Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability in Iodine Nutrition Studies

Iodine Deficiency Clinical Trial

— VIOLET  

Official title:

Variability of Daily Iodine Intake: The Effects of Intra- and Inter-individual Variability on Estimated Intake in Iodine Nutrition Studies

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03731312
• Other study ID #: VIOLET
• Status: Completed
• Start date: October 1, 2018
• Est. completion date: May 4, 2021

Study information

• Verified date: September 2021
• Source: Swiss Federal Institute of Technology
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical 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). 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 206
• Est. completion date: May 4, 2021
• Est. primary completion date: May 4, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 44 Years

Eligibility

Inclusion Criteria:

• 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

Exclusion Criteria:

• Participant is not able to understand the study information or procedure, e.g. due to linguistic barriers

Related Conditions & MeSH terms

• Iodine Deficiency

Intervention

Other:
• No intervention
This is an observational study and no interventions will be administered.

Locations

Country	Name	City	State
Switzerland	ETH Zurich	Zürich

Sponsors (1)

Lead Sponsor	Collaborator
Swiss Federal Institute of Technology

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	7 days
Secondary	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	1 day
Secondary	Thyroid function test TSH	TSH concentration (mU/L) measured in dried blood spots	1 day
Secondary	Thyroid function test total T4	Total T4 concentration (nmol/L) measured in dried blood spots	1 day
Secondary	Thyroid function test Tg	Tg concentration (µg/L) measured in dried blood spots	1 day