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

NCT03731312 | Completed

• 1 other identifier: VIOLET
• Study Type: observational
• Target: 206
• Locations: 1 country
• Sites: 1

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.

Conditions

Iodine Deficiency

Keywords

Iodine; Urinary iodine concentration

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (4)

• Measured daily iodine excretion

  1 day

• Thyroid function test TSH

  1 day

• Thyroid function test total T4

  1 day

• Thyroid function test Tg

  1 day

Study Arms (1)

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

Interventions

No intervention OTHER

This is an observational study and no interventions will be administered.

Study group

Eligibility Criteria

• Age: 18 Years - 44 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Healthy women of reproductive age and residents of Switzerland since at least 12 months

You may qualify if:

• 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

You may not qualify if:

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

Sponsors & Collaborators

• Swiss Federal Institute of Technology: lead

Study Sites (1)

ETH Zurich

Zurich, 8092, Switzerland

Location

Related Publications (1)

• 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.

  PMID: 37270291 DERIVED

Biospecimen

Retention: SAMPLES WITHOUT DNA

Urine, Dried blood spot

Study Officials

• Jessica Rigutto-Farebrother, PhD

  ETH Zurich

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: ECOLOGIC OR COMMUNITY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 1, 2018
• First Posted: November 6, 2018
• Study Start: October 1, 2018
• Primary Completion: May 4, 2021
• Study Completion: May 4, 2021
• Last Updated: September 14, 2021

Record last verified: 2021-09

Locations

CH (1)