Ferritin Is a Marker of Inflammation rather than Iron Deficiency in Overweight and Obese People

Background. In clinical practice, serum ferritin is used as a screening tool to detect iron deficiency. However, its reliability in obesity has been questioned. Objectives. To investigate the role of ferritin in overweight and obese people, either as a marker of inflammation or iron deficiency. Methods. On the basis of body mass index (BMI), 150 participants were divided into three equal groups: A: BMI 18.5-25 kg/m², B: BMI 25-30 kg/m², and C: BMI > 30 kg/m². Serum iron, total iron binding capacity (TIBC), transferrin saturation, ferritin, C-reactive protein, and hemoglobin (Hb) were measured for each participant and analyzed through SPSS version 16. One-way ANOVA and Pearson's correlation tests were applied. Results. Ferritin was the highest in group C (M = 163.48 ± 2.23, P < 0.001) and the lowest in group A, (M = 152.78 ± 1.81, P < 0.001). Contrarily to ferritin, transferrin was the lowest in group C, (M = 30.65 ± 1.39, P < 0.001) and the highest in group A, (M = 38.66 ± 2.14, P < 0.001). Ferritin had a strong positive correlation with both BMI (r = 0.86, P < 0.001) and CRP (r = 0.87, P < 0.001) and strong negative correlation with Hb, iron, TIBC, and transferrin saturation (P < 0.001). Conclusion. Ferritin is a marker of inflammation rather than iron status in overweight and obese people. Complete iron profile including transferrin, rather than serum ferritin alone, can truly predict iron deficiency in such people.