Long-term iodine nutrition is associated with longevity in older adults: a 20 years' follow-up of the Randers-Skagen study.

Iodine intake affects the occurrence of thyroid disorders. However, the association of iodine intake with longevity remains to be described. This led us to perform a 20 years' follow-up on participants from the Randers-Skagen (RaSk) study.

Iodine status in Danish pregnant and breastfeeding women including studies of some challenges in urinary iodine status evaluation.

Denmark was previously iodine deficient with regional differences. Moderate iodine deficiency appeared in West Denmark and mild iodine deficiency in East Denmark and also Danish pregnant and breastfeeding women suffered from iodine deficiency. The Danish mandatory iodine fortification of salt was introduced in the year 2000 and has increased iodine intake in the Danish population.

Thyroglobulin in smoking mothers and their newborns at delivery suggests autoregulation of placental iodide transport overcoming thiocyanate inhibition.

Background: Placental transport of iodide is required for fetal thyroid hormone production. The sodium iodide symporter (NIS) mediates active iodide transport into the thyroid and the lactating mammary gland and is also present in placenta. NIS is competitively inhibited by thiocyanate from maternal smoking, but compensatory autoregulation of iodide transport differs between organs.

Iodine deficiency influences thyroid autoimmunity in old age--a comparative population-based study.

Objective: To assess thyroid autoimmunity among elderly people living in an area with low iodine intake compared to the sustained recommended iodine intake from a natural source, and to estimate the importance of migration.

Design And Setting: Iodine content of drinking water is highly different in the Danish towns Randers and Skagen. We collected blood and spot urine samples from 430 long-term Randers and Skagen dwellers aged 75-80 years, who filled in a questionnaire.

More hypothyroidism and less hyperthyroidism with sufficient iodine nutrition compared to mild iodine deficiency--a comparative population-based study of older people.

Objective: To assess the occurrence of thyroid disorders and autoimmunity in a geriatric population with long-standing recommended iodine intake of natural origin compared to mild iodine deficiency.

Design And Setting: Cross-sectional, comparative, population-based study in two areas with different iodine intakes due to different tap water iodine contents.

Participants: Residents of Randers (n=212) or Skagen (n=218), Denmark, aged 75-80 years.

[Basic registration of risk factors in medical records. Malnutrition, overweight, physical inactivity, smoking and alcohol].

Introduction: Lifestyle factors are important for clinical outcome. Systematic and early identification of these factors is important in order to offer relevant lifestyle intervention programmes. The objective was to evaluate whether basic registration of risk factors was understandable, applicable and sufficient in the clinical workday.

Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals.

The iodine intake level in a population is determined in cross-sectional studies. Urinary iodine varies considerably and the reliability of studies of iodine nutrition and the number of samples needed is unsettled. We performed a longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency.

Naturally occurring iodine in humic substances in drinking water in Denmark is bioavailable and determines population iodine intake.

Iodine intake is important for thyroid function. Iodine content of natural waters is high in some areas and occurs bound in humic substances. Tap water is a major dietary source but bioavailability of organically bound iodine may be impaired.

Sources of circulating 3,5,3'-triiodothyronine in hyperthyroidism estimated after blocking of type 1 and type 2 iodothyronine deiodinases.

Context: Graves' hyperthyroidism and multinodular toxic goiter lead to high serum T(3) compared with serum T(4). The source of this high T(3) has not been clarified.

Objective: Our objective was to assess the role of iodothyronine deiodinase type 1 (D1) and type 2 (D2) for T(3) production and to estimate the sources of T(3) in hyperthyroidism.

Iodine nutrition in breast-fed infants is impaired by maternal smoking.

Lack of iodine for thyroid hormone formation during the fetal stage and/or the first years of life may lead to developmental brain damage. During the period of breastfeeding, thyroid function of the infant depends on iodine in maternal milk. We studied healthy, pregnant women admitted for delivery and their newborn infants.

Biologic variation is important for interpretation of thyroid function tests.

Large variations exist in thyrotropin (TSH) and thyroid hormones in serum. The components of variation include preanalytical, analytical, and biologic variation. This is divided into between- and within-individual variation.

Narrow individual variations in serum T(4) and T(3) in normal subjects: a clue to the understanding of subclinical thyroid disease.

High individuality causes laboratory reference ranges to be insensitive to changes in test results that are significant for the individual. We undertook a longitudinal study of variation in thyroid function tests in 16 healthy men with monthly sampling for 12 months using standard procedures. We measured serum T(4), T(3), free T(4) index, and TSH.