Longitudinal change in estimated GFR among CKD patients: A 10-year follow-up study of an integrated kidney disease care program in Taiwan

Effect of proteinuria on the rapid kidney function decline in chronic kidney disease depends on the underlying disease: A post hoc analysis of the BRIGHTEN study

AIMS

It is unclear whether the effect of proteinuria on rapid kidney function decline is equivalent among diabetic kidney disease (DKD), non-DKD with diabetes (NDKD+DM), and nephrosclerosis without diabetes (NS-DM), particularly in advanced chronic kidney disease patients.

METHODS

In total, 1038 chronic kidney disease patients who participated in the BRIGHTEN study were included in the present study. A linear mixed effect model was applied to estimate the annual estimated glomerular filtration rate decline in each disease group.

RESULTS

The prevalence of rapid decliners (rapid kidney function decline, defined as an eGFR loss of > 5 mL/min/1.73 m2/year) in the DKD group (44.6 %) was significantly higher compared with the NDKD+DM (27.9 %) and NS-DM (27.0 %) groups. By contrast, the prevalence of rapid decliners in different urine total protein to creatinine ratio (UPCR) categories (<0.5, 0.5 to < 1.0, 1.0 to < 3.5, and ≥ 3.5 g/g) were equivalent between the DKD and NS-DM groups. Moreover, the prevalence of a UPCR < 1.0 g/g in rapid decliners of the NS-DM group was more than double than in those of the DKD and NDKD+DM groups.

CONCLUSIONS

The risk of rapid kidney function decline in NS-DM patients with low levels of proteinuria may be greater than initially predicted.

Novel insights in classic versus relative glomerular hyperfiltration and implications on pharmacotherapy

PURPOSE OF REVIEW

Glomerular filtration rate (GFR) assessment and its estimation (eGFR) is a long-lasting challenge in medicine and public health. Current eGFR formulae are indexed for standardized body surface area (BSA) of 1.73 m2, ignoring persons and populations wherein the ratio of BSA or metabolic rate to nephron number might be different, due to increased BSA, increased metabolic rate or reduced nephron number. These equations are based on creatinine, cystatin C or a combination of the two, which adds another confounder to eGFR assessment. Unusually high GFR values, also known as renal hyperfiltration, have not been well defined under these equations.

RECENT FINDINGS

Special conditions such as solitary kidney in kidney donors, high dietary protein intake, obesity and diabetes are often associated with renal hyperfiltration and amenable to errors in GFR estimation. In all hyperfiltration types, there is an increased intraglomerular pressure that can be physiologic, but its persistence over time is detrimental to glomerulus leading to progressive glomerular damage and renal fibrosis. Hyperfiltration might be underdiagnosed due to BSA standardization embedded in the formula. Hence, timely intervention is delayed. Reducing intraglomerular pressure in diabetes can be achieved by SGLT2 inhibitors or low protein diet to reverse the glomerulopathy process.

SUMMARY

Accurate identification of glomerular hyperfiltration as a pre-CKD condition needs accurate estimation of GFR in the above normal range should establish a threshold for timely intervention.

A participatory action research study to inform combined type 2 diabetes and chronic kidney disease care provided in the context of advanced practice nursing

AIM

To outline the development, implementation and evaluation of an alternative combined type 2 diabetes and chronic kidney disease (CKD) care delivery strategy provided in the context of advanced practice nursing informed by co-created knowledge, between patients and healthcare teams to address identified gaps in care provision.

DESIGN

This study was informed by the theoretical underpinnings of critical theory and operationalized using a participatory action research (PAR) design. This approach enabled alignment between the theoretical underpinnings and research methodology to respond to practice-level problems and address issues related to healthcare delivery.

METHODS

The study was undertaken in a series of three cycles of enquiry over a 20 month period (July 2018-February 2020) in five geographically diverse specialist diabetes and nephrology centres. Data collection methods included PAR group minute consensus, retrospective chart review, discovery and focus group interviews. Thematic analysis and descriptive statistics were used to analyse the data.

RESULTS

Compared with international standard care outcomes, a higher proportion of patients attending combined care achieved best practice recommendations for blood pressure, Hba1c and lipid management (64.3% vs. <40%). Patients attending combined care experienced improved detection and management of CKD-related anaemia. Additionally, the combined care service experienced significantly lower levels of patient's failure to attend scheduled reviews compared with participating standard care services (0% vs. 7%-23.3%).

CONCLUSIONS

Best practice clinical care outcomes and patient attendance improved when a combined type 2 diabetes and CKD care delivery strategy provided in the context of advanced practice nursing was adopted.

IMPACT

This alternative care strategy represented a departure from standard care delivery approaches, in which care for type 2 diabetes and CKD is provided separately and led by physicians. Outcomes demonstrate improved clinical and attendance outcomes which may inform the development of future services led by advanced nurse practitioners.

Workplace Outreach Program Improves Management of Chronic Kidney Disease

OBJECTIVE

Assess whether an employee outreach program improved management of chronic kidney disease (CKD).

METHODS

Participants with suspected CKD (eGFR <60 mL/min/1.73m 2 ) identified in employee health assessments in 2017 and 2018 were contacted by phone and offered physician consultation. Subsequent nephrologist visits at 11 months of follow up were compared between those who were (outreach group) and were not (control group) successfully contacted.

RESULTS

Most CKD risk factors at baseline were similar in outreach and control groups. At the end of the follow-up, outreach participants had more than 2-fold greater incidence of visiting a nephrologist compared with controls (HR = 2.3; 95% CI 1.2-4.2, P = 0.01), after adjusting for potential confounders. Conclusions: Employee outreach program increased utilization of nephrologist care.

Clinical parameters among patients in Japan with anemia and non-dialysis-dependent chronic kidney disease with and without diabetes mellitus who received roxadustat

Background

Roxadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor for treating anemia of chronic kidney disease (CKD). This post hoc analysis of a Japanese, open-label, partially randomized, phase 3 study in patients with non-dialysis-dependent (NDD) CKD evaluated disease state–related parameters among patients with and without diabetes mellitus who received roxadustat. In the 1517-CL-0310 study (NCT02988973), roxadustat was noninferior to darbepoetin alfa for change in average hemoglobin levels at Weeks 18–24 from baseline who received roxadustat.

Methods

Patients enrolled in the 1517-CL-0310 study who received roxadustat were included in this post hoc analysis. Hematologic (hemoglobin, reticulocyte/erythrocyte ratio, mean corpuscular volume [MCV], and mean corpuscular hemoglobin [MCH]), iron-related (ferritin, total iron-binding capacity, transferrin, ceruloplasmin, and hepcidin), metabolic (HbA1c, glycated albumin, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol), and renal (eGFR) parameters were summarized descriptively by visit through Week 52.

Results

Among 201 included patients, 105 (52.2%) and 96 (47.8%) were in the Diabetes and No Diabetes subgroups, respectively. There were no clinically meaningful differences through Week 52 for most hematologic, iron-related, metabolic, or renal parameters between patients in the Diabetes and No Diabetes subgroups. MCV and MCH remained lower and HbA1c and glycated albumin remained higher in patients in the Diabetes subgroup through Week 52. Both subgroups experienced a similar benefit from roxadustat in maintaining hemoglobin levels in the target range of 10–12 g/dL.

Conclusion

Roxadustat maintained hemoglobin levels in the target range with similar clinical parameters irrespective of diabetes mellitus presence at baseline.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-022-02225-w.

Trajectory of Estimated Glomerular Filtration Rate and Malnourishment Predict Mortality and Kidney Failure in Older Adults With Chronic Kidney Disease

Objective: The trajectory patterns of estimated glomerular filtration rates (eGFR) in chronic kidney disease (CKD) older adults with malnourishment and their association with subsequent patient outcomes have not been elucidated. We aimed to assess the eGFR trajectory patterns for predicting patient survival and kidney failure in the elderly without or with malnourishment.

Materials and Methods: Based on a prospective longitudinal cohort, CKD patients aged 65 years or older were enrolled from 2001 to 2013. Among the 3,948 patients whose eGFR trajectory patterns were analyzed, 1,872 patients were stratified by the absence or presence of malnourishment, and 765 patients were identified and categorized as having malnourishment. Four eGFR trajectory patterns [gradual decline (T0), early non-decline and then persistent decline (T1), persistent increase (T2), and low baseline and then progressive increase (T3)] were classified by utilizing a linear mixed-effect model with a quadratic term in time. The malnourishment was defined as body mass index < 22 kg/m², serum albumin < 3.0 mg/dL, or Geriatric Nutritional Risk Index (GNRI) < 98. This study assessed the effectiveness of eGFR trajectory patterns in a median follow-up of 2.27 years for predicting all-cause mortality and kidney failure.

Results: The mean age was 76.9 ± 6.7 years, and a total of 82 (10.7%) patients with malnourishment and 57 (5.1%) patients without malnourishment died at the end of the study. Compared with the reference trajectory T0, the overall mortality of T1 was markedly reduced [adjusted hazard ratio (aHR) = 0.52, 95% confidence interval (CI) 0.32–0.83]. In patients with trajectory, T3 was associated with a high risk for kidney failure (aHR = 5.68, 95% CI 3.12–10.4) compared with the reference, especially higher risk in the presence of malnourishment. Patients with high GNRI values were significantly associated with a lower risk of death and kidney failure, but patients with malnourishment and concomitant alcohol consumption had a higher risk of kidney failure.

Conclusions: Low baseline eGFR and progressively increasing eGFR trajectory were high risks for kidney failure in CKD patients. These findings may be attributed to multimorbidity, malnourishment, and decompensation of renal function.

A proposed interval for evaluation of renal function during anticoagulation therapy using direct oral anticoagulants in patients with atrial fibrillation

BACKGROUND

Direct oral anticoagulants (DOACs) have been used to prevent cardiogenic embolism in patients with atrial fibrillation (AF). No evidence has been established for the follow-up renal function evaluation intervals. We hypothesized that a proposed follow-up interval of renal function can be estimated by patient's baseline characteristics including creatinine clearance (CCr).

METHODS

We conducted a single-center retrospective study at Kindai University Hospital from May 2011 to December 2017. Patients were screened and they were enrolled if baseline CCr of ≥50 mL/min. To provide a periodical synchronization for measurements of CCr in all patients, these were evaluated at four different time points (approximately at 3, 6, 9, and 12 months). Primary endpoint was defined as a CCr value of <50 mL/min during the follow-up period. We analyzed associations between the cumulative risk for renal endpoint and baseline characteristics by the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

Renal endpoint was associated with age (95% CI: 0.07 to 0.21, p<0.01), body weight (95% CI: -0.09 to -0.01, p<0.01), CCr (95% CI: -0.18 to -0.07, p<0.01), and CHA2DS2-VASc score (95% CI: 0.14 to 0.63, p<0.01). Combining baseline CCr of <60 mL/min and other risk factors, acceptable intervals for 5% risk levels were 78 days (age ≥75 years old), 100 days (CHA2DS2-VASc score of> 4 points), and 90 days (body weight <60kg), respectively. Under conditions of baseline CCr of <60 mL/min, age ≥75 years old, CHA2DS2-VASc score of> 4 points, or body weight <60 kg, an increased risk of renal endpoints is 4.85, 3.29, 1.24, 2.44 fold, respectively.

CONCLUSIONS

We propose a risk-stratified follow-up interval for renal evaluation in patients with AF and DOACs therapy according to a combination of baseline CCr and other risk factors.

Association between renal function and cardiovascular mortality: a retrospective cohort study of elderly from health check-up

OBJECTIVES

This study aimed to investigate the relationship between cardiovascular mortality in elderly Asians and decline in renal function.

DESIGN

A retrospective cohort study.

SETTING

Community-based health examination database from Taipei city.

PARTICIPANTS

At the beginning, the database included 315 045 health check-up visits of 97 803 elderly persons aged ≥65 years old from 2005 to 2012. After excluding missing values and outliers, there were 64 732 elderly persons with at least two visits retained for further analyses.

PRIMARY OUTCOME MEASURES

Kidney function indicators include estimated glomerular filtration rate (eGFR) and urine protein, and rapid decline in eGFR was defined as slope ≤ -5 mL/min/1.73 m² per year. The endpoint outcome was defined as the cardiovascular deaths registered in the death registry encoded by the International Classification of Diseases. We applied a Cox proportional hazards model to analyse the association between renal function and cardiovascular mortality.

RESULTS

In this study, we found 1264 elderly persons died from cardiovascular diseases, for whom the data included 4055 previous health check-up visits. We observed significant and independent associations of eGFR <60 mL/min/1.73 m² (HR (95% CI) of 60>eGFR≥45 and eGFR<45 in males: 2.85 (1.33 to 6.09) and 3.98 (1.84 to 8.61); in females: 3.66 (1.32 to 10.15) and 6.77 (2.41 to 18.99)), positive proteinuria (HR (95% CI) of +/-, +,++ and +++, ++++ in males: 1.51 (1.29 to 1.78) and 2.31 (1.51 to 3.53); in females: 1.93 (1.54 to 2.42) and 4.23 (2.34 to 7.65)) and rapid decline in eGFR (HR (95% CI) in males: 3.24 (2.73 to 3.85); in females: 2.83 (2.20 to 3.64) with higher risk of cardiovascular mortality. The joint effect of increased concentration of urine protein and reduced eGFR was associated with a higher risk of cardiovascular mortality.

CONCLUSIONS

Renal function and rapid decline in renal function are independent risk factors for cardiovascular mortality in the elderly.

CKD subpopulations defined by risk-factors: A longitudinal analysis of electronic health records

Chronic kidney disease (CKD) is a progressive disease that evades early detection and is associated with various comorbidities. Although clinical comprehension and control of these comorbidities is crucial for CKD management, complex pathophysiological interactions and feedback loops make this a formidable task. We have developed a hybrid semimechanistic modeling methodology to investigate CKD progression. The model is represented as a system of ordinary differential equations with embedded neural networks and takes into account complex disease progression pathways, feedback loops, and effects of 53 medications to generate time trajectories of eight clinical biomarkers that capture CKD progression due to various risk factors. The model was applied to real world data of US patients with CKD to map the available longitudinal information onto a set of time‐invariant patient‐specific parameters with a clear biological interpretation. These parameters describing individual patients were used to segment the cohort using a clustering approach. Model‐based simulations were conducted to investigate cluster‐specific treatment strategies. The model was able to reliably reproduce the variability in biomarkers across the cohort. The clustering procedure segmented the cohort into five subpopulations – four with enhanced sensitivity to a specific risk factor (hypertension, hyperlipidemia, hyperglycemia, or impaired kidney) and one that is largely insensitive to any of the risk factors. Simulation studies were used to identify patient‐specific strategies to restrain or prevent CKD progression through management of specific risk factors. The semimechanistic model enables identification of disease progression phenotypes using longitudinal data that aid in prioritizing treatment strategies at individual patient level.

Association of Genetic Variants for Plasma LRG1 With Rapid Decline in Kidney Function in Patients With Type 2 Diabetes

CONTEXT

Elevated levels of plasma leucine-rich α-2-glycoprotein 1 (LRG1), a component of transforming growth factor beta signaling, are associated with development and progression of chronic kidney disease in patients with type 2 diabetes (T2D). However, whether this relationship is causal is uncertain.

OBJECTIVES

To identify genetic variants associated with plasma LRG1 levels and determine whether genetically predicted plasma LRG1 contributes to a rapid decline in kidney function (RDKF) in patients with T2D.

DESIGN AND PARTICIPANTS

We performed a genome-wide association study of plasma LRG1 among 3694 T2D individuals [1881 (983 Chinese, 420 Malay, and 478 Indian) discovery from Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes cohort and 1813 (Chinese) validation from Diabetic Nephropathy cohort]. One- sample Mendelian randomization analysis was performed among 1337 T2D Chinese participants with preserved glomerular filtration function [baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2)]. RDKF was defined as an eGFR decline of 3 mL/min/1.73 m2/year or greater.

RESULTS

We identified rs4806985 variant near LRG1 locus robustly associated with plasma LRG1 levels (meta P = 6.66 × 10-16). Among 1337 participants, 344 (26%) developed RDKF, and the rs4806985 variant was associated with higher odds of RDKF (meta odds ratio = 1.23, P = 0.030 adjusted for age and sex). Mendelian randomization analysis provided evidence for a potential causal effect of plasma LRG1 on kidney function decline in T2D (P < 0.05).

CONCLUSION

We demonstrate that genetically influenced plasma LRG1 increases the risk of RDKF in T2D patients, suggesting plasma LRG1 as a potential treatment target. However, further studies are warranted to elucidate underlying pathways to provide insight into diabetic kidney disease prevention.

Effectiveness of integrated care on delaying chronic kidney disease progression in rural communities of Thailand (ESCORT-2) trials

AIM

We conducted a prospective cohort study to evaluate the effectiveness of an integrated care model on delaying chronic kidney disease (CKD) progression in routine clinical practice in rural primary care setting.

METHODS

After enrolment, patients with stages 3 to 4 CKD patients from five district hospitals in a northern province of Thailand (400 km from Bangkok) received integrated care comprising hospital multidisciplinary care and home visits by community care teams. Clinical characteristics and biochemical data were collected at baseline and every 3-month interval thereafter for 36 months. The primary outcome was the rate of estimated glomerular filtration rate (eGFR) decline.

RESULTS

Nine hundred and fourteen stage -3 and - 4 CKD patients were enrolled. The mean age of our cohort was 62 years. Diabetic kidney disease (DKD) was the main cause of CKD (53%) whereas hypertension was the most common co-morbidity (92%). The mean rate of eGFR decline was -0.92 mL/min/1.73 m2 /year. The rate of eGFR decline among patients with DKD was about three times faster than patients without DKD. Patients with higher blood pressure, metabolic acidosis, proteinuria or anaemia had a faster rate of eGFR decline.

CONCLUSION

This integrated care model at the community level was effective in delaying CKD progression in routine clinical practice situation.

Serum and urinary soluble α-Klotho levels in patients with chronic kidney disease

Background: Chronic kidney disease is an epidemic global health problem that leads to death. To prevent any disease progression and treatment, the diagnosis must be made in the early stage by studying renal damage. Klotho is a protein found in many organs of the human body, but it is mainly abundant in the kidney. Objectives: This study is aimed to evaluate klotho’s clinical significance as an additional biomarker for diagnosing chronic kidney disease in its early stages. Methods: One hundred subjects were included in this study to measure their serum and urinary klotho. Forty patients with chronic kidney disease (pre-dialysis) and sixty normal subjects were enrolled in this study. Serum and urinary klotho were determined using the ELISA technique in addition to other renal function tests. Results: Serum and urinary alpha klotho were decreased in CKD patients when compared with control subjects. A positive correlation was found between serum creatinine and urinary alpha klotho in the patients’ group. Conclusion: Serum and urinary alpha klotho levels were decreased significantly in patients with chronic kidney disease compared with healthy controls.

Chronic kidney disease progression in aged patients

PURPOSE

Chronic kidney disease (CKD) is a major morbidity, and its prevalence increases with age. However, there appears to be some confusion about the prognosis of CKD in aged patients, because, it has its own characteristics different from youngers. In this study, we investigated the progression of CKD and related factors in aged patients.

METHODS

This was a retrospective study including 334 patients over 80 years of age that were diagnosed with stage 3-4 CKD at our CKD clinic. CKD progression was assessed as an annual decline in the estimated glomerular filtration rate (eGFR). Comorbidities were globally categorized with the Charlson comorbidity index (CCI), but diabetes mellitus, hypertension, and cardiac morbidities were evaluated separately. Patients were grouped as either 'progression to end-stage renal disease (ESRD)' or 'others'.

RESULTS

During the follow-up period, 191 (57.2%) patients exhibited progression; the annual median eGFR declined by 0.8 ml/min/1.73 m². Only 27 (8.1%) of these patients progressed to ESRD. In univariant and multivariate models, respectively, progressing to ESRD was significantly associated with cardiac comorbidities (p < 0.001, p < 0.001), proteinuria (p < 0.001, p = 0.03), and the baseline eGFR value (p < 0.001, p < 0.001).

CONCLUSION

In aged patients, CKD progressed slowly, but particularly high initial creatinine levels and proteinuria could be indicator of progression. In addition, cardiac comorbidities may facilitate progression to ESRD.

Derepression of glomerular filtration, renal blood flow and antioxidant defence in patients with type 2 diabetes at high-risk of cardiorenal disease

BACKGROUND

The role of antioxidant status on microvascular blood flow and glomerular filtration (eGFR) in patients with type 2 diabetes and hypertension whose risk of progressive renal disease varies by ethnicity is unknown.

METHODS

Adult, non-Caucasian (n = 101) and Caucasian (n = 69) patients with type 2 diabetes, hypertension and/or microalbuminuria and an eGFR > 45 mL/min/1.73 m² were randomised to receive 400 IU vitamin E and/or 20 μg selenium daily or matching placebo. eGFR (CKD-EPI) was measured at baseline, 3,6 and 12 months and renal blood flow by contrast-enhanced ultrasonography in a sub-group (n = 9) at baseline and 3 months by assessing the area under the time intensity curve (TIC). Circulating glutathione peroxidase 3 (GPx-3) activity was measured as a biomarker of oxidative defence status.

RESULTS

The time to change in eGFR was shortest with combined vitamin E and selenium than usual care (5.6 [4.0-7.0] vs 8.9 [6.8-10.9 months]; p = 0.006). Area under the TIC was reduced compared to baseline (38.52 [22.41-90.49] vs 123 [86.98-367.03]dB.s; P ≤ 0.05 and 347 [175.88-654.92] vs 928.03 [448.45-1683]dB.s; P ≤ 0.05, respectively] at 3 months suggesting an increase in rate of perfusion. The proportional change in eGFR at 12 months was greater in the group whose GPx-3 activity was above, compared with those below the cohort median (360 U/L) in the non-Caucasian and the Caucasian groups (19.1(12.5-25.7] % vs 6.5[-3.5 to 16.5] % and 12.8 [0.7 to 24] % vs 0.2 [-6.1 to 6.5] %).

CONCLUSION

In these patients with type 2 diabetes and early CKD, antioxidant treatment derepresses renal blood flow and a rise in eGFR correlated directly with GPx-3 activity.

SIGNIFICANCE

Diabetes mellitus is the world's leading cause of end-stage renal disease which has a predilection for black and minor ethnic groups compared with Caucasians. The differences in risk despite the benefits of conventional care may be related to oxidative stress. We found that glomerular filtration and renal blood flow is suppressed when renal function is preserved in high-risk patients with type 2 diabetes. Conventional care supplemented with selenium - the co-factor for glutathione peroxidase-3 (GPx-3) - improves renal perfusion and increase glomerular filtration according to host antioxidant defence determined by GPx-3 activity. Circulating GPx-3 activity warrants further investigation as a novel biomarker of reversible haemodynamic changes in early diabetic kidney disease to better enable targeting of renoprotective strategies.

Aerobic exercise capacity is maintained over a 5-year period in mild-to-moderate chronic kidney disease: a longitudinal study

Background

Aerobic exercise capacity is reduced in non-dialysis chronic kidney disease (CKD), but the magnitude of changes in exercise capacity over time is less known. Our main hypothesis was that aerobic ExCap would decline over 5 years in individuals with mild-to-moderate CKD along with a decline in renal function. A secondary hypothesis was that such a decline in ExCap would be associated with a decline in muscle strength, cardiovascular function and physical activity.

Methods

We performed a 5-year-prospective study on individuals with mild-to-moderate CKD, who were closely monitored at a nephrology clinic. Fiftytwo individuals with CKD stage 2–3 and 54 age- and sex-matched healthy controls were included. Peak workload was assessed through a maximal cycle exercise test. Muscle strength and lean body mass, cardiac function, vascular stiffness, self-reported physical activity level, renal function and haemoglobin level were evaluated. Tests were repeated after 5 years. Statistical analysis of longitudinal data was performed using linear mixed models.

Results

Exercise capacity did not change significantly over time in either the CKD group or controls, although the absolute workloads were significantly lower in the CKD group. Only in a CKD subgroup reporting low physical activity at baseline, exercise capacity declined. Renal function decreased in both groups, with a larger decline in CKD (p = 0.05 between groups). Peak heart rate, haemoglobin level, handgrip strength, lean body mass and cardiovascular function did not decrease significantly over time in CKD individuals.

Conclusions

On a group level, aerobic exercise capacity and peak heart rate were maintained over 5 years in patients with well-controlled mild-to-moderate CKD, despite a slight reduction in glomerular filtration rate. In line with the maintained exercise capacity, cardiovascular and muscular function were also preserved. In individuals with mild-to-moderate CKD, physical activity level at baseline seems to have a predictive value for exercise capacity at follow-up.

Efficient analysis of time-to-event endpoints when the event involves a continuous variable crossing a threshold

In many trials, the duration between patient enrolment and an event occurring is used as the efficacy endpoint. Common endpoints of this type include the time until relapse, progression to the next stage of a disease, or time until remission. The criteria of an event may be defined by multiple components, one or more of which may be a continuous measurement being above or below a threshold. Typical analyses consider all components as binary variables and record the first time at which the patient has an event. This is analysed through constructing and testing survival functions using Kaplan-Meier, parametric models or Cox models. This approach ignores information contained in the continuous components. We propose a method that makes use of this information to improve the precision of analyses using these types of endpoints. We use joint modelling of the continuous and binary components to construct survival curves. We show how to compute confidence intervals for quantities of interest, such as the median or mean event time. We assess the properties of the proposed method using simulations and data from a phase II cancer trial and an observational study in renal disease.

Health Literacy Varies According to Different Background Disease Natures and Characteristics of Participants for Patient Support Groups

Introduction: Patient support groups (PSGs) should be designed according to the backgrounds of participants and the nature of their diseases. Using health literacy as an outcome indicator for PSGs is rare. Methods: All questionnaires (Mandarin Multidimensional Health Literacy Questionnaire, MMHLQ) were collected from eight PSGs to evaluate the health literacy of participants. Background data of participants were also collected, including patient or family, age, and first-time participation or not. Results: A total of 458 questionnaires were collected from eight PSGs. The diseases were: autoimmune disease (systemic lupus nephritis (SLE), malignancy (head and neck cancer (HNC), chronic disease (diabetes mellitus or DM), chronic kidney disease (CKD), hemodialysis and chronic obstructive pulmonary disease (COPD), genetic disease (autosomal dominant polycystic kidney disease (ADPKD), and degenerative disease (osteoporosis). For vasculitis (42.21 ± 16.49 years old for SLE) and genetic disease (48.95 ± 17.58 years old for ADPKD), participants were younger. More significant differences between first-time participation and MMHLQ scores were found in disease of osteoporosis, CKD, COPD, and hemodialysis. More significant differences between role of participation (patients themselves or family) and MMHLQ scores were found in SLE, ADPKD, hemodialysis, and CKD. More significant differences between age (elderly or not) and MMHLQ score were found in HNC, DM, CKD, COPD, and osteoporosis. Conclusion: Background data of participants varied across different diseases. Different disease natures and patient background statuses should therefore demand different designs in PSG. MMHLQ before PSGs can be used to help to improve the PSG curriculum on the health literacy of patients.

Everolimus and long-term decline in renal function after liver transplantation: real-life experience with measured GFR

Switching from calcineurin-inhibitors (CNI) to everolimus >6-12-months after liver transplantation (LT) seems inefficient in improving renal function, but whether everolimus halts further renal-function decline compared to low-dose CNI remains unclear. In a retrospective single-center study of everolimus after LT (2008-2016) with routine measured glomerular filtration rates (mGFR; ⁵¹Cr-EDTA- or iohexol clearance), we compared by propensity-score matching everolimus therapy to low-dose CNI therapy. The study comprised 36 patients with everolimus introduced on average 22 months post-LT (range 2-105 months, median follow-up 3.4 years), and 36 matched controls. Everolimus introduction was associated with a mean improvement in mGFR of 7 mL/min up to 1 year (p = .003), restricted to patients switched <1-year post-transplant and at tacrolimus trough levels >5 ng/mL. The differences between the everolimus group and controls in delta-mGFR from baseline to 1 year (7.3 vs 4.3 mL/min, p = .25) or 1-year to last follow-up (-0.8 vs -0.2 mL/min/year, p = .71) were non-significant. Proportions with mGFR decline >3 mL/min/year were similar between groups (11% and 14%, p = 1.00). Everolimus was stopped in three patients (8%), and acute rejection occurred in 17%. In conclusion, despite an early improvement in renal function after everolimus introduction, we found no evidence that everolimus halts the long-term mGFR decline compared to continued low-dose CNI therapy. Due to retrospective design, small sample size and heterogenous characteristics, definite conclusions require prospective studies.

Chronic kidney disease progression and mortality risk profiles in Germany: results from the Chronic Kidney Disease Outcomes and Practice Patterns Study

BACKGROUND

Chronic kidney disease (CKD) progression among German patients in a representative setting has not been described previously. The Verband Deutsche Nierenzentren and Chronic Kidney Disease Outcomes and Practice Patterns Study established a longitudinal observational cohort among German CKD patients to research variations in patient care and outcomes in real-world nephrology practices.

METHODS

A cohort of CKD Stages 3 (25%) and 4 (75%) patients was established from German nephrologist-run CKD clinics in 2013-16. Linear models were used to determine the estimated glomerular filtration rate (eGFR) slope during follow-up and Cox models were used to assess outcomes of end-stage kidney disease (ESKD) and death.

RESULTS

A total of 1834 patients (median age 75 years, 58% male, 42% diabetics, median baseline eGFR 25 mL/min/1.73 m2) were followed for a median of 29 months. More than 50% had slow or no decline and 17% declined ≥5 mL/min/1.73 m2/year. After 4.5 years, the incidence of ESKD was 8% and of deaths without ESKD 16% among patients with eGFR ≥30 mL/min/1.73 m2 and 37% and 19% for eGFR <30 mL/min/1.73 m2. Adjusted models showed higher risks of ESKD or death for patients with worse kidney function at baseline, male sex, diabetes and higher blood pressure; a higher risk of ESKD with higher albuminuria; and a higher risk of death with older age or cardiovascular comorbidity.

CONCLUSIONS

Routine nephrology care of patients in Germany comprises mostly elderly patients, many with slow CKD progression. Identification of risk factors for CKD progression and mortality may help guide resources by closer follow-up of high-risk patients.

Evolution of eGFR in chronic HCV patients receiving sofosbuvir-based or sofosbuvir-free direct-acting antivirals

BACKGROUND & AIMS

Data regarding the nephrotoxicity of sofosbuvir (SOF) remain controversial. We compared the evolution of estimated glomerular filtration rate (eGFR) in patients with chronic HCV infection receiving SOF-based or SOF-free direct-acting antivirals (DAAs).

METHODS

A total of 481 patients with compensated liver diseases and eGFR ≥30 ml/min/1.73m², receiving SOF-based (n = 308) or SOF-free (n = 173) DAAs for 12 weeks, were prospectively enrolled. The eGFR was assessed from baseline to off-treatment week 24 using the chronic kidney disease (CKD)-epidemiology collaboration equation. Differences in the evolution of eGFR between regimens were compared by a generalized linear mixed-effects model. Multivariate analysis was performed for factors affecting eGFR evolution.

RESULTS

Patients receiving SOF-based DAAs experienced a significant on-treatment decline in eGFR (adjusted slope coefficient difference: -1.24 ml/min/1.73m²/month; 95% CI -1.35 to -1.13; p <0.001) and a significant off-treatment improvement (adjusted slope coefficient difference: 0.14 ml/min/1.73m²/month; 95% CI 0.08 to 0.21; p = 0.004) compared to patients receiving SOF-free DAAs. Multivariate analysis showed age per 1-year increase (adjusted slope coefficient difference: -0.05 ml/min/1.73m²/month; 95% CI -0.05 to -0.04; p <0.001), SOF-based DAAs (adjusted slope coefficient difference: -0.33 ml/min/1.73m²/month; 95% CI -0.49 to -0.17; p <0.001), and CKD stage (adjusted slope coefficient difference: -1.44 ml/min/1.73m²/month; 95% CI -1.58 to -1.30; p <0.001 for stage 3 vs. 1, and -3.59 ml/min/1.73m²/month; 95% CI -3.88 to -3.30; p <0.001 for stage 2 vs. 1) were independent factors affecting eGFR evolution from baseline to off-treatment week 24.

CONCLUSIONS

Patients receiving SOF-based DAAs exhibited a quadratic trend, with eGFR worsening on treatment and improving off treatment. Increasing age, SOF-based DAAs, and more advanced baseline CKD stage are independently associated with a decline in eGFR in patients with HCV receiving DAAs.

LAY SUMMARY

While the efficacy of sofosbuvir for the treatment of hepatitis C virus is clear, data regarding its possible nephrotoxicity are controversial. Herein, we showed that sofosbuvir worsened on-treatment kidney function but led to an off-treatment improvement. Our findings suggest that treating physicians should be alert to risk factors for kidney dysfunction before initiating direct-acting antiviral treatment for patients with hepatitis C virus infection.

CLINICAL TRIAL NUMBER

NCT04047680.

Kidney Function Decline among Black Patients with Sickle Cell Trait and Sickle Cell Disease: An Observational Cohort Study

BACKGROUND

Sickle cell trait and sickle cell disease are thought to be independent risk factors for CKD, but the trajectory and predictors of kidney function decline in patients with these phenotypes are not well understood.

METHODS

Our multicenter, observational study used registry data (collected January 2005 through June 2018) and included adult black patients with sickle cell trait or disease (exposures) or normal hemoglobin phenotype (reference) status (ascertained by electrophoresis) and at least 1 year of follow-up and three eGFR values. We used linear mixed models to evaluate the difference in the mean change in eGFR per year.

RESULTS

We identified 1251 patients with sickle cell trait, 230 with sickle cell disease, and 8729 reference patients, with a median follow-up of 8 years. After adjustment, eGFR declined significantly faster in patients with sickle cell trait or sickle cell disease compared with reference patients; it also declined significantly faster in patients with sickle cell disease than in patients with sickle cell trait. Male sex, diabetes mellitus, and baseline eGFR ≥90 ml/min per 1.73 m² were associated with faster eGFR decline for both phenotypes. In sickle cell trait, low hemoglobin S and elevated hemoglobin A were associated with faster eGFR decline, but elevated hemoglobins F and A₂ were renoprotective.

CONCLUSIONS

Sickle cell trait and disease are associated with faster eGFR decline in black patients, with faster decline in sickle cell disease. Low hemoglobin S was associated with faster eGFR decline in sickle cell trait but may be confounded by concurrent hemoglobinopathies. Prospective and mechanistic studies are needed to develop best practices to attenuate eGFR decline in such patients.

Old age is a positive modifier of renal outcome in Taiwanese patients with stages 3-5 chronic kidney disease

BACKGROUND

The incidence of end-stage renal disease (ESRD) is increasing in elderly patients with chronic kidney disease (CKD). This contradicts the general notion that elderly people are more likely to die than to ever reach ESRD. And racial disparity in relation to age on kidney disease outcomes has always been a subject of research interest.

AIMS

We investigated the effect of age on outcome in a cohort with stages 3-5 CKD patients by age category.

METHODS

A total of 430 patients with a mean age of 65.6 years were enrolled and followed till death, ESRD, or end of 2015. Multivariable Cox regression was used to identify predictors of all-cause mortality. Competing risk-adjusted Cox regression was used to identify determinants of ESRD. The median follow-up was 7.3 (interquartile range 8.8) years.

RESULTS

Cox regression showed old age and low mean arterial pressure were predictors of mortality before and after onset of ESRD. Competing risk analysis revealed patients aged 20-39 years and 40-64 years exhibited greater risks of ESRD, compared to those aged over 75 years. These effects of age on outcomes occurred independently of traditional risk factors such as low estimated glomerular filtration rate and high proteinuria.

CONCLUSIONS

Age over 75 years is associated with decreased risk for ESRD even after adjustment for competing mortality. Given the global trends in population aging, there is a need to develop age-specific strategies, on top of the existing stage-based measures, to optimize the management of CKD in the elderly.

Risk of Kidney Dysfunction from Polypharmacy among Older Patients: A Nested Case-Control Study of the South Korean Senior Cohort

Polypharmacy, the concurrent use of multiple medicines, could increase the risk of kidney dysfunction among older adults because it likely burdens the aging kidneys to excrete multiple pharmaceutical ingredients and their metabolites. This study aimed to examine the relation between polypharmacy and kidney dysfunction among older patients. A nested case-control study was conducted using the National Health Insurance Service - Senior Cohort (NHIS-SC, 2009-2013), representative of the Korean senior population. It consisted of all health insurance claims linked to records of mandatory health examination. Kidney dysfunction was defined as having an eGFR lower than 60, with a decline rate of 10% or more compared to the baseline eGFR. Polypharmacy was defined based on daily counts of pharmaceutical ingredients during one year prior to the case's event date. It was classified into polypharmacy (five to 10 ingredients) and excessive polypharmacy (10 or more ingredients). After matching case and control groups based on a range of potential confounders, conditional logistic regression was performed incorporating adjustments on disease-specific, medication-specific, and lifestyle-related risk factors. The matching resulted in 14,577 pairs of cases and controls. Exposure to polypharmacy was significantly associated with increase in the risk of kidney dysfunction; i.e., crude model (polypharmacy: OR = 1.572, 95% CI = 1.492-1.656; excessive polypharmacy: OR = 2.069, 95% CI = 1.876-2.283) and risk adjustment model (polypharmacy: OR = 1.213, 95% CI = 1.139-1.292; excessive polypharmacy: OR = 1.461, 95% CI = 1.303-1.639). The significant associations were robust across different definitions of kidney dysfunction. These findings inform healthcare providers and policy makers of the importance of polypharmacy prevention to protect older adults from kidney dysfunction.

Serum uric acid to creatinine ratio is a useful predictor of renal dysfunction among diabetic persons

BACKGROUND

Serum uric acid (SUA) has been shown to be a predictor of renal disease progression in most but not all studies. This study aims to test whether renal function-normalized SUA {i.e, SUA/creatinine (Cr) ratio} is a predictor of decreased renal function among diabetic patients.

METHODS

The subjects comprised 185 men aged 72 ± 11 (mean ± standard deviation) years and 175 women aged 77 ± 10 years from a rural hospital. We examined the relationship between SUA/creatinine (Cr) ratio and renal function evaluated by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study Group equation.

RESULTS

Annual eGFR decline rate was significantly increased with increased tertile of baseline SUA/Cr ratio (p = 0.011), and prevalence of the rapid progression types (≥3.0 ml/min/1.73 m²/year) was significantly higher in the second and third tertile (≥7,21) of baseline SUA/Cr ratio than the first tertile (<5.86) (p = 0.032). Pearson's correlation coefficient showed that baseline SUA/Cr ratio (r = 0.136, p = 0.012) as well as systolic blood pressure (SBP) and SUA were significantly correlated with annual eGFR decline rate. Multiple regression analysis using annual eGFR decline rate as an objective variable, adjusted for confounding factors as explanatory variables, showed that baseline SUA/Cr ratio (β = 0.334, p < 0.001) as well as gender and SBP were significantly and independently associated with annual eGFR decline rate. The multivariate-adjusted odds ratios (ORs) (95% confidence interval) of the baseline tertile of the SUA/Cr ratio for rapid progression of annual eGFR decline rate were 1.0, 3.15 (1.66-5.95) and 3.19 (1.57-6.51), respectively.

CONCLUSION

Our data demonstrated that baseline SUA/Cr ratio was independently and significantly associated with future renal function decline among diabetic patients.

Goal attainment and renal outcomes in patients enrolled in the chronic kidney disease care program in Taiwan: a 3-year observational study

OBJECTIVE

To analyze the effects of chronic kidney disease (CKD) care programs on clinical outcomes.

DESIGN

An observational, retrospective study with medical record review.

SETTING

Kaohsiung Chang Gung Memorial Hospital.

PARTICIPANTS

Patients diagnosed with CKD.

INTERVENTIONS

CKD care programs conducted by nephrologists-based team from 2006 to 2013 in our hospital.

MAIN OUTCOME MEASURES

We set 10 goals with treatment target ranges based on the guidelines suggested by the following organizations: Kidney Disease Improving Global Outcomes (2012) and the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (2003).

RESULTS

In total, 1486 patients were enrolled. Their average estimated glomerular filtration rate (ml/min/1.73 m2) was 31.9 at baseline and declined to 28.9 in Year 3 (P < 0.001). The all-goals attainment rate increased from 59.4% at baseline to 60.5% in Year 3, with an especially significant improvement for low-density lipoprotein (from 46.8% to 67.0%) and glycated hemoglobin (from 55.0% to 64.0%). Achievement rates decreased for hemoglobin (from 34.2% to 31.0%), calcium (from 94.6% to 92.3%) and phosphate (from 89.9% to 82.5%) between baseline and Year 3. Albuminuria was the least achieved goal (from 23.4% to 24.0%). Subgroup analysis revealed that estimated glomerular filtration rate did not decline in patients who had a good achievement rate, but decreased significantly in patients with a poor achievement rate.

CONCLUSION

Enrolment in CKD care programs resulted in a significant improvement in goal attainment by patients. Further, a good achievement rate was associated with better preservation of residual renal function.

Influence of diabetes mellitus on patients with lumbar spinal stenosis: A nationwide population-based study

Purpose

To evaluate the relationship between comorbidities, medical cost, and surgical outcome in patients with lumbar spinal stenosis (LSS) and diabetes mellitus (DM).

Methods

Data on patients with LSS (n = 14,298) were collected from the Korean National Health Insurance Service database from 2005 to 2007. After 8 years of follow-up, a “DM group” (n = 3,478) and a “non-DM group” (n = 10,820) were compared according to outcome measures. Cox proportional hazard regressions were performed to examine the relationship between DM, hypertension (HTN), cardiovascular disease (CVD), chronic kidney disease (CKD), cerebrovascular disease (CbVD), and surgery for LSS. The admission rate and medical cost as well asthe overall survival rate for those who underwent lumbar surgery were also assessed among patients with DM and LSS.

Results

Mortality was about 1.35 times higher in the DM group than in the non-DM group. Patients with DM and comorbidities including HTN (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.25–1.56; p<0.001), CVD (HR, 1.53; 95% CI, 1.36–1.73; p<0.001), CKD (HR, 3.18; 95% CI, 2.7–3.76; p<0.001), and CbVD (HR, 1.69; 95% CI, 1.49–1.91; p<0.001) showed an increased risk of mortality. The mean hospitalization time and average medical cost of patients with DM who underwent lumbar surgery were 60.8 days, and 7,127 USD, respectively. This was 31.3 days longer, and 6,207 USD higher, respectively, than those of patients with DM who underwent conservative treatment for LSS. Within the DM group, the survival rate of surgical management of LSS had a significant tendency for positive prognosis compared with those administered conservative treatment (p = 0.046).

Conclusions

In patients with LSS, DM was associated both with poor prognosis (most significantly in those with CKD), and increased medical cost in those who underwent surgery. Nevertheless, surgical treatment for LSS in patients with DM was related to favorable prognosis compared with conservative treatment.

Longitudinal lipid trends and adverse outcomes in patients with CKD: a 13-year observational cohort study

Studies on the effects of longitudinal lipid trajectories on end-stage renal disease (ESRD) development and deaths among patients with chronic kidney disease (CKD) are limited. We conducted a registry-based prospective study using data from a 13-year multidisciplinary pre-ESRD care program. The final study population comprised 4,647 patients with CKD. Using group-based trajectory modeling, we dichotomized longitudinal trajectories of total cholesterol (T-CHO), triglyceride (TG), LDL cholesterol (LDL-C), and HDL cholesterol (HDL-C). Time to ESRD or death was analyzed using multiple Cox regression. At baseline, higher levels of T-CHO and LDL-C were associated with rapid progression to ESRD, whereas only HDL-C was positively associated with all-cause mortality [adjusted hazard ratio (HR), 1.20; 95% CI, 1.06-1.36; P-value, 0.005]. Compared with those with a normal T-CHO trajectory, the fully adjusted HR of patients with a high T-CHO trajectory for ESRD risk was 1.21 (P-value, 0.019). Subgroup analysis showed that a high TG trajectory was associated with a 49% increase in mortality risk in CKD patients without diabetes (P-value for interaction, 0.012). In contrast to what was observed based on baseline HDL-C, patients with a trajectory of frequent hypo-HDL cholesterolemia had higher risk of all-cause mortality (adjusted HR, 1.53; P-value, 0.014). Thus, only T-CHO, both at baseline and over the longitudinal course, demonstrated a significant potential risk of incident ESRD. The inconsistency in the observed directions of association between baseline levels and longitudinal trajectories of HDL-C warrants further research to unveil specific pathogenic mechanisms underlying the HDL-C metabolism in patients with CKD.

Being Overweight Is Related to Faster Decline in Annual Glomerular Filtration Rate in Kidney Transplant

Few studies have examined the relationship between non-immunological factors and glomerular filtration rate (GFR) decline in kidney transplant. Correcting these factors in native kidneys slows the progression of chronic kidney disease. The aim of this study was to analyze the association between the control of non-immunological factors and the annual decline of GFR.

METHODS

A single-center, retrospective study was performed. We included 128 patients who received kidney transplants between 2000 and 2015, with at least 1-year post-transplant follow-up. Clinical records were reviewed. GFR was estimated by CKD-EPI. Three groups were defined according to the annual change in eGFR (ΔGFR 2016-1015): non-progressors (> -1 mL/min/1.73 m²), slow progressors (> -1 and < -5 mL/min/1.73 m²), and fast progressors (< -5 mL/min/1.73 m²). Percentage of achievement of KDIGO target was also analyzed.

RESULTS

The mean GFR was 62.5 mL/min/1.73 m². Glomerulonephritis was the most common cause of kidney failure (36%). When the fast progressor group was compared with the non-progressor group, they differed significantly in age-patients were younger (40 ± 12.3 vs 45 ± 13.1 years)-post-transplant body mass index (27.4 ± 5.6 vs 25.2 x ± 5.9 kg/m²), and serum uric acid, which was significantly higher (6.4 ± 1.7 vs 5.5 ± 1.58 mg/dL). There were no differences between the groups with regard to blood pressure, dyslipidemia, proteinuria, or venous bicarbonate. Target systolic blood pressure was achieved by 45% of patients. Biopsy-proven acute rejection was higher in the fast progression group, although this was not statistically significant (13 [24.5%] vs 8 [13.1%]).

CONCLUSIONS

High body mass index was associated with a faster decline in glomerular filtration rate in this study. Target blood pressure <140/90 mm Hg was achieved in less than 50% of cases.

Clinical and metabolomic risk factors associated with rapid renal function decline in sickle cell disease

Sickle cell disease (SCD) nephropathy and lower estimated glomerular filtration rate (eGFR) are risk factors for early mortality. Furthermore, rate of eGFR decline predicts progression to end-stage renal disease in many clinical settings. However, factors predicting renal function decline in SCD are poorly documented. Using clinical, laboratory, genetic, and metabolomic data, we evaluated predictors of renal function decline in a longitudinal cohort of 288 adults (mean age 33.0 years). In 193 subjects with 5-year follow-up data, mean rate of eGFR decline was 2.35 mL/min/1.73 m² /year, nearly twice that of African American adults overall. Hyperfiltration was prevalent at baseline (61.1%), and 36.8% of subjects experienced rapid eGFR decline (≥3 mL/min/1.73 m² /year). Severe Hb genotype; proteinuria; higher platelet and reticulocyte counts, and systolic BP; and lower Hb level and BMI were associated with rapid decline. A risk scoring system was created using these 7 variables and was highly predictive of rapid eGFR decline, with odds of rapid decline increasing 1.635-fold for every point increment (P < 0.0001). Rapid eGFR decline was also associated with higher organ system severity score and peak creatinine. Additionally, two metabolites (asymmetric dimethylarginine and quinolinic acid) were associated with rapid decline. Further investigation into longitudinal SCD nephropathy (SCDN) trajectory, early markers of SCDN, and tools for risk stratification should inform interventional studies targeted to slowing GFR decline and improving SCD outcomes.

Chronological renal resistive index increases related to atherosclerotic factors, and effect of renin-angiotensin system inhibitors

BACKGROUND

Renal resistive index (RI) calculated using renal Doppler ultrasonography (RDU) has recently been considered a clinically important indicator of renal outcome, survival, and systemic arteriosclerotic disorders. However, the cause of RI elevation remains unclear. The present study was an effort to first, identify the factors related to RI elevation, and second, understand the effect of renin-angiotensin system inhibitors (RAS-Is) on renal RI elevation.

METHODS

We carried out this single-center case-control study among 100 CKD patients, recruited from outpatients who underwent RDU more than twice, at least a year apart. The rate of renal RI change per year (dRIpy) was chosen as the dependent variable: [(last examined renal RI-initial examined renal RI)/(initial examined renal RI × period of observation) × 100 (%/year)]. We examined the association between dRIpy and other clinical and biological data.

RESULTS

Among 100 CKD patients, the average serum creatinine and eGFR were 1.76 ± 0.84 mg/dL and 37.0 ± 18.2 ml/min/1.73 m², respectively. The average dRIpy in all patients was 1.8 ± 1.4%/year. The linear multiple regression demonstrated that dRIpy was positively associated with the presence of diabetes mellitus (DM) and high low-density lipoprotein cholesterol (LDL) levels, and negatively with eGFR and RAS-I use.

CONCLUSIONS

This study demonstrated that the elevation of RI was related to DM, eGFR, high LDL, and the use of RAS-Is. In particular, RAS-Is could contribute towards suppressing the elevation of RI in CKD patients and towards preventing the development of renal failure in CKD patients.

Phenotyping normal kidney function in elderly patients with type 2 diabetes: a cross-sectional multicentre study

AIMS

Type 2 diabetes (T2D) accelerates the decline in glomerular function; however, some individuals do not develop chronic kidney disease despite advanced age and long-lasting T2D. We aimed to phenotype patients with T2D aged 80 years or older who presented with a fully preserved kidney function.

METHODS

From an Italian population of 281,217 T2D outpatients, we collected data on demographics, anthropometrics, diabetes duration, HbA1c, fasting plasma glucose, lipids, liver enzymes, estimated glomerular filtration rate (eGFR), albumin excretion rate (AER), chronic complications, and medication use. We primarily compared patients with a fully preserved kidney function (eGFR > 90 ml/min/1.73 m² and AER < 30 mg/24 h, or G1A1) with those with mild kidney impairment (eGFR 60-90 ml/min/1.73 m² and AER < 30 mg/24 h, or G2A1).

RESULTS

N = 113,860 had available data for eGFR and AER, 21,648 of whom were aged ≥ 80. G1A1 (n = 278) and G2A1 (n = 6647) patients represented 1.3 and 30.7% of aged T2D patients, respectively, with an average diabetes duration of 16 years. Differences between the G1A1 and G2A1 groups were entered in a multiple logistic regression analysis with and without imputation of missing data. After adjustment and in both imputed and non-imputed datasets, younger age, lower BMI and lower triglycerides were associated with fully preserved versus mildly impaired kidney function. The comparison between G1A1 and G1A2/3 yielded different results.

CONCLUSIONS

In a rare population of patients with a fully preserved kidney function despite old age and long-lasting diabetes, lower BMI and triglycerides suggest that protection from lipotoxicity may preserve kidney function over time.

10-Year Renal Function Trajectories in Community-Dwelling Older Adults: Exploring the Risk Factors for Different Patterns

Longitudinal changes of renal function help inform patients’ clinical courses and improve risk stratification. Rare studies address risk factors predicting changes in estimated glomerular filtration rate (eGFR) over time in older adults, particularly of Chinese ethnicity. We identified prospectively enrolled community-dwelling older adults (≥65 years) receiving annual health examinations between 2005 and 2015 with serum creatinine available continuously in a single institute, and used linear regression to derive individual’s annual eGFR changes, followed by multivariate logistic regression analyses to identify features associated with different eGFR change patterns. Among 500 elderly (71.3 ± 4.2 years), their mean annual eGFR changes were 0.84 ± 1.67 mL/min/1.73 m²/year, with 136 (27.2%) and 238 (47.6%) classified as having downward (annual eGFR change <0 mL/min/1.73 m²/year) and upward eGFR (≥1 mL/min/1.73 m²/year) trajectories, respectively. Multivariate logistic regression showed that higher age (odds ratio (OR) 1.08), worse renal function (OR 13.2), and more severe proteinuria (OR 9.86) or hematuria (OR 3.39) were predictive of a declining eGFR while greater waist circumference (OR 1.06) and higher leukocyte counts (OR 1.21) were predictive of an uprising 10-year eGFR. These findings elucidate important features associated with geriatric renal function variations, which are expected to improve their renal care.

Machine Learning to Compare Frequent Medical Problems of African American and Caucasian Diabetic Kidney Patients

Objectives

End-stage renal disease (ESRD), which is primarily a consequence of diabetes mellitus, shows an exemplary health disparity between African American and Caucasian patients in the United States. Because diabetic chronic kidney disease (CKD) patients of these two groups show differences in their medical problems, the markers leading to ESRD are also expected to differ. The purpose of this study was, therefore, to compare their medical complications at various levels of kidney function and to identify markers that can be used to predict ESRD.

Methods

The data of type 2 diabetic patients was obtained from the 2012 Cerner database, which totaled 1,038,499 records. The data was then filtered to include only African American and Caucasian outpatients with estimated glomerular filtration rates (eGFR), leaving 4,623 records. A priori machine learning was used to discover frequently appearing medical problems within the filtered data. CKD is defined as abnormalities of kidney structure, present for >3 months.

Results

This study found that African Americans have much higher rates of CKD-related medical problems than Caucasians for all five stages, and prominent markers leading to ESRD were discovered only for the African American group. These markers are high glucose, high systolic blood pressure (BP), obesity, alcohol/drug use, and low hematocrit. Additionally, the roles of systolic BP and diastolic BP vary depending on the CKD stage.

Conclusions

This research discovered frequently appearing medical problems across five stages of CKD and further showed that many of the markers reported in previous studies are more applicable to African American patients than Caucasian patients.

Patterns of progression of chronic kidney disease at later stages

Background

At later stages of chronic kidney disease (CKD), a pattern of linear and irreversible renal function decline is thought to be the most common. The objective of this study was to describe the characteristics of the different patterns of CKD progression, and to investigate potentially modifiable factors associated with the rate of decline of renal function.

Methods

This was a retrospective, observational study in a cohort of adult patients with CKD Stage 4 or 5 not on dialysis. Decline in renal function was estimated as the slope of the individual linear regression line of estimated glomerular filtration rate (eGFR) over time. The following patterns of CKD progression were considered: unidentifiable, linear, nonlinear (curvilinear) and positive (improvement of renal function).

Results

The study group consisted of 915 patients (mean ±SD age 65 ± 14 years, 48% females, median follow-up time 16 months). A linear pattern was observed in 38%, unidentifiable in 23%, nonlinear in 24% and positive in 15% of the study patients. The mean eGFR slope was: −3.35 ± 4.45 mL/min/year. Linear and unidentifiable patterns were associated with more rapid loss of renal function. By multiple linear and logistic regression analysis, the magnitude of proteinuria, the systolic blood pressure and the treatment with dual renin–angiotensin system blockade were associated with more rapid CKD progression. On the contrary, older age and discontinuation of commonly prescribed medication with potential influence on renal function or eGFR measurements were associated with slower CKD progression.

Conclusions

A majority of patients with advanced CKD show patterns of renal function decline different from linear, and several of the main determinants of CKD progression are potentially modifiable.