Nonanemic Iron Deficiency in Cardiac Surgery: A Retrospective Observational Study.

OBJECTIVES: Anemia and iron deficiency in patients having cardiac surgery increases their perioperative risk. Nonanemic iron deficiency (NAID) in this group is less well-described. We aimed to investigate the incidence and outcomes of patients with NAID undergoing cardiac surgery. DESIGN: Retrospective observational study. SETTING: A single, tertiary referral center. PARTICIPANTS: Adult patients who were preassessed and underwent cardiac surgery during the study period had data collected. We enrolled 537 patients enrolled and divided them into 4 groups according to hemoglobin and ferritin: NAID, nonanemic iron replete, iron-deficiency anemia (IDA), and non-iron-deficiency anemia. INTERVENTIONS: This study was not interventional, but assessed the impact of anemia and iron deficiency on patient outcomes. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the incidence of NAID. Secondary outcomes included the number of patients who became anemic awaiting surgery, allogeneic transfusion burden, length of stay, postoperative complications, and death. 179 of 537 patients (33.3%) had NAID. Seventeen patients (9.5%) became anemic in the NAID group compared with 7 (3.3%) in the nonanemic iron replete group while awaiting for surgery (p = 0.02). Patients with NAID were more likely to receive allogeneic transfusions (33% vs 23%; p = 0.04) and had poorer recovery of hemoglobin at follow-up (13.2 ± 1.46 g/dL vs 13.9 ± 1.46 g/dL; p < 0.001). CONCLUSIONS: NAID is common and can lead to progression to anemia and increased transfusion. Iron replacement should be considered in patients with NAID in the preoperative setting. A prospective interventional trial is required to demonstrate the benefit of being iron replete.

A Food-Derived Dietary Supplement Containing a Low Dose of Iron Improved Markers of Iron Status Among Nonanemic Iron-Deficient Women.

OBJECTIVE: Iron deficiency is the most common nutrient deficiency in the world. While deficiency can often be resolved through dietary supplementation with iron, adverse events are common and frequently preclude compliance. The objective of this study was to determine whether a food-derived dietary supplement containing a low dose of iron and nutrients that increase iron absorption could resolve iron deficiency with fewer adverse events than reported at higher doses. METHODS: A pilot clinical trial (NCT02683369) was conducted among premenopausal women with nonanemic iron deficiency that was verified by blood screening. Participants consumed a dietary supplement (Blood Builder®/Iron Response®) once daily for 8 weeks containing 26 mg of iron, vitamin C, folate, and other food-derived nutrients. Primary outcomes were markers of iron status (serum ferritin, hemoglobin, soluble transferrin receptor, total body iron stores) and secondary outcomes were self-reported fatigue and energy. All outcomes were assessed at baseline and 8 weeks. Adverse events were monitored with questionnaires, daily diaries, and contact with a physician. Dependent samples t test and Wilcoxon signed-rank test were used to analyze outcomes. RESULTS: Twenty-three participants enrolled in the study. Iron deficiency was resolved in the sample (mean serum ferritin: baseline = 13.9 µg/L, 8 weeks = 21.1 µg/L, p < 0.001). All other markers of iron status, fatigue, and energy also improved during the study (p < 0.04). No adverse events were reported. CONCLUSIONS: While larger and controlled studies are needed to confirm these findings, a food-derived dietary supplement with a low dose of iron and absorption-enhancing nutrients resolved iron deficiency and improved all other markers of iron status without any adverse events.