Case Control Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. Jul 6, 2016; 5(4): 358-366
Published online Jul 6, 2016. doi: 10.5527/wjn.v5.i4.358
Diabetes mellitus increases the prevalence of anemia in patients with chronic kidney disease: A nested case-control study
Charalampos Loutradis, Alexandra Skodra, Panagiotis Georgianos, Panagiota Tolika, Dimitris Alexandrou, Afroditi Avdelidou, Pantelis A Sarafidis
Charalampos Loutradis, Pantelis A Sarafidis, Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, 54642 Thessaloniki, Greece
Alexandra Skodra, Panagiota Tolika, Dimitris Alexandrou, Afroditi Avdelidou, Hemodialysis Unit, General Hospital of Grevena, 52100 Grevena, Greece
Panagiotis Georgianos, Section of Nephrology and Hypertension, 1st Department of Medicine, AHEPA Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece
Author contributions: Loutradis C performed the statistical analysis and wrote the manuscript; Skodra A, Tolika P, Alexandrou D collected study material; Georgianos P participated in the statistical analysis; Avdelidou A prospectively collected data and supervised the study material collection; Sarafidis PA designed the study, supervised the statistical analysis and edited the manuscript.
Institutional review board statement: The study was reviewed and approved by the Review Board of General Hospital of Grevena.
Informed consent statement: This is a nested case-control study, deriving from a prospectively assembled clinic database. All study participants had provided informed consent for their data to be kept in the clinic’s database.
Conflict-of-interest statement: All authors disclose that they don’t have any financial or other relationships, which might lead to a conflict of interest relevant to this study.
Data sharing statement: The study dataset is anonymized and kept by the two senior authors (Avdelidou A and Sarafidis PA).
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: Pantelis A Sarafidis, MD, MSc, PhD, Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Konstantinoupoleos 49, 54642 Thessaloniki, Greece. psarafidis11@yahoo.gr
Telephone: +30-2313-312930
Received: February 19, 2016
Peer-review started: February 22, 2016
First decision: March 25, 2016
Revised: April 1, 2016
Accepted: May 10, 2016
Article in press: May 11, 2016
Published online: July 6, 2016
Processing time: 131 Days and 9.5 Hours
Abstract

AIM: To compare anemia prevalence between matched chronic kidney disease (CKD) patients with and without diabetes mellitus (DM) and to assess factors associated with anemia development.

METHODS: This is a nested case-control study of 184 type-2 diabetic and 184 non-diabetic CKD patients from a prospectively assembled database of a Nephrology outpatient clinic, matched for gender, age and estimated glomerular filtration rate (eGFR). Prevalence of anemia (hemoglobin: Men: < 13 g/dL, women: < 12 g/dL and/or use of recombinant erythropoietin) was examined in comparison, in the total population and by CKD Stage. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with anemia.

RESULTS: The total prevalence of anemia was higher in diabetics (47.8% vs 33.2%, P = 0.004). Accordingly, prevalence was higher in diabetics in CKD Stage 3 (53.5% vs 33.1%, P < 0.001) and particularly in Stage 3a (60.4% vs 26.4%, P < 0.001), whereas it was non-significantly higher in Stage 4 (61.3% vs 48.4%; P = 0.307). Serum ferritin was higher in diabetics in total and in CKD stages, while serum iron was similar between groups. In multivariate analyses, DM (OR = 2.206, 95%CI: 1.196-4.069), CKD Stages 3a, 3b, 4 (Stage 4: OR = 12.169, 95%CI: 3.783-39.147) and serum iron (OR = 0.976, 95%CI: 0.968-0.985 per mg/dL increase) were independently associated with anemia.

CONCLUSION: Prevalence of anemia progressively increases with advancing stages of CKD and is higher in diabetic than matched non-diabetic CKD patients and diabetes is independently associated with anemia occurrence. Detection and treatment of anemia in diabetic CKD patients should be performed earlier than non-diabetic counterparts.

Keywords: Anemia; Diabetes; Chronic kidney disease; Ferritin; Prevalence of anemia

Core tip: Anemia is an established complication of chronic kidney disease (CKD) and diabetes mellitus is proposed to further increase anemia occurrence through various mechanisms. However, a direct comparison between diabetic and non-diabetic CKD patients with regards to anemia is currently missing. This study evaluates in comparison the prevalence of anemia in carefully matched CKD patients with and without diabetes mellitus.