Glomerular filtration rate (GFR) is recognized as the most reliable indicator of renal function and is usually estimated based on the serum creatinine equations. However, the reliability of these equations in specific regions needs to be properly quantified. We evaluated the applicability of the abbreviated MDRD equation (aGFR), the modified abbreviated MDRD equation (maGFR), the CKD-EPI creatinine equation (C-GFRcr), the CKD-EPI creatinine-cystatin C equation (C-GFRcr-cys), the EKFC creatinine equation (E-GFRcr), and the EKFC creatinine-cystatin C equation (E-GFRcr-cys) to chronic kidney disease (CKD) patients in Chongqing, China.

A total of 234 adult patients with CKD were selected for the study. Their sex, age, and etiology of CKD were recorded, and serum creatinine and cystatin C were measured and traceable to primary reference materials. The technetium 99 m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) renal scintigraphy was used as the reference method for GFR measurement. Six GFR estimation equations were analyzed in the overall analysis and across various stages of CKD to evaluate differences, absolute differences, bias, precision, and accuracy.

In the validation dataset, the differences for maGFR were smaller compared to other equations, while those for C-GFRcr-cys and E-GFRcr-cys were larger. The bias for C-GFRcr-cys and E-GFRcr-cys was significantly higher than that of the other equations, although all six equations exhibited similar levels of precision. In CKD stages 1 through 3, the accuracy of C-GFRcr-cys and E-GFRcr-cys was significantly lower when compared to the other equations. Conversely, in CKD stages 4 and 5, maGFR and E-GFRcr-cys demonstrated significantly greater accuracy than the other equations. In CKD stage 1, maGFR misclassified only 5.21 % of patients, whereas C-GFRcr-cys and E-GFRcr-cys had significantly higher misclassification rates of 66.67 % and 68.75 %, respectively, compared to the other equations.

Overall, maGFR performed better than other equations and can be used as a confirmatory test in CKD patients in Chongqing, China.

Some living kidney donors (LKDs) experience proteinuria after donation. Based on several studies, preoperative non-donated side kidney volume (pre-KV) and postoperative percentage change in preserved kidney hypertrophy (%PKH) are associated with proteinuria. This study explored the association of the combination of pre-KV and %PKH with new-onset proteinuria.

This single-center, retrospective, observational study included eligible LKDs who underwent donor nephrectomy between January 2008 and July 2022 (N = 195). Among those, LKDs in whom KV and either urinary protein or albumin were obtained both pre-donation and 1 year post-donation were finally included (N = 70). The LKDs were assigned to four groups according to the mean body surface area-adjusted pre-KV and %PKH, and their association with the occurrence of proteinuria or albuminuria was investigated.

Among the 70 LKDs, mean age was 59.8 ± 7.9 years, and 50 (71.4%) were females. The mean preoperative estimated glomerular filtration rate, %PKH, and pre-KV was 78.0 ± 13.6 mL/min/1.73 m2, 20.3 ± 7.0%, and 161.4 ± 24.1 cm3/1.73 m2, respectively. During the 2.4 year follow-up period, there was no significant difference in the occurrence of proteinuria among the four groups (log-rank test, P = 0.111). However, after adjustment, the large pre-KV and small %PKH group had a significantly higher hazard ratio (HR) for proteinuria than the small pre-KV and large %PKH groups (adjusted HR 3.12, 95% confidence interval: 1.09-8.91, P = 0.033).

Proteinuria is more likely to occur postoperatively in LKDs whose kidneys are already enlarged before donation and cannot appropriately hypertrophy.

Considering the heart failure (HF) pandemic, numerous older adults in the community may exhibit potential cardiac overload or asymptomatic HF without apparent HF diagnosis. This study aimed to examine the distribution of serum N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels in community-dwelling old age adults aged ≥ 75 years, and to investigate the associated factors for each NT-proBNP classification.

A cross-sectional analysis revealed that 52.0% of 611 participants had NT-proBNP ≥ 125 pg/mL. Multinomial logistic regression analysis showed that female sex, older age (80s and 90s), and uncontrolled high blood pressure were significantly associated with 125 ≤ NT-proBNP < 300 pg/mL, while older age (80s and 90s), coronary artery disease, atrial fibrillation, and renal dysfunction were significantly associated with NT-proBNP ≥ 300 pg/mL. Independent association between higher salt intake and NT-proBNP ≥ 300 pg/mL was also observed. Appropriate management of common HF risk factors, such as uncontrolled high blood pressure and high salt intake, is crucial to prevent the progression of overt HF.

The Kidney Disease: Improving Global Outcomes (KDIGO) organization updated its existing clinical practice guideline in 2024 to provide guidance on the evaluation, management, and treatment of chronic kidney disease (CKD) in adults and children who are not receiving kidney replacement therapy.

The KDIGO CKD Guideline Work Group defined the scope of the guideline and determined topics for systematic review. An independent Evidence Review Team systematically reviewed the evidence and graded the certainty of evidence for each of the review topics. Latest searches of the English-language literature were done in July 2023. Final modification of the guideline was informed by a public review process during summer of 2023 involving registered stakeholders.

The full guideline included 28 recommendations and 141 practice points. This synopsis focuses on the recommendations that have the greatest evidence. Practice points reflect the expert opinion of the group where evidence is not that strong. Recommendations include greater emphasis on cystatin C for assessment of glomerular filtration rate, point-of-care testing in remote areas, a shift to an individualized risk-based approach to predict kidney failure, sodium-glucose cotransporter-2 inhibitors for some patients with CKD with and without diabetes, and statin use for adults older than 50 years and CKD. Together the recommendations and practice points provide guidance for how to evaluate and manage persons with CKD.

Although dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, delays the progression of chronic kidney disease (CKD), its effect on patients with autosomal dominant polycystic kidney disease (ADPKD) has not been established. We conducted an open-label, randomized controlled crossover trial to evaluate the additive effects of dapagliflozin in patients with ADPKD receiving tolvaptan.

A total of 27 patients were randomly counterbalanced to receive dapagliflozin 10 mg or usual care without dapagliflozin for 6 months. The primary endpoint was the slope of the estimated glomerular filtration rate (eGFR) determined by linear regression from 1 to 6 months, and the secondary endpoints included changes in total kidney volume (TKV). eGFR was calculated based on creatinine levels (eGFRcr), cystatin C levels (eGFRcys), and the mean of eGFRcr and eGFRcys (eGFRcr-cys).

There were significant attenuations in the eGFRcr-cys and eGFRcys slopes during the dapagliflozin trial compared with the one without dapagliflozin (2.57 ± 7.88 vs. -5.65 ± 9.57 ml/min per 1.73 m2 per year, P = 0.002; 3.91 ± 11.40 vs. -8.43 ± 13.44 ml/min per 1.73 m2 per year, P = 0.003, respectively). Meanwhile, the eGFRcr slope was potentially moderate during the trial with dapagliflozin (1.03 ± 10.78 vs. -3.66 ± 8.88 ml/min per 1.73 m2 per year, P = 0.06). The 6-month change in TKV was significantly attenuated during the trial with dapagliflozin compared with the one without dapagliflozin (-0.44 ± 4.91% vs. 5.04 ± 8.09%, P = 0.01).

In patients with ADPKD treated with tolvaptan, dapagliflozin may have an additive effect in slowing ADPKD progression.

Acute coronary syndromes (ACS) often cause rapid decline in renal and cardiac function. In patients with ACS, combined renal dysfunction is associated with increased overall mortality and cardiovascular events. Physical activity (PA) management may crucially contribute towards protection of renal function in patients with ACS. This article describes the study protocol of a randomized controlled trial (RCT) assessing whether online support for PA management using wearable devices and information communication technology for patients with ACS facing difficulties in participating in outpatient cardiac rehabilitation after discharge can protect renal function following disease onset.

We have designed a two-arm RCT with a 3-month follow-up period. The online support intervention incorporates monitoring of PA, pulse rate, and blood pressure using a wearable device with an accelerometer and a web application system, as well as periodic educational feedback and goal setting. The primary study endpoint is the estimated glomerular filtration rate based on serum cystatin C (eGFRcys). The intervention effect will be assessed using the eGFRcys at 3 months adjusted for baseline values. The secondary endpoints are the urine albumin/creatinine ratio, brain natriuretic peptide levels, average step count, peak oxygen uptake, quality of life, and incidence of adverse events.

This RCT will provide evidence regarding the effectiveness of online support for PA management as a renal protection strategy following ACS onset. This novel strategy not only mitigates barriers impeding participation in outpatient cardiac rehabilitation and protects cardiac and renal function in patients with ACS, but also may contribute towards improving survival and recurrence rates, preventing dialysis, and reducing medical and long-term care costs.

The trial was registered in the Japan Registry of Clinical Trials on July 5, 2024. The registration number is jRCT1022240014 (Impact of Online Support of Physical Activity Management Using a Wearable Device on Renal Function in Patients with Acute Coronary Syndrome).

We describe the case of a 25-year-old male with Duchenne muscular dystrophy and acute kidney injury who was receiving mechanical ventilation. The patient's estimated glomerular filtration rate (eGFR) was assessed using formulas based on creatinine, cystatin C, and inulin levels over time during the recovery of his renal function. The creatinine-based eGFR was extremely high throughout the study period. The Cystatin C-based eGFR was also higher than the inulin clearance. These findings suggest that cystatin C-based eGFR may also exceed inulin clearance in patients with an extremely reduced fat mass, in addition to a reduced muscle mass.

Recent studies have reported the prognostic implications of the discordance between creatinine-based and cystatin C-based estimated glomerular filtration rates (eGFRcr and eGFRcys, respectively); however, the associations of protein intake with the eGFR discordance have not been investigated. The present study investigated whether protein intake was associated with the discordance between eGFRcr and eGFRcys.

We cross-sectionally analyzed data from a Japanese community-based cohort including 6,143 participants (50.7% women; age range, 40-97 years). Protein intake was estimated by food groups derived from a validated food frequency questionnaire. As a measure of discordance, we modeled the ratio of eGFRcys and eGFRcr (eGFRcys divided by eGFRcr) continuously in multivariable linear regression models and categorically (<0.8, 0.8-1.1, and ≥1.2) in multinomial logistic regression models. We analyzed men and women separately given their distinct dietary patterns.

The mean eGFR ratio was 1.15 in men and 1.19 in women. In multivariable linear regression analysis, total protein was positively associated with the eGFR ratio in men (regression coefficient, 0.005 [95% confidence interval, 0.003, 0.007]). When animal and plant proteins were analyzed separately, a significant positive association was seen for animal protein only in men (0.005 [0.003, 0.007]). The results were similar when we modeled protein intake categorically by multinomial logistic regression.

This study suggests intake of dietary protein, especially animal protein in men, as a determinant of eGFR discordance. Future studies exploring eGFR discordance and health outcomes should consider simultaneously assessing dietary protein intake.

An increase in proximal tubule fluid phosphate concentration is caused by increased serum fibroblast growth factor-23 (FGF23) levels, which resulted in renal tubular damage in a mouse model of chronic kidney disease (CKD). However, few human studies have supported this concept. This study aimed to explore the association among estimated proximal tubule fluid phosphate concentration (ePTFp), serum FGF23 levels, and renal tubular damage biomarkers in middle-aged and older populations with mild decline in renal function.

This cross-sectional study included 218 participants aged ≥45 with CKD stages G2-G4. Anthropometric measurements, blood tests, spot urine biomarkers, renal ultrasonography, cardiovascular assessment, smoking status, and medication usage were obtained in the morning in fasted states. The ePTFp was calculated using serum creatinine, urine phosphate, and creatinine concentrations. Urinary β2-microglobulin (β2-MG) and liver-type fatty acid-binding protein (L-FABP) levels were evaluated to assess renal tubular damage.

PTFp, serum FGF23, urinary β2-MG, and urinary L-FABP levels increased with CKD stage progression (stages G2, G3, and G4). However, serum and urine phosphate concentrations were comparable across the CKD stages. Univariate analysis revealed a stronger correlation of ePTFp with serum FGF23, urinary β2-MG, and urinary L-FABP levels than with the corresponding serum and urine phosphate concentrations. Multivariate analyses demonstrated that increased ePTFp was independently associated with elevated serum FGF23 and urinary β2-MG levels, even after adjusting for potential covariates, including the estimated glomerular filtration rate and urinary albumin-to-creatinine ratio.

Our results are consistent with the concept in mouse model and suggest that increased ePTFp are associated with increased serum FGF23 levels and renal tubular damage during the early stages of CKD.

This study focuses on mild-to-moderate severity cases to examine the triggers initiating kidney injury.

Patients aged ≥18 years with suspected heat-related illnesses at the Juntendo University Hospital Emergency and Primary Care Center between July and September 2020 and June and August 2022 were included.

Blood samples were obtained during their visit, and the patients were categorized into two groups based on their cystatin-based estimated GFR (eGFRcys) values: a kidney injury group (eGFRcys < 60 mL/min/1.73 m2) and a non-kidney injury group (eGFRcys ≥ 60 mL/min/1.73 m2). Inflammation, coagulation, and skeletal muscle damage markers were compared between the groups, and markers related to the early development of kidney injury were examined.

Thirty-five patients were diagnosed with heat-related illnesses, and 10 were diagnosed with kidney injury. White blood cell count was higher in the kidney injury group (P < 0.01), whereas the levels of CRP and Interleukin-6 showed no significant difference between the groups. No statistically significant differences in coagulation markers were observed. In contrast, myoglobin, a marker of skeletal muscle damage, showed elevated levels in the kidney injury group (r = -0.80, P < 0.01) and demonstrated a stronger association with early kidney injury than creatine kinase (r = -0.38, P < 0.05).

The predominant mechanism of acute kidney injury in mild to moderate heat-related illnesses appears to be tubular damage caused by myoglobin. Measuring myoglobin levels is essential to identify and exclude patients at risk of acute kidney injury due to heat-related illnesses.

Assessing glomerular filtration rate (GFR) is critical for diagnosis, staging, and management of kidney disease. However, accuracy of estimated GFR (eGFR) is limited by large errors (>30% error present in >10-50% of patients), adversely impacting patient care. Errors often result from variation across populations of non-GFR determinants affecting the filtration markers used to estimate GFR. We hypothesized that combining multiple filtration markers with non-overlapping non-GFR determinants into a panel GFR could improve eGFR accuracy, extending current recognition that adding cystatin C to serum creatinine improves accuracy. Non-GFR determinants of markers can affect the accuracy of eGFR in two ways: first, increased variability in the non-GFR determinants of some filtration markers among application populations compared to the development population may result in outlying values for those markers. Second, systematic differences in the non-GFR determinants of some markers between application and development populations can lead to biased estimates in the application populations. Here, we propose and evaluate methods for estimating GFR based on multiple markers in applications with potentially higher rates of outlying predictors than in development data. We apply transfer learning to address systematic differences between application and development populations. We evaluated a panel of 8 markers (5 metabolites and 3 low molecular weight proteins) in 3,554 participants from 9 studies. Results show that contamination in two strongly predictive markers can increase imprecision by more than two-fold, but outlier identification with robust estimation can restore precision nearly fully to uncontaminated data. Furthermore, transfer learning can yield similar results with even modest training set sample size. Combining both approaches addresses both sources of error in GFR estimates. Once the laboratory challenge of developing a validated targeted assay for additional metabolites is overcome, these methods can inform the use of a panel eGFR across diverse clinical settings, ensuring accuracy despite differing non-GFR determinants.

Glomerular filtration rate (GFR) estimation equations have not been extensively validated in the Indian population. Preliminary data showed that the widely used creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICr) 2009 significantly overestimated GFR in Indians. Newer estimated GFR (eGFR) equations based on creatinine and cystatin C, omitting the race, have been recently proposed. We investigated the performance of race-free eGFR equations in the Indian population.

Patients with chronic kidney disease (CKD) and potential kidney donors attending the outpatient clinic at the Postgraduate Institute of Medical Education and Research Chandigarh, India, were screened for enrolment. GFR was measured by urinary clearance of inulin and plasma clearance of iohexol. Performance of eGFR equations (CKD-EPICr(2021), CKD-EPICr-Cys(2021), CKD-EPICr(2009), CKD-EPICr-Cys(2012), CKD-EPICys, 2020Csy-B2M-BTP and 2020Cr-Csy-B2M-BTP, EKFCcr, EKFCcys, and EKFCcr-cys) were assessed against measured GFR (mGFR) using bias, precision, and accuracy (root mean square error [RMSE], mean absolute error [MAE] and P30 [% with eGFR within 30% of mGFR]).

A total of 412 subjects (55% with CKD), average age 47 ± 11 years with an equal distribution of males and females were enrolled. The mean mGFR in the study population was 54.2 ± 30.2 ml/min per 1.73 m2. The average mGFR in the potential kidney donor's subgroup was 79.5 ± 23.2 ml/min per 1.73 m2. Bias was highest for creatinine-based eGFR equations (CKD-EPIcr(2021): -19.2 [-21.3 to -17.0] ml/min per 1.73 m2and CKD-EPIcr(2009): -17.0 [-19.1 to -15.0] ml/min per 1.73 m2). Cystatin C- (either alone or with other markers) based equations were slightly better but still did not reach P30 ≥ 80%.

Race-neutral CKD-EPICr(2021) equation did not significantly improve performance as compared to CKD-EPICr(2009) equation. These observations emphasize the need for developing new eGFR equations for Indians and to standardize the mGFR for easy access to care providers for individualized patient care.

Frailty increases the risk of needing nursing care and significantly affects the life and functional prognosis of older individuals. Early detection and tailored interventions are crucial for maintaining and enhancing their life functions. Recognizing distinct clinical phenotypes is essential for devising appropriate interventions. This study aimed to explore diverse frailty phenotypes, focusing on poor nutrition in older Japanese individuals through observational research.

Twenty-one nursing home residents underwent a comprehensive survey covering physical, blood, dietary, cardiac, cognitive, nutritional, nursing care, frailty, agitated behavior, and gut microbiome assessments (high-throughput 16S rRNA gene sequencing). Using clustering analysis with 239 survey items (excluding gut microbiome), participants were classified into subgroups based on clinical phenotypes, and group characteristics were compared through analysis.

Individuals with moderate or severe frailty and suspected dementia formed subgroups with distinct clinical phenotypes based on nutritional, defecation, and nursing care statuses. The gut microbiome significantly varied among these groups (p = 0.007), indicating its correlation with changes in clinical phenotype. Nutritional status differences suggested poor nutrition as a differentiating factor in the core clinical phenotype.

This study proposes that the gut microbiome differs based on the clinical phenotype of Japanese older individuals with frailty, and targeted interventions addressing the gut microbiome may contribute to preventing frailty in this population.

Chronic kidney disease (CKD) contributes to decreased life expectancy. We examined the association between leisure-time physical activity (LTPA), non-leisure-time physical activity (non-LTPA) and kidney function.

This was a cross-sectional study including 32 162 community-dwelling adults aged ≥ 20 years from the Tohoku Medical MegaBank community-based cohort study. Kidney function was evaluated using cystatin C-based estimated glomerular filtration rate (eGFR) as well as self-reported LTPA and non-LTPA. CKD was defined as either eGFR decline (≤ 60 mL/min/1.73 m2) or presence of albuminuria (albumin-creatinine ≥ 30 mg/g). The association between domain-specific physical activity and kidney function, and CKD prevalence was examined using multivariable-adjusted ordinary least squares and modified Poisson models.

The mean eGFR was 98.1 (± 13.2) mL/min/1.73 m2. 3 185 (9.9%) participants were classified as having CKD. The mean LTPA and non-LTPA levels were 2.9 (± 4.2) and 16.6 (± 14.2) METs-hour/day, respectively. For LTPA, in the adjusted model, the quartile groups with higher levels had a higher kidney function (β, 0.36; 95% confidence intervals [CI], [0.06, 0.66]; p = 0.019 for the 2nd quartile, β, 0.82; 95% CI, [0.51, 1.14]; p < 0.001 for the 3rd quartile, and β, 1.16; 95% CI, [0.83, 1.49]; p < 0.001 for the 4th quartile), whereas there were no apparent associations for prevalence of CKD. For non-LTPA, 4th quartile was associated with decreased eGFR (β, -0.42; 95% CI, [-0.72, -0.11]; p = 0.007) and higher prevalence of CKD prevalence (Prevalence ratio, 1.12; 95% CI, [1.02, 1.24]; p = 0.022). These associations with kidney function remained consistent in the subgroup analyses divided by demographic and biological variables.

We observed a positive association between higher LTPA levels and better kidney function, but not association with CKD prevalence. In contrast, higher non-LTPA was negatively associated with both kidney function and CKD prevalence. These findings suggest that promoting LTPA is beneficial for kidney function.

Accurate preoperative evaluation of renal function in living kidney donor candidates (LKDCs) is crucial to prevent kidney failure after nephrectomy. We examined the performance of various estimated glomerular filtration rate (eGFR) equations, including the new chronic kidney disease epidemiology collaboration (CKD-EPI) equation in LKDCs.

We analyzed 752 LKDCs who were assessed for measured GFR by inulin clearance as part of routine pretransplant examination from 2006 to 2020. CKD-EPI2012 from cystatin C (CKD-EPI12cys), CKD-EPI2021 from creatinine (CKD-EPI21cr), CKD-EPI21cr-cys, Japanese modified (JPN) eGFRcr, and JPN eGFRcys were compared in determining the suitability for LKDCs.

CKD-EPI12cys had the lowest absolute and relative biases, with higher P30 and P10, followed by JPN eGFRcys, CKD-EPI21cr, and CKD-EPI21cr-cys. The root mean square error was least for CKD-EPI12cys, then JPN eGFRcys, CKD-EPI21cr-cys, CKD-EPI21cr, and JPN eGFRcr. CKD-EPI21cr, CKD-EPI12cys, and CKD-EPI21cr-cys estimated GFR higher, whereas JPN eGFRcr estimated GFR lower. At the threshold of 90 mL/min/1.73 m2, CKD-EPI21cr had the highest percentage of misclassification at 37.37%, whereas JPN eGFRcr had the lowest percentage of misclassification at 6.91%. Using the age-adapted approach, JPN eGFRcr had the lowest percentage of misclassification into overestimation at 7.31%. All eGFR had >5.0%, and CKD-EPI21cr had the highest percentage of misclassification at 21.94%. Conversely, CKD-EPI21cr-cys had the lowest percentage of misclassification into underestimation at 3.19%, both at the threshold of 90 mL/min/1.73 m2 and the age-adapted approach. JPN eGFRcr had the highest percentage at 33.38% and 40.69%, respectively.

In evaluating the renal function of Japanese LKDCs, the new CKD-EPI equation had a lower rate of underestimation but a relatively high rate of overestimation. New GFR estimation formulas are needed to be tailored to each ethnic group to enhance the accuracy and reliability of donor selection processes.

The adverse effects of low daily protein intake (DPI) on clinical outcomes in patients with heart failure (HF) are known; however, an optimal DPI to predict event adverse outcomes remains undetermined. Moreover, whether protein restriction therapy for chronic kidney disease is applicable in patients with HF and renal dysfunction remains unclear.

In this single-centre, ambispective cohort study, we included 405 patients with HF aged ≥65 years (mean age, 78.6 ± 7.5 years; 50% women). DPI was estimated from consumption over three consecutive days before discharge and normalized relative to the ideal body weight [IBW, 22 kg/m2 × height (m)2]. The primary outcome was a composite of all-cause mortality and HF-related readmission within the 2 year post-discharge period.

During an average follow-up period of 1.49 ± 0.74 years, 100 patients experienced composite events. Kaplan-Meier survival curves revealed a significantly lower composite event-free rate in patients within the lowest quartile of DPI than in the upper quartiles (log-rank test, P = 0.02). A multivariate Cox proportional hazards analysis after adjusting for established prognostic markers and non-proteogenic energy intake revealed that patients in the lowest DPI quartile faced a two-fold higher risk of composite events than those in the highest quartile [hazard ratio (HR), 2.03; 95% confidence interval (CI), 1.08-3.82; P = 0.03]. The composite event risk linearly increased as DPI decreased (P for nonlinearity = 0.90), with each standard deviation (0.26 g/kg IBW/day) decrease in DPI associated with a 32% increase in composite event risk (HR, 1.32; 95% CI, 1.10-1.71; P = 0.04). There was significant heterogeneity in the effect of DPI, with the possible disadvantage of lower DPI in patients with HF with cystatin C-based estimated glomerular filtration rate <30 mL/min/1.73 m2. The cutoff value of DPI for predicting the occurrence of composite events calculated from the Youden index was 1.12 g/kg IBW/day. Incorporating a DPI < 1.12 g/kg IBW/day into the baseline model significantly improved the prediction of post-discharge composite events (continuous net reclassification improvement, 0.294; 95% CI, 0.072-0.516; P = 0.01).

Lower DPI during hospitalization is associated with an increased risk of mortality and HF readmission independent of non-proteogenic energy intake, and the possible optimal DPI for predicting adverse clinical outcomes is >1.12 g/kg IBW/day in older patients with HF. Caution is warranted when protein restriction therapy is administered to older patients with HF and renal dysfunction.

This observational longitudinal study aimed to explore the risk factors for disabilities in older Japanese individuals with diabetes at a frailty clinic, an outpatient clinic specializing in comprehensive geriatric assessments for older patients.

The outcome was the onset of disability as a new certification of long-term care needs in outpatients aged ≥65 years. Multivariable Cox regression analyses examined the independent associations between the onset of disability and the variables that reached significance in the bivariate analysis, after adjusting for age and sex, years of education, and certification of need for support.

A total of 182 participants (mean age 77.8 years, 59.9% female) were included in the study. During a mean follow-up period of 1070 days, 28 patients (15.4%) developed disabilities. Multivariable analysis showed that poor glycemic control (higher levels of glycosylated albumin and HbA1c), frailty as measured by the Clinical Frailty Scale (CFS), cognitive decline as assessed by the revised Hasegawa Dementia Scale (especially "5 object recall" and verbal fluency as assessed by the number of "vegetable names"), poor adherence to medications, and reduced muscle mass were significantly associated with the development of disability. Multivariable Cox regression analyses revealed independent and significant associations between the development of disability and HbA1c ≥7.5%, CFS ≥4, and generating vegetable names≤9.

In identifying older patients with diabetes who are at risk of developing disabilities, it may be useful to evaluate glycemic control, CFS, cognition, and medication adherence. Verbal fluency tests using vegetable names may serve as simple tools for assessing the risk of disability. Geriatr Gerontol Int 2024; 24: 1030-1038.

Duchenne muscular dystrophy (DMD) is an inherited disease characterized by progressive degeneration of the skeletal muscles. Renal dysfunction in patients with DMD has recently become more apparent as life expectancy has increased owing to advances in respiratory devices and heart failure therapies. A 23-year-old man with DMD who required nasal tube feeding was referred to our hospital with a 4-month history of renal dysfunction and anemia. The patient's serum creatinine (sCr) level was within the normal range (0.84 mg/dL), but his serum cystatin C level and estimated glomerular filtration rate calculated by cystatin C (5.90 mg/L and 7.5 mL/min/1.73 m2, respectively) indicated severe renal impairment. A urinalysis revealed elevated levels of protein and tubular markers. The patient's hemoglobin and erythropoietin levels indicated renal anemia. Hypotension, a collapsed inferior vena cava, and a poor tube feeding episode suggested that the kidney injury was due to renal ischemia, which progressed to tubulointerstitial kidney injury, an intrinsic kidney injury. The angiotensin-converting enzyme inhibitors and beta-blockers were discontinued, and extracellular fluid was infused. Thereafter, the patient's renal function recovered. Subsequently, the patient's urinary findings and anemia improved. Although advances in cardioprotective agents are expected to improve the prognosis of patients with DMD, it is important to consider that the number of patients with kidney injury due to renal ischemia may increase and that it is difficult to evaluate renal function using sCr level in patients with DMD because of decreased skeletal muscle mass.

In primary aldosteronism (PA), aldosterone could affect glomerular hemodynamics by elevating renal vascular resistance and glomerular capillary pressure. However, the relationship between plasma aldosterone concentrations (PAC) and glomerular hemodynamics including efferent arteriolar resistance (Re), and afferent arteriolar resistance (Ra) in humans is still unclear. The aim of this study was to investigate the relationships of PAC with intraglomerular hemodynamic parameters in patients with PA.

An observational study of glomerular hemodynamics was performed using simultaneous measurements of plasma clearance of para-aminohippurate and inulin (Cin; glomerular filtration rate (GFR)) in 17 patients with PA. Kidney function was evaluated by Cin, estimated GFR based on serum creatine (eGFRcre) and serum cystatin C (eGFRcys) and creatine clearance (Ccr). Intraglomerular hemodynamic parameters, including Re, Ra, and intraglomerular hydrostatic pressure (Pglo) were calculated using Gomez's formulae.

In the 17 PA cases, PAC was significantly correlated with Cin (rho = 0.752, P = 0.001) and eGFRcys (rho = 0.567, P = 0.018), but was not correlated with eGFRcre and Ccr. PAC was also significantly correlated with Pglo, Re, and urinary protein/day (rho = 0.775, P = 0.0004, rho = 0.625, P = 0.009, and rho = 0.625, P = 0.007, respectively). Multivariable regression analysis showed that PAC was significantly associated with Cin and Re. In comparing aldosterone-producing adenoma (APA) and non-APA cases, Cin was significantly elevated in APA (P = 0.037), whereas eGFRcre, eGFRcys, and Ccr were not. Re tended to be higher in APA (P = 0.064).

These results suggest high aldosterone causes glomerular hyperfiltration by constricting Re. Cin, but not eGFRcre and Ccr, may be useful for evaluating kidney function in PA.

Osteoporosis and osteopenia are more frequent in patients who have received kidney transplants than in healthy individuals. Although osteoporosis and sarcopenia are closely related, only few studies have considered them in the post-transplantation period. We aimed to investigate the relationship between lower bone mineral density and skeletal muscle in kidney transplant recipients.

We included 371 patients in the maintenance phase of kidney transplantation (> 6 months after transplantation) followed-up at our institution from January to December 2019. The primary endpoint was the association between bone mineral density and skeletal muscle mass index. As secondary endpoints, in addition to skeletal muscle mass index, we investigated other factors associated with low bone mineral density, including kidney function and 25-hydroxy vitamin D (25(OH)D) concentration. Considering the possibility that factors affecting bone mineral density differ between men and women, we explored these factors separately for both sexes.

Of the 371 participants, 243 (65.4%) were men. The median age and time after transplantation were 52 and 14 years, respectively. Univariate analysis showed that age, female sex, time since transplantation, cystatin C-based estimated glomerular filtration rate (eGFRcysC), 25(OH)D, and skeletal muscle mass index were associated with bone mineral density. Multivariate analysis showed associations of bone mineral density with eGFRcysC, 25(OH)D, and skeletal muscle mass index. Multivariate analysis by sex showed significant associations with eGFRcysC, hemoglobin, and skeletal muscle mass index in men and with age, eGFRcysC, albumin, and skeletal muscle mass index in women. Bone mineral density was not associated with history of dialysis prior to transplantation or time since transplantation.

In kidney transplant recipients, an independent association between lower bone mineral density and skeletal muscle mass index was observed in both sexes.

Elderly living kidney donors (LKDs) are becoming increasingly important in countries with a high prevalence of living-donor kidney transplants and an aging society. This study explored the features of elderly LKDs, focusing on their subsequent outcomes.

This single-center, retrospective, observational study included eligible LKDs who donated their kidneys between April 2008 and July 2022. LKDs were categorized into an elderly (≥70 years at donation) or a non-elderly group (<70 years). We examined pre-operative characteristics and post-operative outcomes, such as kidney function, complications, development of end-stage kidney disease (ESKD), and mortality.

Of the 188 LKDs observed for a median of 5.7 years, 31 were in the elderly group (16.5%) and 157 (83.5%) were in the non-elderly group (mean age 72.5 ± 2.7 and 58.2 ± 7.3 years, respectively). No significant differences were observed in hospital stay length or peri-operative complications between groups. Both groups experienced a similar decline in post-donation estimated glomerular filtration rate (eGFR)-approximately 37%. In the elderly group, four LKDs died, and one progressed to ESKD. In the non-elderly group, two LKDs died, and none progressed to ESKD. The cause of death was not strongly suspected to be associated with the donation.

eGFR was maintained even in elderly LKDs post-donation. Prioritizing LKDs' safety is paramount; however, donations from elderly people would be acceptable, considering their life expectancy. This can expand the pool of living kidney donors and address the growing demand for kidney transplants.

The serum creatinine/cystatin C ratio (CCR) or sarcopenia index is considered a useful marker of muscle mass. However, its usefulness in late-stage older adults remains unclear. We aimed to determine the usefulness of CCR as an indicator of sarcopenia in community-dwelling Japanese adults aged >75 years.

Our study recruited participants aged 70, 80, and 90 ± 1 years during the baseline years, and included a 3-year follow-up in the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians study. From 2015 to 2018, 955 participants were eligible: 367 in their 70s, 304 in their 80s, and 284 in their 90s. The diagnostic components of sarcopenia, including "low muscle mass, plus low muscle strength, and/or low physical performance," were evaluated using the bioelectrical impedance analysis-measured skeletal muscle mass index (SMI), handgrip strength, and short physical performance battery (SPPB) score, respectively, in accordance with the Asia Working Group for Sarcopenia 2019 criteria. Separate analyses were performed between each component and CCR, adjusting for sex, body mass index, and other blood biomarkers in each group.

The relationship between CCR and sarcopenia components was significant for handgrip strength (β = 0.21, 0.13, 0.19, and P < 0.0001, =0.0088, <0.0001, for the 70s, 80s, and 90s age groups, respectively); however, it was limited for SMI (β = 0.14; P = 0.0022, only for the 90s) and not significant for the SPPB score.

CCR is a limited indicator of sarcopenia in late-stage older adults. Although its association with muscle strength was significant, its relationship with muscle mass and physical performance was less pronounced. Geriatr Gerontol Int 2024; 24: 529-536.

This study examined the effects of pemafibrate, a selective peroxisome proliferator-activated receptor α agonist, on the serum biochemical parameters of male patients with coronary artery disease and metabolic syndrome (MetS). This was a post hoc analysis of a randomized, crossover study that treated hypertriglyceridemia with pemafibrate or bezafibrate for 24 weeks, followed by a crossover of another 24 weeks. Of the 60 patients enrolled in the study, 55 were male. Forty-one of 55 male patients were found to have MetS. In this sub-analysis, male patients with MetS (MetS group, n = 41) and those without MetS (non-MetS group, n = 14) were compared. The primary endpoint was a change in fasting serum triglyceride (TG) levels during pemafibrate therapy, and the secondary endpoints were changes in insulin resistance-related markers and liver function parameters. Serum TG levels significantly decreased (MetS group, from 266.6 to 148.0 mg/dL, p < 0.001; non-MetS group, from 203.9 to 97.6 mg/dL, p < 0.001); however, a percent change (%Change) was not significantly different between the groups (- 44.1% vs. - 51.6%, p = 0.084). Serum insulin levels and homeostasis model assessment of insulin resistance significantly decreased in the MetS group but not in the non-MetS group. %Change in liver enzyme levels was markedly decreased in the MetS group compared with that in the non-MetS group (alanine aminotransferase, - 25.1% vs. - 11.3%, p = 0.027; gamma-glutamyl transferase, - 45.8% vs. - 36.2%, p = 0.020). In conclusion, pemafibrate can effectively decrease TG levels in patients with MetS, and it may be a more efficient drug for improving insulin resistance and liver function in such patients.

The effects of exercise therapy (ET) on renal function in chronic kidney disease (CKD) remain unclear.

In a randomized controlled trial (UMIN-CTR number: UMIN000038415), we investigated whether ET affects renal function in CKD; eligible patients had undergone renal biopsy in the past 3 months. We stratified patients by disease (immunoglobulin A [IgA] nephropathy, n = 16; diabetic nephropathy, n = 4; benign nephrosclerosis, n = 13; and other CKD types, n = 13) and randomized them to 12 weeks' observation and 24 weeks' ET comprising home-based aerobic exercise 3×/week and resistance training 2×/week (intervention group) or usual care (non-intervention group). Primary endpoint was creatinine-based estimated glomerular filtration rate (eGFR) or serum cystatin C-based eGFR (eGFRcys). Secondary endpoints included urinary protein and exercise tolerance.

Seventy patients were enrolled, 50 fulfilled the inclusion criteria, but 4 discontinued before randomization. No items significantly differed between week 0 to 24 in either group (intervention group, n = 23; non-intervention group, n = 23) or between groups at week 24 (intention-to-treat population) in the total study population. The eGFRcys slope showed no significant intergroup difference in the observation period, but eGFRcys improved significantly in IgA nephropathy patients (n = 16) in the intervention group (stratified comparison; week 0, 48.3 ± 18.2; week 24, 51.6 ± 17.6; p = 0.043). In these patients, urinary protein was significantly worse at week 24 in the non-intervention group (p = 0.046) and worsened significantly less in the intervention group (p = 0.039).

ET did not improve renal function overall in CKD patients but might help maintain renal function in patients with IgA nephropathy.

Tolvaptan, a vasopressin V2 receptor antagonist, is used for treating autosomal dominant polycystic kidney disease (ADPKD). We focused on changes in urinary osmolality (U-Osm) after tolvaptan initiation to determine whether they were associated with the therapeutic response to tolvaptan.

This was a single-centre, prospective, observational cohort study. Seventy-two patients with ADPKD who received tolvaptan were recruited. We analysed the relationship between changes in U-Osm and annual estimated glomerular filtration rate (eGFR) in terms of renal prognostic value using univariable and multivariable linear regression analyses.

The mean value of U-Osm immediately before tolvaptan initiation was 351.8 ± 142.2 mOsm/kg H2O, which decreased to 97.6 ± 23.8 mOsm/kg H2O in the evening. The decrease in U-Osm was maintained in the outpatient clinic 1 month later. However, the 1-month values of U-Osm showed higher variability (160.2 ± 83.8 mOsm/kg H2O) than did those in the first evening of tolvaptan administration. Multivariate analysis revealed that the baseline eGFR, baseline urinary protein and U-Osm change in the evening of the day of admission (initial U-Osm drop) were significantly correlated with the subsequent annual change in eGFR.

U-Osm can be measured easily and rapidly, and U-Osm change within a short time after tolvaptan initiation may be a useful index for the renal prognosis in actual clinical practice.

Global studies exploring the relationship between parity and chronic kidney disease (CKD) are scarce. Furthermore, no study has examined the relationship between parity and CKD in Japan. Therefore, this study aimed to examine the relationship between parity and the prevalence of CKD in a Japanese population, considering the clinical history of hypertensive disorders of pregnancy (HDP) and current body mass index (BMI) based on menopausal status.

This cross-sectional study included 26,945 Japanese multiparous women (5,006 premenopausal and 21,939 postmenopausal women) and 3,247 nulliparous women (1,599 premenopausal and 1,648 postmenopausal women). Participants were divided into two groups based on their menopausal status (premenopausal and postmenopausal women). The relationship between parity and the prevalence of CKD was evaluated using a multiple logistic regression model adjusted for several covariates, including a clinical history of HDP and current BMI.

The relationship between parity and the prevalence of CKD was not statistically significant in either premenopausal or postmenopausal multiparous women. A clinical history of HDP was significantly associated with an increased risk of CKD in premenopausal and postmenopausal multiparous women. However, the relationship between a clinical history of HDP and CKD in premenopausal women was weakened after adjusting for current BMI. Furthermore, the current BMI was significantly associated with an increased risk of CKD in both premenopausal and postmenopausal women.

Parity is not significantly associated with the prevalence of CKD in premenopausal and postmenopausal multiparous women. A clinical history of HDP is a risk factor for CKD in both premenopausal and postmenopausal women. Current BMI is also associated with an increased risk of CKD in premenopausal and postmenopausal women. Therefore, continuous surveillance and preventive measures against CKD should be provided to women with a clinical history of HDP. In addition, maintaining an appropriate body weight is beneficial in reducing the risk of CKD.

Acute myocardial infarction (AMI) is associated with a decline in renal function. This study aimed to investigate the impact of engaging in moderate to vigorous intensity physical activity (MVPA) for more than 30 min per day on changes in renal function during the first 3 months after AMI onset. A prospective, observational study was conducted, enrolling 87 patients (75 men; average age, 65.2 ± 12.5 years) who had experienced AMI. The cystatin C-based estimated glomerular filtration rate (eGFRcys) was collected at and 3 months after discharge. Daily MVPA was measured using triaxial accelerometers at a threshold of 3.0 Metabolic equivalent of the task for 3 months. Generalized estimating equations (GEE) were applied to evaluate the longitudinal association between the number of days per week of MVPA for 30 min or more and within-patient changes in eGFRcys. The patients were categorized into three groups based on their MVPA engagement days: 0 days (n = 20), 1-2 days (n = 14), and 3-7 days (n = 53) groups. After adjusting for potential confounding variables, GEE analysis revealed that the eGFRcys slope over 3 months was significantly higher in the 3-7 days group than in 0 days group (B = 2.9, (95% confidence interval: 1.5-4.2), p < 0.001). Similar results were obtained when MVPA time thresholds were set to 40 and 60 min. These findings suggest a significant positive effect of engaging in MVPA for 30 min or more for 3-7 days per week in the improvement of renal function after AMI onset.

Proton pump inhibitors (PPIs) have recently been reported to be linked with nephrotoxicity. PPIs are metabolized mainly or partly by cytochrome P450 2C19 (CYP2C19). However, the relationship between CYP2C19 genetic polymorphism and PPI-induced nephrotoxicity is unclear. In this study, we aimed to analyze the association between the time of occurrence of renal injury by PPIs, including lansoprazole, esomeprazole, rabeprazole, and vonoprazan, and CYP2C19 metabolizer status classified by CYP2C19 genotypes. Patients prescribed PPIs were reviewed in this retrospective cohort study. The primary outcome was the time to a 30% decrease in estimated glomerular filtration rate (eGFR) from baseline. In patients treated with lansoprazole, the time to a 30% decrease in eGFR for the CYP2C19 poor metabolizer (PM) group was significantly shorter than that for the non-PM group (hazard ratio for PM vs. non-PM, 2.43, 95% confidence interval, 1.21 to 4.87, P = 0.012). In contrast, in patients that received esomeprazole, rabeprazole, or vonoprazan, no significant differences were found in the time to a 30% decrease in eGFR between non-PM and PM groups. The adjusted hazard ratios for the time to a 30% eGFR decrease in patients treated with lansoprazole were significantly higher for CYP2C19 PM, hypertension, and a history of myocardial infarction. In conclusion, this retrospective study showed that CYP2C19 metabolizer status was associated with the time to a 30% eGFR decrease in patients treated with lansoprazole, but not with esomeprazole, rabeprazole, or vonoprazan.