Predicting iron absorption from an effervescent iron supplement in obese patients before and after Roux-en-Y gastric bypass: a preliminary study

• Published in: Journal of trace elements in medicine and biology 2019-03, Vol.52, p.68-73
• Main Authors: Gesquiere, Ina, Steenackers, Nele, Lannoo, Matthias, Foulon, Veerle, Mertens, Ann, Gils, Ann, de Hoon, Jan, Augustijns, Patrick, Matthys, Christophe, Van der Schueren, Bart
• Format: Article
• Language: English
• Subjects: Bariatric Surgery; Hepcidin; Iron Deficiency; Obesity; Oral Iron Absorption; Roux-en-Y Gastric Bypass
• ISSN: 0946-672X; 1878-3252
• DOI: 10.1016/j.jtemb.2018.12.002

•Careful monitoring of the iron status is necessary in obese and bariatric patients.•Necessary to distinguish responders from non-responders for iron supplementation.•Hepcidin and TSAT are predictors for iron absorption pre- and post-RYGB•Pharmacokinetic properties of an effervescent iron tablet are unaffected by RYGB Oral iron absorption is hampered in obese and bariatric patients, especially after Roux-en-Y gastric bypass (RYGB). As a result, iron deficiency, which is common in both patient groups, can be difficult to treat by oral supplements, often necessitating a switch to parenteral administration. The aim of this study was to find possible predictors of the extent of absorption of an effervescent iron gluconate oral supplement, which enables to pre-emptively identify those patients in which oral supplementation is likely to fail. The pharmacokinetic properties of 695 mg effervescent iron gluconate (80 mg Fe2+) were assessed in 13 obese patients (female = 10; mean age ± SD: 45.2 ± 12.5years) pre- and six months post-RYGB by measuring serum iron concentrations during 24 hours and by calculating the adjusted for baseline AUC0-24h, Cmax and Tmax. A multivariate regression analysis was performed to investigate the effect of hepcidin concentration, iron and hematologic indices, personal and anthropometric characteristics on iron absorption. Subsequently, Receiver Operating Characteristic (ROC) curves were used to propose the cut-off value for hepcidin concentrations above which obese patients are unlikely to benefit from oral iron supplementation. Data are expressed as mean ± SD. Low iron status persisted after surgery as there was no significant difference observed in TSAT (17.3 ± 5.2 vs. 20.2 ± 6.6%), ferritin (91.8 ± 68.6 vs. 136.2 ± 176.9 μg/L) and hepcidin concentration (32.0 ± 30.1 vs. 28.3 ± 21.3 ng/mL) after RYGB. The absorption of effervescent iron gluconate was similar pre- and post-RYGB [AUC0-24h,pre-RYGB: 28.6 ± 10.8 μg/dL*h; AUC0-24h,post-RYGB: 27.5 ± 9.11 μg/dL*h (P = 0.84)]. Post-RYGB, iron AUC0-24h showed a strong negative correlation with both hepcidin concentrations and TSAT (R=-0.51; P = 0.08 and R=-0.81; P = 0.001), respectively. Pre-RYGB, there was a clear trend for the same negative correlations for hepcidin concentrations and TSAT (R=-0.47; P = 0.11 ;R=-0.41; P = 0.16), respectively. Taking pre-and post-RYGB data together, the negative correlations were confirmed for hepcidin concentrations and TSAT (R=-0.54; P = 0.004; R=-0.60; P =