Author Interviews, Biomarkers, Gender Differences, Kidney Disease, NEJM, Race/Ethnic Diversity / 26.01.2023 Interview with: Prof. dr. Hans Pottel KU Leuven Kulak Department of Public Health and Primary Care Belgium What is the background for this study? Response:  The glomerular filtration rate (GFR) is used to diagnose patients with chronic kidney disease and is also used to adjust the dose of drugs that are eliminated by the kidneys. An accurate estimation of GFR is considered of importance in the management of kidney health in patients. In 2021 we published a new serum creatinine based equation, called the European Kidney Function Consortium (EKFC) equation (Pottel H. et al, Development and Validation of a Modified Full Age Spectrum Creatinine-Based Equation to Estimate Glomerular Filtration Rate : A Cross-sectional Analysis of Pooled Data. Ann Intern Med (2021) 174: 183-191): EKFC-eGFR = 107.3 / [Biomarker/Q]a x [0.990(Age – 40) if age > 40 years] With a = 0.322 if Biomarker/Q is less than 1, and a = 1.132 if Biomarker/Q is 1 or more. The equation can easily be interpreted: the leading coefficient equals the glomerular filtration rate (GFR) of 107.3 mL/min/1.73m², which is the average GFR in healthy children (aged > 2 years), adolescents and young adults. The average healthy GFR remains constant until the age of 40 years, and starts decreasing beyond that age. The GFR is inversely related to the ‘rescaled’ biomarker. The rescaling factor (Q) is the average biomarker value for healthy people of a specific population (e.g. children, adult men, adult women, white people, black people, …). Biomarker/Q equals ‘1’ for the average healthy person, corresponding with eGFR = 107.3 mL/min/1.73m² (up to 40 years of age). It should be noted that for serum creatinine, the Q-value depends on sex and race. Our hypothesis was that the above equation is valid for any renal biomarker, on the condition that the biomarker is appropriately scaled. We showed that the same equation was able to estimate GFR from 2 years to oldest ages. In the current study we tested and validated our hypothesis by applying the above formula for appropriately ‘rescaled’ cystatin C. (more…)
Author Interviews, Clots - Coagulation, Heart Disease, Karolinski Institute, Kidney Disease / 06.10.2022 Interview with: Juan Jesus Carrero Pharm PhD Professor of Epidemiology Cardio-renal Department of Medical Epidemiology and Biostatistics Karolinska Institutet, Stockholm What is the background for this study? What are the main findings?  Response: Concerns on the possibility of (direct oral anticoagulants)  DOAC-related nephropathy may limit its use. In this cohort study of non-valvular AF patients from routine clinical practice, initiation of DOAC vs (vitamin K antagonists) VKA was associated with more favorable kidney outcomes, i.e., a lower risk of the composite of kidney failure and sustained 30% eGFR decline, as well as a lower risk of AKI occurrence. In agreement with trial evidence, we also showed that DOAC vs VKA treatment was associated with a lower risk of major bleeding, but a similar risk of the composite of stroke, systemic embolism or death. (more…)
Author Interviews, Gout, JAMA, Kidney Disease / 06.06.2022 Interview with: Csaba P Kovesdy MD FASN Fred Hatch Professor of Medicine Director, Clinical Outcomes and Clinical Trials Program Division of Nephrology, University of Tennessee Health Science Center Nephrology Section Chief, Memphis VA Medical Center Memphis TN, 38163  What is the background for this study?  What are the main findings?  Response: Hyperuricemia has unfavorable metabolic effects and has been associated with higher risk of progressive kidney disease and mortality. Despite this, earlier clinical trials have failed to prove a beneficial impact on kidney disease progression from uric acid lowering therapy in patients with preexisting CKD. The effect of uric acid lowering therapy on the development of new onset CKD in patients with normal kidney function has not been well studied. In our large observational study we did not find a beneficial association between newly initiated uric acid lowering therapy (the majority of which was in the form of allopurinol). On the contrary, uric acid lowering therapy was associated with a slightly higher risk of new onset low eGFR and new onset albuminuria, especially in patients with less elevated baseline serum acid levels. (more…)
Author Interviews, Critical Care - Intensive Care - ICUs, JAMA, Kidney Disease / 15.03.2022 Interview with: Susan P. Y. Wong, MD MS Assistant Professor Division of Nephrology University of Washington VA Puget Sound Health Care System  What is the background for this study?  What are the main findings? Response: Very little is known about the care and outcomes of patients who reach the end stages of kidney disease and do not pursue dialysis. We conducted a systematic review of longitudinal studies on patients with advanced kidney disease who forgo dialysis to determine their long-term outcomes. We found that many patients survived several years and experienced sustained quality of life until late in the illness course. However, use of acute care services was common and there was a high degree of variability in access to supportive care services near the end of life. (more…)
Author Interviews, Kidney Disease, Race/Ethnic Diversity / 13.01.2022 Interview with: Joshua D. Bundy, PhD, MPH Department of Epidemiology Tulane University School of Public Health and Tropical Medicine and Tulane University Translational Science Institute New Orleans Louisiana What is the background for this study? What is included in the KFRE score? Response: Kidney function is quantified using estimated glomerular filtration rate (eGFR), which is often calculated in clinical practice using filtration markers like serum creatinine and/or cystatin C, and patient characteristics like age, sex, and race. Recently, new eGFR equations were created that remove race adjustment because of concerns that using a patient’s race may perpetuate racial inequities in healthcare delivery. The Kidney Failure Risk Equation (KFRE) is the most commonly-used tool to predict end-stage kidney disease (ESKD) risk and includes age, sex, eGFR, and urinary albumin-creatinine ratio. We sought to evaluate the impact of removing race from eGFR on prediction of ESKD.  (more…)
Author Interviews, JAMA, Kidney Disease, Race/Ethnic Diversity, UCSF / 17.07.2021 Interview with: Chi-yuan Hsu, MD, MSc (he/him/his) Professor and Division Chief Division of Nephrology University of California, San Francisco San Francisco, CA 94143-0532 What is the background for this study? Response: There has been a great deal of controversy recently about how race should be considered in medicine, including its use in estimating kidney function (e.g.  A recent paper published in JAMA Network Open by Zelnick et al suggested that removing the race coefficient improves the accuracy of estimating kidney function ( in the Chronic Renal Insufficiency Cohort, a NIH-funded study ( We are core investigators of the Chronic Renal Insufficiency Cohort Study and were not involved in the Zelnick’s study that was based on a public use dataset.  Because we were surprised by the methodological approach they took and the conclusion they came to, we implemented our own analysis of the data. (more…)