ObesityNCT01884506
Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume
A study testing labeled iron solution and labeled iron solution and ascorbic acid in people with Obesity, run by Swiss Federal Institute of Technology at 1 site in Switzerland.
Trial summary
A total of 75 subjects will be recruited for this study (25 normal weight, 25 overweight, 25 obese). In each subject blood volume will be determined using the minimally invasive carbon monoxide-rebreathing method (substudy 1) and iron absorption will be measured from a test meal labeled with stable iron isotopes. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- labeled iron solution and labeled iron solution and ascorbic acid
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 64 participants
- Where
- 1 siteSwitzerland
- Study dates
- Jun 2013to Oct 2013
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Women
- Age 18-45 years
- Pre-menopausal (no absence of a menstrual cycle in the past 12 months)
- BMI 18.5-39.9 kg/m2 (n=25 18.5-24.9, n=25 25-29.9, n=25 30-39.9)
- Apparently healthy (no significant medical conditions that could influence iron or inflammatory status other than obesity (i.e., cancer, HIV/AIDS, inflammatory bowel disease, gastrointestinal bleeding, and rheumatoid arthritis, renal disease or hemochromatosis) (judged by study physician)
Who cannot join
- Moderate/sever anemia (Hb<11 g/dl)
- Use of medication which interferes with study measurements (judged by the study physician)
- Smoking
- Pregnancy and lactation; planning to become pregnant during the course of the study (pregnancy test will be conducted at visit 2 and subjects will be asked about contraception*)
- Consumption of vitamin- or mineral supplements unless they consent to discontinue intake two weeks before the start of the study until the final blood sampling
- Prior participation in studies using stable iron isotopes
Show all 14Show fewer
- Food allergies/intolerances (gluten, lactose, milk protein)
- Blood donation during the two months prior to the study
- Major injuries during the 6 months prior to the study
- Illness during the 4 weeks prior to the study (judged by study physician)
- Administration of recombinant erythropoietin (rhEPO)
- More than 5 days at altitudes above 1600 m above sea level during the 3 weeks prior to the study
- Long distance flight (>8 h) during the 3 weeks prior to the study
- Chronic alcohol abuse
Trial locations and contacts
1 site in 1 country.
About this study
A total of 75 subjects will be recruited for this study (25 normal weight, 25 overweight, 25 obese). In each subject blood volume will be determined using the minimally invasive carbon monoxide-rebreathing method (substudy 1) and iron absorption will be measured from a test meal labeled with stable iron isotopes. The effect of ascorbic acid on iron absorption will further be determined using a second labeled test meal (substudy 2). In addition, inflammation, hepcidin and iron status will be determined. In order to study the effect of body fat content on blood volume and iron absorption weight and height will be measured, and body fat will de determined by dual energy X-ray absorptiometry.
Read the detailed description
Obesity has repeatedly been shown to be a risk factor for iron deficiency. The reason for this is believed to be reduced iron absorption as a result of increased circulating hepcidin concentrations. However, the direct interactions between body fat mass, iron absorption, inflammation and hepcidin have not been studied to date. Whether the low iron absorption in obese subjects could be overcome by conventional methods to increasing iron absorption, e.g. the addition of ascorbic acid and whether a reduction of inflammation could improve absorption is further unclear. For the calculation of fractional iron absorption from oral doses of stable iron isotopes an estimation of blood volume is required. Several equations to estimate blood volume from weight and height or calculated body surface area or volume are available, but have rarely been validated or used in obese subjects. The aim of the described study is therefore: 1) to determine blood volume using the carbon monoxide-rebreathing method over a large BMI range and to use those values to validate existing blood volume equations; 2) to measure iron absorption, hepcidin and inflammation in relation to BMI and body fat and 3) to assess the effect of ascorbic acid on iron absorption.
- Conditions
- Obesity
- Being tested
- labeled iron solution, labeled iron solution and ascorbic acid
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
labeled iron solutionDietary supplement
labeled iron as ferrous sulfate (6mg/test meal)
labeled iron solution and ascorbic acidDietary supplement
labeled iron as ferrous sulfate plus ascorbic acid (6mg:30mg /test meal)
| Study group | Role | What they receive |
|---|---|---|
| labeled iron meal | Experimental | Test meal (bread with honey) with a labeled iron solution Receives: Dietary Supplement: labeled iron solution; Dietary Supplement: labeled iron solution and ascorbic acid |
| labeled iron and ascorbic acid meal | Experimental | Test meal (bread with honey) with a labeled iron solution and ascorbic acid Receives: Dietary Supplement: labeled iron solution; Dietary Supplement: labeled iron solution and ascorbic acid |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fractional iron absorption from the isotopically labeled test meals.
Iron absorption will be determined by incorporation of labeled iron into erythrocytes, 14 days after the administration of the last test meal containing labeled iron (stable isotope technique). Based on the shift of the iron isotope ratios in the blood samples and the amount of iron circulating in the body, the amounts of isotopic label iron present in the blood 14 days after the test meal administration will be calculated based on the principles of isotope dilution and considering that the iron isotopic labels are not monoisotopic. Circulating iron will be calculated based on blood volume as determined by carbon monoxide-rebreathing. For calculation of fractional absorption, 80% incorporation of the absorbed iron into red blood cells will be assumed.
Measured: Baseline
Secondary outcomes (1)
Hemoglobin mass will be measured with the carbon monoxide-rebreathing method.
Blood volume will be calculated from hemoglobin mass and compared to values determined by the different equations.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jun 2013 (estimated)
- Study startJun 2013
- Primary completionAug 2013
- Study completionOct 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 64 participants (actual)
Sponsor and investigators
- Lead sponsor
- Swiss Federal Institute of Technology
- Sponsor type
- University, hospital or other
- Collaborators
- Wageningen University, Universidad de Monterrey
- Responsible party
- Principal investigator, Prof. Michael B. Zimmermann, Swiss Federal Institute of Technology
- Investigators
- Isabelle Aeberli, PhD, Principal investigator, ETH Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01884506
- Sponsor's protocol ID
- KEKZH-2013-0110
- Status last verified
- Oct 2013
- First submitted
- 19 Jun 2013
- Last updated
- 14 Oct 2013
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Cepeda-Lopez AC, Melse-Boonstra A, Zimmermann MB, Herter-Aeberli I. In overweight and obese women, dietary iron absorption is reduced and the enhancement of iron absorption by ascorbic acid is one-half that in normal-weight women. Am J Clin Nutr. 2015 Dec;102(6):1389-97. doi: 10.3945/ajcn.114.099218. Epub 2015 Nov 11.
PubMed 26561622
Study at a glance
From the registry record, last updated by the sponsor on 14 Oct 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume
- ClinicalTrials.gov ID
- NCT01884506
- Acronym / sponsor ID
- KEKZH-2013-0110
- Conditions
- Obesity
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 64 participants (actual)
- Lead sponsor
- Swiss Federal Institute of TechnologyUniversity, hospital or other
- Collaborators
- Wageningen University, Universidad de Monterrey
- Study start
- Jun 2013
- Primary completion
- Aug 2013 (actual)
- Study completion
- Oct 2013 (actual)
- First posted
- 24 Jun 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A total of 75 subjects will be recruited for this study (25 normal weight, 25 overweight, 25 obese). In each subject blood volume will be determined using the minimally invasive carbon monoxide-rebreathing method (substudy 1) and iron absorption will be measured from a test meal labeled with stable iron isotopes. The effect of ascorbic acid on iron absorption will further be determined using a second labeled test meal (substudy 2). In addition, inflammation, hepcidin and iron status will be determined. In order to study the effect of body fat content on blood volume and iron absorption weight and height will be measured, and body fat will de determined by dual energy X-ray absorptiometry.
Detailed description
Obesity has repeatedly been shown to be a risk factor for iron deficiency. The reason for this is believed to be reduced iron absorption as a result of increased circulating hepcidin concentrations. However, the direct interactions between body fat mass, iron absorption, inflammation and hepcidin have not been studied to date. Whether the low iron absorption in obese subjects could be overcome by conventional methods to increasing iron absorption, e.g. the addition of ascorbic acid and whether a reduction of inflammation could improve absorption is further unclear. For the calculation of fractional iron absorption from oral doses of stable iron isotopes an estimation of blood volume is required. Several equations to estimate blood volume from weight and height or calculated body surface area or volume are available, but have rarely been validated or used in obese subjects. The aim of the described study is therefore: 1) to determine blood volume using the carbon monoxide-rebreathing method over a large BMI range and to use those values to validate existing blood volume equations; 2) to measure iron absorption, hepcidin and inflammation in relation to BMI and body fat and 3) to assess the effect of ascorbic acid on iron absorption.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| labeled iron meal | Experimental | Dietary Supplement: labeled iron solution, Dietary Supplement: labeled iron solution and ascorbic acidTest meal (bread with honey) with a labeled iron solution |
| labeled iron and ascorbic acid meal | Experimental | Dietary Supplement: labeled iron solution, Dietary Supplement: labeled iron solution and ascorbic acidTest meal (bread with honey) with a labeled iron solution and ascorbic acid |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Women
- Age 18-45 years
- Pre-menopausal (no absence of a menstrual cycle in the past 12 months)
- BMI 18.5-39.9 kg/m2 (n=25 18.5-24.9, n=25 25-29.9, n=25 30-39.9)
- Apparently healthy (no significant medical conditions that could influence iron or inflammatory status other than obesity (i.e., cancer, HIV/AIDS, inflammatory bowel disease, gastrointestinal bleeding, and rheumatoid arthritis, renal disease or hemochromatosis) (judged by study physician)
Key exclusion criteria (14 listed)
- Moderate/sever anemia (Hb<11 g/dl)
- Use of medication which interferes with study measurements (judged by the study physician)
- Smoking
- Pregnancy and lactation; planning to become pregnant during the course of the study (pregnancy test will be conducted at visit 2 and subjects will be asked about contraception*)
- Consumption of vitamin- or mineral supplements unless they consent to discontinue intake two weeks before the start of the study until the final blood sampling
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| labeled iron solutionlabeled iron as ferrous sulfate (6mg/test meal) | Dietary supplement | labeled iron and ascorbic acid meal, labeled iron meal |
| labeled iron solution and ascorbic acidlabeled iron as ferrous sulfate plus ascorbic acid (6mg:30mg /test meal) | Dietary supplement | labeled iron and ascorbic acid meal, labeled iron meal |
Primary outcome
Fractional iron absorption from the isotopically labeled test meals.
Time frame: Baseline
Iron absorption will be determined by incorporation of labeled iron into erythrocytes, 14 days after the administration of the last test meal containing labeled iron (stable isotope technique). Based on the shift of the iron isotope ratios in the blood samples and the amount of iron circulating in the body, the amounts of isotopic label iron present in the blood 14 days after the test meal administration will be calculated based on the principles of isotope dilution and considering that the iron isotopic labels are not monoisotopic. Circulating iron will be calculated based on blood volume as determined by carbon monoxide-rebreathing. For calculation of fractional absorption, 80% incorporation of the absorbed iron into red blood cells will be assumed.
1 secondary outcome
Hemoglobin mass will be measured with the carbon monoxide-rebreathing method.
Time frame: Baseline
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Oct 2013.
- Derived from this study: PubMed 26561622Cepeda-Lopez AC, Melse-Boonstra A, Zimmermann MB, Herter-Aeberli I. In overweight and obese women, dietary iron absorption is reduced and the enhancement of iron absorption by ascorbic acid is one-half that in normal-weight women. Am J Clin Nutr. 2015 Dec;102(6):1389-97. doi: 10.3945/ajcn.114.099218. Epub 2015 Nov 11.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Isabelle Aeberli, PhD principal investigator
ETH Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing labeled iron solution and labeled iron solution and ascorbic acid in people with Obesity, run by Swiss Federal Institute of Technology at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Oct 2013. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fractional iron absorption from the isotopically labeled test meals. (time frame: Baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01884506, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Oct 2013; AzTrials last refreshed its copy on 8 Nov 2026.