Journal of Nephrology最新文献

Background: Medullary sponge kidney is an entity characterized by pre-calyceal dilatation of the renal tubules, whose pathophysiology is unknown. Tubular anomalies have been described, suggesting impaired medullary function. To better characterize these patients, tools for assessing medullary function and structure are needed. The latter can be evaluated with functional magnetic resonance imaging (fMRI), using blood-oxygen-level-dependent imaging, which quantifies tissue oxygenation, and diffusion-weighted-imaging and T1-mapping sequences which allow fibrosis assessment. The aim of this study was to deeply phenotype medullary sponge kidney patients.

Methods: We carried out fMRI, measured glomerular filtration rate (mGFR) by iohexol clearance, and metabolic assessment of urolithiasis in patients with medullary sponge kidney and in healthy controls. The primary endpoint was the comparison of R2*, inversely proportional to oxygen content, measured by blood-oxygen-level-dependent MRI. Secondary endpoints included comparison of T1 and apparent diffusion coefficient, comparison of GFR between medullary sponge kidney patients and controls, and the correlations between fMRI, GFR and biological abnormalities in medullary sponge kidney.

Results: Twenty patients with medullary sponge kidney were included, as well as 13 controls. We observed a higher R2* cortex-to-medulla ratio in medullary sponge kidney patients compared to controls (0.60 vs. 0.55; p = 0.04). No difference was observed for T1 and apparent diffusion coefficient cortex-to-medulla ratio. mGFR was significantly lower in medullary sponge kidney patients (90 ml/min/1.73m² vs 78 ml/min/1.73m²; p = 0.008) although estimated GFR did not differ. Medullary cysts were visible on MRI in 60% of medullary sponge kidney patients.

Conclusion: We identified impaired renal oxygenation in patients with medullary sponge kidney. We did not find evidence of kidney fibrosis in medullary sponge kidney. GFR estimation was not accurate in medullary sponge kidney patients. MRI can visualize medullary cystic appearance of medullary sponge kidney.

Background: Chronic kidney disease (CKD) is a global health concern, contributing to high morbidity, mortality, and cardiovascular risk. Intensive monitoring of clinical parameters and timely therapeutic interventions can improve disease management.

Methods: This study developed and tested a telemonitoring system using wearable sensors and a smartphone app to support chronic kidney disease patients on dialysis or during pre-dialysis care. The system was evaluated for its feasibility and sustainability, analyzing the usability, patient adherence, and potential impact on healthcare outcomes. Eight patients tested the prototype.

Results: Results showed that the overall protocol adherence rate was 8.8%, much lower than expected. Patients enrolled in pre-dialysis care demonstrated higher adherence compared to patients living with hemodialysis or peritoneal dialysis. While most users found the system intuitive, some reported that the time requested for measurements was excessive. Recommendations for further development include improving reminder notifications and using multi-parametric devices to streamline data collection.

Conclusions: In patients with CKD, intensive remote monitoring could allow the acquisition of clinical data to facilitate achievement of clinical targets by timely therapeutic adjustments. However, long-term monitoring was not widely accepted. Further testing with larger samples and future refinements, integrating miniaturized wearable devices and AI-driven analytics, could enhance adherence and personalized care.

Background: Physical activity is important for health and longevity, but little is known on patients living with chronic kidney disease (CKD). In fact, most studies in patients with CKD have relied on self-reported data, highlighting an unmet need for studies using objective measurements. We investigated the association between device-measured physical activity and adverse outcomes by CKD status.

Methods: This study included 65,088 participants without CKD and 1170 with CKD, from the UK Biobank, who completed a one-week accelerometer assessment. CKD was defined as either baseline estimated glomerualr filtration rate (eGFR) < 60 mL/min/1.73 m² or two consecutive eGFR measurements < 60 mL/min/1.73 m² from primary care data recorded prior to the accelerometer study. The main predictor was device-measured physical activity, categorized into quartiles. The primary outcome was all-cause mortality; secondary outcomes included three-point major adverse cardiovascular events and non-cardiovascular death. We used cause-specific competing risk models adjusting for multiple covariates.

Results: Over a median follow-up period of 8.04 years, all-cause mortality occurred in 2028 (3.06%) participants, with an incidence of 3.84/1000 person-years. Compared with the 1st quartile, the adjusted hazard ratios (95% confidence intervals) for all-cause mortality for the 2nd, 3rd, and 4th quartiles were 0.72 (0.64-0.80), 0.65 (0.57-0.72), and 0.57 (0.49-0.66) in non-CKD, and 0.56 (0.33-0.96), 0.42 (0.23-0.79), and 0.33 (0.16-0.68) in CKD participants. This pattern was consistent for non-cardiovascular deaths. However, device-measured physical activity was not significantly associated with three-point major adverse cardiovascular events in CKD, while a significant association was observed in the non-CKD group.

Conclusion: Device-measured physical activity showed differential associations with outcomes by CKD status. The null association between physical activity and three-point major adverse cardiovascular events in CKD suggests a complex cardiovascular pathophysiology in this population.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a progressive genetic disease with few effective treatments available to slow the decline in kidney function. In ADPKD, there has been increasing interest in ketogenic diets, largely based on experimental data showing favorable effects on cyst growth and kidney function. High-quality clinical trials of sufficient duration using clinically relevant endpoints (estimated glomerular filtration rate [eGFR], kidney volume) are crucial to establish efficacy and safety in ADPKD. Although extensive reviews have been published about potential mechanisms of ketogenic diets to slow ADPKD progression, there is no guidance on how these diets should be designed to align with the unique clinical and nutritional needs of people with ADPKD. Potential safety and feasibility concerns for ketogenic diets (risk for nephrolithiasis and cardiovascular disease) should be evaluated in clinical trials to determine whether adherence to a complex diet can be sustained over years. Prior to embarking on a clinical trial, careful development of an ADPKD-appropriate ketogenic diet is required to mitigate against these risks. Thus, the aim of this narrative review is to provide a framework for the specific nutritional factors that should be considered when developing and designing a ketogenic dietary intervention in future clinical trials involving ADPKD patients.

Background: To increase the diagnostic rate of primary hyperoxaluria type 1 (PH1) in the adult dialysis setting, a prediction model based on five readily available clinical parameters was recently developed and validated in an adult hemodialysis population. To further test the prediction model in clinical practice, this case series describes the retrospective application of the diagnostic algorithm in a group of adult dialysis patients with PH1 treated at different Italian nephrology centers.

Methods: Between January and May 2023, adult patients (≥ 18 years) undergoing chronic hemodialysis with a genetic diagnosis of PH1, followed at 14 Italian nephrology centers, were selected for the retrospective application of the prediction model.

Results: The presence of at least one red flag of the diagnostic algorithm was reported in most patients (14 out of 15; 93%), two red flags were present in four patients (27%), and three red flags in two patients (13%). A history of active nephrolithiasis was the most common clinical feature (87% of patients), followed by early dialysis initiation, nephrocalcinosis and a family history of CKD (20-27%).

Conclusions: Our study provides further evidence on the real-world application of a simple algorithm, implemented by easily accessible clinical parameters, to be used as a screening tool for diagnosing PH1 in adult patients undergoing dialysis. The successful implementation of this prediction model has the potential to facilitate timely diagnosis, improve patient outcomes, and inform targeted therapeutic interventions in this patient setting.

Background: Person-centered care and trust in physicians influence medication adherence among dialysis patients. However, the mechanisms linking person-centered care to medication adherence, particularly the mediating effect of trust in physicians, remain unclear. This study investigated the interrelationships between person-centered care, trust in physicians, and medication adherence.

Methods: Using a multicenter cross-sectional study of Japanese adults receiving outpatient hemodialysis at six dialysis centers, person-centered care was assessed using the 13-item Japanese Primary Care Assessment Tool-Short Form (JPCAT-SF), which included longitudinality and care coordination. Trust in physicians was measured using the five-item Wake Forest Physician Trust Scale. Medication adherence was measured using the 12-item Adherence Starts Knowledge (ASK-12) scale. General linear models examined person-centered care, physician trust, and medication adherence relationships. Mediation analysis determined how much trust in physicians mediated the person-centered care-medication adherence relationship.

Results: A total of 483 patients, with median age and dialysis vintage of 71.9 and 5.7 years, respectively, were included in the analysis. High-quality person-centered care was associated with lower barriers to medication adherence in a dose-response manner across JPCAT-SF quartiles compared to no usual source of care. Trust in physicians partially mediated this relationship in a dose-response pattern, with the proportion of the indirect effect increasing from 16.1% (95% CI 4.5-33.8%) in Q2 to 33.3% (95% CI 17.4-65.5%) in Q4. Similar findings were observed for person-centered care subdomains.

Conclusions: High-quality person-centered care was associated with medication adherence, with trust in physicians playing a key mediating role. Strategies to enhance medication adherence in hemodialysis patients should incorporate multidimensional person-centered care approaches, building trust and strengthening continuity and care coordination.

Background: Ultrafiltration (UF) insufficiency in peritoneal dialysis (PD) often leads to transfer to hemodialysis. Therefore, strategies to prolong time on therapy are needed. The use of a combined crystalloid and colloid solution, also called bimodal PD, can help improve UF.

Methods: We propose a method for reconstituting bimodal solutions. Three bimodal PD solutions, with respectively 100 ml (solution 100), 150 ml (solution 150) and 200 ml (solution 200) of 30% glucose for intravenous (IV) infusion, were prepared to explore whether a variation of the amount of glucose can be useful to adapt the PD prescription. Biochemical analyses and computer simulations (based on the 3-pore model) were carried out on these solutions to assess their Na and UF efficiency. Data on the clinical use of solution 200 were retrospectively collected.

Results: The addition of 30% glucose to the icodextrin 7.5% bag resulted in a low-sodium solution. After a 6-h dwell with the solution 200, in a high-average transporter patient with a Dialysate over Plasma (D/P) creatinine at 0.7, the theoretical volume of ultrafiltration was 943.0 ml and the amount of sodium removed was 8.29 g compared to 650.3 ml and 6.14 g with solution 100. When considering the glucose absorption during the dwell, solution 100 was associated with the best ultrafiltration efficiency, defined as the volume of UF obtained divided by the amount of free glucose absorbed, and the best sodium efficiency, defined as the mass of sodium removed divided by the amount of free glucose absorbed during the dwell. Four patients used bimodal solution 200 for at least 2 months between 2018 and 2023 and were included in the retrospective study on clinical use. Mean time spent on PD before bimodal PD first prescription was 26 months (6-38 months). Median time spent using a bimodal PD regimen was 15 months (12-19 months). No episodes of peritonitis were reported while using this strategy.

Conclusion: Our study describes a simple method to prepare a bimodal solution. Biochemical and computer study of 3 solutions suggested that using 100 ml of 30% glucose to 2 L of icodextrin 7.5% gives the best UF and Na efficiency.