Eicosanoids and oxylipin signature in HH patients are similar to DIOS patients but are impacted by dietary iron absorption.

INTRODUCTION: Oxylipins are mediators of oxidative stress. To characterize the underlying inflammatory processes and phenotype the effect of iron metabolism disorders, we investigated the oxylipin profile in hereditary hemochromatosis (HH) and dysmetabolic iron overload syndrome (DIOS) patients.

METHODS: LC-MS/MS based method to quantify plasma oxylipins in 20 HH and 20 DIOS patients in fasting conditions and 3 hours after an iron-rich meal in HH patients.

RESULTS: Principal component analysis showed no separation between HH and DIOS, suggesting that the clinical phenotype has no direct impact on oxylipin metabolism. 20-HETE was higher in DIOS and correlated with hypertension (p = 0.03). Different oxylipin signatures were observed in HH before and after the iron-rich meal. Discriminant oxylipins include epoxy fatty acids derived from docosahexaenoic acid and arachidonic acid as well as 13-HODE and 9-HODE. Mediation analysis found no major contribution of dietary iron absorption for 16/22 oxylipins significantly affected by the meal.

DISCUSSION: The oxylipin profiles of HH and DIOS seemed similar except for 20-HETE, possibly reflecting different hypertension prevalence between the two groups. Oxylipins were significantly affected by the iron-rich meal but the specific contribution of iron was not clear. Although iron may contribute to oxidative stress and inflammation in HH and DIOS, this does not seem to directly affect oxylipin metabolism.