| According to the monitor of iodine deficiency disorders (IDD for short), in some province with low environment iodine such as Tibet and Qinghai, there is hardly epidemiology of IDD in pastoral areas, while agricultural areas around have serious IDD epidemiology. It is paradoxes that also exist in other countries. From existing data, it could be inferred as follows:(1) The environment iodine in pastoral area was low; (2) The level of urinary iodine in pastoral areas was low; (3) There is no epidemiology of endemic goiter or cretinism in pastoral areas. However, as to pastoral areas, there are following questions that have not been answered so far:(1) People's dietary intake of iodine and other nutrients relating to IDD; (2) Whether the level of thyroid hormone is normal or not; (3) Whether there are other forms of IDD expect for goiter and cretinism, such as abnormal pregnancy.PurposesTo research People's intake of iodine and other nutrients on quantity and food source among pastoral areas and agricultural regions in Tibet. To explore the status of iodine nutrition combined with dietary intake and urine iodine level. To investigate the morbidity of goiter, the level of thyroid hormone about women of childbearing age, and whether there are other forms of IDD in pastoral areas.MethodsIn pastoral Dangxiong County and agricultural Qushui County of Lhasa,30 families with target population including children aged 8～10, women of child-bearing age and male adults were selected respectively. Three consecutive days of dietary survey with 24-hour history recalls on respondents, the drinking water and edible salt were collected for testing iodine content and the daily intake of iodine, protein, vitamins, etc. were calculated. Subjects no less than 50 each type of following populations including children aged 8-10, women of child-bearing age and male adults were random sampled to examine their urinary iodine content, among them,50 children and 50 women were random selected for goiter examination by palpation, women were sampled to examine the serum thyroid hormone.ResultsThe water iodine was less than 2μg/L both in pasturing area and agricultural areas. There was no iodized salt used in the families of pasturing areas, while 90% people eat iodized salt in agricultural areas.In the pastoral areas and agricultural areas the median iodine intake per capita per day from drinking water were 2.5μg,2.1μg, with no statistically significant difference; daily dietary iodine intake per capita in pastoral areas was higher than agricultural areas (Z=-8.242, P<0.001), but lower than the recommended intake; Excepted carbohydrates, the dietary nutrients intake of pastoral population were significantly higher than the population of agricultural areas (P<0.001).The median of urinary iodine in pasturing area was 50.2μg/L which was significantly lower than that of agricultural area (193.2μg/L). The urinary iodine level of men (39.3μg/L) and women of childbearing age (35.5μg/L) is low, which shows serious lack of iodine nutrition, while the urinary iodine level of children (107.9μg/L) is in appropriate range.The goiter rate in pasturing area (none of women and 2% of children) was significantly lower than that in agricultural area (16% of women and 20% of children). The serum level of FT4, TT4 in pastoral population was significantly lower than that in agricultural area (P<0.05). The thyroid dysfunction rate and subclinical hypothyroidism rate in pastoral population was significantly lower than that in agricultural area (P<0.05). Surveys of pastoral women were reported having more abnormal pregnancy histories than the number of agricultural areas, but according to maternal and child health sector, abnormal pregnancy rate is not high among hospital delivery women.Conclusions1. In pastoral areas, where the supply of iodized salt is not popular, people with low urinary iodine show lack of iodine nutrition.2. In pastoral areas, people were lack of dietary iodine intake though higher than agricultural areas. However, the supply of protein has reached the recommended intake, particularly high proportion of animal protein, which may help to improve the synthesis of thyroid hormones and efficiency.3. There is no epidemiology of goiter. The thyroid dysfunction rate and subclinical hypothyroidism rate was low. But the low level of thyroxin shows recessive iodine deficiency in pastoral population, so iodine supplementation is necessary.4. Other forms of IDD have not been found.
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