Elevated Serum Thyroglobulin and Low Iodine Intake Are Associated with Nontoxic Nodular Goiter among Adults Living near the Eastern Mediterranean Coast

Background. Information about iodine intake is crucial for preventing thyroid diseases. Inadequate iodine intake can lead to thyroid diseases, including nontoxic nodular goiter (NNG). Objective. To estimate iodine intake and explore its correlation with thyroid diseases among Israeli adults living near the Mediterranean coast, where iodine-depleted desalinated water has become a major source of drinking water. Methods. Cross-sectional study of patients attending Barzilai Medical Center Ashkelon. Participants, who were classified as either NNG (n=17), hypothyroidism (n=14), or control (n=31), provided serum thyroglobulin (Tg) and completed a semiquantitative iodine food frequency questionnaire. Results. Elevated serum Tg values (Tg > 60 ng/mL) were significantly more prevalent in the NNG group than in the other groups (29% versus 7% and 0% for hypothyroidism and controls, resp., P<0.05). Mean estimated iodine intake was significantly lower in the NNG group (65±30 μg/d) than in controls (115±60 μg/d) (P<0.05) with intermediate intake in the hypothyroid group (73±38 μg/d). Conclusions. Elevated serum Tg values and low dietary iodine intake are associated with NNG among adult patients in Ashkelon District, Israel. Larger studies are needed in order to expand on these important initial findings.