Hepatic iron content is independently associated with serum hepcidin levels in subjects with obesity

Serum hepcidin concentration is known to increase in parallel to circulating markers of iron stores. We aimed to investigate whether this is reflected at the tissue level in subjects with obesity.

Serum hepcidin and ferritin levels (ELISA) and hepatic iron content (using magnetic resonance imaging) were analyzed longitudinally in 44 participants (19 without obesity and 25 with obesity). In a subgroup of 16 participants with obesity, a weight loss intervention was performed.

Serum hepcidin, ferritin and hepatic iron content (HIC) were significantly increased in participants with obesity. Age- and gender-adjusted serum hepcidin was positively correlated with BMI, hsCRP, ferritin and HIC. In addition, age- and gender-adjusted serum hepcidin was positively correlated with ferritin and HIC in both non-obese and obese participants. In multivariate regression analysis, hepatic iron content (p < 0.01) and serum ferritin (p < 0.001) contributed independently to circulating hepcidin concentration variation after controlling for age, gender, BMI and hsCRP. Diet intervention-induced weight loss led to decreased serum hepcidin (p = 0.01), serum ferritin concentration (p = 0.01) and HIC (p = 0.002). Of note, the percent change of serum hepcidin strongly correlated with the percent change of serum ferritin (r = 0.69, p = 0.01) and HIC (r = 0.61, p = 0.03) even after controlling for age and gender.

Serum hepcidin is a reliable marker of the hepatic iron content in subjects with obesity.