This article is more than 5 years old. Information may no longer be current.
Testing for iron deficiency, anemia beneficial for young women
Female adolescents should undergo blood tests within a few years of menses to assess for iron deficiency, according to results of two cross-sectional studies.
In one study, Deepa L. Sekhar, MD, MSc, physician and associate professor of pediatrics at Penn State College of Medicine, and colleagues pooled data on 6.216 females (age range, 12 to 49 years) included in the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2010. Women were iron deficient but had not yet depleted their iron stores to the point of anemia.
The researchers assessed the association of various sociodemographic, behavioral and reproductive risk factors with nonanemic iron deficiency in the overall study population. They additionally compared these factors between two subsets based on age — those aged 12 to 21 years, and those aged 22 to 49 years.
Results — published in PLoS One — showed that 494 women (8%) were iron deficient. A slightly higher percentage of nonanemic younger women than older women had iron deficiency (8.7% vs. 7.3%).
Only one risk factor — menstruation for more than 3 years among the younger-aged cohort (risk ratio = 3.18; 95% CI, 2.03-4.96) — appeared significantly associated with nonanemic iron deficiency.
In the second study, Sekhar and colleagues compared use of the Bright Futures Adolescent Anemia Previsit Questionnaire with a questionnaire developed by the researchers for predicting iron status and anemia among 96 adolescent girls. The researcher-developed questionnaire included validated tools for depression, inattention and daytime sleepiness.
The researchers focused on risk factors that have been associated with iron deficiency or iron-deficiency anemia but were not extensively assessed in prior research.
Results — published in The Journal of Pediatrics — showed neither questionnaire successfully predicted iron deficiency or anemia in the overall study population.
HemOnc Today spoke with Sekhar about the two studies and their potential clinical implications.
Question: What prompted this research?
Answer: My interest in iron-deficiency anemia in teenagers came out of my experience as a general pediatrician. I had always been advised to check teenage girls for anemia once they started menses. Although this seems straightforward, it is challenging for a few reasons. For one, the timing of ‘after menarche’ is unclear. Does this mean 1 year, 2 years or 5 years? Second, guidelines from the American Academy of Pediatrics and Bright Futures suggest blood testing for adolescents at high risk for iron-deficiency anemia. However, determining who qualifies as high risk can be difficult. Many adolescents cannot reliably answer questions such as, ‘Does your diet contain iron-rich foods?’ Clinicians are left to make a subjective judgment of risk, based upon what the adolescent and parent share in terms of diet and menses history. Finally, screening for anemia alone with hemoglobin means we miss the larger number of women with iron deficiency who are not yet anemic but would benefit from treatment, such as the group in our study published in PLoS One. I began to wonder if there was a better way to identify young women at high risk for iron deficiency or iron-deficiency anemia for objective laboratory testing. In other words, could we develop a reliable set of questions to pick out women at greatest risk?
Q: How did you conduct the research?
A: For both studies, we attempted to determine if there were certain risk factors or screening questionnaires that would reliably identify young women at high risk for iron deficiency or iron-deficiency anemia. Instead of ordering hemoglobin and more costly iron studies on everyone, the laboratory testing could be reserved for these high-risk women. In the study published in PLoS One, we used the NHANES national dataset. The study published in The Journal of Pediatrics evaluated risk factor questions from Bright Futures and the American Academy of Pediatrics, along with a set of validated screening tools on items associated with iron deficiency or iron-deficiency anemia, such as food insecurity and inattention. We had 96 adolescent women take the screening questionnaires and then we drew their blood. We compared the predictability of the questionnaires to the actual objective results for iron status and anemia.
Q: What did you find?
A: The risk-based questionnaires were poorly predictive of the objective measures of iron status and anemia. These data, in addition to our prior work with NHANES, led us to conclude that it probably makes more sense to do a blood test on these young women instead of using a subjective feel on a poorly predictive risk-assessment survey. Because of variability with current testing, we are missing iron deficiency and anemia in many adolescent women.
Q: Did any of your findings surprise you?
A: We were hopeful that, with the questions we pulled together, we would be able to create an evidence-based risk-assessment tool. Because most adolescents prefer to avoid blood testing, we hoped this could be reserved for the high-risk group. Adding the time and costs associated with a blood draw, it would have been great if we could have come up with something that worked a little better. I was surprised that the study published in The Journal of Pediatrics revealed no associations. This was a somewhat small group of women, but there were no close associations. In my opinion, examining this in a larger group of women will not change our findings.
Q: What are the clinical implications of the findings?
A: We now need to obtain blood testing for iron deficiency and anemia from all adolescent females, with clear guidelines on which tests and at what age blood testing should be conducted. Based on our work to date, I would suggest 16 years of age. Most females have menarche at age 11 or 12 years, so testing at 16 years is likely to be after most have been menstruating for 3 or more years. Hemoglobin is a good test for anemia, but there will need to be consensus of which of the numerous available iron status indicators to use.
Q: What needs to be done to reach consensus ?
A : One major missing piece is a cost analysis. Right now, we check for anemia with an office hemoglobin. It is cheap and can be done in about 10 minutes without sending families to a laboratory. However, as I mentioned, checking for anemia with only a hemoglobin test actually misses a large subset of women who are iron deficient but not yet anemic. Iron tests are more costly and must be drawn in the laboratory, as opposed to a quick finger prick in the office. A cost-effectiveness analysis considering the costs of laboratory testing for iron deficiency and anemia vs. missing cases and the long-term implications would be valuable in terms of reaching consensus.
Q: Is there anything else that you would like to mention?
A: Most people do not think it is a big deal to be slightly anemic. Iron deficiency develops slowly and progresses gradually to iron-deficiency anemia, so adolescents typically adjust to symptoms such as fatigue and decreased exercise tolerance as their ‘new normal.’ Yet, I find these individuals notice the difference after they have had their iron replenished. Iron deficiency and iron-deficiency anemia are common and correctable. It is definitely worth pursuing a consensus on screening for adolescent women. – by Jennifer Southall
Reference:
Sekhar DL, et al. PLoS One. 2017;doi:10.1371/journal.pone.0177183.
Sekhar DL, et al. J Pediatr. 2017;doi:10.1016/j.jpeds.2017.04.007.
For more information:
Deepa L. Sekhar, MD, can be reached at Penn State College of Medicine, 90 Hope Drive, Hershey, PA 17033.
Disclosure: Sekhar reports no relevant financial disclosures. The studies were funded by The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the NIH, as well as nongovernment support from Sackler Institute for Nutrition Science at The New York Academy of Sciences.