Body Iron Stores Are Associated With Serum Insulin and Blood Glucose Concentrations: Population study in 1,013 eastern Finnish men

OBJECTIVE To study if there is an association between mildly elevated body iron and glucose homeostasis indexes. RESEARCH DESIGN AND METHODS A cross-sectional population study was conducted in 1,013 middle-aged men, and an association of serum ferritin with concentrations of serum insulin, blood glucose, and serum fructosamine was tested. RESULTS The mean concentration of fasting serum insulin was 21.6% higher (95% CI 7.3–37.9%, P < 0.001) in the 5th quintile of serum ferritin compared with the 1st quintile. The elevation in blood glucose was 6.1% (95% CI 2.3–9.9%, P < 0.001) and in serum fructosamine 3.9% (1.5–6.9%, P < 0.01). CONCLUSIONS Mildly elevated body iron stores are associated with statistically significant elevations in glucose homeostasis indexes.