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Trial registered on ANZCTR


Registration number
ACTRN12621001580864
Ethics application status
Approved
Date submitted
13/10/2021
Date registered
18/11/2021
Date last updated
2/08/2024
Date data sharing statement initially provided
18/11/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
Quantifying Iron Absorption, Loss and Balance in Endurance Trained Athletes Across a 12-Month Training Cycle
Scientific title
Quantifying Iron Absorption, Loss and Balance in Endurance Trained Athletes Across a 12-Month Training Cycle
Secondary ID [1] 305541 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Iron deficiency 323931 0
Condition category
Condition code
Diet and Nutrition 321443 321443 0 0
Other diet and nutrition disorders

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The aim of this study is to quantify iron loss, absorption and turnover in 3 different participant cohorts in order to determine more specific recommended daily intake targets for dietary iron. Outcomes of this study will aid in the prevention of iron deficiency and anemia. Three cohorts will be recruited for this study:
1. Male endurance athletes (>50 km of running/race walking per week)
2. Female endurance athletes (>50 km of running/race walking per week)
3. Male, recreationally active individuals (<2 endurance sessions/week, otherwise healthy).

Stable iron isotopes (<10 mg Fe57) will be orally administered to participants with 200 mL of distilled water. 12 months after administration, participants will return for 5 more laboratory visits at 3 month intervals. At each visit (anticipated to last <60 min), a hemoglobin mass assessment and venous blood sample will be collected to determine blood volume, iron status and the isotopic signature. Furthermore, information around habitual dietary intake (specifically iron), menstrual cycle history and training volume will also be collected at each visit. Each visit will be conducted in the morning (between 6-10 am), prior to undertaking any exercise for the day and will be supervised by an accredited sports scientist (ESSA ASpS1). The total study duration for each participant will be 2 years.
Intervention code [1] 321940 0
Not applicable
Comparator / control treatment
Comparisons between male recreational vs male athlete, as well as male athlete vs female athlete will be made.
Control group
Active

Outcomes
Primary outcome [1] 329227 0
Changes in iron isotope composition in the blood
Timepoint [1] 329227 0
Blood samples will be collected on 5 occasions, each separated by a 3 month interval (12, 15, 18, 21 and 24 months post stable iron isotope tracer administration).
Secondary outcome [1] 401823 0
Dietary Intake
Timepoint [1] 401823 0
The Dietary Questionnaire for Epidemiological Studies Version 3.2 (DQES v3.2) will be administered on 5 occasions at 3 monthly intervals to capture changes to dietary intake across the 12 month observation period. The questionnaire will be completed at 12, 15, 18, 21 and 24 months post stable iron isotope tracer administration
Secondary outcome [2] 401825 0
Training Volume
Timepoint [2] 401825 0
In athletes, weekly millage (kilometers travelled per week) will be collected over the 12 month period. In recreationally active participants, the International Physical Activity Questionnaire (Long, Last 7 days self-administered format) will be implemented on 5 occasions at 3 month intervals to determine habitual physical activity levels.

The questionnaire will be completed at 12, 15, 18, 21 and 24 months post stable iron isotope tracer administration

Eligibility
Key inclusion criteria
Three different cohorts will be recruited:

1. Highly trained male runners and race walkers with a minimum training volume of ~50 km/week.
2. Highly trained female runners and race walkers with a minimum training volume of ~50 km/week. Participants will have regular menstrual cycles (>9 per year; naturally menstruating or on hormonal contraception)
3. Male, recreationally active individuals, not performing more than 2 endurance based exercise sessions per week.
Minimum age
18 Years
Maximum age
45 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Free from lifestyle and/or metabolic diseases (i.e. obesity, diabetes)
BMI >30 kg/m2
Do not meet the required exercise volume
Experience large blood loss (surgery/blood donation/pregnancy).

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Power calculations have based on the data from the study by Speich et al. AJCN 2021; https://doi.org/10.1093/ajcn/nqaa433. This has been done to discern a difference in iron turnover for adult women or men of 30%. Here, to detect a difference corresponding to 1/3 of the median iron requirement in women (0.5 mg/day) assuming a width of the confidence interval of 0.5 mg /day, this would require 14 subjects to be studied (assuming an SD of 0.46). If we were to resolve a difference of 0.4 mg /day, 21 subject would need to be studied.

Primary outcome measures (iron turnover) will be expressed as a mg/day change. Linear mixed models will be used to determine differences between athletes and non-athletes (i.e. the effect of exercise), as well as female and male athletes (i.e. the effect of sex).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
10/01/2022
Actual
22/01/2022
Date of last participant enrolment
Anticipated
Actual
4/04/2022
Date of last data collection
Anticipated
1/04/2024
Actual
1/06/2024
Sample size
Target
80
Accrual to date
Final
57
Recruitment in Australia
Recruitment state(s)
ACT,VIC

Funding & Sponsors
Funding source category [1] 309907 0
University
Name [1] 309907 0
Swiss Federal Institute of Technology
Country [1] 309907 0
Switzerland
Primary sponsor type
University
Name
Australian Catholic Univeristy
Address
Australian Catholic University
223 Antill Street, Watson, ACT, 2062
Country
Australia
Secondary sponsor category [1] 310938 0
None
Name [1] 310938 0
Address [1] 310938 0
Country [1] 310938 0
Other collaborator category [1] 282020 0
University
Name [1] 282020 0
Dr Diego Moretti
Address [1] 282020 0
Swiss Federal Institute of Technology
Rämistrasse 101, 8092 Zürich, Switzerland
Country [1] 282020 0
Switzerland

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 309629 0
Australian Catholic Univeristy
Ethics committee address [1] 309629 0
Australian Catholic University
223 Antill Street, Watson, ACT, 2602
Ethics committee country [1] 309629 0
Australia
Date submitted for ethics approval [1] 309629 0
14/10/2021
Approval date [1] 309629 0
20/12/2021
Ethics approval number [1] 309629 0
2021-241H

Summary
Brief summary
Iron deficiency (ID) is the most common worldwide nutrient deficiency, is of particular concern to athletes due to the fundamental role of iron in optimal sports performance. Exercise-induced physiologic changes may be a possible explanation for the high rates of ID in athletic cohorts. These mechanisms include iron losses via sweat, gastrointestinal bleeding, hematuria, and repeated inflammatory mediated increases in the iron regulatory hormone hepcidin. Furthermore, in female athletes, the iron losses associated with menstruation add an extra burden that may contribute to the high rates of ID seen in female compared to male athletes (~35% vs ~10%, respectively). Although these mechanisms have been examined in isolation, whether the sustained and combined effects seen in high performance athletes have a meaningful impact on iron metabolism and long-term iron balance is unknown. Therefore, the primary aim of this study is to compare iron absorption, loss and overall balance using iron isotope tracers in endurance trained athletes with recreationally active individuals at regular intervals across a 12-month training cycle.

12 months after the iron isotope tracer is administered, participants will attend the laboratory at 3 monthly intervals for a 12 month period (5 visits). Participants will have a venous blood sample collected and measured for markers of iron status and isotopic the isotopic iron composition, as well as an assessment of hemoglobin mass. Information around habitual dietary intake (specifically iron), menstrual cycle history and training volume will also be collected at each visit. Outcomes of this study will increase our understanding of iron requirements for athletes against those of the general population.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 114830 0
Dr Alannah McKay
Address 114830 0
Australian Catholic University
223 Antill Street, Watson, ACT, 2602
Country 114830 0
Australia
Phone 114830 0
+61 4 3970 8968
Fax 114830 0
Email 114830 0
[email protected]
Contact person for public queries
Name 114831 0
Alannah McKay
Address 114831 0
Australian Catholic University
223 Antill Street, Watson, ACT, 2602
Country 114831 0
Australia
Phone 114831 0
+61 4 3970 8968
Fax 114831 0
Email 114831 0
[email protected]
Contact person for scientific queries
Name 114832 0
Alannah McKay
Address 114832 0
Australian Catholic University
223 Antill Street, Watson, ACT, 2602
Country 114832 0
Australia
Phone 114832 0
+61 4 3970 8968
Fax 114832 0
Email 114832 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
This is not included within the ethics application. Data will be published in a de-identified, grouped format. Data queries or document requests can be made to Dr Alannah McKay ([email protected]).


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.