The effects of reducing chronic inflammation in overweight women on serum hepcidin and iron absorption with and without supplemental ascorbic acid

Abstract

Although hepcidin synthesis is stimulated by inflammation and inhibited by Fe deficiency, the strength of their opposing effects on serum hepcidin (SHep) in humans remains unclear. It was recently shown that an inflammatory stimulus in anaemic women did not increase SHep or decrease Fe absorption. The enhancing effect of ascorbic acid on Fe absorption may not be effective during inflammation because of increased SHep. Our study aim was to test whether reducing inflammation in Fe-depleted overweight (OW) women with low-grade inflammation would lower SHep and improve Fe absorption with and without ascorbic acid, compared with normal-weight (NW) women without inflammation. Before and after 14 d of anti-inflammatory treatment (3 × 600 mg ibuprofen daily) in OW and NW women (n 36; 19-46 years of age), we measured SHep and fractional Fe absorption (FIA) (erythrocyte Fe incorporation) from 57Fe- and 58Fe-labelled test meals with and without ascorbic acid. There were significant group effects on IL-6, C-reactive protein, serum ferritin and SHep (for all, P < 0·05). There was a significant treatment effect on SHep (P < 0·05): in OW women, treatment decreased IL-6 by approximately 30 % and SHep by approximately 45 %. However, there were no significant treatment or group effects on FIA. Body Fe stores (BIS) were a significant positive predictor of SHep before and after treatment (P < 0·001), but IL-6 was not. Reducing chronic inflammation in OW women halved SHep but did not affect Fe absorption with or without ascorbic acid, and the main predictor of Fe absorption was BIS.