Serum ferritin and risk of the metabolic syndrome: a population-based study.

Ferritin concentrations in circulation reflect iron stores in healthy individuals. However, elevated serum ferritin (SF) concentrations have recently been implicated in the pathogenesis of the metabolic syndrome (MetS). We aim to investigate factors associated with elevated SF and to evaluate the association between SF and risk of MetS in Taiwanese adults. Data was collected from 2654 healthy individuals aged >=19 years old, who participated in the Nutrition and Health Survey in Taiwan (NAHSIT Adults 2005-2008). Mean concentrations of SF were 173±282 ng/mL (men 229±349 ng/mL and women 119±180 ng/mL). Prevalence proportion of MetS was 34.6% (men 43.1% and women 26.5%). Prevalence proportion of iron overload was 18.6% (men 21.5% and women 15.8%) and iron deficiency anemia was 5.2% (2.0% for men and 8.3% for women). Individuals with the highest SF tertile (T3) were more likely to consume higher amount of animal protein (p=0.001), betel nuts (p=0.004), and lower amounts of carbohydrates (p<0.0001), compared with the lowest SF group (T1). After adjustments, individuals with the highest SF tertile were associated with risk of MetS compared with those with the lowest (OR=1.724, 95% CI: 1.21-2.45). Serum ferritin concentrations showed a gradient relationship with individual components of MetS (all p<0.0001). Individuals with the highest SF tertile were significantly associated with fasting serum glucose (OR=2.16, 95% CI: 1.75-2.65) and serum triglyceride (OR=2.58, 95% CI: 1.07-3.22) than those with the lowest. In conclusions, our results highlight the crucial role of serum ferritin in the pathogenesis of the MetS in healthy Taiwanese adults.