Determination of iodine concentration in urine by isotope dilution analysis and thyroid volume of school children in the west coast of Turkey after mandatory salt iodization

Objective This study was designed to evaluate iodine deficiency status in children 6-12 years in the west coast (Aegean Region) of Turkey after 5 years of mandatory iodine prophylaxis. A total of 2300 children from 72 populations (rural and urban area) were evaluated with urinary iodine excretion and thyroid volume. Design Cross-sectional, observational study designed and performed according to surveillance methods for iodine deficiency disease (IDD) prevalence recommended by WHO/UNICEF/ICCIDD. Subjects The study population consisted of 2300 school children age ranging from 6 to 12 years. The children were selected by multiple stage randomization from 91 primary schools of 76 zones (91 clusters). Information about the use of iodized salt was obtained from the families. Measurements Data on the following were collected: birth date, sex, weight, height, thyroid size by palpation and ultrasonography; and urinary iodine by isotope dilution analysis method. Thyroid volumes above 97th percentile according to the WHO/ICCIDD by age and body surface area (BSA) were accepted as goitre. Results Iodized salt consumption was 51.7%. The prevalence of goitre determined by palpation was 12.1% and by ultrasound based on BSA and age were 9.8% and 5.5%, respectively. Median urinary iodine was 53 (2-142) mu g/l. Conclusion Mild to severe degree of iodine deficiency was detected in the west coast of Turkey.