Evaluation of iron deficiency in young women in relation to oral contraceptive use.
BACKGROUND
The purpose of this study was to identify the optimal measures for diagnosing iron deficiency (ID) in oral contraceptive (OC) users and nonusers, and to estimate ID frequency in relation to OC use.


METHODS
Conventional biomarkers of iron status - serum ferritin, iron, transferrin (Tf) and transferrin saturation (TfS) - were compared with serum soluble Tf receptor (sTfR) and the sTfR/log ferritin ratio (sTfR-F index). Two hundred two healthy menstruating white Italian women (aged 24+/-4.8 years) were analyzed. Serum ferritin concentrations <12 microg/L were considered as ID.


RESULTS
ID was detected in 29.7% (60/202) of the study women. Fifty-nine women were OC users (59/202, 29.2%). OC use did not significantly affect ID prevalence (p=.24). However, OC use markedly increased Tf in OC users, who had an odds ratio (OR) of 9.3 (CI 3.8-22.7, p<.001) for elevated Tf >330 mg/dL. No other iron status measure was affected by OC. Of the markers for ID adjunctive to ferritin, an elevated sTfR-F index >or =1.5 showed the best performance. Specifically in OC users, the elevated sTfR-F index had better sensitivity (81.0% vs. 33.3%), specificity (94.7% vs. 92.1%), efficiency (89.8% vs. 71.2%), positive predictive value (89.5% vs. 70.0%) and negative predictive value (90.0% vs. 71.1%) than a TfS <15%. Additionally, the sTfR-F index allowed the identification of low iron stores in 4.5% (9/202) of women with ferritin > or =12 microg/L.


CONCLUSIONS
Among healthy OC users and non-OC users, the sTfR-F index had the highest performance for diagnosing ID compared with other serum markers adjunctive to ferritin measurements, whereas sTfR by itself had a low sensitivity. We showed that neither the sTfR nor sTfR-F index was affected by third-generation OC use. The sTfR measurement is useful in the diagnosis of ID, especially in women using OC, where Tf and TfS tests may be misleading.
Casabellata
Giorgia
G
Department of Biomedical Sciences and Technologies, School of Medicine, University of Udine, 33100 Udine, Italy.
Di Santolo
Manuela
M
Banfi
Giuseppe
G
Stel
Giuliana
G
Gonano
Fabio
F
Cauci
Sabina
S
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007501:Iron / Q000097:blood; D000090463:Iron Deficiencies
D015415:Biomarkers; D003277:Contraceptives, Oral, Combined; D007501:Iron