Women’s Health Reports Volume 1.1, 2020 DOI: 10.1089/whr.2019.0011 ORIGINAL ARTICLE Open Access Iron Deficiency in Menstruating Adult Women: Much More than Anemia M. Cristina Fernandez-Jimenez, MD,1 Gemma Moreno, MD,2 Ione Wright, MD,3 Pei-Chun Shih, PhD,4 M. Pilar Vaquero, MD, PhD,3,* and Angel F. Remacha, MD, PhD5 Abstract Background: Iron deficiency anemia (IDA) is highly prevalent in women of child-bearing age. However, their nonhematological symptoms have been overlooked. This study aims to analyze the nonhematological features and symptoms of IDA in a group of women of reproductive age and the changes occurred during iron therapy. Materials and Methods: IDA women underwent dietary, physical activity, menstrual blood loss, and cognitive function assessment at baseline. Hematological and biochemical parameters were analyzed. Executive attention was tested by the flanker task and working memory by the 2-back task. Oral iron therapy (ferrous sulfate) was given to 35 women for 8 weeks and the changes in iron status, biochemical markers, cognitive function, and nonhematological symptoms were evaluated. Results: Patients presented nonhematological symptoms: pica, 32.4%; cheilitis, 20.6%; restless legs syndrome (RLS), 20.6%; diffuse hair loss, 55.9%; and ungual alterations, 38.2%. Two or more symptoms were present in 58.8% of women. Serum iron and working memory were correlated at baseline. Multivariate analyses show as- sociations (odds ratio [OR], 95% confidence interval [CI]) between pica and reaction time in the working memory test (OR 2.14, 95% CI 1.19–3.87, p = 0.012); RLS with total serum protein (OR 0.08, 95% CI 0.06–0.92, p = 0.043); and cheilitis with mean corpuscular hemoglobin (OR 0.388, 95% CI 0.189–0.799, p = 0.01). Pica, cheilitis, and RLS com- pletely resolved with iron therapy, and ungual alterations and hair loss improved in 92.3% and 84.2% of women, respectively. Better performance in executive attention and working memory was observed after iron therapy. Conclusions: More attention should be given to the nonhematological manifestations of IDA to improve the quality of life of menstruating women. Keywords: iron deficiency anemia; nonhematological symptoms; cognitive function; menstruation; women Introduction ID occurs as a spectrum beginning with tissue iron Iron deficiency (ID) is the most common nutritional store depletion and progressing to impaired eryth- deficiency in the world and is the leading cause of ane- ropoiesis and anemia. Iron is an essential element re- mia in both developed and developing countries. The quired for numerous vital processes, including energy greatest prevalence of iron deficiency anemia (IDA) is metabolism, cell signaling, gene expression, and cell found in women of reproductive age and preschool growth regulation and differentiation.2 These functions children, regardless of geographic region or economic are so basic that ID has far reaching consequences on status.1 systemic functions apart from the well-known feature 1 Hematology Department, Complejo Hospitalario de Toledo, Toledo, Spain. 2 Hematology Department, Hospital Ramón y Cajal, Madrid, Spain. 3 Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition (ICTAN), Consejo Superior de Investigaciones Cientı́ficas (CSIC), Madrid, Spain. 4 Faculty of Psychology, Universidad Autónoma de Madrid, Madrid, Spain. 5 Hematology Laboratory Department, Hospital Sant Pau, Barcelona, Spain. *Address correspondence to: M. Pilar Vaquero, MD, PhD, Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition (ICTAN), Consejo Superior de Investigaciones Cientı́ficas (CSIC), C/José Antonio Novais 10, Madrid 28040, Spain, E-mail: mpvaquero@ictan.csic.es ª Fernandez-Jimenez et al. 2020; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 26 Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 27 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 of anemia, but the nonhematological symptoms of this plied, 36 women agreed to participate: 1 subject aban- trace element deficiency have been often overlooked. doned the study due to a change of residence. Nonhematological manifestations of ID include fa- tigue, reduced physical endurance, defective structure Study protocol or function of epithelial tissues, pica, restless legs syn- This prospective interventional study was conducted at drome (RLS), decreased cognitive performance, and the Complejo Hospitalario de Toledo, Spain, in 2014, as behavioral disturbances.3,4 ID impairs the health and a part of a larger long-term project. The study followed well-being of women and increases the risk of ad- guidelines stated in the Declaration of Helsinki and was verse maternal and neonatal outcomes.5,6 Our research approved by the Complejo Hospitalario de Toledo Clin- group has observed elevated bone remodeling in IDA ical Research Ethics Committee and the Spanish National young adult women that improved during iron recovery, Research Council Ethics Committee (Bioethics subcom- suggesting that chronic ID may be a risk factor for future mittee). Written informed consent was obtained from osteoporosis in women.7–9 According to the Global Bur- all participants before study commencement. den of Disease Study 2016, IDA is the first cause of years At enrolment, a full medical history was recorded, lived with disability burden in women.10 Nevertheless, and anthropometric measurements were carried out. there remains a lack of awareness of the clinical conse- Patients underwent dietary, physical activity, menstrual quences of IDA among this population. blood loss, and cognitive function assessment. Blood The aim of this study was to prospectively analyze samples were taken for complete blood count (CBC), the characteristics, analytical data, and nonhematolog- coagulation tests, and measures of iron status and ical signs and symptoms of IDA in a homogeneous other biochemical parameters. group of women of reproductive age and their response Patients were prescribed 8 weeks of oral iron ther- to iron therapy. apy in the form of ferrous sulfate tablets (Tardyferon; Pierre Fabre Médicament, Boulogne, France): one tab- Materials and Methods let (80 mg Fe) daily if hemoglobin >100 g/L, or two Subjects tablets a day (160 mg Fe) if hemoglobin <100 g/L. Participants were required to be Caucasian women aged Patients were instructed to take the tablets in fasting between 18 and 40 years with IDA. Patients were in- conditions with water or orange juice. At the time the cluded when they had hemoglobin £110 g/L, mean cor- study was conducted, this was the conventional treat- puscular volume <98 fL, transferrin saturation <15% ment for ID, but mounting evidence indicates that and ferritin <20 ng/mL, or if ferritin was 20–50 ng/mL, low doses and treatment on alternate days are more soluble transferrin receptor (sTfR) was >5 mg/L. effective and better tolerated.11–13 Exclusion criteria were as follows: smoking, amen- A follow-up visit was scheduled 9 weeks after the orrhea, menopause, current pregnancy or pregnancy baseline visit, 1 week after completing the prescribed within the previous year, breastfeeding, thalassemia, pharmacological treatment to allow iron levels to stabi- iron metabolism-related diseases such as hemochroma- lize. Blood samples were taken to repeat the CBC and tosis, bleeding disorders, autoimmune diseases, chronic biochemical parameters measurement and cognitive gastrointestinal diseases (inflammatory bowel disease, function was assessed again. Patients were asked to re- gastric ulcers, coeliac disease, and Crohn’s disease), port possible side effects associated with the treatment neoplastic diseases, renal disease or hormone-related and any health problems from their last visit. If patients diseases independent of IDA, chronic inflammation had not recovered from anemia and/or ID after the first (C-reactive protein >5 mg/L), creatinine levels >1.0 mg/ 8-week cycle of treatment (hemoglobin >120 g/L and dL (120 lmol/L), abnormal liver tests (>2 times nor- ferritin ‡15 ng/mL), a further 8 weeks of treatment mal), blood donation in the past 3 months, current was prescribed, with a second follow-up visit scheduled use of iron supplements, and excess alcohol consump- 1 week after finishing the second cycle of treatment. tion or use of recreational drugs, prescription drugs, or Figure 1 shows the study flow chart. herbal preparations that could interfere with iron ab- Complete response was defined by normalization of sorption and/or affect mental performance. Hb (Hb >120 g/L) and serum ferritin ‡15 ng/mL, the Over 18 months, 84 women who met the inclusion ferritin cutoff value suggested by the World Health criteria were interviewed by telephone to assess all Organization to indicate depleted iron stores for individ- exclusion criteria. After the exclusion criteria were ap- uals of 5 years of age or older.14 A final Hb >120 g/L but Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 28 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 FIG. 1. Flow chart. serum ferritin <15 lg/L, or an increase in Hb ‡20 g/L (hair loss, angular cheilitis, and brittle nails), and neu- were regarded as incomplete response. romuscular symptoms (RLS). Pica was defined as the The compliance of the study was assessed by ques- compulsive eating of food or nonfood items, singly or tionnaires and a personal interview in each visit. Patients in combination, not part of the patient’s habitual diet were asked about the number of tablets that were taken or preferences. throughout treatment. Menstrual cycle duration, period length, and num- ber of days with intense menstrual blood loss (heavy Data collection bleeding days) were monitored using a self-administered Clinical data. Medical history was taken by an hema- paper questionnaire, as described previously.15,16 Ques- tologist at the time of initial evaluation through a pre- tions on the presence of blood clots, bleeding lasting structured questionnaire that included medication, >7 days, and whether multiple pads or tampons were dietary supplements, any past or present prestructured saturated during the menstrual flow period were also questionnaire medical conditions, previous opera- included. Patients with heavy blood loss were voluntar- tions, and reproductive history. Particular attention ily referred to a gynecologist for further evaluation. The was given to a family history of anemia, hypercholes- use of oral contraceptives was also recorded. terolemia, hypertension, osteoporosis, and kidney or A short questionnaire was used to assess overall thyroid disease. Patients were questioned specifically physical activity. Questions included duration and in- about whether they had pica or other symptoms attrib- tensity of daily walking and moderate- and vigorous- uted to ID, such as fatigue, epithelial manifestations intensity activities per week.17 Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 29 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 Anthropometric data. Height and weight were were a total of 22 practice trials and 80 test trials. Half obtained at baseline and weight measurements were of the trials were compatible, and they were randomly repeated on next visit/s. Weight was measured to the presented across the session. Mean reaction time for nearest 100 g using a medical weighing scale (Seca Ltd, correct responses and number of hits and errors were Hamburg, Germany) and height was measured with a recorded. Given that speed–accuracy trade-off could stadiometer incorporated into the scale. Body mass vary between experiments, participants, and conditions, index (BMI) was worked out via the formula: weight we used the inverse efficiency score (IES),22 which (kg)/height (m2). adjusts the reaction time by the proportion of correct answers, combining speed and accuracy into a single Hematological and biochemical assays measure. High IES values indicate a less efficient perfor- Blood samples were collected between 8:00 and 10:00 by mance, that is, greater difficulties in solving the task. In venepuncture after a 12-hour fasting period. Serum and the 2-back task, upper and lower case letters were pre- plasma were obtained after centrifugation (for 5 minutes sented in one of eight equidistant spatial locations at 1000 g). The CBC was measured in whole blood fol- around the center of the screen. Stimuli were presented lowing standard laboratory techniques using the Beck- for 200 ms and 1300 ms were given for responding. man Coulter LH780 Analyzer (Beckman Coulter, Brea, There were 75 test stimuli of which 24 were match stim- CA). Routine coagulation tests including prothrombin uli. Participants pressed the space bar of the keyboard to time, activated partial thromboplastin time, and fibrin- make a match response (a letter presented in the same ogen were assayed on a blood coagulation analyzer ACL spatial location two positions back in the sequence). TOP 700 (Beckman Coulter). Serum iron, serum ferri- To assess potential confounding variables, subjects tin, total iron binding capacity, serum vitamin B12, filled out a short questionnaire aimed to determine pa- serum folate, sTfR, and other biochemical variables tients’ latest education level, profession, urban–rural were determined by modular analyzers (Elecsys and residence, and level of interaction with computers, Modular DP; Roche Diagnostics, Mannheim, Germany). before completing the computerized cognitive tests. All sessions were monitored by trained research staff, Dietary assessment overhead lighting was kept low, the subject was asked Each subject’s dietary intake was evaluated at baseline to maintain a fixed distance from the screen, and envi- with a 72-hour detailed dietary intake report, previ- ronmental distractions were minimized. ously validated and proved valuable to assess nutrient intake18 specifying the types of food consumed and Statistical analysis serving weights. The possible food intake changes The collected data were analyzed using the SPSS for throughout the study were monitored using a food Windows program (version 25.0; IBM Corp., Armonk, frequency questionnaire. The options of frequency of NY). All continuous variables were analyzed for nor- consumption and their corresponding codes were as mality and, when required, were log-transformed to follows: never (0), less than once a week (0.5), once a achieve normality. Pearson correlation coefficient was week (1), two to three times a week, four to six times used to analyze correlations between continuous vari- a week (2.5), daily (7), and more than once a day (10). ables. A stepwise-forward multiple linear regression analysis was used to determine which variables con- Cognitive testing tribute significantly to the results of cognitive tests. Cognitive performance was assessed at baseline and To identify factors associated with nonhematological follow-up. Two cognitive tasks were included in this symptomatology, univariate and multivariate logistic study: Verbal version of the flanker task19 that tests ex- regression analyses were applied. Pretreatment and ecutive attention and 2-back task20 that is widely used post-treatment cognitive assessments were compared to measure working memory. The computerized pro- using paired t-tests. The level of statistical significance grams of both tasks were taken from the COG-LAB- was considered as p < 0.05. UAM Battery.21 Verbal flanker task required deciding, as fast as possible, whether the letter in the center of a Results set of three letters was vowel or consonant. The target Patient characteristics and evaluation (e.g., vowel) could be surrounded by compatible (e.g., A total of 35 anemic young women completed the vowel) or incompatible letters (e.g., consonant). There study. In total, 74.3% of participants reported past Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 30 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 Table 1. Patient Characteristics and Hematological Data phagia (without esophageal webs). In total, 58.8% of at Baseline women had two or more symptoms associated with IDA. Mean SD Heavy menstrual bleeding according to the ques- Age 35.0 5.5 tionnaire was reported by 24 patients (68.6%), 9 out Body mass index 26.1 4.6 of them presented some physical condition affecting Energy intake (kcal/day) 2194 415 the uterus, such as fibroids and polyps, after further Dietary iron intake (mg/day) 16.5 5.7 Hemoglobin (g/dL) 9.99 0.97 evaluation. Seven women refused gynecological exam- Hematocrit (%) 31.14 2.46 ination. All patients showed normal coagulation tests. Mean corpuscular volume (fL) 73.11 6.72 Mean corpuscular hemoglobin 32.03 0.97 Only four women used oral contraceptives. concentration (g/dL) No significant differences were found in nutrient Red blood cell distribution width (%) 17.51 1.80 Serum ferritin (ng/mL) 4.23 1.96 intake between patients nor in women’s diet among base- Transferrin (mg/dL) 381.1 46.9 line and end of treatment, except for ‘‘fruit juices at Serum iron (lg/dL) 24.83 7.87 PTH (pg/mL) 39.29 14.12 breakfast’’ that showed an increased consumption (me- dian increased from never to once a week) ( p = 0.015) Median IQR and ‘‘other dairy products at breakfast’’ that decreased Age at menarche (years) 13 3 (median values lower than once a week) ( p = 0.022). Menstrual cycle length (days) 28 5 Most patients reported low physical activity and Period length (days) 5 3 Heavy bleeding (days) 2 1 none high-intensity exercise. BMI was 26.1 – 4.6 kg/m2 at baseline and did not significantly vary through- Values of the women who completed the study (n = 35). IQR, interquartile range; PTH, parathyroid hormone; SD, standard out study. In total, 50% of the patients were overweight deviation. and three out of the patients had grade 1 obesity (BMI >30 kg/m2). personal history of IDA and 57.1% had female family Significant associations between parameters at base- history of IDA (first- and/or second-grade relatives). line are presented in Tables 2 and 3. Interestingly, pica, Patient characteristics and hematological data at base- RLS, and ungual changes were related to age of men- line are summarized in Table 1. arche. In addition, associations between cognitive func- Most participants (85.3%) reported IDA-related non- tion measures and neurological symptoms, specifically hematological symptomatology: 32.4% pica (ice or pica and reaction time in 2-back test, were observed. one particular food, especially crunchy foods), 20.6% cheilitis, 20.6% RLS, 55.9% diffuse hair loss, 38.2% un- Outcome after iron therapy gual changes, and 20.6% intense fatigue. Four patients Thirty-four out of 35 patients showed response to oral reported headache, one tinnitus and another one dys- iron treatment, 24 showed complete response (16 at Table 2. Univariate and Multivariate Logistic Regression Analyses of Several Clinical and Biochemical Variables Associated with Nonhematological Symptomatology at Baseline Univariate Multivariate Symptom Variables OR (95% CI) p OR (95% CI) p Pica Menarche age 1.84 (1.05–3.22) 0.034 — — Reaction time (2-back) 1.6 (1.06–2.45) 0.027 2.14 (1.19–3.87) 0.012 RLS Menarche age 0.57 (0.32–0.99) 0.045 — — Serum total protein 0.07 (0.005–0.82) 0.035 0.08 (0.06–0.92) 0.043 Platelet count 1.03 (1.03–1.04) 0.023 — — Cheilitis Mean corpuscular volume 0.64 (0.46–0.9) 0.01 — — Mean corpuscular hemoglobin 0.37 (0.18–0.78) 0.008 0.388 (0.189–0.799) 0.01 Mean corpuscular hemoglobin concentration 0.26 (0.09–0.79) 0.017 — — Red blood cell distribution width 1.79 (1.02–3.13) 0.041 — — Serum iron 0.7 (0.52–0.96) 0.027 — — Soluble transferrin receptor 1.35 (1.02–1.78) 0.038 — — Transferrin saturation 0.28 (0.08–0.9) 0.033 — — Serum folate 0.51 (0.28–0.95) 0.034 — — Diffuse hair loss Procollagen type 1N-terminal propeptide 1.06 (1.01–1.13) 0.045 NA — Ungual changes Menarche age 0.62 (0.39–0.9) 0.045 NA CI, confidence interval; RLS, restless leg syndrome; NA, nonapplicable; OR, odds ratio. Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 31 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 Table 3. Associations Between Cognitive Function Measures and Other Parameters at Baseline Test Variable Correlations Multiple regression analysis b coefficient (SE), p Flanker task Inverse efficiency score PTH: r = 0.43, p = 0.015 PTH b: 0.36 (1.4), p = 0.035 for compatible trials Serum albumin level: r = 0.47, p = 0.019 Fasting glucose b: 0.57 (3.5), p = 0.002 Reticulocyte count: r = 0.44, p = 0.019 (R2 = 0.63, p < 0.001) Fasting glucose: r = 0.41, p = 0.025 Inverse efficiency score PTH: r = 0.4, p = 0.041 PTH b: 0.52 (1.4), p = 0.003 for incompatible trials Serum iron levels: r = 0.42, p = 0.016 (R2 = 0.52, p = 0.003) 2-Back test Reaction time Transferrin saturation: r = 0.37, p = 0.041 No variables were entered into the equation Fasting glucose: r = 0.42, p = 0.025 Correct responses BMI: r = 0.37, p = 0.043 Serum iron levels b: 0.44 (0.45), p = 0.01 Transferrin saturation: r = 0.4, p = 0.027 BMI b: 0.37 (0.93), p = 0.029 Serum iron levels: r = 0.43, p = 0.018 (R2 = 0.32, p = 0.006) Omission errors BMI: r = 0.37, p = 0.043 Serum iron levels b: 0.4 (0.39), p = 0.018 Serum protein level: r = 0.45, p = 0.025 BMI b: 0.37 (0.8), p = 0.037 Serum albumin level: r = 0.42, p = 0.047 Fasting glucose b: 0.49 (0.58), p = 0.007 Fasting glucose: r = 0.4, p = 0.03 (R2 = 0.54, p < 0.001) Transferrin saturation: r = 0.34, p = 0.027 Serum iron levels: r = 0.43, p = 0.018 Commission errors Significant correlations not found BMI, body mass index; SE, standard error. 8 weeks and 8 at 16 weeks follow-up), and 10 showed changes and hair loss improved in 92.3% and 84.2% incomplete response. The patient who did not respond of women, respectively, but were not totally resolved. to therapy (refractoriness) was excluded from the Fatigue, headache, tinnitus, and dysphagia disappeared study. This patient was further diagnosed with Helico- after treatment. The clinical data and response to iron bacter pylori infection. treatment are summarized in Table 4. Nineteen patients (54.3%) notified side effects Regarding cognitive function assessment, a better that were gastrointestinal symptoms including nau- performance in executive attention and working mem- sea, constipation, loose stools, and epigastric pain. ory was observed after iron therapy, measured by Reported side effects were all mild, transient, and Flanker and 2-back tests, as is shown in Table 5. In self-limited and did not require discontinuation of the Flanker task, an improvement of the IES was seen treatment. in compatible and incompatible trials, and in the 2- All cases of pica, cheilitis, and RLS completely re- back task, a decrease in response latencies and an in- solved with iron therapy, even when some patients did crease in accuracy were observed. not achieve complete response to treatment. Ungual Different patterns of associations among cognitive function measures and biochemical and clinical data were observed after treatment. The only correlations Table 4. Characteristics of Nonhematological Symptoms that remained statistically significant were between in Patients with Iron Deficiency Anemia and Response to Therapy IES for incompatible trials (Flanker task) and BMI (r = 0.42, p = 0.020), and between correct responses Nonhematological symptoms Patients (%) Oral iron response (%) and omission errors (2-back test) and BMI (r = 0.43, Cheilitis 20.6 100 p = 0.016; r = 0.43, p = 0.015). In addition, increase in Pica 32.4 100 Restless leg syndrome 20.6 100 ferritin levels and reticulocyte count was associated Hair loss 55.9 84.2 with a reduction in omission errors (r = 0.40, p = Ungual changes 38.2 92.3 0.034; r = 0.49, p = 0.026) and an increment in correct Headache 11.7 100 Others 5.8 100 responses (r = 0.42, p = 0.027; r = 0.50, p = 0.026). Changes in biochemical parameters after iron treat- No. of symptoms Patients (%) ment included significant increases in serum folate, 1 35.3 vitamin B12, glucose, uric acid, total cholesterol, high- 2 26.5 3 17.6 density lipoprotein cholesterol, and bilirubin. Urea 4 3 decreased significantly. These results have been dis- 5 3 cussed elsewhere.23 Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 32 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 Table 5. Changes in Cognitive Function Measures after Iron Therapy Paired t-test Test Variable Baseline (mean – SD) End of treatment (mean – SD) t p Flanker task Inverse efficiency score for compatible trials (ms) 301.9 – 132.5 233.5 – 37.7 3.2 0.004 Inverse efficiency score for incompatible trials (ms) 312.2 – 131 253.6 – 41.4 2.6 0.014 2-Back test Reaction time (ms) 1333 – 2.2 1332.4 – 1.8 2.9 0.008 Correct responses (%) 57.9 – 22.5 68 – 21.6 2.3 0.029 Omission errors (%) 42.1 – 22.5 32 – 21.6 2.3 0.029 Commission errors (%) 15.9 – 14.6 15 – 14.2 0.3 ns Discussion (55.9% of patients) followed by brittle nails (38.2%). In This research has focused on emphasizing the impor- the literature, both signs have been associated with tance of the nonhematological manifestations of chronic ID and could at least partly arise from alter- IDA in women of reproductive age and on identifying ation in epithelial cellular replication produced by factors associated with this condition. Although sev- ID.2 Telogen effluvium, or the rapid shift of hair eral published studies have concentrated on one spe- from anagen (growing period) to telogen (resting peri- cific aspect such as pica and cognitive function od) phase, has been described as the mechanism under- impairment, we have tried to analyze all the data lying hair loss in women with ID.29 The most typical taken as a whole. lesion seen in nails associated with ID is koilonychia, Concerning medical history, we found that more defined as a concavity of the outer surface of the nail than half of our patients reported family history of but it seems that this finding is now encountered rarely, IDA, which is consistent with studies suggesting that possible due to earlier detection of ID. Thinning and susceptibility to ID is, in part, influenced by genetics. flattening of the nail, as well as brittle nails, precede Genetic variants of iron genes, especially TMPRSS6, the development of koilonychia.30 The fact that our pa- HFE, transferrin, and hepcidin, may predispose indi- tients reported improvement but not complete resolu- viduals to IDA or protect them from it.16,18,24,25 In tion of hair loss or brittle nails after iron administration contrast, a personal history of IDA was present in al- could indicate that there are other factors involved or most three quarters of the patients. These findings that a longer follow-up is necessary. In line with this, support the convenience of screening for IDA in it has been reported that, even with therapy, koilony- those with either prior personal or family histories chia takes a long period of time to return to a normal of IDA. appearance.30 Regarding hair loss, most authors recom- As regards etiology, among women of reproductive mend maintaining serum ferritin at levels >40 ng/mL,29 age, menstrual blood loss is the most common cause which would need longer to be achieved. Another ID- of ID and IDA. Women with heavy menstrual bleeding related alteration of epithelium, angular cheilitis, char- are at a higher risk.15,18,26 In line with these data, acterized by ulcerations or fissures at the corners of the 68.6% of the patients in our study reported heavy mouth, was observed in 20.6% of patients and com- menstrual bleeding and few women used oral contra- pletely resolved with iron treatment. Angular stomatitis ceptives that are known to regulate menstruation. is not specific of ID and can also been seen in other Regarding the different factors for IDA, high menstrual nutritional deficiencies. It has been reported that IDA blood losses and no use of oral contraceptives, but not predisposes to angular cheilitis and the lesions healed dietary iron intake, have been consistently associated with iron supplementation.31 with poor iron status in women,15,18,27,28 emphasizing IDA and ID also have a well-known association with the importance of recognition and diagnosis of ID in intense fatigue,32 which was present in almost a quarter this particularly vulnerable female population. of the patients in our study. All cases reversed with iron Most of our patients (85.3%) reported nonhemato- therapy. It could be argued that anemia could be re- logical symptoms, highlighting its high incidence and sponsible for fatigue, but it has been observed in non- the fact that this symptomatology is often overlooked anemic individuals with ID in several reports. A recent if patients are not directly questioned about it. Diffuse meta-analysis of studies in iron-deficient non-anemic hair loss was the most prevalent symptom we observed patients found that iron therapy improved objective Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 33 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 and self-rated assessments of fatigue,33 reinforcing the in this group, focusing instead on infants and children. fact that ID is a broader condition with extensive health Our study found a correlation between iron serum consequences in addition to the well-known feature of level and working memory measured by 2-back task anemia. These data highlight that for women of child- at baseline. After iron treatment, we detected an im- bearing age with unexplained prolonged fatigue, ID provement in attention and working memory tests should be considered. measured by Flanker and 2-back tasks, corroborating Iron is also recognized to play a crucial role in main- others’ previous findings that show that cognitive al- tenance of neuronal activity and networks.2 Linked to terations are responsive to iron administration.46–48 this function, two neurological symptoms, pica and Of note, there was a significant decrease in omission RLS, have been associated with ID. Pica was reported but not commission errors in 2-back. This is in line by 32.4% of our patients, consistent with the preva- with studies reporting that these two types of errors lence observed in other studies.34 Careful inquiry was have different correlates and, thus, may represent dif- necessary because some patients were ashamed of ferent processes.49 their behavior or underrated its importance. Various In addition to correlations related to iron metabo- forms of pica have been associated with ID, pagophagia lism, we observed an intriguing association between (pica for ice) being considered quite specific.35 In our parathyroid hormone (PTH) levels and IES (in com- study, patients reported either pagophagia or food patible as well as in incompatible trials) in Flanker pica, a subtype of pica that consists of compulsively eat- task at baseline. This finding could be related to the ing one particular food, especially if crunchy.36 Exact link between higher serum PTH levels and increased pathophysiology of pica in association with ID is odds of poor cognition suggested by some reports, al- unknown but it is probably attributable to ID in the though it is not yet well established.50 Despite the central nervous system. The reasons why some patients fact our study initially seemed to corroborate this pos- with ID manifest pica and others do not have yet to be sible link, the association between PTH levels and satisfactorily explained, but heritable traits could con- Flanker test was not significant after iron therapy. tribute to pica susceptibility in adults with ID. All One possible explanation could be that IDA patients cases of pica in this study resolved rapidly with iron presented higher PTH levels at the beginning of the therapy even before any increase was noted in the he- trial. Linked to this, higher levels of PTH have been moglobin concentration, in agreement with previous reported in patients with low hemoglobin and low fer- reports.34 ritin.51 Nevertheless, we could not detect statistically RLS is a common disorder that manifests as an in- significant differences in PTH levels before and after tense urge to move the legs that is uncomfortable and therapy, although the small size of our sample limits interferes with sleep. Although the exact pathophysiol- the results of our study. We also found an association ogy remains unclear, brain ID and altered dopaminer- between BMI and accuracy in 2-back task both at the gic function appear to play an important role in the baseline and after treatment, which agrees with the im- pathogenesis of this condition.37 In our patients, the paired working memory performance reported in over- prevalence of clinically significant RLS was 20.6%, weight and obese young adults compared with healthy higher than that seen in the general population (5%– weight controls.52 15%),38 and all cases resolved with iron administration. Despite its significant sleep morbidity, RLS with IDA is Conclusions often overlooked. In addition, we found that patients Despite the high prevalence of ID and IDA among with RLS showed lower serum protein level than the women, there is insufficient awareness of its unfavor- rest of IDA women, which is according to a recent able consequences beyond anemia. Iron plays an inte- study reporting lower serum albumin levels in RLS gral role in a wide range of physiological functions; patients than in a control group.39 therefore, the health consequences of ID and IDA are A considerable body of evidence has established that extensive and affect all aspects of the physical health appropriate levels of brain iron are necessary for opti- and well-being of women. mal brain development and functioning.40 Nonethe- less, despite the high prevalence of ID in women of Acknowledgments reproductive age, relatively few studies41–45 have exam- We thank all the women who voluntarily participated ined the relationship between iron status and cognition in the study. Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 34 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 Author Disclosure Statement placebo-controlled study in Spanish iron-deficient women. Br J Nutr 2011;105:1652–1659. No competing financial interests exist. 18. Blanco-Rojo R, Toxqui L, Lopez-Parra AM, et al. Influence of diet, menstruation and genetic factors on iron status: A cross-sectional study in Spanish women of childbearing age. Int J Mol Sci 2014;15: Funding Information 4077–4087. This study was supported by project ref. 201170E15 19. Eriksen BA, Eriksen CW. Effects of noise letters upon identification of a target letter in a non-search task Percept Psychophysics 1974;16: from Consejo Superior de Investigaciones Cientı́ficas, 143–149. Spain. 20. Kirchner WK. Age differences in short-term retention of rapidly changing information. J Exp Psychol 1958;55:352–358. 21. Shih PC, Privado J, Colom R. Cog-Lab-UAM. Poster presented at the X References meeting of the Spanish Society for the Study of Individual Differences 1. Kassebaum NJ, Jasrasaria R, Naghavi M, et al. A systematic analysis (SEIDI). Salamanca, September 26, 2008. of global anemia burden from 1990 to 2010. Blood 2014;123:615–624. 22. Townsend JT, Ashby FG. Methods of modeling capacity in simple 2. Musallam KM, Taher AT. Iron deficiency beyond erythropoiesis: Should processing systems. In J Castellan, F Restle (Eds.), Cognitive theory. Vol. 3. we be concerned? Curr Med Res Opin 2018;34:81–93. (pp. 200–239). Hillsdale, NJ: Erlbaum. 1978. 3. Lopez A, Cacoub P, Macdougall IC, Peyrin-Biroulet L. Iron deficiency 23. Remacha AF, Wright I, Fernandez-Jimenez MC, et al. Vitamin B12 and anaemia. Lancet (London) 2016;387:907–916. folate levels increase during treatment of iron deficiency anaemia in 4. Pompano LM, Haas JD. Increasing iron status through dietary young adult woman. Int J Lab Hematol 2015;37:641–648. supplementation in iron-depleted, sedentary women increases 24. Camaschella C. Iron deficiency. Blood 2019;133:30–39. endurance performance at both near-maximal and submaximal exercise 25. Sarria B, Navas-Carretero S, Lopez-Parra AM, et al. The G277S intensities. J Nutr 2019;149:231–239. transferrin mutation does not affect iron absorption in iron deficient 5. Janbek J, Sarki M, Specht IO, Heitmann BL. A systematic literature review women. Eur J Nutr 2007;46:57–60. of the relation between iron status/anemia in pregnancy and offspring 26. Mirza FG, Abdul-Kadir R, Breymann C, Fraser IS, Taher A. Impact and neurodevelopment. Eur JClin Nutr 2019;73:1561–1578. management of iron deficiency and iron deficiency anemia in women’s 6. Friedman AJ, Chen Z, Ford P, et al. Iron deficiency anemia in health. Expert Rev Hematol 2018;11:727–736. women across the life span. J Womens Health (Larchmt) 2012;21: 27. Gallego-Narbon A, Zapatera B, Vaquero MP. Physiological and dietary 1282–1289. determinants of iron status in Spanish vegetarians. Nutrients 2019;11: 7. Wright I, Blanco-Rojo R, Fernandez MC, et al. Bone remodelling is reduced pii: E1734. by recovery from iron-deficiency anaemia in premenopausal women. 28. Sekhar DL, Murray-Kolb LE, Kunselman AR, Weisman CS, Paul IM. Differ- J Physiol Biochem 2013;69:889–896. ences in risk factors for anemia between adolescent and adult women. 8. Toxqui L, Vaquero MP. Chronic iron deficiency as an emerging risk factor J Womens Health (Larchmt) 2016;25:505–513. for osteoporosis: A hypothesis. Nutrients 2015;7:2324–2344. 29. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The role of 9. Toxqui L, Perez-Granados AM, Blanco-Rojo R, Wright I, de la Piedra C, vitamins and minerals in hair loss: A review. Dermatol Ther 2019; Vaquero MP. Low iron status as a factor of increased bone resorption 9:51–70. and effects of an iron and vitamin D-fortified skimmed milk on 30. Sato S. Iron deficiency: Structural and microchemical changes in hair, bone remodelling in young Spanish women. Eur J Nutr 2014;53: nails, and skin. Sem Dermatol 1991;10:313–319. 441–448. 31. Murphy NC, Bissada NF. Iron deficiency: An overlooked 10. GBD 2016 Disease and Injury Incidence and Prevalence Collaborators. predisposing factor in angular cheilitis. J Am Dietec Assoc (1939) Global, regional, and national incidence, prevalence, and years lived with 1979;99:640–641. disability for 328 diseases and injuries for 195 countries, 1990–2016: 32. DeLoughery TG. Iron deficiency anemia. Med Clin North Am 2017;101: A systematic analysis for the Global Burden of Disease Study 2016. Lancet 319–332. (London) 2017;390:1211–1259. 33. Yokoi K, Konomi A. Iron deficiency without anaemia is a potential 11. Stoffel NU, Zeder C, Brittenham GM, Moretti D, Zimmermann MB. Iron cause of fatigue: Meta-analyses of randomised controlled trials and absorption from supplements is greater with alternate day than with cross-sectional studies. Br J Nutr 2017;117:1422–1431. consecutive day dosing in iron-deficient anemic women. Haematologica 34. Borgna-Pignatti C, Zanella S. Pica as a manifestation of iron deficiency. 2019 Aug 14. doi: 10.3324/haematol.2019.220830 [Epub ahead of print]. Expert Rev Hematol 2016;9:1075–1080. 12. Stoffel NU, Cercamondi CI, Brittenham G, et al. Iron absorption from oral 35. Brown WD, Dyment PG. Pagophagia and iron deficiency anemia in iron supplements given on consecutive versus alternate days and as adolescent girls. Pediatrics 1972;49:766–767. single morning doses versus twice-daily split dosing in iron-depleted 36. Crosby WH. Food pica and iron deficiency. Arch Int Med 1971;127: women: Two open-label, randomised controlled trials. Haematology 960–961. 2017;4:e524–e533. 37. Bollu PC, Yelam A, Thakkar MM. Sleep medicine: Restless legs syndrome. 13. Moretti D, Goede JS, Zeder C, et al. Oral iron supplements increase Mo Med 2018;115:380–387. hepcidin and decrease iron absorption from daily or twice-daily doses 38. Yeh P, Walters AS, Tsuang JW. Restless legs syndrome: A comprehensive in iron-depleted young women. Blood 2015;126:1981–1989. overview on its epidemiology, risk factors, and treatment. Sleep Breath 14. World Health Organization. Serum ferritin concentrations for 2012;16:987–1007. the assessment of iron status and iron deficiency in populations. 39. Olgun Yazar H, Yazar T, Ozdemir S, Kasko Arici Y. Serum C-reactive Geneva, Switzerland: Vitamin and Mineral Nutrition Information protein/albumin ratio and restless legs syndrome. Sleep Med 2019;58: System, 2011. 61–65. 15. Toxqui L, Perez-Granados AM, Blanco-Rojo R, Wright I, Vaquero MP. 40. Murray-Kolb LE. Iron and brain functions. Curr Opp Clin Nutr Met Care A simple and feasible questionnaire to estimate menstrual blood loss: 2013;16:703–707. Relationship with hematological and gynecological parameters 41. Greig AJ, Patterson AJ, Collins CE, Chalmers KA. Iron deficiency, cognition, in young women. BMC Women’s Health 2014;14:71. mental health and fatigue in women of childbearing age: A systematic 16. Blanco-Rojo R, Baeza-Richer C, Lopez-Parra AM, et al. Four variants in review. J Nutr Sci 2013;2:e14. transferrin and HFE genes as potential markers of iron deficiency anaemia 42. Lomagno KA, Hu F, Riddell LJ, et al. Increasing iron and zinc in pre- risk: An association study in menstruating women. Nutr Metab (Lond) menopausal women and its effects on mood and cognition: A systematic 2011;8:69. review. Nutrients 2014;6:5117–5141. 17. Blanco-Rojo R, Perez-Granados AM, Toxqui L, Gonzalez-Vizcayno C, 43. Scott SP, Murray-Kolb LE. Iron status is associated with performance on Delgado MA, Vaquero MP. Efficacy of a microencapsulated iron executive functioning tasks in nonanemic young women. J Nutr 2016; pyrophosphate-fortified fruit juice: A randomised, double-blind, 146:30–37. Fernandez-Jimenez, et al.; Women’s Health Report 2020, 1.1 35 http://online.liebertpub.com/doi/10.1089/whr.2019.0011 44. Blanton CA, Green MW, Kretsch MJ. Body iron is associated with 52. Dye L, Boyle NB, Champ C, Lawton C. The relationship between obesity cognitive executive planning function in college women. Br J Nutr and cognitive health and decline. Proc Nutr Soc 2017;76:443–454. 2013;109:906–913. 45. Wenger MJ, Rhoten SE, Murray-Kolb LE, et al. Changes in iron status are related to changes in brain activity and behavior in rwandan female university students: Results from a randomized controlled Cite this article as: Fernandez-Jimenez MC, Moreno G, Wright I, efficacy trial involving iron-biofortified beans. J Nutr 2019;149: Shih P-C, Vaquero MP, Remacha AF (2020) Iron deficiency in 687–697. menstruating adult women: much more than anemia, Women’s 46. Falkingham M, Abdelhamid A, Curtis P, Fairweather-Tait S, Dye L, Health Report 1:1, 26–35, DOI: 10.1089/whr.2019.0011. Hooper L. The effects of oral iron supplementation on cognition in older children and adults: A systematic review and meta-analysis. Nutr J 2010;9:4. 47. Scott SP, Murray-Kolb LE, Wenger MJ, et al. Cognitive performance in indian school-going adolescents is positively affected by consumption Abbreviations Used of iron-biofortified pearl millet: A 6-month randomized controlled efficacy trial. J Nutr 2018;148:1462–1471. BMI ¼ body mass index 48. Wenger MJ, Murray-Kolb LE, Nevins JE, et al. Consumption of a double- CI ¼ confidence interval fortified salt affects perceptual, attentional, and mnemonic functioning CBC ¼ complete blood count in women in a randomized controlled trial in India. J Nutr 2017;147: IES ¼ inverse efficiency score 2297–2308. IQR ¼ interquartile range 49. Meule A. Reporting and interpreting working memory performance in ID ¼ iron deficiency n-back tasks. Front Psychol 2017;8:352. IDA ¼ iron deficiency anemia 50. Lourida I, Thompson-Coon J, Dickens CM, et al. Parathyroid hormone, OR ¼ odds ratio cognitive function and dementia: A systematic review. PLoS One 2015;10: PTH ¼ parathyroid hormone e0127574. RLS ¼ restless legs syndrome 51. Atmaca M OM, Tasdemir E, Ozbay M. Correlation of parathyroid SD ¼ standard deviation hormone and hemoglobin levels in normal renal function. Acta Endo SE ¼ standard error (Buc) 2011;7:317–323. Publish in Women’s Health Reports - Immediate, unrestricted online access - Rigorous peer review - Compliance with open access mandates - Authors retain copyright - Highly indexed - Targeted email marketing liebertpub.com/whr