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Publication Information
Affiliation
1Department of Public Health and Primary Care, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
2Department of Clinical Chemistry, University of Liège (ULiege), CHU Sart Tilman, Liège, Belgium
3Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
4Clinical Studies Sweden, Forum South, Skåne University Hospital, Lund, Sweden
5Department of Translational Medicine, Division of Medical Radiology, Lund University, Malmö,
Sweden
6Department of Clinical Chemistry, Skåne University Hospital, Lund, Lund University, Sweden
7Charité Universitätsmedizin Berlin, Institute of Public Health, Berlin, Germany
8
Section of Nephrology, University Hospital of North Norway and Metabolic and Renal Research
Group, UiT The Arctic University of Norway, Tromsö, Norway
9Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, United
Kingdom
10
Service de Néphrologie, Dialyse et Transplantation Rénale, Hôpital Nord, CHU de Saint-Etienne,
France
11Néphrologie, Dialyse, Hypertension et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot,
Hospices Civils de Lyon, France.
12Function area Clinical Chemistry, Karolinska University Laboratory, Karolinska University Hospital
Huddinge and Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
13 Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institute, Huddinge,
Sweden
14Department of Geriatrics, School of Medical Sciences, Örebro University, Örebro, Sweden.
15Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden
16Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
2
17Nephrology-Dialysis-Transplantation, University of Liège, CHU Sart Tilman, Liège, Belgium
18Department of Nephrology-Dialysis-Apheresis, Hôpital Universitaire Carémeau, Nîmes, France
Authors
Åkesson A, Björk J, Cavalier E, Delanaye P, Dubourg L, Ebert N, Eriksen BO, Grubb A, Hansson M, Lamb EJ, Larsson A, Littmann K, Mariat C, Melsom T, Nyman U, Pottel H, Rule A, Schaeffner E, Sundin P
Studies
Abstract
Background: Differences in performance of estimating glomerular filtration rate (eGFR) equations
have been attributed to the mathematical form of the equations and to differences between patient
demographics and measurement methods. We evaluated differences in serum creatinine (SCr) and
eGFR in cohorts matching for age, sex, BMI and measured GFR (mGFR).
Methods: White North Americans from Minnesota (n=1093) and the Chronic Renal Insufficiency
Cohort (CRIC) (n=1548), and White subjects from the European Kidney Function Consortium (EKFC)
cohort (n=7727), were matched for demographic patient characteristics (equal sex, age±3 years,
BMI±2.5kg/m²) and renal function (measured GFR±3mL/min/1.73m²). SCr was measured with
isotope dilution mass spectrometry (IDMS) traceable assays in Minnesota and EKFC and with nonstandardized SCr-assays recalculated to IDMS in CRIC. Minnesota and CRIC shared the common
method to measure GFR (renal clearance of iothalamate) while EKFC used a variety of exogenous
markers and methods, all with recognized sufficient accuracy. We compared the SCr-levels and eGFRpredictions (for CKD-EPI and EKFC-equations) of patients fulfilling these matching criteria.
Results: For 305 matched individuals, mean SCr was not different between Minnesota and EKFC
0.83±0.20 vs 0.86±0.23, females and 1.06±0.23 vs 1.12±0.37, males (p>0.05), but significantly
different from CRIC (1.13±0.23 (p<0.0001), females and 1.42±0.31 (p<0.0001), males). CKD-EPIequations performed better than the EKFC-equation in the CRIC-cohort, while the opposite was true
in the Minnesota and EKFC-cohort.
Conclusion: Significant differences in SCr-concentrations between Minnesota/EKFC versus CRIC were
observed in subjects with the same level of mGFR and equal demographic characteristics and can be
explained by the difference in SCr-calibration.