TY - JOUR
T1 - The Danish investigation on iodine intake and thyroid disease (DanThyr): history and implications
AU - Møllehave, Line Tang
AU - Knudsen, Nils
AU - Linneberg, Allan
AU - Bülow Pedersen, Inge
AU - Ravn-Haren, Gitte
AU - Madsen, Anja Lykke
AU - Carlé, Allan
AU - Cerqueira, Charlotte
AU - Krejbjerg, Anne
AU - Rasmussen, Lone Banke
AU - Ovesen, Lars
AU - Perrild, Hans
AU - Sigurd, Lena Bjergved
AU - Thuesen, Betina Heinsbæk
AU - Vejbjerg, Pernille
AU - Jørgensen, Torben
PY - 2024/6
Y1 - 2024/6
N2 - Due to mild-to-moderate iodine deficiency in Denmark, health authorities initiated a voluntary iodine fortification (IF) program in 1998, which became mandatory in 2000. In line with recommendations from the World Health Organization, the Danish investigation on iodine intake and thyroid disease (DanThyr) was established to monitor the effect on thyroid health and disease. The program involved different study designs and followed two Danish sub-populations in the years before IF and up till 20 years after. Results showed that the IF was successfully implemented and increased the level of iodine intake from mild-moderate iodine deficiency to low adequacy. The level of thyroglobulin and thyroid volume decreased following IF, and there was an indication of fewer thyroid nodules. The incidence of hyperthyroidism increased transiently following IF but subsequently decreased below the pre-fortification level. Conversely, thyroid-stimulating hormone levels and the prevalence of thyroid autoimmunity increased along with an increase in the incidence of hypothyroidism. These trends were mirrored in the trends in treatments for thyroid disease. Most differences in thyroid health and disease between regions with different iodine intake levels before IF attenuated. This review illustrates the importance of a monitoring program to detect both beneficial and adverse effects and exemplifies how a monitoring program can be conducted when a nationwide health promotion program - as IF - is initiated.
AB - Due to mild-to-moderate iodine deficiency in Denmark, health authorities initiated a voluntary iodine fortification (IF) program in 1998, which became mandatory in 2000. In line with recommendations from the World Health Organization, the Danish investigation on iodine intake and thyroid disease (DanThyr) was established to monitor the effect on thyroid health and disease. The program involved different study designs and followed two Danish sub-populations in the years before IF and up till 20 years after. Results showed that the IF was successfully implemented and increased the level of iodine intake from mild-moderate iodine deficiency to low adequacy. The level of thyroglobulin and thyroid volume decreased following IF, and there was an indication of fewer thyroid nodules. The incidence of hyperthyroidism increased transiently following IF but subsequently decreased below the pre-fortification level. Conversely, thyroid-stimulating hormone levels and the prevalence of thyroid autoimmunity increased along with an increase in the incidence of hypothyroidism. These trends were mirrored in the trends in treatments for thyroid disease. Most differences in thyroid health and disease between regions with different iodine intake levels before IF attenuated. This review illustrates the importance of a monitoring program to detect both beneficial and adverse effects and exemplifies how a monitoring program can be conducted when a nationwide health promotion program - as IF - is initiated.
KW - Denmark/epidemiology
KW - Food, Fortified
KW - History, 20th Century
KW - History, 21st Century
KW - Humans
KW - Hyperthyroidism/epidemiology
KW - Hypothyroidism/epidemiology
KW - Incidence
KW - Iodine/administration & dosage
KW - Prevalence
KW - Thyroglobulin/immunology
KW - Thyroid Diseases/epidemiology
KW - Thyroid Gland/pathology
KW - Thyrotropin/blood
KW - thyroid disease
KW - epidemiology
KW - iodine
KW - public health
UR - http://www.scopus.com/inward/record.url?scp=85194421116&partnerID=8YFLogxK
U2 - 10.1530/ETJ-23-0230
DO - 10.1530/ETJ-23-0230
M3 - Review article
C2 - 38657651
SN - 2235-0640
VL - 13
JO - European Thyroid Journal
JF - European Thyroid Journal
IS - 3
M1 - e230230
ER -