Common Presence of Non–Transferrin-Bound Iron Among Patients With Type 2 Diabetes

作者：Duk‐Hee Lee, Ding Yong Liu, David R. Jacobs, Hai‐Rim Shin, Kyungeun Song, In‐Kyu Lee, Bowan Kim, Robert C. Hider · 发表于：Diabetes Care · 年份：2006 · DOI：10.2337/dc05-2471 · 被引用次数：108 · 研究领域：Iron Metabolism and Disorders、Vitamin C and Antioxidants Research、Trace Elements in Health

OBJECTIVE—Recently, we reported increased cardiovascular disease mortality among supplemental vitamin C users with type 2 diabetes in a prospective cohort study. Because vitamin C may cause oxidative stress in the presence of redox active iron, we hypothesized that non–transferrin-bound iron (NTBI), a form of iron susceptible to redox activity, may be present in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS—We measured serum NTBI levels using high-performance liquid chromatography in 48 patients with known diabetes (at least 5 years duration since diagnosis), 49 patients with newly diagnosed diabetes, and 47 healthy control subjects (frequency matched on age and sex). RESULTS—NTBI was commonly present in diabetes: 59% in newly diagnosed diabetes and 92% in advanced diabetes. Mean NTBI values varied significantly between the three groups, with the highest values being observed in patients with known diabetes and the lowest in the control subjects (0.62 ± 0.43 vs. 0.24 ± 0.29 vs. 0.04 ± 0.13 μmol/l Fe). Serum total iron or percent transferrin saturation were very similar among the three groups, yet NTBI was strongly associated with serum total iron (r = 0.74, P < 0.01) and percent transferrin saturation (r = 0.70, P < 0.01) among the patients with known diabetes. CONCLUSIONS—Consistent with our hypothesis, these data demonstrate the common existence of NTBI in type 2 diabetic patients with a strong gradient with severity. Prospective cohort studies are required to ...