VIOLET: Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability in Iodine Nutrition Studies
Study Details
Study Description
Brief 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). 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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| 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. |
Other: No intervention
This is an observational study and no interventions will be administered.
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Outcome Measures
Primary Outcome Measures
- Estimated daily urinary iodine excretion [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
Secondary Outcome Measures
- Measured daily iodine excretion [1 day]
Measured daily iodine excretion (µg/day) will be obtained from urinary iodine concentration (UIC) and urine volume in a 24 h urine collection
- Thyroid function test TSH [1 day]
TSH concentration (mU/L) measured in dried blood spots
- Thyroid function test total T4 [1 day]
Total T4 concentration (nmol/L) measured in dried blood spots
- Thyroid function test Tg [1 day]
Tg concentration (µg/L) measured in dried blood spots
Eligibility Criteria
Criteria
Inclusion Criteria:
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Non-pregnant
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Non-lactating
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Non-smoking
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Residence in Switzerland ≥12 months
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Generally healthy
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No family history of goiter
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No exposure to iodine containing contrast agents during the last 12 months - Informed consent given
Exclusion Criteria:
- Participant is not able to understand the study information or procedure, e.g. due to linguistic barriers
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | ETH Zurich | Zürich | Switzerland | 8092 |
Sponsors and Collaborators
- Swiss Federal Institute of Technology
Investigators
- Principal Investigator: Jessica Rigutto-Farebrother, PhD, ETH Zurich
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- VIOLET