Clinical trial NCT02312466: Swiss National Iodine Survey 2015
Official title: Swiss National Iodine Survey 2015; A Cross-sectional Study to Assess Iodine Status in School Children, Women of Reproductive Age and Pregnant Women
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Healthy Subjects
Lead sponsor: Swiss Federal Institute of Technology
Sponsor class: OTHER
Collaborators: name: Federal Food Safety and Veterinary Office (Switzerland)
First posted: 2014-12-09
Enrollment: 1430
Sex: ALL
Minimum age (years): 6
Maximum age (years): 44
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: school aged children, 6-12 years pregnant women, 18-44 years women of reproductive age, 18-44 years

Brief summary: The aim of this study is to monitor iodine nutrition in Switzerland in order to inform the authorities regarding iodine content in iodized salt. As a proxy for the entire population the investigators will study school aged children, pregnant women and women of reproduction age.

Detailed description: In a national sample of school aged children (n=990), pregnant women (n=700) and women of reproductive age (n=700) urinary iodine will be determined in order to assess iodine nutrition in Switzerland. In addition, in both groups of women a blood sample will be taken for the determination of thyroid hormones, iron- and folate status. Questionnaires will be used for the determination of dietary iodine and salt intake as well as sociodemographic parameters.

Eligibility criteria: Inclusion Criteria:

* Healthy
* Living in Switzerland for at least 1 year
* For pregnant women: singleton pregnancy

Exclusion Criteria:

* Major known medical illness: thyroid dysfunction, gastrointestinal or metabolic disorders and taking chronic medications
* For women of reproductive age: pregnancy, breastfeeding
* Use of X-ray or CT contrast agent or iodine containing medication within the past year

Primary outcomes:
measure: Median urinary iodine concentration in school aged children, pregnant women and women of reproductive age
timeFrame: Baseline
Secondary outcomes:
measure: Population mean thyroglobulin
timeFrame: Baseline
measure: Population mean thyroid stimulating hormone
timeFrame: Baseline
measure: Population mean thyroxine
timeFrame: Baseline
measure: Median urinary sodium concentration
timeFrame: Baseline
measure: Median urinary creatinin concentration
timeFrame: Baseline
Other outcomes:
measure: Mean height of school aged children and women of reproductive age
timeFrame: Baseline
measure: Mean weight of school aged children and women of reproductive age
timeFrame: Baseline
measure: Median urinary fluoride
timeFrame: Baseline
measure: Population mean folate status
timeFrame: Baseline
measure: Populations mean iron status
timeFrame: Baseline
measure: Individual inflammatory state
timeFrame: Baseline
measure: Intake of iodine in micro grams per day
timeFrame: Baseline
measure: % of households with adequate iodine coverage
timeFrame: Baseline
Locations:
city: Zurich
country: Switzerland
facility: Human Nutrition Laboratory, ETH Zurich
Study officials:
References:
citation: Andersson M, Hunziker S, Fingerhut R, Zimmermann MB, Herter-Aeberli I. Effectiveness of increased salt iodine concentration on iodine status: trend analysis of cross-sectional national studies in Switzerland. Eur J Nutr. 2020 Mar;59(2):581-593. doi: 10.1007/s00394-019-01927-4. Epub 2019 Mar 1.