Serum ferritin, diabetes, diabetes control, and insulin resistance

Aims The present study aims to investigate the association between serum ferritin and diabetes, diabetes control, and insulin resistance (IR) and examine whether gender is a modifier for these associations in a community-based sample. Methods A cross-sectional survey of 8,235 participants was conducted in 2009. Serum ferritin, glucose, hemoglobin A1c (HbA1c), insulin, inflammatory markers, and lipid markers were measured. IR was estimated with a Homeostasis Model Assessment (HOMA-IR) equation. Multiple logistic and linear regression models were applied to evaluate these associations. Results The numbers of diabetic patients and non-diabetic participants in the present study were 644 (7.8 %) and 7,591 (92.2 %). After adjusting for multiple confounders, the odds ratios (ORs) and 95 % confidence intervals (CIs) for diabetes were 1.48 (1.31-1.69) in men and 1.43 (1.24-1.65) in women for one-unit increase in log-transformed serum ferritin levels. Likewise, ORs (95 % CIs) for poor diabetes control (HbA1c >= 7.5 %) were 1.58 (1.21-2.05) and 1.37 (1.07-1.77) in men and women, respectively. As for HOMA-IR, the respective betas (P value) for one-unit increase in log-transformed serum ferritin were 0.07 (P < 0.0001) and 0.06 (P < 0.0001) in men and women. Conclusions In conclusion, elevated serum ferritin levels were associated with higher risks of diabetes, higher levels of HbA1c, and HOMA-IR independent of several confounders.