Editor’s Note: We asked authors of Original Investigations to provide short plain-language summaries that would briefly summarize what inspired their study, the basic approach taken, what was learned, and why it matters. We hope our readers will find this valuable in helping them keep up with the latest research in the field of nephrology. From the September 2021 issue:

Association of Treatment Effects on Early Change in Urine Protein and Treatment Effects on GFR Slope in IgA Nephropathy: An Individual Participant Meta-analysis by Lesley A. Inker et al

From the authors: Drug regulatory agencies allow changes in urine protein level to be used as end points for trials in immunoglobulin A nephropathy as part of accelerated approval of treatments as long as there is confirmation of the treatment benefit in postmarketing trials following approval. We performed an individual-patient meta-analysis including data from 1,037 patients across 12 trials to assess how treatment effects on the change in proteinuria predicts the treatment effects on the change in estimated glomerular filtration rate (GFR), a surrogate outcome that has recently been validated. We found that treatment effects on urine protein accurately predicted treatment effects on the total GFR slope at 3 years and on chronic GFR slope. These results provide new evidence supporting that a change in proteinuria can be used as a surrogate end point in treatment trials of progression of immunoglobulin A nephropathy.

DOI: 10.1053/j.ajkd.2021.03.007

Editorial: Using GFR, Albuminuria, and Their Changes in Clinical Trials and Clinical Care by Josef Coresh et al [FREE] 

Arteriovenous Vascular Access–Related Procedural Burden Among Incident Hemodialysis Patients in the United States by Kenneth J. Woodside et al

From the authors: To connect to the hemodialysis machine, patients with kidney failure require vascular access such as an arteriovenous fistula or graft. To develop and maintain arteriovenous fistulas and grafts, endovascular interventions are common. We studied the rates of interventions on arteriovenous fistulas and grafts during the maturation and maintenance phases in patients new to hemodialysis who had arteriovenous fistulas and grafts placed for the first time during the first year of hemodialysis treatment. We found that during maturation, grafts required fewer interventions. If they successfully mature, fistulas had lower interventional requirements. For fistulas, but not grafts, we also noted that there were differences in the number of interventions based on geographic location, with a higher burden on the East Coast.

DOI: 10.1053/j.ajkd.2021.01.019

Editorial: Recurrent Arteriovenous Hemodialysis Access Procedures: The Hidden Details by Adrian P. Abreo et al [FREE] 

Mortality in Children Treated With Maintenance Peritoneal Dialysis: Findings From the International Pediatric Peritoneal Dialysis Network Registry by Sophie Ploos van Amstel et al [Open Access] 

From the authors: So far, research on children who are treated with dialysis or have received a kidney transplant has focused on Europe and North America. In this study, we describe the mortality risk of children on maintenance peritoneal dialysis in different parts of the world and assess which factors are associated with patient survival. We included 2,956 patients younger than 19 years from the International Pediatric Peritoneal Dialysis Network who started maintenance peritoneal dialysis between 1996 and 2017. After 3 years, the overall probability of death was 5%, ranging from 2% in North America to 9% in Eastern Europe. Mortality was higher in low-income countries than in high-income countries. This study shows that the overall patient survival on maintenance peritoneal dialysis is high in children, and that country income is associated with patient survival.

DOI: 10.1053/j.ajkd.2020.11.031

Association of Physical Activity and Poor Health Outcomes in Patients With Advanced CKD by Christie Rampersad et al 

From the authors: Adults with chronic kidney disease (CKD) are more likely to be sedentary. This lack of physical activity is associated with poor health outcomes, including lower quality of life and increased risk of death. We prospectively studied the association of physical activity with death, risk of kidney failure, and falls in a cohort of 600 patients with advanced CKD treated in 4 Cana-dian kidney health clinics. Physical activity was self-reported using the Physical Activity Scale for the Elderly (PASE) questionnaire. Higher levels of physical activity were associated with about a 50% lower risk of all-cause death, but not with progression to kidney failure or risk of future falls. These findings highlight the potential importance of maintaining physical activity among patients with CKD.

DOI: 10.1053/j.ajkd.2020.12.018

Catheter Dependence After Arteriovenous Fistula or Graft Placement Among Elderly Patients on Hemodialysis by Beini Lyu et al 

From the authors: Creation of an arteriovenous fistula (AVF), compared to an arteriovenous graft (AVG), is associated with longer initial catheter dependence after starting hemodialysis. It is hoped that this initial dependence is overcome by lower long-term dependence, but it is not clear whether this is realized in older patients. We examined catheter dependence among patients aged 67 years or older who received an AVF/AVG within the first year after starting hemodialysis. We found that the initial higher dependence was not reversed with follow-up to 3 years. Cumulative catheter dependence remained greater for those with an AVF. These findings emphasize the importance of patient characteristics when choosing a vascular access type.

DOI: 10.1053/j.ajkd.2020.12.019

Risk of Symptomatic Kidney Stones During and After Pregnancy by Charat Thongprayoon et al 

From the authors: Although several well-known anatomical and physiological changes during pregnancy could contribute to kidney stone formation, the evidence that these changes increase the risk of kidney stones during pregnancy is lacking. In a population-based case-control study using 945 female first-time symptomatic stone formers and 1,890 aged-matched female controls in Olmsted County, MN, pregnancy was associated with an increased risk of a symptomatic kidney stone, starting during the second trimester, peaking around the time of delivery, and persisting until 1 year after delivery. Awareness of the higher risk of symptomatic kidney stones during pregnancy and the postpartum period informs diagnostic and preventive strategies in women, particularly for women who are already at high risk for kidney stones.

DOI: 10.1053/j.ajkd.2021.01.008

Brief Guide: Interpreting the Evidence from the August 2021 Issue:

A Practical Guide to Interpret Individual Participant Data Meta-analysis of Observational Studies by Shoshana H. Ballew et al [FREE] 

From the authors: In the past 2 decades, several consortia have been established to compile and meta-analyze individual participant data (IPD), advancing the field of nephrology. Both IPD meta-analysis and aggregate data (AD) meta-analyses (conventional meta-analysis based on published data) may use similar methods to pool estimates from individual cohorts, but IPD meta-analysis has various advantages over AD meta-analysis and is likely to be used more often in the future. In this Brief Guide, we summarize key properties of IPD meta-analysis and provide a practical guide to interpret results from observational studies according to IPD meta-analysis, using an example from the Chronic Kidney Disease Prognosis Consortium (CKD-PC).

DOI: 10.1053/j.ajkd.2021.02.333

On the Cover: The Kiagna River wends its way through the wilderness of the Wrangelle-St. Elias National Park and Preserve in Alaska. Though the journey is a long one, the river’s branching course is clear and its flow unimpeded, evoking the image of a well-functioning hemodialysis vascular access. However, all too often, arteriovenous accesses for hemodialysis do not mature or fail after some period of clinical use. These complications often require endovascular interventions to achieve and maintain patency. In this issue of AJKD, Woodside et al report on the high rate of interventions required to successfully create and sustain vascular accesses as well variations across access type and geographic area.

The photograph “East Fork Kiagna River” is by US National Park Service/Jacob W. Frank, available via Flickr and released into the public domain.

SPECIAL 40th ANNIVERSARY COLLECTION: CKD

AJKD is celebrating its 40th year in 2021. In this special collection, the editors highlight landmark papers on chronic kidney disease that have been published in the journal over the past four decades.