Chandra Amar K, Ray Indrajit
Department of Physiology, University of Calcutta, Kolkata, India.
Indian J Med Res. 2002 Jan;115:22-7.
BACKGROUND & OBJECTIVES: Universal salt iodization programme was initiated during 1988-89 in the goitre endemic state of Tripura. However, no decline in goitre prevalence was found about a decade after the initiation of programme. The present work evaluates the quality of implementation of the salt iodization programme and the possible involvement of dietary goitrogens in the process.
The study areas were selected at random and in the selected areas only, school children were chosen purposively instead of the entire population. Iodine nutritional status was evaluated by measuring the urinary iodine excretion. The iodine content of salt collected from households was tested by iodometric titration, urinary iodine was measured by dry ashing method and thiocyanate by oxidising bromine and then developing colour by benzedine hydrochloride.
Urinary iodine level was measured in 1,123 samples from 22 study areas. In 17 areas, the median urinary iodine values were > 100 micrograms/l indicating no biochemical iodine deficiency. However, the iodine intake of about 40 per cent of the studied population was below the cut-off level i.e., iodine level were < 100 micrograms/l. About two-thirds of salt samples were found to contain iodine less than the adequacy level of 15 ppm. Thiocyanate was present in the 1,032 urine samples studied, in different concentrations.
INTERPRETATION & CONCLUSION: The people of region are exposed to inadequately iodized salt in spite of the salt iodization programme. Further, they are exposed to a thiocyanate load. This study suggests that monitoring of salt iodization programme is essential to ensure the recommended level of iodine (15 ppm) in at least 90 per cent salt samples. The goitrogenic/antithyroid potential of cyanogenic foods used in the region need to be ascertained to understand the nature of action on thyroid function.
1988 - 1989年期间，在甲状腺肿流行的特里普拉邦启动了全民食盐加碘计划。然而，该计划启动约十年后，甲状腺肿患病率并未下降。本研究评估了食盐加碘计划的实施质量以及膳食致甲状腺肿物质在此过程中可能发挥的作用。
随机选择研究区域，且仅在选定区域内，有目的地选取学童而非全体人群。通过测量尿碘排泄量评估碘营养状况。采用碘量滴定法检测从家庭收集的食盐中的碘含量，采用干灰化法测量尿碘，采用氧化溴法测定硫氰酸盐，然后用盐酸联苯胺显色。
对来自22个研究区域的1123份样本测量了尿碘水平。在17个区域，尿碘中位数>100微克/升，表明不存在生化性碘缺乏。然而，约40%的研究人群碘摄入量低于临界水平，即碘水平<100微克/升。约三分之二的食盐样本碘含量低于15 ppm的适宜水平。在所研究的1032份尿样中均检测到不同浓度的硫氰酸盐。
尽管实施了食盐加碘计划，但该地区民众仍接触到碘含量不足的食盐。此外，他们还接触到硫氰酸盐负荷。本研究表明，监测食盐加碘计划对于确保至少90%的食盐样本达到推荐的碘水平（15 ppm）至关重要。需要确定该地区使用的含氰食物的致甲状腺肿/抗甲状腺潜能，以了解其对甲状腺功能的作用性质。
