Measuring Menstrual Iron Loss Using the Iron Isotope Dilution Technique

Study Overview
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Brief Summary
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It is very difficult to quantify menstrual blood loss, the reference method is a tedious one. This is a problem, as it is not conducive to objectively measuring menstrual blood loss and understanding the contribution of menstrual iron loss to iron deficiency anemia. With this study, the investigators aim to investigate iron loss during the menstrual cycle and aim to validate a much simpler technique.

Detailed Description
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Anemia reduction efforts have largely focused on increasing iron intakes such as improving diet quality, food fortification with iron, iron supplementation, biofortification. There is little information on the contribution of menstrual iron loss to iron deficiency anemia. Indeed, the accurate measurement of menstrual blood loss volume and iron loss is difficult. Self-perception of heavy menstrual blood loss poorly predicts actual blood loss, and the objective measurement of menstrual blood loss remains a tedious method. Various methods have been used to objectively measure menstrual blood loss volume including radioisotopes, but these methods are invasive. The investigators aim to validate a much simpler technique, namely the stable iron isotope dilution methodology. This is a promising new method for quantifying long-term body iron balance, absorption, and loss which has not been applied previously to measure menstrual iron losses. Validating this new method against the alkaline hematin reference method would be an important step to encourage menstrual blood loss measurements and shed light on the contribution of menstrual blood loss to iron deficiency and iron deficiency anemia.

Official Title
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Quantifying Menstrual Blood Loss: Validating the Methodology for Stable Iron Isotopes Dilution Against the Alkaline Hematin Method

Conditions
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Iron-deficiency, Menorrhagia, Anemia

Intervention / Treatment
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* Other: Iron isotope dilution
* Other: Alkaline hematin method


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female, 18-30 years old Already labelled with stable iron isotopes at least 12 months prior to study start Weight <70 kg Normal body mass index (18.5 - 25kg/m2) Regular menstrual cycle (self-reported cycle length between 28 and 35 days in the past 6 months) Signed informed consent Able to read and understand English Exclusion Criteria: Use of hormonal contraceptives within a 3-month recall period Anemia (hemoglobin < 117 g/L) Any known major metabolic, gastrointestinal, kidney or chronic disease such as diabetes, renal failure, hepatic dysfunction, hepatitis, hypertension, cancer, or cardiovascular diseases (according to the participants own statement) Women with severe menstrual cramps Consumption of iron-containing supplements within 1 month prior to the start of study Known difficulties with blood sampling Pregnancy (serum human chorionic gonadotropin (hCG) < 5 mIU/mL) Current smoking (>1 cigarette per week over a 1-month recall period) Women who are planning to get pregnant Inability to follow the study protocol

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Participants<br>Female 18-30 year olds, who have already been labelled with stable iron isotopes at least 12 months prior to study start. | Other: Iron isotope dilution<br>* Menstrual blood loss will be determined using the iron isotope dilution technique and compared to the amount determined via the alkaline hematin method.<br>Other: Alkaline hematin method<br>* Menstrual blood loss will be determined using the alkaline hematin method and compared to the amount determined via the iron isotope dilution technique.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of menstrual blood lost (mL/cycle) | The amount of menstrual blood lost will be determined using the alkaline hematin reference method. All sanitary material is collected during menstruation in each cycle and the amount of blood lost is measured directly in this material. For each cycle the total amount of blood lost during this cycle is determined (there will be one value only during each cycle). | At the beginning of menstrual cycle 1 (cycle length between 28 and 35 days) | 
| Amount of menstrual blood lost (mL/cycle) | The amount of menstrual blood lost will be determined using the alkaline hematin reference method. All sanitary material is collected during menstruation in each cycle and the amount of blood lost is measured directly in this material. For each cycle the total amount of blood lost during this cycle is determined (there will be one value only during each cycle). | At the beginning of menstrual cycle 2 (cycle length between 28 and 35 days) | 
| Amount of menstrual blood lost (mL/cycle) | The amount of menstrual blood lost will be determined using the alkaline hematin reference method. All sanitary material is collected during menstruation in each cycle and the amount of blood lost is measured directly in this material. For each cycle the total amount of blood lost during this cycle is determined (there will be one value only during each cycle). | At the beginning of menstrual cycle 3 (cycle length between 28 and 35 days) | 
| Change in isotopic ratio per cycle | The change in iron losses between the time of menstruation and the remaining duration of the cycle will be measured based on the dilution of the stable iron isotopes in the blood | Screening, day 1, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78 and 85 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hemoglobin concentration (g/L) | Hemoglobin will be measured to determine the presence of anemia and for the standardization of menstrual blood loss measurement | Screening, day 1, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78 and 85 | 
| Serum ferritin (microg/L) | Iron status parameter | Day 1 and 85 | 
| Serum transferrin receptor (mg/L) | Iron status parameter | Day 1 and 85 | 
| Alpha-1-acid glycoprotein (g/L) | Chronic inflammation parameter | Day 1 and 85 | 
| C-reactive protein (mg/L) | Acute inflammation parameter | Day 1 and 85 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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anemia, menstruation, alkaline hematin, iron isotope dilution, blood loss, menorrhagia