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Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume

Primary Purpose

Obesity

Status
Completed
Phase
Not Applicable
Locations
Switzerland
Study Type
Interventional
Intervention
labeled iron solution
labeled iron solution and ascorbic acid
Sponsored by
Swiss Federal Institute of Technology
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Obesity

Eligibility Criteria

18 Years - 45 Years (Adult)FemaleAccepts Healthy Volunteers

Inclusion Criteria:

  • 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)

Exclusion Criteria:

  • 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
  • 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

Sites / Locations

  • Human Nutrition Laboratory, ETH Zurich

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Experimental

Arm Label

labeled iron meal

labeled iron and ascorbic acid meal

Arm Description

Test meal (bread with honey) with a labeled iron solution

Test meal (bread with honey) with a labeled iron solution and ascorbic acid

Outcomes

Primary Outcome Measures

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.

Secondary Outcome Measures

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.

Full Information

First Posted
June 19, 2013
Last Updated
October 11, 2013
Sponsor
Swiss Federal Institute of Technology
Collaborators
Wageningen University, Universidad de Monterrey
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1. Study Identification

Unique Protocol Identification Number
NCT01884506
Brief Title
Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume
Official Title
Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume
Study Type
Interventional

2. Study Status

Record Verification Date
October 2013
Overall Recruitment Status
Completed
Study Start Date
June 2013 (undefined)
Primary Completion Date
August 2013 (Actual)
Study Completion Date
October 2013 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Swiss Federal Institute of Technology
Collaborators
Wageningen University, Universidad de Monterrey

4. Oversight

Data Monitoring Committee
Yes

5. Study Description

Brief 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. 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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Obesity

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
64 (Actual)

8. Arms, Groups, and Interventions

Arm Title
labeled iron meal
Arm Type
Experimental
Arm Description
Test meal (bread with honey) with a labeled iron solution
Arm Title
labeled iron and ascorbic acid meal
Arm Type
Experimental
Arm Description
Test meal (bread with honey) with a labeled iron solution and ascorbic acid
Intervention Type
Dietary Supplement
Intervention Name(s)
labeled iron solution
Intervention Description
labeled iron as ferrous sulfate (6mg/test meal)
Intervention Type
Dietary Supplement
Intervention Name(s)
labeled iron solution and ascorbic acid
Intervention Description
labeled iron as ferrous sulfate plus ascorbic acid (6mg:30mg /test meal)
Primary Outcome Measure Information:
Title
Fractional iron absorption from the isotopically labeled test meals.
Description
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.
Time Frame
Baseline
Secondary Outcome Measure Information:
Title
Hemoglobin mass will be measured with the carbon monoxide-rebreathing method.
Description
Blood volume will be calculated from hemoglobin mass and compared to values determined by the different equations.
Time Frame
Baseline

10. Eligibility

Sex
Female
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
45 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: 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) Exclusion Criteria: 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 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
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Isabelle Aeberli, PhD
Organizational Affiliation
ETH Zurich
Official's Role
Principal Investigator
Facility Information:
Facility Name
Human Nutrition Laboratory, ETH Zurich
City
Zurich
ZIP/Postal Code
8092
Country
Switzerland

12. IPD Sharing Statement

Citations:
PubMed Identifier
26561622
Citation
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.
Results Reference
derived

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Evaluation of the Effect of Body Weight and Composition on Iron Absorption and Blood Volume

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