Swiss National Iodine Survey 2015 (SIS)

Swiss National Iodine Survey 2015; A Cross-sectional Study to Assess Iodine Status in School Children, Women of Reproductive Age and Pregnant Women

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.

Study Overview

• Status: Completed
• Conditions: Healthy Subjects

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.

• Study Type: Observational
• Enrollment (Actual): 1430

Contacts and Locations

Study Locations

• Switzerland
  • Zurich, Switzerland, 8092
    • Human Nutrition Laboratory, ETH Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 years to 44 years (Child, Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

school aged children, 6-12 years pregnant women, 18-44 years women of reproductive age, 18-44 years

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
Pregnant women
School aged children
Women of reproductive age

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Median urinary iodine concentration in school aged children, pregnant women and women of reproductive age	analysis of urine samples	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Population mean thyroglobulin	Analysis of venous blood samples. Assessed only in women	Baseline
Population mean thyroid stimulating hormone	Analysis of venous blood samples. Assessed only in women	Baseline
Population mean thyroxine	Analysis of venous blood samples. Assessed only in women	Baseline
Median urinary sodium concentration		Baseline
Median urinary creatinin concentration		Baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean height of school aged children and women of reproductive age		Baseline
Mean weight of school aged children and women of reproductive age		Baseline
Median urinary fluoride	Analyzed in urine samples from school aged children only.	Baseline
Population mean folate status	Analysis of red blood cell folate and plasma folate in venous blood samples.	Baseline
Populations mean iron status	Serum analysis: ferritin, transferrin receptor; in women of reproductive age and pregnant women.	Baseline
Individual inflammatory state	Serum analysis of CRP and AGP, analyzed only in women	Baseline
Intake of iodine in micro grams per day	iodine intake assessed by food frequency questionnaire, only in women	Baseline
% of households with adequate iodine coverage	Salt samples only collected from children (subgroup)	Baseline

Collaborators and Investigators

• Sponsor: Isabelle Herter-Aeberli
• Collaborators: Federal Food Safety and Veterinary Office (Switzerland)

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: March 1, 2015
• Primary Completion (Actual): September 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: December 3, 2014
• First Submitted That Met QC Criteria: December 5, 2014
• First Posted (Estimate): December 9, 2014

Study Record Updates

• Last Update Posted (Actual): September 16, 2020
• Last Update Submitted That Met QC Criteria: September 15, 2020
• Last Verified: September 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: SIS 2015