Association between Serum Ferritin Levels and Diabetes Mellitus in a Korean Population

Several studies have suggested that increased iron storage may promote the development of diabetes mellitus (DM).This study examined the association between the serum ferritin levels and DM in a Korean population.The study population consisted of 8,991 subjects (3,588 males and 5,403 females) aged 50 years and older in the Gwangju Study.DM was defined by fasting glucose 126 mg/dL or HbA1c 6.5% or people on blood glucose-lowering medication.The serum ferritin levels were determined using a chemiluminescent microparticle immunoassay.Multiple linear regression and logistic regression were performed to evaluate the relationship of serum ferritin with DM, fasting glucose, and HbA1c after adjusting for potential confounders.The ferritin levels showed a J-shaped association with the DM risk, with the highest odds in the 5th quintile (odds ratio 1.77, 95% confidence interval 1.502.09).The fasting glucose level showed a positive quadratic relationship with log-transformed ferritin levels, while the HbA1c levels showed a J-shape association.The ferritin levels displayed a J-shape association with the risk of DM and the HbA1c levels and a quadratic association with the fasting glucose levels in a large population-based cohort.These results suggest that the body iron load may play an important role in diabetes.