Abstract | OBJECTIVE: Our objective was to investigate individual serum thyroglobulin (Tg) changes in relation to iodine fortification (IF) and to clarify possible predictors of these changes. DESIGN: We performed a longitudinal population-based study (DanThyr) in two regions with different iodine intake at baseline: Aalborg (moderate iodine deficiency (ID)) and Copenhagen (mild ID). Participants were examined at baseline (1997) before the mandatory IF of salt (2000) and again at follow-up (2008) after IF. METHODS: We examined 2465 adults and a total of 1417 participants with no previous thyroid disease and without Tg- autoantibodies were included in the analyses. Serum Tg was measured by immunoradiometric method. We registered participants with a daily intake of iodine from supplements in addition to IF. RESULTS: Overall, the follow-up period saw no change in median Tg in Copenhagen (9.1/9.1 μg/l, P=0.67) while Tg decreased significantly in Aalborg (11.4/9.0 μg/l, P<0.001). Regional differences were evident before IF (Copenhagen/Aalborg, 9.1/11.4 μg/l, P<0.001), whereas no differences existed after IF (9.1/9.0 μg/l, P=1.00). Living in Aalborg (P<0.001) and not using iodine supplements at baseline (P=0.001) predicted a decrease in Tg whereas baseline thyroid enlargement (P=0.02) and multinodularity (P=0.01) were associated with an individual increase in Tg during follow-up. CONCLUSIONS: After IF we observed a decrease in median Tg in Aalborg and the previously observed regional differences between Aalborg and Copenhagen had levelled out. Likewise, living in Aalborg was a strong predictor of an individual decrease in serum Tg. Thus, even small differences in iodine intake at baseline were very important for the individual response to IF.
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Authors | Anne Krejbjerg, Lena Bjergved, Inge Bülow Pedersen, Allan Carlé, Nils Knudsen, Hans Perrild, Lars Ovesen, Lone Banke Rasmussen, Peter Laurberg |
Journal | European journal of endocrinology
(Eur J Endocrinol)
Vol. 173
Issue 5
Pg. 573-81
(Nov 2015)
ISSN: 1479-683X [Electronic] England |
PMID | 26245764
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © 2015 European Society of Endocrinology. |
Chemical References |
- Sodium Chloride, Dietary
- Thyroglobulin
- Iodine
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Topics |
- Adolescent
- Adult
- Aged
- Denmark
- Female
- Follow-Up Studies
- Food, Fortified
- Humans
- Iodine
(administration & dosage, pharmacology)
- Male
- Middle Aged
- Sodium Chloride, Dietary
- Thyroglobulin
(blood)
- Young Adult
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