Non-anemic iron deficiency: correlations between symptoms and iron status parameters

Objectives: To register all symptoms reported by non-anemic menstruating women, and examine the links between these symptoms and iron status parameters available including serum ferritin (SF) in primary care.

Subjects and methods: In this cross-sectional study, we collected clinical and biological data from 780 French menstruating women aged 18-50 years. The data included an anonymous questionnaire (biometric information, physical and cognitive symptoms, reduction in physical performance, current quality of life with SF-36 questionnaire) and seven biological parameters available in primary care. We excluded women with anemia (hemoglobin < 12 g/dl) or chronic disease. Correlations were studied for 554 participants in bivariate analysis (BVA) and multivariate analysis (MVA), with adjusted odds ratio (OR). Receiver operating characteristic (ROC) curves were established for significant correlations in MVA (p < 0.05).

Results: Among these 554 non-anemic women included, 304 (54.9%) had SF level below 50 µg/l, 103 (18.6%) had SF level below 20 µg/l, and 60 (10.8%) had SF level below 15 µg/l. Iron deficiency was significantly correlated with recent hair loss for SF ≤ 15 µg/l (OR = 2.19 with p = 0.02 in MVA) and SF ≤ 20 µg/l (OR = 2.26 with p < 0.01 in MVA). SF ≤ 20 µg/l was also correlated with limitations due to emotional problems according to SF-36 questionnaire (p = 0.01 in MVA). SF ≤ 50 µg/l was significantly correlated with restless legs syndrome (OR = 2.82 with p = 0.01 in MVA). Only one ROC curve for restless legs syndrome could suggest an optimal SF cut-off point at 39 µg/l (sensitivity 73%, specificity 61%).

Conclusion: We identified two symptoms significantly more reported by non-anemic iron-deficient menstruating women: recent hair loss for serum ferritin (SF) ≤ 20 µg/l and restless legs syndrome for SF ≤ 50 µg/l. Non-anemic iron deficiency may also impact their quality of life, but further investigation is needed. If one of these symptoms is reported in primary care, the possibility of a symptomatic iron deficiency cannot be ruled out, and iron supplementation should be considered.