A TEDDY Study Update on the Identified Causes of and Prevention Methods for Type 1 Diabetes in Youth
by IDS Director of Intensive Diabetes Management, Tavia Vital
The Environmental Determinants of (Type 1) Diabetes in Youth Study (TEDDY Study) recently published additional findings from its longstanding research.
About 8,700 children from Sweden, Finland, Germany, and the US enrolled in the TEDDY Study. Enrollment eligibility could start from a cord blood sample at birth showing specific genetic risks for being susceptible to T1D. Infants were enrolled by 3 to 4.5 months of age.
Parents and research study sites collected and submitted survey data collected a variety of environmental samples such as tap water, toenail clippings, urine and stool samples, blood samples, vaccine records, logs of illnesses, social interactions, allergies, prescribed or over-the-counter medications, stressful life events, and more.
They follow children from infancy to age 15 or until a diagnosis of T1D. Enrollment into the TEDDY Study took place from 2004 to 2010. Final data collections are due to be submitted by March 2025.
So far, of the nearly 8700 children enrolled in the study:
- 455 were diagnosed with T1D
- 83 were diagnosed with Autoimmune Thyroid Disease
- 579 were diagnosed with Celiac Disease
To date, the TEDDY Study has published hundreds of articles sharing what they learned along the way. A new article published this month in Nature Reviews Endocrinology provides an overview of key findings to date.
Key Findings:
- In children who went on to develop T1D before the age of 15, antibodies showing T1D is developing were most commonly present before age 3. However, the study showed it often took several years for most children to get to Stage 3 T1D. Prior to the TEDDY study, it was thought that once antibodies appear, T1D should progress to diagnosis within a few weeks to months. (Stage 3 T1D is where the glucose levels are elevated enough to diagnose diabetes and autoantibodies are present).
- Giving probiotics to infants at high genetic risk for T1D reduced the risk for autoantibodies to develop and thus prevented T1D in a statistically significant portion of the study participants.
- There is a direct link between Enterovirus and the start of autoantibody production.
- 12% of those enrolled had at least 1 autoantibody for T1D during the study.
- About 7% of children with the highest genetic risk will develop T1D during their lifetime, and about 5% of the children in this study already developed it by age 15.
- Low levels of Vitamin D and Vitamin C increase the risk of developing an autoantibody for T1D or for Celiac Disease.
- Low levels of Vitamin D and Vitamin C contribute to a child developing symptoms of a viral illness.
- Stress experienced by the mother during pregnancy increased the risk of a child with a high-risk genetic profile to develop autoantibodies. The type of stress and the child’s genetic makeup impacts which autoantibody develops first. Serious personal conflicts and work-related stress were tied to autoantibody development in the child.
- Introduction of gluten-free flours (for example, corn or rice) at the age of 4-6 months in the US increased the risk of 2 types of autoantibody formation (GADA* and IAA*).
- Gastroenteritis and norovirus reported by parents in children younger than 1 year old increased the risk for IAA production when the child was 2-4 years old.
- 22% of the children in the TEDDY Study developed the TGA* antibody and 7.2% of the children in the study have been diagnosed with Celiac Disease.
If Vitamin D levels are too low (below 30 nmol/L) or too high (above 75 nmol/L), it increases the risk for developing T1D or Celiac Disease - A dietary pattern at 18 months of a higher intake of vegetable fats, wheat, processed meat, and juice increased the risk of TGA antibody production compared to those who mostly ate milk, oats, meat, and legumes.
- 6.6% of children in the TEDDY Study developed TG* antibody and 5% developed TPO* antibody. The youngest child was 10 months for TG antibody and 15 months old for TPO antibody detection.
- The highest rates of T1D conversion and autoantibody production takes place in Sweden, as does the highest rates for Celiac autoantibody production and diagnosis.
Antibodies Studied in the TEDDY Study
Antibody Types Associated with T1D:
- GADA or GAD-65 – Glutamic acid decarboxylase 65 antibody
- IAA – Insulin autoantibody
- ICA – Islet cell antibody
- IA-2 (IA-2A) – Tyrosine phosphatase-like protein IA-2
- ZnT8A – Zinc transporter 8
Antibody Type Associated with Celiac Disease:
- TGA – Tissue transglutaminase
Antibody Types Associated with Autoimmune Thyroiditis:
- TG – Thyroglobulin
- TPO – Thyroid peroxidase
Due to the huge volumes of international data TEDDY has been collecting and the subsets of data findings TEDDY has published, a large number of follow-up and spin-off studies have been completed with more studies enrolling and being developed.
Scientists are studying the impact of different dietary styles, supplementing with pro-biotics, trialing oral insulin powder, the impact of vaccines for COVID-19, and more to see if data found in TEDDY study can be rolled into different ways to screen for, prevent, stop, or reverse the autoimmune attack.
TEDDY study information is freely available in English at: https://teddy.epi.usf.edu/ and all TEDDY-related publications are freely available for download at: https://repository.niddk.nih.gov/studies/teddy/
A final TEDDY Study summary will be published in 2025-2026.
Source: https://dagensdiabetes.se/images/filer_att_ladda_ner/DN_nr_6-7_2024_compressed.pdf
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