Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. May 15, 2017; 8(5): 222-229
Published online May 15, 2017. doi: 10.4239/wjd.v8.i5.222
Impact of creatinine methodology on glomerular filtration rate estimation in diabetes
Marijana Vučić Lovrenčić, Vanja Radišić Biljak, Kristina Blaslov, Sandra Božičević, Lea Smirčić Duvnjak
Marijana Vučić Lovrenčić, Vanja Radišić Biljak, Sandra Božičević, Department of Laboratory Medicine, Merkur University Hospital, HR-10000 Zagreb, Croatia
Kristina Blaslov, Lea Smirčić Duvnjak, Vuk Vrhovac University Clinic, Merkur University Hospital, HR-10000 Zagreb, Croatia
Author contributions: Lovrenčić MV designed the study and wrote the article; Biljak VR and Lovrenčić MV analyzed the data, Biljak VR and Božičević B performed the laboratory part of the study; Blaslov K and Duvnjak LS performed the clinical part of the study; all authors discussed the results and approved the final version of the manuscript.
Institutional review board statement: The study was approved by the Ethics Committee of the Merkur University Hospital, Zagreb, Croatia.
Informed consent statement: This study was waived by IRB due to the retrospective nature of the study, with the post-hoc selection of anonymized samples from the routine laboratory visits, according to creatinine and glucose results.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article are reported.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Marijana Vučić Lovrenčić, PhD, Department of Laboratory Medicine, Merkur University Hospital, Zajčeva 19, HR-10000 Zagreb, Croatia. vucic@idb.hr
Telephone: +385-1-2353861 Fax: +385-1-2353847
Received: October 29, 2016
Peer-review started: November 2, 2016
First decision: December 1, 2016
Revised: December 20, 2016
Accepted: February 28, 2017
Article in press: March 2, 2017
Published online: May 15, 2017
Abstract
AIM

To evaluate the influence of creatinine methodology on the performance of chronic kidney disease (CKD)-Epidemiology Collaboration Group-calculated estimated glomerular filtration rate (CKD-EPI-eGFR) for CKD diagnosis/staging in a large cohort of diabetic patients.

METHODS

Fasting blood samples were taken from diabetic patients attending our clinic for their regular annual examination, including laboratory measurement of serum creatinine and eGFR.

RESULTS

Our results indicated an overall excellent agreement in CKD staging (kappa = 0.918) between the Jaffé serum creatinine- and enzymatic serum creatinine-based CKD-EPI-eGFR, with 9% of discordant cases. As compared to the enzymatic creatinine, the majority of discordances (8%) were positive, i.e., associated with the more advanced CKD stage re-classification, whereas only 1% of cases were negatively discordant if Jaffé creatinine was used for eGFR calculation. A minor proportion of the discordant cases (3.5%) were re-classified into clinically relevant CKD stage indicating mildly to moderately decreased kidney function (< 60 mL/min per 1.73 m2). Significant acute and chronic hyperglycaemia, assessed as plasma glucose and HbA1c levels far above the recommended glycaemic goals, was associated with positively discordant cases. Due to a very low frequency, positive discordance is not likely to present a great burden for the health-care providers, while intensified medical care may actually be beneficial for the small number of discordant patients. On the other hand, a very low proportion of negatively discordant cases (1%) at the 60 mL/min per 1.73 m2 eGFR level indicate a negligible possibility to miss the CKD diagnosis, which could be the most prominent clinical problem affecting patient care, considering high risk of CKD for adverse patient outcomes.

CONCLUSION

This study indicate that compensated Jaffé creatinine procedure, in spite of the glucose-dependent bias, is not inferior to enzymatic creatinine in CKD diagnosis/staging and therefore may provide a reliable and cost-effective tool for the renal function assessment in diabetic patients.

Keywords: Diabetes, Estimated glomerular filtration rate, Chronic kidney disease-Epidemiology Collaboration Group, Creatinine, Enzymatic method, Chronic kidney disease, Impact, Compensated Jaffé method

Core tip: Analytical performance of the serum creatinine assays is the critical determinant of estimated glomerular filtration rate (eGFR) accuracy. The most widely used compensated Jaffé creatinine assay suffers from a non-specific bias from pseudo-creatinine chromogens (glucose, ketones), which is not the case with the costly enzymatic assays. We evaluated the influence of creatinine methodology on the performance of chronic kidney disease (CKD)-Epidemiology-calculated eGFR for CKD diagnosis/staging in diabetic patients. Our results indicate that compensated Jaffé creatinine procedure, in spite of the glucose-dependent bias, is not inferior to enzymatic creatinine in CKD diagnosis/staging and therefore may provide a reliable and cost-effective tool for the renal function assessment in diabetic patients.