Iron Deficiency in Non-dialyzed Patients with Type 2 Diabetes: A Cross-Sectional Study

摘要

Background. Iron deficiency (ID) is a major cause of anemia in diabetes. Data are sparse regarding iron metabolism and its association with anemia in non-dialyzed patients with diabetes and without other overt causes for low haemoglobin level. The objective of this study was to determine the prevalence and characteristics of ID in non-dialysis dependent patients with type 2 diabetes and to assess its association with anemia and diabetic complications. Methods. Data from 400 non-dialysis dependent patients with type 2 diabetes (≥2 years) (excluding patients treated with iron therapy or erythropoietin-stimulating agents, or with foot lesions or amputations or other known clinical causes of ID) were analyzed in a cross-sectional, single-center study. ID was defined as ferritin <100 ng/mL (absolute ID), or ferritin ≥100 ng/mL and transferrin saturation (TSAT) < 20% (functional ID), and anemia as hemoglobin 70 years and <11.5 g/dL in women. Results. 315 patients (78.8%) were iron deficient (186 absolute ID, 129 functional ID). ID anemia (IDA) was present in 74 patients (18.5%) of 89 patients with anemia from any cause (22.3%). Female gender was the only independent predictor of absolute ID (OR=2.30 95%CI 1.44-3.38, p<0.001). Increasing C-reactive protein was predictive of functional ID (OR=1.03 95%CI 1.01-1.05, p=0.001). The prevalence of IDA and all-cause anemia increased significantly with severity of chronic kidney disease (CKD) and urinary protein excretion (both p<0.001). Concerning diabetes complications we found that severe CKD was significantly associated with IDA (OR 5.32, 95% CI 2.52-11.25; p<0.001) and anemia of any cause (OR 8.39, 95% CI 3.87-18.23; p<0.001); autonomic neuropathy was significantly associated with absolute ID (OR=2.18, 95%CI 1.08-4.43, p=0.027) and proliferative retinopathy was significantly associated with functional ID (OR=1.75, 95% CI 1.02-3-02, p=0.041). Conclusions. Iron metabolism abnormalities, as determined by metabolic inflammatory status and the presence of ID, are frequent in type 2 diabetes and increase with severity of CKD, particularly in patients with autonomic neuropathy and proliferative retinopathy.