Ferritin and Percent Transferrin Saturation Levels Predict Type 2 Diabetes Risk and Cardiovascular Disease Outcomes

摘要

Introduction: Type 2 diabetes (T2D) and cardiovascular disease (CVD) risk associate with ferritin and percent transferrin saturation (TS) levels. However, increased risk has been observed at levels considered within the "normal range" for these markers. Objective: To define normative ferritin and TS levels associated with T2D and CVD risk. Methods: Six-monthly ferritin, TS and hemoglobin levels from 1,277 iron reduction clinical trial participants with CVD (peripheral arterial disease, 37 diabetic) permitted pair-wise analysis using Loess Locally Weighted Smoothing plots. Curves showed continuous quantitative ferritin, hemoglobin (reflecting physiologic iron requirements), and TS (reflecting iron transport and sequestration) levels over a wide range of values. Inflection points in the curves were compared to ferritin and TS levels indicating increased T2D and CVD risk in epidemiologic and intervention studies. Results: Increasing ferritin up to about 80 ng/mL and TS up to about 25 TS corresponded to increasing hemoglobin levels, and minimal T2D and CVD risk. Displaced Loess trajectories reflected lower hemoglobin levels in diabetics compared to non-diabetics. Ferritin levels up to about 100 ng/mL paralleled proportionately increasing TS levels up to about 55TS corresponding to further limitation of T2D and CVD risk. Ferritin levels over 100 ng/mL did not associate with hemoglobin levels and coincided with increased T2D and CVD risk.