More hypothyroidism and less hyperthyroidism with sufficient iodine nutrition compared to mild iodine deficiency-A comparative population-based study of the old.
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. MEASURES: Blood samples were collected for measuring thyrotropin (TSH), triiodothyronine, thyroxine, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), thyroglobulin (TG); iodine excretion estimated from iodine and creatinine measured in spot urine samples; questionnaire on history of thyroid disease, medication and vitamin use; clinical examination of the neck. RESULTS: Median urinary iodine excretion was 50mug/24h in Randers and 177mug/24h in Skagen (p