Changes in Iron Absorption and Availability Before and After Weight Loss in Obese Pre-menopausal Women and Men.

The recruitment status of this study is unknown because the information has not been verified recently.
Verified June 2012 by Wageningen University.
Recruitment status was  Recruiting
Sponsor:
Collaborators:
Universidad de Monterrey
Mexican National Institute of Public Health
Swiss Federal Institute of Technology
Unilever R&D
Information provided by (Responsible Party):
Wageningen University
ClinicalTrials.gov Identifier:
NCT01347905
First received: May 3, 2011
Last updated: June 28, 2012
Last verified: June 2012
  Purpose

The objective of this study is to investigate if weight loss, in particular due to adipose tissue loss, in obese patients will reverse the obesity-related reduction of iron absorption, and if this is due to a decrease in hepcidin concentrations. Additionally, the investigators will investigate changes in iron incorporation into erythrocytes due to a reduction of iron sequestration by the adipose tissue and reticuloendothelial system. The investigators expect that by decreasing adiposity, circulating hepcidin levels will decrease, iron absorption and incorporation into erythrocytes will increase and as a result iron status will be improved.


Condition Intervention
Obesity
Other: Stable-isotope techniques

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Changes in Iron Absorption and Availability Before and After Weight Loss in Obese Pre-menopausal Women and Men.

Resource links provided by NLM:


Further study details as provided by Wageningen University:

Primary Outcome Measures:
  • Fractional iron absorption before and after weight loss, based on 57Fe and 58Fe isotope concentrations in erythrocytes. [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Iron status and regulatory markers (Hb, serum ferritin, transferrin receptor, hepcidin),(pro)inflammatory markers (CRP, AGP, TNF-α, IL-6, leptin), blood volume, body composition (DXA). [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples With DNA

whole blood and serum


Estimated Enrollment: 43
Study Start Date: February 2011
Estimated Study Completion Date: November 2012
Estimated Primary Completion Date: November 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Obese women and men
Obese women and men undergoing restrictive bariatric surgery
Other: Stable-isotope techniques
Iron absorption will be estimated using stable-isotope techniques where incorporation of 57Fe and 58Fe into erythrocytes is measured 14 days after administration. The subjects will provide an initial blood sample (20ml) and then receive a test drink, containing 6 mg of 57Fe labeled ferrous sulphate. One hour later, 2 ml of an aqueous solution containing 100 μg 58Fe, as iron citrate in 250cc of normal saline will be infused over 50 min. Post infusion a 4ml blood sample will be taken. This procedure will be performed at baseline (6 weeks post-surgery) and at the end of the study (6-7 months post baseline).
Other Names:
  • 57Fe ferrous sulphate
  • 58Fe iron citrate

Detailed Description:

Until now adiposity has been associated with low iron status and with higher hepcidin levels. Moreover, weight loss and thereby loss of fat mass, has been associated with decreased hepcidin levels and improved iron status. However, until now no direct measures of iron absorption or incorporation into erythrocytes have been assessed before and after losing weight/fat mass.

We hypothesize that:

  • body fat loss in obese women and men will improve iron absorption, corrected for iron status, from a labeled test meal measured by using a stable isotopes technique by on average 30%.
  • body fat loss in obese women and men will decrease the related inflammatory state.
  • greater subclinical inflammation in obese women and men will be correlated with a decreased incorporation of iron into erythrocytes, and that this will improve after loss of body fat.

The study is a prospective cohort in which iron bioavailability will be assessed in obese women and men before and after weight loss and associated loss of body fat over a period of 6 months.

Iron absorption will be estimated using stable-isotope techniques where incorporation of 57Fe and 58Fe into erythrocytes is measured 14 days after administration. Preparation of isotopically labelled iron will be done at the Laboratory of Human Nutrition of the Swiss Federal Institute of Technology Zurich (ETH Zürich).

A baseline venous blood sample will be drawn 6-8 weeks after the surgery when surgery-related inflammation has been resolved. The subjects will receive a test drink, containing 6 mg of 57Fe labelled ferrous sulphate. One hour later, 2 ml of an aqueous solution containing 100 μg 58Fe as iron citrate in 250 cc of normal saline will be infused over 50 min. This infusion protocol has been used safely and successfully to examine iron metabolism in both adults and infants. Fourteen days later, a second venous blood sample will be drawn. This procedure will be performed at baseline (6-8 weeks post-surgery) and at the end of the study (6 months post baseline).

Our study could provide important information to establish the mechanism by which obesity-mediated inflammation could induce iron deficiency. This will be the first human trial that will evaluate if the obesity-related reduction of iron absorption is reversible in a context where obesity and iron deficiency are both highly prevalent.

  Eligibility

Ages Eligible for Study:   18 Years to 50 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Obese, premenopausal women and men aged 18 to 50 years after having undergone restrictive bariatric surgery.

Criteria

Inclusion Criteria:

  • Women and men
  • aged 18 to 50 years
  • Premenopausal (had no absence of menstrual cycle in the past 12 months)
  • BMI ≥35<45
  • Indication for laparoscopic Sleeve Gastrectomy (LSG) or Laparoscopic Adjustable Gastric Band (LAGB).

Subjects are eligible for this surgery if they:

  1. have BMI ≥35<45 and one of the following two conditions:

    • Medical, physical or psychosocial problems associated with their obesity.
    • A history of prolonged attempts at weight loss by other means.
  2. have been adequately informed and understood and accepted the potential -- risks and benefits of the procedure, and expressed a commitment to follow the rules regarding eating and exercise permanently after the procedure.

    • No postoperative complications after the surgery
    • 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).
    • No use of medication which interferes with study measurements (as judged by the study physician)
    • Willing to not change their intake of dietary iron and not take additional iron supplements, other than provided by the study team, between baseline and study end.
    • Not being pregnant during the study period or in the six months prior to the study and not planning to become pregnant until at least 3 months after the last study visit.
    • Non-lactating in the 6 weeks prior to the study and for the duration of the study
    • No reported weight loss ≥ 10 % of bodyweight during a period of six months before pre-surgery examination.
    • No full or partial hysterectomy in the past 3 months
    • Informed consent signed
    • Agreeing to be informed about medically relevant personal test-results by a physician.
    • Agreeing to be informed about medically relevant personal test-results by a physician.
    • No reported participation in night shift work two weeks prior to pre-study investigation and during the study. Night work is defined as working between midnight and 6.00 AM.
    • Consumption of =< 14 alcoholic drinks in a typical week
    • Strenuous exercise =< 10 hours per week

Exclusion Criteria:

  • Reported excessive blood loss at surgery (> 500 ml) and/or moderate/severe anemic (Hb < 100 g/L)
  • Complications during restrictive bariatric surgery defined as either:
  • Surgery duration of > 3 hours
  • Blood loss of > 500 ml
  • Perforation of the gastrointestinal tract
  • Inability to adjust lapband
  • Women and men with diagnosed abnormalities in iron metabolism (diagnosed from routine pre-surgery blood sample)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01347905

Contacts
Contact: Rogelio D Cervantes Madrid, MD PHD 5281821000 ext 1795 rogelio.david.cervantes@udem.edu.mx
Contact: Ana C Cepeda-Lopez, MD MNH 5281821000 ext 1212 anacarla.cepedalopez@wur.nl

Locations
Mexico
Universidad de Monterrey (UDEM) División de Ciencias de la Salud Recruiting
San Pedro Garza García, Nuevo Leon, Mexico, 66238
Contact: Ana C Cepeda-Lopez, MD MNH    52811000 ext 1265    anacarla.cepedalopez@wur.nl   
Sub-Investigator: Ana C Cepeda-Lopez, MD MNH         
Principal Investigator: Rogelio D Cervantes-Madrid, MD PHD         
Sponsors and Collaborators
Wageningen University
Universidad de Monterrey
Mexican National Institute of Public Health
Swiss Federal Institute of Technology
Unilever R&D
Investigators
Study Director: Michael B Zimmermann, MD PHD Wageningen University
  More Information

Additional Information:
No publications provided

Responsible Party: Wageningen University
ClinicalTrials.gov Identifier: NCT01347905     History of Changes
Other Study ID Numbers: Iron absorption and obesity
Study First Received: May 3, 2011
Last Updated: June 28, 2012
Health Authority: Mexico: Secretaria de Salud

Additional relevant MeSH terms:
Obesity
Weight Loss
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Body Weight Changes
Iron
Trace Elements
Micronutrients
Growth Substances
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on July 20, 2014