[Effect of iron deficiency level on oral iron absorption]

Objective: To study the effect of iron deficiency level for oral iron absorption in iron deficient patients. Methods: 37 non-pregnant female patients who were diagnosed with iron deficiency and 13 healthy females who completed their physical examination at the outpatient department of the Anemia Center of the Institute of Hematology & Blood Diseases Hospital from July 2018 to June 2020 were included. Hepcidin and C2-C0 of oral iron absorption test were analyzed in different iron deficiency and serum ferritin level. Results: The median of Hepcidin in IDA, ID/IDE and healthy control group were 4.9 (2.17-32.86) , 26.98 (11.02-49.71) and 69.89 (42.23-138.96) μg/L (P<0.001) , respectively. Hepcidin level of IDA group was lower than that of ID/IDE group (adjusted P=0.005) and healthy control (adjusted P<0.001) . Hepcidin level of ID/IDE group had no significant difference compared with healthy control (adjusted P=0.22) . The mean of C2-C0 in IDA, ID/IDE and healthy control group were (35.30±21.68) , (37.90±14.06) and (23.57±10.14) μmol/L (P=0.130) , respectively. Multilinear regression analysis showed C0, SF, sTFR and HGB were independent factors for Hepcidin in iron deficient patients, with an equation of Hepcidin=-31.842-0.642*C0+2.239*SF+1.778*sTFR+0.365*HGB-0.274*RET-HB. We didn't find independent factor of C2-C0. Conclusion: The degree of iron deficiency had an effect on oral iron absorption. Patients of ID/IDE group absorbed iron more slowly than patients of IDA group. Iron deficient patients with normal gastrointestinal function absorbed more iron by oral administration when they were in a more serious iron deficient stage. Hepcidin was a better parameter to distinguish iron absorption level among different iron deficient patients than C2-C0 of oral iron absorption test.