Year: 2013
Type: article
Study design: Observational Study
Abstract: Purpose: To describe markers of iron status in recreational female runners and the relationship of iron intake and iron status in this population.Methods: Of the 121 consented participants, 93 met the inclusion criteria and were included in the final analyses.After refraining from running for 24 hours and fasting for 8 hours, venous blood was drawn for markers of iron status (hemoglobin (Hgb), hematocrit (Hct), ferritin (Ferr).Ferritin and soluble transferrin receptor (sTfR) concentrations were measured using the ELISA method (ALPCO Diagnostics).Dietary data were collected and analyzed (ESHA Research).Statistical analysis was conducted with SPSS version 20. Results:The mean values for markers of iron status + standard deviation are as follows:Hgb 13.02 + 1.00 g/dL, Hct 38.21 ± 2.84 %, Ferr 17.22 + 6.15 ng/mL, sTfR 4.29 + 2.15 mg/mL, and soluble transferrin receptor/log (Ferr) ratio (TfR ratio) 3.68 + 2.03.Twelve runners had clinically low Hgb (<12 g/dL).Ferritin was below the literature defined (<20ng/mL) 'normal-low' in 63 runners while values outside the normal range for sTfR were found in 30 runners.There was a significant inverse relationship between ferritin and sTfR (p <0.001) with a Pearson correlation coefficient of -0.482.Additionally, there was a significant inverse relationship between ferritin and TfR ratio (p< 0.001).When using 3 literature based clinical ferritin categories, the associated sTfR were found to be significantly different (p<0.001) in two of the three ferritin groups (Ferr <12) and (Ferr >20).Iron intake did not correlate with ferritin or TfR ratio and iron intake did not improve the correlation between ferritin and sTfR or ferritin and TfR ratio; however, the correlation between ferritin and sTfR did improve when vitamin C was added to the iii model.Inadequate dietary iron intake correlated with iron status markers ferritin and sTfR indicating it is influential in iron status.Conclusions: Although only 12 of 93 recreational female runners had low Hgb, the majority (n=63) had significantly low iron stores as noted by sTfR and ferritin.This suggests improved early prediction of iron status.Use of sTfR and TfR ratio highlight the significant negative relationships to the clinical categories of iron deficiency (without anemia) when assessed with ferritin.We conclude that the additional iron status markers, ferritin, sTfR, and TfR ratio demonstrated more precision in identifying low iron stores and set the stage for additional work to evaluate the impact of iron supplementation on the iron status of recreational female runners and their performance. INTENDED USEThis Ferritin ELISA is intended for the quantitative determination of ferritin in human serum.This assay is to be used in the diagnosis of diseases affecting iron metabolism.
Author: Jenna E. Stangland
Institution: The Ohio State University
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: Ohio State University
OpenAlex ID: W1007491706