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Towards the elimination of iodine deficiency and preventable thyroid-related diseases in Europe

Periodic Reporting for period 2 - EUthyroid (Towards the elimination of iodine deficiency and preventable thyroid-related diseases in Europe)

Reporting period: 2016-12-01 to 2018-05-31

Iodine deficiency is the world’s leading cause of preventable brain damage and for years the World Health Organization has warned that Europeans are increasingly affected by its consequences. Europe currently has no harmonised approach to ensure that the iodine intake of European citizens is sufficient to prevent health problems. EUthyroid is an EU-funded research project evaluating national efforts aimed at preventing iodine deficiency disorders (IDD). By analysing current national approaches, creating critical mass and capacities for harmonised monitoring of iodine intake we aim to pave the way for improved and cost-effective strategies to ensure a euthyroid Europe in cooperation with national authorities. EUthyroid evaluated existing IDD prevention programmes by collating and analysing data from disease registries in 18 of the 27 countries participating in EUthyroid. The pooled data resulted in the first valid map of comparable data about iodine status and thyroid disorders in Europe.
EUthyroid supports harmonisation of national and regional surveys of iodine supply and thyroid disorders in up to 56 studies from 27 countries, through the provision of standardised questionnaires, guidelines and training tools, and for the first time, provides standardised thyroid-related measurements yielding a reliable view of the current status of iodine-related disorders in Europe. The project explores the potential of thyroglobulin as marker for the individual iodine status according to WHO recommendations with a focus on pregnant women and women of reproductive age, two key target groups for IDD prevention due to the high risk of adverse effects on cognition of babies exposed to moderate iodine deficiency. This research contributes to a new international recommended thyroglobulin (Tg) reference range for pregnant women and women of reproductive age. Importantly, EUthyroid studies the consequences of maternal iodine status during pregnancy in relation to the cognitive development of their children (as measured by child IQ, autism, ADHD and language development) using retrospective data from three countries (Spain, UK and the Netherlands). In order to support decision making processes in healthcare systems a decision-analytic model was developed to explore the long-term effectiveness and cost-effectiveness of prevention and monitoring strategies for iodine deficiency disorders. Furthermore, EUthyroid follows through on an ambitious dissemination strategy to engage actively policy makers, stakeholders and the general public to promote harmonised IDD prevention and monitoring in European countries.
The EUthyroid consortium successfully established a joint European database combining national and regional registry based outcome data related to iodine status from 18 European countries. The database also collated data from 56 IDD monitoring studies spanning 27 European countries. Measurements for 39 IDD monitoring studies from 23 European countries were harmonised, generating the first harmonised European map of iodine status. This was supplemented by additional European prevalence maps of thyroid related biomarkers and thyroid dysfunction.
The EUthyroid infrastructure to support the harmonisation of studies, accessible through the project´s website, includes recommendations for questionnaires on the socio-economic status of adults and children; an instructional video and guide on thyroid ultrasound examination, a web-based training and certification tool (ARCUS) for ultrasound observers, and a guide for researchers conducting population studies.
EUthyroid developed a dried blood spot (DBS) Tg ELISA assay to analyse DBS cards of pregnant women and women of reproductive age collected from various IDD monitoring studies across European and non-European countries, to establish and further cross-validate Tg reference ranges for these vulnerable groups for future ID monitoring.
Data from three major European birth cohort studies in the Netherlands, UK and Spain were harmonised and integrated into one large dataset, enabling us to study the effects of low maternal iodine on child neurodevelopment. A proof-of-principle study was performed on the effects of thyroid function on child IQ and the risk of behavioural disorders in over 9,500 mothers and their children. Results showed that both low and high maternal thyroid hormone levels during early pregnancy are associated with a lower child IQ and a higher risk of autism.
In order to provide evidence for the long-term benefit-harm balance and cost-effectiveness of IDD prevention and monitoring programmes in Europe a decision-analytic Markov state-transition cohort model was developed and expert input and systematic literature searches undertaken to parameterise the model.
Policy makers, stakeholders and the general public have been targeted through a range of media including a project website, conference presentations, scientific publications, national press, television and social media as part of a coordinated dissemination strategy.
With the Krakow Declaration on Iodine, EUthyroid presented recommendations towards preventing IDD and securing sufficient iodine status in Europe as a call to action for policy makers, public health officials, scientists and the general public. High-level meetings were held with policy makers in 20 countries, with several already yielding policy change.
EUthyroid aims to progress beyond the state of the art of fragmented national strategies towards iodine deficiency prevention through the harmonisation of: existing registry data; guidelines for study conduction; training of study staff and measurement of samples.
A joint European database for registry data and standardised IDD monitoring studies using geo-coding to improve comparability, yielded a leap in knowledge, producing the first European map of iodine status and thyroid disease load. Significantly, inter-laboratory comparisons revealed major deviations compared to standardised results, clearly demonstrating the importance of continued standardisation and harmonisation in the field.
EUthyroid is the first project to evaluate DBS thyroglobulin as a promising functional biomarker for individual iodine status. A new assay facilitates sample collection, storage and handling.
EUthyroid overcame a major knowledge gap by providing new data on the effect of maternal iodine status in relation to neurodevelopment.
EUthyroid is the first project to investigate the cost-effectiveness of IDD prevention programmes in regions with mild-to-moderate iodine deficiency. These data will provide a sound basis for policy makers to assess current IDD prevention and monitoring programmes.
Reaching millions of people through various activities (TV, radio, press) in addition to high-level meetings with policy makers in 20 countries and endorsement of the Krakow Declaration on Iodine by over 60 organisations, it is hoped that the dissemination of EUthyroid outcomes has put the important issue of IDD back on the political agenda.
EUthyroid conducted the most in-depth analysis of iodine deficiency and health outcomes providing a solid foundation of data to fill the current lack of health outcome research, a major stumbling block to initiating national monitoring and prevention programmes. The expectation is that EUthyroid infrastructure and policy recommendations with continue to pave the way towards Europe becoming the benchmark for IDD prevention worldwide.