ABSTRACT
Objective To analyze the change of urinary iodine in a cohort of intervention trial and to observe the role of different doses on salt iodization and related impact factors on nutritional condition of iodine. Methods Multistage cluster sampling was used to sample three townships in two counties for community intervention with different doses (15 ± 5, 25 ± 5, 35 ± 5)mg/kg. Results Compared to the (35 ± 5)mg/kg group, the urine iodine levels of three experimental townships were gradually declining in county B when time went on, and the (15 ± 5) mg/kg group showed anobvious results, at 6,12,18 and 24 months, with the urine iodine level as 180.00,186.10,150.04,191.28 μg/L respectively, which were in accordance with the WHO standard and reached to appropriate range (187.96μg/L) at the 18 month. The townships at county Y under intervention had declined slightly, but the urine iodine levels did not reach the WHO standard. The thyroid volume declined from 3.65 ml to 3.40 ml in two counties and the difference between them was statistically significant. Conclusion To some extent, reducing the iodine concentration in salt, had a role of lowering the urine iodine level and reducing the strumous rate.