To access the independent associations between serum ferritin quintile levels and metabolic syndrome (MS) in adults of different genders.

19 563 participants over the age of 18 years were recruited from "TCLSIH Cohort Study" from 2007 to 2015. Serum ferritin concentration was measured by Enzyme-linked immunoassay, while metabolic syndrome was diagnosed according to MS diagnostic criteria formulated by Chinese Diabetes Society in 2013. Multiple logistic regression analysis was used to assess the association between serum ferritin quintile levels and the prevalence of MS in males and females.

After adjusting the confounding factors, the overall prevalence of MS gradually increased with the increasing of serum ferritin levels, similar results were observed in males and females. Subjects were divided into 5 subgroups according to serum ferritin levels. Compared with level 1 group, logistic regression showed that the serum ferritin quintiles of males and females ranged from low to high, the OR (95% confidence interval) for metabolic syndrome were 1.142 (0.998, 1.307), 1.382 (1.210, 1.579), 1.680 (1.472, 1.917), 2.085 (1.827, 2.380), respectively (P_trend<0.01), and 1.147 (0.911, 1.444), 1.346 (1.075, 1.687), 1.567 (1.268, 1.941), 2.444 (1.981, 3.023), respectively (P_trend<0.01).

The elevated ferritin levels were positively related to the prevalence of metabolic syndrome in adults of different genders.

Serum ferritin; Metabolic syndrome; Insulin resistance; Chronic inflammation; Cross-sectional study