Genetic Variants and Iron Absorption

Metabolic Adaptation to Plant-based Diets in Asian Populations

The two specific aims of this study are: 1) to assess the impact of a genetic variant on iron status; 2) to assess the impact of a genetic variant on non-heme absorption among Asian women. The investigators hypothesize that the genetic variant could enhance iron status and iron absorption in Asian women.

Study Overview

• Status: Completed
• Conditions: Iron Absorption

Detailed Description

To determine the HFE genotype of female Asian study volunteers, we collected venous blood samples and extracted DNA from these blood samples. HFE genotype was determined as CC, CT, and TT and used to assess possible differences in iron status as a function of genotype. To measure the impact of genotype on non-heme Fe absorption, a sub-group of women with the CC (n=10) or TT (n=11) genotype were invited to return for an Fe absorption study. Each volunteer consumed stable 57Fe (as ferrous sulfate). Two weeks after ingesting this tracer, a blood sample was collected from each woman and the amount of non-heme (57Fe) iron incorporated into red blood cells was measured with magnetic sector thermal ionization mass spectrometry. Possible associations between iron status and iron absorption as a function of genotypes were explored. Data from this study will provide information that aims to improve human health by better understanding the iron requirements of individuals with different genetic background.

• Study Type: Observational
• Enrollment (Actual): 57

Contacts and Locations

Study Locations

• United States
  • New York
    • Ithaca, New York, United States, 14853
      • Human Metabolic Research Unit, Cornell University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Women were eligible for the study if they met the following criteria: 1) non-pregnant and between the ages of 18~35 y; 2) of East Asian descent with both maternal and paternal grandparents from East Asia, including China, Japan, South Korea, Vietnam, Thailand, Malaysia and Singapore; 3) not taking any vitamin or mineral supplements for at least 1 month before the study and during the 2-week study interval; 4) no pre-existing medical problems including malabsorption, blood disorders, ulcers, joint diseases or asthma that might impact inflammation or Fe status; 5) not taking any prescribed medications known to affect iron homeostasis.

Description

Inclusion Criteria:

• non-pregnant and between the ages of 18~35 y
• East Asian descent with both maternal and paternal grandparents from East Asia, including China, Japan, South Korea, Vietnam, Thailand, Malaysia and Singapore

Exclusion Criteria:

• taking or planing to take any vitamin or mineral supplements during the study period
• pre-existing medical problems that might impact inflammation or Fe status, including malabsorption, blood disorders, ulcers, joint diseases and asthma
• taking any prescribed medications known to affect iron homeostasis

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Genotype at SNP rs9366637	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining genotype.	2 weeks after the participant's visit to the laboratory
Hemoglobin	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of hemoglobin.	Up to 2 days after the participant's visit to the laboratory
Serum Ferritin	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of serum ferritin.	Up to 6 months after the participant's visit to the laboratory
Serum transferrin receptor	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of serum transferrin receptor.	Up to 6 months after the participant's visit to the laboratory
Non-heme Iron absorption in women with 2 HFE genotypes	Women donated a blood sample for genotyping. Women with particular HFE genotypes were invited to return for an absorption study. Two weeks after women consume the iron tracer, a blood sample was obtained to measure the amount of iron absorbed.	one month for screening with genotype then 2 weeks for iron absorption study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Folate	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of folate.	Up to 6 months after the participant's visit to the laboratory
Vitamin B-12	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of vitamin B-12.	Up to 6 months after the participant's visit to the laboratory
C-reactive protein	At the participant's visit to the laboratory, a 10 mL blood sample was collected. The blood sample was used for determining the concentration of C-reactive protein.	Up to 6 months after the participant's visit to the laboratory

Collaborators and Investigators

• Sponsor: Cornell University

Study record dates

Study Major Dates

• Study Start: June 1, 2012
• Primary Completion (Actual): April 1, 2013
• Study Completion (Actual): May 1, 2014

Study Registration Dates

• First Submitted: July 16, 2014
• First Submitted That Met QC Criteria: July 21, 2014
• First Posted (Estimate): July 23, 2014

Study Record Updates

• Last Update Posted (Estimate): July 23, 2014
• Last Update Submitted That Met QC Criteria: July 21, 2014
• Last Verified: July 1, 2014

More Information

Terms related to this study

• Keywords: Non-heme iron absorption; HFE
• Other Study ID Numbers: IRB #: 1206003117