Diabetes May Increase Anemia Risk in CKD Patients

Type 2 diabetes mellitus increases the risk of anemia among patients with chronic kidney disease (CKD) patients, a new study confirms.

Previous observational studies indicating an association prompted Charalampos Loutradis, MD, MSc, of Aristotle University in Thessaloniki, Greece, and colleagues to directly compare anemia prevalence. Among CKD stages 2 to 4 outpatients attending the General Hospital of Grevena during 2007 to January 2015, they matched 184 with type 2 diabetes to 184 without diabetes by age, gender, and estimated glomerular filtration rate (eGFR).

Results published in the World Journal of Nephrology (2016;5:358-366) showed increasing anemia prevalence with CKD progression from stage 2 to 4, in agreement with past research. In addition, anemia was more common among CKD patients with type 2 diabetes than without: 47.8% vs 33.2%. By CKD stage, anemia was more prevalent in stage 3 patients with diabetes (53.5% vs 33.1%), and especially in stage 3a (60.4% vs 26.4%).

In multivariate analyses, the odds of anemia were 2.2 times greater for patients with versus without diabetes and 6, 7.5, and 12 times greater among patients with CKD stage 3a, 3b, and 4, respectively, compared with patients who had CKD stage 2.

The investigators defined anemia as a hemoglobin level below 13 g/dL in men and below 12 g/dL in women and/or use of recombinant erythropoietin.

Examination of laboratory values showed that serum ferritin levels were higher in patients with diabetes. Among several possible mechanisms linking anemia to diabetes and CKD, these findings support a role of chronic inflammation, they noted. Ferritin may be a marker of inflammation and hepcidin, and hepcidin has a role in functional iron deficiency. Ferritin did not appear to be a marker of iron stores in this study.

“The difference between diabetic and non-diabetic patients with CKD was more prominent in CKD Stage 3, where the majority of individuals with CKD belongs,” the investigators concluded. “Subclinical inflammation in diabetic patients with moderate CKD may be the most important underlying factor for this association, as indicated by increased ferritin levels in diabetics in our study.”

To rule out possible confounders, the investigators also examined the use of medications such as renin-angiotensin-aldosterone system inhibitors, and determined that they were not major contributors to the findings. Likewise, comorbidities did not appear to play a decisive role. Although proteinuria was higher in diabetes patients, it also was not deemed a significant factor in multivariate analysis.

With regard to the clinical implications of the study, Dr Loutradis and colleagues stated: “Both detection and treatment of anemia in diabetic CKD patients should be performed earlier than in non-diabetics, in order to prevent anemia-associated complications.”