Iodine DeficiencyVIOLETNCT03731312
Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability in Iodine Nutrition Studies
An observational study of Iodine Deficiency, run by Swiss Federal Institute of Technology at 1 site in Switzerland.
Trial summary
Iodine status in populations is assessed using urinary iodine concentration (UIC) measured in spot urine samples. The iodine intake is classified as deficient, sufficient, or excessive iodine based on the median UIC (mUIC). Read more about this study
- Who is it for?
- Ages 18 to 44 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Iodine Deficiency
- How many people
- 206 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Oct 2018to 4 May 2021
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 44 years
- Women only
- Healthy volunteers accepted
- Adult
Study population: Healthy women of reproductive age and residents of Switzerland since at least 12 months
Who may be able to join
- Non-pregnant
- Non-lactating
- Non-smoking
- Residence in Switzerland ≥12 months
- Generally healthy
- No family history of goiter
- No exposure to iodine containing contrast agents during the last 12 months - Informed consent given
Who cannot join
- Participant is not able to understand the study information or procedure, e.g. due to linguistic barriers
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability on Estimated Intake in Iodine Nutrition Studies
Iodine status in populations is assessed using urinary iodine concentration (UIC) measured in spot urine samples. The iodine intake is classified as deficient, sufficient, or excessive iodine based on the median UIC (mUIC). However, this approach has limitations, as it does not quantify the prevalence of individuals with habitually deficient or excess iodine intakes. The EAR cut-point method has the potential to quantify prevalence of iodine deficiency and excess. However, little is known about the effects of the inter- and intra-individual variance of UIC.
The aim of the study is to quantify the intra-individual variability in dietary iodine intake. The overall goal is to estimate the prevalence of iodine deficiency and excess in the study population and propose sample size recommendations for future iodine nutrition population studies. The results will provide evidence guiding international recommendations for iodine nutrition studies.
- Conditions
- Iodine Deficiency
- Being tested
- No intervention
- Keywords
- Iodine, Urinary iodine concentration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No interventionOther
This is an observational study and no interventions will be administered.
| Study group | Role | What they receive |
|---|---|---|
| Study group | We will collect two repeated spot urine samples, a DBS sample and obtain weight in all 600 study participants. In a randomly selected subsample (n=200) a third repeat spot urine sample and one 24 h urine will additionally be collected. Receives: Other: No intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Estimated daily urinary iodine excretion
Estimated urinary iodine excretion (µg/day) will be obtained from urinary iodine concentration (UIC) and urinary creatinine concentration (UCC) measured in two repeat spot urine samples collected within 7 days
Measured: 7 days
Secondary outcomes (4)
Measured daily iodine excretion
Measured daily iodine excretion (µg/day) will be obtained from urinary iodine concentration (UIC) and urine volume in a 24 h urine collection
Measured: 1 day
Thyroid function test TSH
TSH concentration (mU/L) measured in dried blood spots
Measured: 1 day
Thyroid function test total T4
Total T4 concentration (nmol/L) measured in dried blood spots
Measured: 1 day
Thyroid function test Tg
Tg concentration (µg/L) measured in dried blood spots
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2018
- Study start1 Oct 2018
- Primary completion4 May 2021
- Study completion4 May 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Iodine DeficiencyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Ecologic or community
- Time perspective
- Cross-sectional
- Enrolment
- 206 participants (actual)
Sponsor and investigators
- Lead sponsor
- Swiss Federal Institute of Technology
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jessica Rigutto-Farebrother, PhD, Principal investigator, ETH Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03731312
- Sponsor's protocol ID
- VIOLET
- Acronym
- VIOLET
- Status last verified
- Sep 2021
- First submitted
- 1 Oct 2018
- Last updated
- 14 Sep 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Arns-Glaser L, Zihlmann R, Gessler S, Verkaik-Kloosterman J, Zandberg L, Assey VD, Rigutto-Farebrother J, Braegger CP, Zimmermann MB, Andersson M. Estimating habitual iodine intake and prevalence of inadequacy from spot urine in cross-sectional studies: a modeling analysis to determine the required sample size. Am J Clin Nutr. 2023 Jun;117(6):1270-1277. doi: 10.1016/j.ajcnut.2023.03.012. Epub 2023 May 4.
PubMed 37270291
Study at a glance
From the registry record, last updated by the sponsor on 14 Sep 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability on Estimated Intake in Iodine Nutrition Studies
- ClinicalTrials.gov ID
- NCT03731312
- Acronym / sponsor ID
- VIOLET / VIOLET
- Conditions
- Iodine Deficiency
- Keywords
- Iodine, Urinary iodine concentration
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 206 participants (actual)
- Lead sponsor
- Swiss Federal Institute of TechnologyUniversity, hospital or other
- Study start
- 1 Oct 2018 (actual)
- Primary completion
- 4 May 2021 (actual)
- Study completion
- 4 May 2021 (actual)
- First posted
- 6 Nov 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Iodine status in populations is assessed using urinary iodine concentration (UIC) measured in spot urine samples. The iodine intake is classified as deficient, sufficient, or excessive iodine based on the median UIC (mUIC). However, this approach has limitations, as it does not quantify the prevalence of individuals with habitually deficient or excess iodine intakes. The EAR cut-point method has the potential to quantify prevalence of iodine deficiency and excess. However, little is known about the effects of the inter- and intra-individual variance of UIC.
The aim of the study is to quantify the intra-individual variability in dietary iodine intake. The overall goal is to estimate the prevalence of iodine deficiency and excess in the study population and propose sample size recommendations for future iodine nutrition population studies. The results will provide evidence guiding international recommendations for iodine nutrition studies.
Study design
- Observational model
- Ecologic or community
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Other: No interventionWe will collect two repeated spot urine samples, a DBS sample and obtain weight in all 600 study participants. In a randomly selected subsample (n=200) a third repeat spot urine sample and one 24 h urine will additionally be collected. |
Who may qualify
- Ages
- 18 to 44 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy women of reproductive age and residents of Switzerland since at least 12 months
Key inclusion criteria (7 listed)
- Non-pregnant
- Non-lactating
- Non-smoking
- Residence in Switzerland ≥12 months
- Generally healthy
Key exclusion criteria (1 listed)
- Participant is not able to understand the study information or procedure, e.g. due to linguistic barriers
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No interventionThis is an observational study and no interventions will be administered. | Other | Study group |
Primary outcome
Estimated daily urinary iodine excretion
Time frame: 7 days
Estimated urinary iodine excretion (µg/day) will be obtained from urinary iodine concentration (UIC) and urinary creatinine concentration (UCC) measured in two repeat spot urine samples collected within 7 days
4 secondary outcomes
Measured daily iodine excretion
Time frame: 1 day
Thyroid function test TSH
Time frame: 1 day
Thyroid function test total T4
Time frame: 1 day
Thyroid function test Tg
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Sep 2021.
- Derived from this study: PubMed 37270291Arns-Glaser L, Zihlmann R, Gessler S, Verkaik-Kloosterman J, Zandberg L, Assey VD, Rigutto-Farebrother J, Braegger CP, Zimmermann MB, Andersson M. Estimating habitual iodine intake and prevalence of inadequacy from spot urine in cross-sectional studies: a modeling analysis to determine the required sample size. Am J Clin Nutr. 2023 Jun;117(6):1270-1277. doi: 10.1016/j.ajcnut.2023.03.012. Epub 2023 May 4.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jessica Rigutto-Farebrother, PhD principal investigator
ETH Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Iodine Deficiency, run by Swiss Federal Institute of Technology at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Sep 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Estimated daily urinary iodine excretion (time frame: 7 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03731312, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Sep 2021.