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Iodine-rich herbs such as seaweed, kelp, and sea tangle were widely used to treat various types of goiter with good effect and without any adverse side effects in China. When compared with potassium iodate (PI), iodine-rich herbs had a positive effect on the recovery of goiter resulting from iodine deficiency without any obvious harmful effects. In NOD.H-2h4 mice, an autoimmune thyroiditis-prone model, iodine excess can increase infiltration of lymphocytes and structural damage of the thyroid follicles, hence resulting in thyroiditis. Until now, there has been little research on the comparative effects of PI and iodine-rich herbs on thyroid in an autoimmune thyroiditis-prone model. This study was designed to compare the different effects of iodine-rich herbs and PI on the thyroid gland in iodine-deficient NOD.H-2h4 mice. Excessive intake of PI cause oxidative injury in the thyroid gland and increase the risk of autoimmune thyroiditis, while iodine-rich herbs cause less oxidative injury, significantly enhancing antioxidant capacity, and inhibit the high differentiation of Th17 cells in the thyroid glands of NOD.H-2h4 mice.

Iodine-rich herbs such as seaweed, kelp, and sea tangle were widely used to treat various types of goiter with good effect and without any adverse side effects in China. When compared with potassium iodate (PI), iodine-rich herbs had a positive effect on the recovery of goiter resulting from iodine deficiency without any obvious harmful effects. In NOD.H-2

To discuss the mechanism of traditional Chinese medicines reducing phlegm and resolving masses in treatment of iodine deficiency-induced goiter by observing the expression of growth factors and the balance-regulating mechanism of proliferation and apoptosis.180 four-week-old Wistar rats were selected to establish the iodine deficiency model. After the modeling, the rats were randomly divided into six groups: the normal control group, the model control group, the iodine group, the phlegm compound group, the L-T4 group and the phlegm compound and L-T4 group. At the 21st day and 77th day after administration, 15 rats in each group were killed to collect specimens. Doses were calculated and adjusted according to body surface area and body weight. TT3, TT4 radioimmunoassay, TSH, immunoradiometric method were adopted. Fas, FasL and PCNA protein expressions are detected using immunohistochemical methods.Compared with the normal group and the model group, the expressions of fas and FasL in the phlegm Group significantly increased, the expressions of fas and FasL in the phlegm and L-T4 group were also increased significantly. The expression of fas in the L-T4 Group was significantly lower than that of the L-T4 group and the phlegm compound and L-T4 group. Compared with the normal group, the expression of PCNA of the phlegm group and the phlegm and L-T4 group was significantly lower. Compared with the model group, the expression of PCNA of the iodine group, the phlegm groups and the phlegm and L-T4 group were significantly lower. Compared with the normal group, the expression of VEGF in the iodine group significantly decreased after treatment. Compared with the iodine group, the expression of VEGF in the phlegm group and the L-T4 group significantly reduced. Compared with the normal group, the expression of TGF-beta1 in the model group and the phlegm group significantly increased. Compared with model group, the expression of TGF-beta1 in the iodine group significantly reduced. Compared with the phlegm group, the expression of TGF-beta1 in the phlegm compound and L-T4 group was significantly reduced.Traditional Chinese medicines reducing phlegm and resolving masses can completely recover goiter by promoting apoptosis of thyroid cells, inhibiting their proliferation and the expression of growth factors and enhancing the expression of TGF-beta, without causing injury on thyroid cells.

To investigate the changes in reactive oxygen species (ROS) and dimethyl- arginine dimethylaminohydrolase-asymmetric dimethylarginine (DDAH-ADMA) system in the process of endothelial cell senescence after exposure to high glucose.The human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of glucose, e.g. 5.5 mmol/L (normal level), and high levels as 11.0, 22.0 and 33.0 mmol/L, for 48 hours, respectively. Subsequently, SA-β-gal staining was used to evaluate senescence of cells. Telomerase activity was detected by polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA). The intracellular ROS level was measured by flow cytometry. The ADMA concentration and DDAH activity were determined with high-performance liquid chromatography.Compared with normal glucose concentration group, after the endothelial cells were treated with high glucose concentration (11.0-33.0 mmol/L) for 48 hours, the number of SA-β-gal positive cells was increased significantly [(7.00±1.73)%, (12.67±2.03)%, (16.00±2.26)% vs. (4.00±1.33)%, P0.05, P0.05, P0.05] and the telomerase activity was inhibited dramatically [(91.32±4.01)%, (78.44±3.78)%, (56.04±3.35)% vs. 100%, all P0.05]. The ROS level (mfi) was increased in all high glucose groups (159.84±27.52, 188.99±18.77, 244.56±20.96 vs.117.11±18.76, P0.05 or P0.01). At the same time, the ADMA (μmol/L) production was increas ed (0.78±0.14, 0.88±0.18, 1.08±0.15 vs. 0.70±0.12, P0.05, P0.05, P0.05), and DDAH activity was decreased [(91.32±4.01)%, (78.44±3.78)%, (56.04±3.35)% vs.100%, all P0.05].High glucose can accelerate endothelial cells senescence in dose-dependent manner and the underlying mechanism may be related to an increased oxidative stress and change in DDAH-ADMA system.

Summary Objective The aim of the present study was to evaluate whether the status of iodine nutrition influences the TSH concentration in a selected Chinese reference population according to the criteria proposed by National Academy of Clinical Biochemistry (NACB) and regular thyroid ultrasonography, to establish a new reference interval of TSH based on the wide variation of iodine nutrition in populations, and to identify an optimal interval of TSH by following up the cohort with normal TSH concentrations at baseline. Design The study was conducted in Panshan, Zhangwu and Huanghua, the regions with mildly deficient, more than adequate and excessive iodine intake, respectively. Of the 3761 unselected subjects who were enrolled at baseline, 2237 met the criteria for a reference population. Of 3048 subjects with normal serum TSH at baseline, 2727 (80·0%) participated in the 5-year follow-up study. TSH and thyroid autoantibodies in serum and iodine in urine were measured, and B-mode ultrasonography of the thyroid was performed. Results In the reference population, there was a urinary iodine-related increment of serum TSH levels (r = 0·21, P = 0·000), and the mean levels of TSH in Panshan, Zhangwu and Huanghua were 1·15, 1·28 and 1·93 mIU/l, respectively (P = 0·000), corresponding to the rising regional iodine intake. Based on the overall data, we obtained a reference interval of 0·3–4·8 mIU/l. TSH concentrations obtained in the follow-up study correlated well with those at baseline (r = 0·58, P = 0·000). A baseline serum TSH > 1·9 mIU/l was associated with an increased incidence of development of supranormal TSH and a baseline serum TSH

This study was to evaluate the usefulness of serum thymoglobulin (Tg) in adults to assess iodine status through a 5-year cohort study which was conducted in three regions with different levels of iodine intake: mild deficiency, more than adequate, and excess, from 1999 to 2004 in China. A total of 3099 subjects over 14 years old with normal serum levels of Tg in 1999 were eligible, of whom 2448 were followed in 2004. Serum levels of thyroid hormones and thyroid autoantibodies as well as urine iodine were measured, and B-mode ultrasonography of the thyroid was performed. A general linear model was performed to determine the determinant factors of serum Tg. Among subjects with mildly deficient iodine intake, those with more than adequate intake, and those with excessive intake, the baseline levels of serum Tg were substantially different (7.5μg/L, 5.9μg/L, and 6.8μg/L respectively, P

Background Iodine is an essential component of thyroid hormones; either low or high intake may lead to thyroid disease. We observed an increase in the prevalence of overt hypothyroidism, subclinical hypothyroidism, and autoimmune thyroiditis with increasing iodine intake in China in cohorts from three regions with different levels of iodine intake: mildly deficient (median urinary iodine excretion, 84 μg per liter), more than adequate (median, 243 μg per liter), and excessive (median, 651 μg per liter). Participants enrolled in a baseline study in 1999, and during the five-year follow-up through 2004, we examined the effect of regional differences in iodine intake on the incidence of thyroid disease. Methods Of the 3761 unselected subjects who were enrolled at baseline, 3018 (80.2 percent) participated in this follow-up study. Levels of thyroid hormones and thyroid autoantibodies in serum, and iodine in urine, were measured and B-mode ultrasonography of the thyroid was performed at baseline and follow-up. Results Among subjects with mildly deficient iodine intake, those with more than adequate intake, and those with excessive intake, the cumulative incidence of overt hypothyroidism was 0.2 percent, 0.5 percent, and 0.3 percent, respectively; that of subclinical hypothyroidism, 0.2 percent, 2.6 percent, and 2.9 percent, respectively; and that of autoimmune thyroiditis, 0.2 percent, 1.0 percent, and 1.3 percent, respectively. Among subjects with euthyroidism and antithyroid antibodies at baseline, the five-year incidence of elevated serum thyrotropin levels was greater among those with more than adequate or excessive iodine intake than among those with mildly deficient iodine intake. A baseline serum thyrotropin level of 1.0 to 1.9 mIU per liter was associated with the lowest subsequent incidence of abnormal thyroid function. Conclusions More than adequate or excessive iodine intake may lead to hypothyroidism and autoimmune thyroiditis.

Reports are increasingly appearing on the side effects caused by excessive iodine intake. Our objective was to find out whether iodine excess would impair the thyroid function and intelligence of schoolchildren in rural areas of China.A comparative epidemiological study was made on thyroid function and intelligence of the schoolchildren in the areas of low, moderate or excessive intake of iodine. In the area of low intake of iodine (Panshan, Liaoning province, median urinary iodine (MUI) was 99 microg/L), of moderate intake of iodine (Zhangwu, Liaoning Province, MUI was 338 microg/L) and of excessive intake of iodine (Huanghua, Hebei Province, MUI was 631 microg/L). The numbers of schoolchildren from each area selected to take part in a Chinese version of Raven's Test were 190, 236 and 313, respectively, and then 116, 110 and 112 of them were tested for thyroid function, thyroid autoantibody (TAA) and urinary iodine (UI).There were no significant differences in the incidences of overt hyperthyroidism, subclinical hyperthyroidism and overt hypothyroidism in Panshan, Zhangwu and Huanghua. But significant differences were found in the incidences of subclinical hypothyroidism (P = 0.001) in these three areas. The incidences of subclinical hypothyroidism in Huanghua and Zhangwu were 4.76 and 3.37 times higher than that in Panshan. TAA were negative in all the schoolchildren with subclinical hypothyroidism except for one. No significant difference was found among the rates of thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) in these three areas. Mean serum thyroglobulin (TG) value of Huanghua was markedly higher than those of the other two (P = 0.02). Mean serum TG value of Zhangwu was higher than that of Panshan but the difference was not significant. Mean IQ value of the schoolchildren in Huanghua was markedly higher than that for Zhangwu (P = 0.001). Mean IQ value of the schoolchildren in Panshan was lower than that of Huanghua and higher than that of Zhangwu but, again, the differences were not significant.The increase of iodine intake may increase the risk for schoolchildren of subclinical hypothyroidism. In the area of iodine excess, most of the subclinical hypothyroidism cases are not of autoimmune origin. No obvious effect of excess iodine was found on mental development of schoolchildren.

To assess the relationship between the biological exposure to iodine and hypothyroidism.Logistic regression model was used to analyze the risk factors of hypothyroidism, according to the epidemiologic data of 3761 adults in 3 kinds of rural communities: mild iodine deficiency area (4 natural villages in Panshan County, Liaoning Province), more than adequate iodine (7 natural villages of Zhangwu County, Liaoning Province), and excessive iodine area (2 natural villages of Huanghua City, Hebei Province).More than adequate iodine and excessive iodine were independent risk factors of subclinical hypothyroidism (OR = 3.172 and 6.391, P0.05) and overt hypothyroidism (OR = 3.696 and 9.213, P0.05). When interactions of iodine exposure and thyroid peroxidase antibody (TPOAb) or thyroglobulin antibody (TgAb) were included, more than adequate iodine was still a risk factor of subclinical hypothyroidism (OR = 2.788, P0.01), but had no such effect on overt hypothyroidism. Interaction of more than adequate iodine and positive TgAb significantly affected subclinical hypothyroidism and overt hypothyroidism (OR = 2.656 and 3.347, P0.05).More than adequate and excessive iodine exposure are independent risk factors of hypothyroidism. The risk of hypothyroidism grows up and thyroid dysfunction becomes more serious with the increasing of the biological exposure to iodine.

To investigate the relationship between selenium status and thyroid dysfunction in 3 areas with different iodine intake.An epidemiological research was performed in the rural communities of Panshan County (iodine-deficient area) and Zhangwu County (iodine-sufficient area), Liaoning Province, and Huanghua County, Hebei Province (iodine-excessive area). Serum selenium, TSH, FT3 and FT4 levels were examined in 329 patients with thyroid dysfunction (including clinical hypothyroidism, subclinical hypothyroidism, clinical hyperthyroidism and subclinical hyperthyroidism) and 183 normal inhabitants.The median serum selenium concentrations in Panshan, Zhangwu and Huanghua were 91.4, 89.1, and 83.2 microg/L respectively. There was no difference in serum selenium levels between the patients with subclinical hypothyroidism, clinical hypothyroidism, and clinical hyperthyroidism and their normal controls. The median serum selenium concentration of the subclinical hyperthyroidism patients was 82.6 microg/L, significantly lower than that of the normal controls (87.3 microg/L). The FT3/FT4 ratio was decreased, the FT4 level was increased in the subclinical hyperthyroidism patients in comparison with the normal controls, and no significant difference in FT3 level was found between them. No significant effect of sex and age was found on serum selenium level of normal inhabitants. In normal controls serum selenium was inversely correlated with serum TSH level, and the subjects with serum seleniumor = 80 microg/L had the median TSH level of 2.10 mU/L, markedly higher than that of the subjects with the serum selenium of 80-100 microg/L (1.29 mU/L) and that of the subjects with the serum selenium of 100 approximately 120 micro g/L (1.28 mU/L). For the thyroid dysfunction patients with positive thyroid auto-antibody (TPOAb) in Zhangwu County, the serum selenium was negatively associated with TPOAb level. The serum selenium level of the TPOAb highly positive group (TPOAb600 IU/ml) was 83.6 IU/ml, significantly lower than those of the TPOAb lowly positive group and TPOAb moderately positive group (83.6, 92.9 and 95.6 microg/L respectively).No obvious effect of selenium status is found on the development of thyroid dysfunction in these three areas. But selenium deficiency can impair thyroid function by means of disturbing thyroid hormone metabolism and decreasing antioxidant ability of the thyroid.

To investigate the correlation between serum thyroglobulin (Tg) and thyroid stimulating hormone (TSH) in populations with non-toxic goiter.Thyroid ultrasonography was conducted, and determination of serum triiodothyronine (FT3), thyroxin (FT4), Tg, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) and TSH, and urine iodine were carried out among 609 persons with an average age of 35.4 in Panshan county, a mild iodine-deficient area in Liaoning province, and 1136 persons aged 39.1 on average in Zhangwu county, an iodine sufficient area in Liaoning province, totally 2 320 persons.The serum TSH levels of the populations with diffuse and nodular goiter in Panshan county were (0.11 +/- 0.08) mU/L and (0.90 +/- 0.10) mU/L, significantly higher than those of the normal population in the same areas (1.33 +/- 0.04) mU/L, both P0.01. The serum TSH levels of the populations with diffuse and nodular goiter in Zhangwu county were (1.29 +/- 0.13) mU/L and (0.89 +/- 0.14) mU/L, significantly higher than those of the normal population in the same areas (1.74 +/- 0.04) mU/L, both P0.01. The serum TSH level of normal population in iodine deficient area was significantly lower than that of normal population in iodine sufficient area (P0.01). The serum TSH level of the normal population in Panshan County was significantly lower than that of the normal population in Zhangwu County (P0.01). The serum Tg level of the populations with diffuse and nodular goiter in Panshan county were (12.0 +/- 1.21) ng/L and (50.1 +/- 12.20) ng/L, significantly higher than that of the normal population in the same area (9.1 +/- 2.44) ng/L, P0.05 and P0.01. The serum Tg level of the populations with diffuse and nodular goiter in Zhangwu county were (12.4 +/- 2.11) ng/L and (61.2 +/- 11.86) ng/L, significantly higher than that of the normal population in the same area (7.7 +/- 2.3) ng/L, P0.05 and P0.01. The Tg level of the normal population in Panshan County was significantly higher than that of the normal population in Zhangwu county (P0.01). The Tg level was positively correlated with the thyroid volume in the nodular goiter population.The occurrence of goiter is not directly related to TSH stimulation in mild iodine deficient area. Nontoxic goiter shows a thyroid autonomic function. The major cause of high serum Tg in nodular goiter may be the leakage of Tg into blood circulation caused by degeneration of large colloid follicles and destruction of follicular architecture, not the volume increase of thyroid and its autonomic function.

To investigate the effects of several factors affecting serum thyroglobulin (TG) levels among people aged 14 or more.We selected Panshan with median urinary iodine (MUI) 83.45 micro g/L as a deficient iodine intake community, Zhangwu with MUI 242.85 micro g/L as a sufficient iodine intake community and Huanghua with MUI 650.87 micro g/L as an excessive iodine intake community. Serum TG and thyroid stimulating hormone (TSH) were measured in 3,335 subjects whose thyroglobulin antibody (TGAb) were negative and thyroid volume were examined using B-ultrasound.In the population with MUI of 80 - 650 micro g/L, serum TG levels presented a "V" curve. An elevated serum TG was found in both the communities with deficient iodine intake and excessive iodine intake. The same trend was shown in the groups with different levels of serum TSH. An elevated serum TG was found in both the groups of TSH0.3 mU/L and TSH4.8 mU/L. The serum TG levels was positively correlated with thyroid volume and was higher in female subjects than in male. An increased serum TG was found in subjects of aged 50 in the community with deficient iodine intake.Serum TG level is affected by gender, amount of iodine intake, serum TSH level and thyroid volume.