify the altered pathways. KEY FINDINGS: Proteomic analysis of endothelial cells revealed that IS causes an increase in proteins related to adipogenesis, inflammation, and xenobiotic metabolism and a decrease in proliferation. Extracellular matrix elements, as well as proteins associated with myogenesis, response to UV irradiation, and inflammation, were found to be downregulated in IS-treated EVs. Fatty acid metabolism was also found to be increased along with adipogenesis and inflammation observed in cells. SIGNIFICANCE: The treatment of endothelial cells with IS increased the expression of proteins related to adipogenesis, inflammation, and xenobiotic metabolism and was less associated with proliferation. Furthermore, EVs from cells treated with IS may mediate endothelial dysfunction, since they present fewer extracellular matrix elements, myogenesis, inflammatory factors, and proteins downregulated in response to UV radiation.

Bariatric surgery and the diseased kidney: a 5-year assessment of safety and postoperative renal outcomes.

BACKGROUND: Obesity and its related medical conditions are well-established contributors to the development of chronic kidney disease (CKD). Metabolic and bariatric surgery (MBS), including procedures such as sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), is a potential intervention for these individuals. However, the heightened risk of postoperative complications casts doubts on the suitability of MBS in this population. Our aim is to evaluate the long-term safety, anthropometric and renal outcomes of MBS in patients with CKD. METHODS: A retrospective review of patients who underwent primary laparoscopic MBS with a BMI ≥ 35 kg/m2 and a preoperative diagnosis of stage 2 to 5 CKD. Criteria for CKD diagnosis and staging were based on estimated glomerular filtration rate measurements in accordance with established guidelines. Anthropometric and renal outcomes were measured at 3-, 6-, 12-, 24- and 60-months postoperatively. RESULTS: A total of 302 patients (177 SG, 125 RYGB) were included. RYGB was preferred for patients with stage 3 CKD, while SG was more common in stages 4 and 5. At 5-year follow-up, percentage of total weight loss was higher in the RYGB cohort compared to SG (25.1% vs. 18.6%, p = 0.036). Despite SG patients having more advanced CKD, the incidence of late complications was significantly higher following RYGB, with 11 incidents (8.8%), compared to the SG cohort with only 4 cases (2.3%) (p = 0.014). In those with preoperative CKD stage 3, 76 patients (43.2%) improved to stage 2, with another 9 patients (5.1%) improving further to stage 1. Of all patients, 63 (20.8%) eventually received a successful renal transplant. CONCLUSIONS: MBS is an effective strategy for sustained weight loss in patients with CKD with acceptable complications rates. RYGB leads to a higher percentage of overall weight loss, albeit with an elevated likelihood of late surgical complications. Future studies are needed to determine the safety of MBS in this demographic.

Gut microbiota dynamics and association with chronic kidney disease: A longitudinal study within the PREDIMED-Plus trial.

AIMS: Chronic kidney disease (CKD) represents a global health concern, disproportionately affecting the elderly with heightened cardiovascular risk. The emerging focus on the gut microbiota's role in CKD pathophysiology represents a pivotal area in nephrology; however, the evidence on this topic is limited. This observational prospective study, in the framework of the PREDIMED-Plus trial, investigates associations between gut microbiota composition and the 1-year trajectory of CKD in 343 participants aged 55-75 years with high cardiovascular risk. MATERIALS AND METHODS: Kidney function was assessed at baseline and at 1-year of follow-up through the estimated glomerular filtration rate based on cystatin C (eGFR-CysC) and CKD defined by eGFR-CysC <60 mL/min/1.73 m2. Participants were grouped based on their 1-year CKD trajectory: Group 1 maintained normal status or improved from CKD to normal, while Group 2 maintained CKD or worsened from normal to CKD. Fecal microbiota composition was assessed through 16S sequencing. KEY FINDINGS: We observed differences in gut microbiota composition between CKD trajectory groups. Notably, the baseline relative abundance of Lachnoclostridium and Lachnospira, both butyrate-producing genera, was lower in participants maintaining or progressing to CKD. Longitudinally, a decrease in Lachnospira abundance was associated with CKD progression. The improved Chao1 index after 1-year follow-up suggests a link between enhanced microbial richness and stable/better kidney function. SIGNIFICANCE: The findings underscore the potential of gut microbiota analysis in non-invasively monitoring CKD, especially in older populations, and hint at future interventions targeting gut microbiota to manage CKD progression. Further research is needed for causal relationships and generalizability.

Bibliometric and visual analyses of advancements in chronic kidney disease management.

Chronic kidney disease (CKD) is characterized by high incidence, prolonged course, significant health damage, and a heavy societal burden. Understanding the history and content of CKD research is crucial to further its recognition and management, in addition to reducing its individual and societal burdens. This study aimed to assess the management history of CKD to provide a foundation for clinical medical staff to systematically understand its evolution. The Web of Science Core Collection database was screened for CKD management studies published between January 1, 1948, and December 31, 2021. From the search results, we performed statistical descriptions of the publication date, volume, and type. Using VOS-viewer 1.6.19, variables from the included articles were obtained for keyword co-occurrence clustering and sequence analyses to determine research themes, segment phases based on publication volumes over varied timeframes, assess the dynamic progression of CKD management, and anticipate future research trends. In total, 26,133 articles met the inclusion criteria. The analysis revealed 3 stages of CKD management research: the slow development stage (1948-1998), which was initiated by epidemiological studies without ideal clustering; the steady growth stage (1999-2010), which was focused on CKD complication management and quality-of-life research; and the rapid development stage (2011-2022), which was dominated by 7 major clusters, mainly regarding the treatment and management of severe conditions and management patterns. The CKD research journey is comprised of 3 stages, the contents of which form an interconnected research model. Future research should focus on the establishment of management models and the application of intelligent management tools. Furthermore, this work can serve as a reference for the further expansion of research in this field and in improving its management.

Comfort Level of Patients Undergoing Hemodialysis and Associated Factors in Turkey: A Cross-Sectional Study.

BACKGROUND: Hemodialysis is one of the treatment methods for chronic kidney disease, which is a common disease around the world. The problems that occur during the hemodialysis process may cause discomfort in patients. Therefore, it is important to regularly evaluate the concept of comfort in hemodialysis patients. AIM: To determine the comfort level of patients undergoing hemodialysis and the associated factors. METHODS: This study was a descriptive cross-sectional study conducted among 95 patients who had been undergoing hemodialysis for at least 6 months. Data were collected using the sociodemographic characteristics form and the Hemodialysis Comfort Scale (HDCS). RESULTS: The mean age of the participants was 58.37 ± 16.62 years. The median duration of hemodialysis was 5 (1-25) years. A total of 51% of the patients were male, 54.7% were married, 34.7% had completed primary school, and 85.3% had a comorbid chronic disease. The mean hemodialysis comfort score was 23.85 ± 6.93. The mean score was significantly higher in male patients (P = 0.041) and those without comorbid chronic disease (P = 0.013). There was a significant negative correlation between the age of hemodialysis patients and the mean hemodialysis comfort score (r = -0.260, P = 0.011). CONCLUSION: The comfort level was significantly better in hemodialysis patients who were male, those without comorbid disease, and those who were younger. There is a need to periodically assess the comfort level of hemodialysis patients and intervene when necessary in order to improve their quality of life.

Renal Complications in Portal Hypertension.

Acute kidney injury (AKI) is a common complication among patients with decompensated cirrhosis and its development is associated with worse prognosis in terms of survival. Patients with decompensated cirrhosis may develop a unique type of AKI, known as hepatorenal syndrome (HRS-AKI), characterized by marked impairment of kidney function due to haemodynamic changes that occur in late stages of liver cirrhosis. Besides, patients with cirrhosis also may develop chronic alterations of kidney function (chronic kidney disease, CKD), the incidence of which is increasing markedly and may be associated with clinical complications. The aim of this review is to provide the reader with an update of the most relevant aspects of alterations of kidney function in patients with cirrhossi that may be useful for theri clinical practice.

Vitamin K for Vascular Calcification in Kidney Patients: Still Alive and Kicking, but Still a Lot to Learn.

Patients with chronic kidney disease (CKD) suffer disproportionately from a high burden of cardiovascular disease, which, despite recent scientific advances, remains partly understood. Vascular calcification (VC) is the result of an ongoing process of misplaced calcium in the inner and medial layers of the arteries, which has emerged as a critical contributor to cardiovascular events in CKD. Beyond its established role in blood clotting and bone health, vitamin K appears crucial in regulating VC via vitamin K-dependent proteins (VKDPs). Among these, the matrix Gla protein (MGP) serves as both a potent inhibitor of VC and a valuable biomarker (in its inactive form) for reflecting circulating vitamin K levels. CKD patients, especially in advanced stages, often present with vitamin K deficiency due to dietary restrictions, medications, and impaired intestinal absorption in the uremic environment. Epidemiological studies confirm a strong association between vitamin K levels, inactive MGP, and increased CVD risk across CKD stages. Based on the promising results of pre-clinical data, an increasing number of clinical trials have investigated the potential benefits of vitamin K supplementation to prevent, delay, or even reverse VC, but the results have remained inconsistent.

Dietary Phosphorus Levels Influence Protein-Derived Uremic Toxin Production in Nephrectomized Male Rats.

Gut microbiota-derived uremic toxins (UT) accumulate in patients with chronic kidney disease (CKD). Dietary phosphorus and protein restriction are common in CKD treatment, but the relationship between dietary phosphorus, a key nutrient for the gut microbiota, and protein-derived UT is poorly studied. Thus, we explored the relationship between dietary phosphorus and serum UT in CKD rats. For this exploratory study, we used serum samples from a larger study on the effects of dietary phosphorus on intestinal phosphorus absorption in nephrectomized (Nx, n = 22) or sham-operated (sham, n = 18) male Sprague Dawley rats. Rats were randomized to diet treatment groups of low or high phosphorus (0.1% or 1.2% w/w, respectively) for 1 week, with serum trimethylamine oxide (TMAO), indoxyl sulfate (IS), and p-cresol sulfate (pCS) analyzed by LC-MS. Nx rats had significantly higher levels of serum TMAO, IS, and pCS compared to sham rats (all p < 0.0001). IS showed a significant interaction between diet and CKD status, where serum IS was higher with the high-phosphorus diet in both Nx and sham rats, but to a greater extent in the Nx rats. Serum TMAO (p = 0.24) and pCS (p = 0.34) were not affected by dietary phosphorus levels. High dietary phosphorus intake for 1 week results in higher serum IS in both Nx and sham rats. The results of this exploratory study indicate that reducing dietary phosphorus intake in CKD may have beneficial effects on UT accumulation.