Bioavailability of Iron Supplement Formulations by Bariatric Surgery Type: A Pilot Study (P23-013-19)

Abstract

ObjectivesOur previous research demonstrated that ferrous sulfate, the gold standard iron supplement treats iron deficiency in bariatric surgery patients but wasn’t well tolerated. We also found that the bioavailability of iron supplements, assessed by a serum iron absorption test, predicts treatment response. The objective of the current study is to determine whether bariatric surgery type (gastric bypass [GB] and sleeve gastrectomy [SG]) or iron formulation type (inorganic ferrous sulfate versus and an organic, slow-release form of iron, called AspironTM) predicts iron supplement bioavailability. MethodsIron-deficient GB and SG females, ages 18–65 years, who had surgery at least 6 months previously, participated in an 8-hour iron absorption test. Participants were considered iron deficient if two of the following values were abnormal: serum transferrin receptor greater than 2012 mcg/L, ferritin below 30 mcg/L, total iron binding capacity above 370 mcg/dL, and a serum transferrin receptor: ferritin ratio greater than 500. Participants received a low-iron breakfast with a 65 mg iron supplement. We assessed serum iron every 30 minutes for 8 hours following the supplementation using a calorimetric assay (South Bend Medical Foundation, South Bend, IN). ResultsWe report our preliminary findings to date; the study is ongoing. Out of the 10 participants, 8 had GB and 2 had SG. Six of the GB patients and both SG patients received AspironTM, and two of the GB patients received ferrous sulfate. In GB participants, following ferrous sulfate, serum iron increased 80.5 ± 6.4 mcg/dL compared to baseline, whereas following AspironTM, serum iron increased 6.7 ± 4.6 mcg/dL compared to baseline (P = 0.000). Compared to the GB group, serum iron increased 58.5 ± 57.3 mcg/dL in the SG group following AspironTM supplementation (P = 0.037). ConclusionsOur preliminary findings suggest that AspironTM is not as bioavailable as ferrous sulfate in GB patients. AspironTM may be better absorbed in SG patients, indicating that it could be an effective treatment to reverse iron deficiency in the SG population. Funding SourcesCura Global Health Inc.