Determination of Iron Absorption and Losses in People Living at High Altitude to Investigate the Requirements in This Population Group Using a Newly Developed Technique

NCT07142590 | Recruiting

• 1 other identifier: Iron_ARIA_2024
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Iron is an essential micronutrient responsible for a whealth of biological processes of the human body. Iron plays a fundamental role especially in oxygen transport, by binding to hemoglobin in the blood circulation. Iron intake from the diet needs to be in balance the unavoidable losses that occur daily via different pathways. The recommended daily requirement of iron is based on the balance between absorption and losses and is calculated to maintain a balance so that the absorption equals losses. At higher altitudes, the absorption of iron may be higher due to adaptation mechanisms in response to low oxygen concentration, and to maintain a larger erytroid compartement. However, the long-term effects of altitude on iron balance are unknown. Filling this knowledge gap is important to better understand iron deficiency in populations living at high and moderate altitudes. Therefore, the investigators plan to study people that live at two different altitudes and measure iron absorption and losses over the long term. This will be useful to formulate specific recommendations for this population groups, to expand the knowledge base to better prevent iron deficiency in Switzerland but also worldwide. Participants will be asked to consume a dose of stable iron isotopes. After one year from isotope administration, the isotopes will be equally distributed in all body compartments and any change in the isotope abundance with the normal occurring body iron can be detected. From this point onwards, the investigators can observe the iron turnover and calculate iron absorption and losses per unit of time. At 4 different visits blood samples will be taken from each participant.

Conditions

Iron Requirements; Iron Absorption; Altitude

Keywords

iron absorption; altitude; stable iron isotopes; long-term iron balance

Outcome Measures

Primary Outcomes (1)

• 57Fe tracer concentration in the circulation

  The measurement of the isotopic tracer concentration in the circulation allows to calculate the lon-term iron absorption in the participants, and the rate of change of the tracer allows to calculate the rate of change of body iron.

  1 year after isotopic administration and every four months afterwards, for a total of 4 measurements.

Secondary Outcomes (8)

• Hemoglobin mass

  1 year after isotopic administration and every four months afterwards, for a total of 2 measurements for each participant.

• Ferritin concentration

  1 year after isotopic administration and every four months afterwards, for a total of 4 measurements.

• Hepcidin concentration

  1 year after isotopic administration and every four months afterwards, for a total of 4 measurements.

• Serum transferrin receptor concentration

  1 year after isotopic administration and every four months afterwards, for a total of 4 measurements.

• Concentration of c-reactive protein (CRP)

  1 year after isotopic administration and every four months afterwards, for a total of 4 measurements.

Study Arms (1)

Isotopic labeled participants

EXPERIMENTAL

The two groups of participants differ only for their residence location at different altitudes. The intervention (administration of iron isotopes) does not differ among the two groups.

Dietary Supplement: Stable Isotopes

Interventions

Stable Isotopes DIETARY_SUPPLEMENT

15 mg of stable iron isotopes in the form of ferrous sulphate 57FeSO4 will be orally administered to each participant.

Isotopic labeled participants

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Females and males aged 18-45 y
• BMI: 18 to 25 kg/m2
• Body weight \<70 kg for females, \<85 kg for males
• Plasma ferritin \>25 µg/L
• Signed informed consent

You may not qualify if:

• Hb \<12 g/dL (females), Hb \<13 g/dL (males), corrected for altitude using the 2024 WHO guidance values for hemoglobin adjustments
• Inflammation (CRP \> 5 mg/L)1
• Plasma ferritin \>150 µg/L for females and \>200 µg/L for males
• Chronic disease known to affect iron metabolism
• Chronic medications (except for oral contraceptives)
• Pregnancy (tested at screening) or intention to become pregnant during the course of the study
• Lactation
• High physical activity (MET-min/week \> 3000 calculated according to the IPAQ, short version, administered at the screening)
• Difficulty with blood withdrawal
• Earlier participation in a study using stable iron isotopes or participation in any clinical study within the last 30 days
• Smoking
• Blood donation, blood transfusion or significant blood loss (more than 400 mL) over the past 6 months
• Intention to regularly donate blood during the 2 years duration of the study
• No residence in the respective location/altitude for at least the last 2 years
• No intention to reside in the respective location/altitude at least for the next 2 years

Sponsors & Collaborators

• Diego Moretti: lead
• Swiss Federal Institute of Technology: collaborator
• University of Lausanne: collaborator

Study Sites (1)

Fernfachhochschule Schweiz (FFHS)

Zurich, Canton of Zurich, 8005, Switzerland

RECRUITING

Study Officials

• Diego Moretti, Prof. Dr.

  Fernfachhochschule Schweiz (FFHS), SUPSI

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Nora Barloggio

CONTACT

+41 44 512 10 01; nora.barloggio@ffhs.ch

Diego Moretti, Prof. Dr.

CONTACT

+41445120920; diego.moretti@ffhs.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof. Dr. Diego Moretti

Model Details: Two different groups of people residing at different altitudes will ingest the same amount of stable iron isotopes and during the observational period they will undergo the same measurements.

Study Record Dates

• First Submitted: February 6, 2025
• First Posted: August 26, 2025
• Study Start: August 22, 2025
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): February 1, 2028
• Last Updated: January 14, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1)