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Objective To investigate the changes and related factors of maternal thyroid autoantibodies during early pregnancy. Methods Urinary iodine concentration( UIC) , serum thyroid stimulating hormone( TSH) , free thyroxine ( FT4 ) , thyroid-peroxidase antibody ( TPOAb ) , thyroglobulin antibody ( TgAb ) concentrations were determined in 7 190 women during early pregnancy in an iodine-sufficient region of China. Results The prevalence of TPOAb positivity and TgAb positivity were 8. 7% and 12. 0% respectively. The prevalence of overt hypothyroidism and subclinical hypothyroidism increased significantly in group of thyroid antibody positivity. The prevalence of TPOAb positivity and TgAb positivity presented a U-shaped curve, ranging from mild iodine deficiency to iodine excess, especially increased significantly in the group with UIC<100 μg/L. Conclusion Prevalence of thyroid antibodies positivity became higher during early pregnancy. The positive thyroid autoantibodies during pregnancy were significantly associated with maternal hypothyroidism. Both iodine excess and iodine deficiency are risk factors of positive thyroid antibodies.
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A total of 1151 subjects were enrolled in this study.Metabolic syndrome (MS) was diagnosed according to the International Diabetes Federation (IDF) criteria.Significant differences in waist circumference,body mass index(BMI),diastolic blood pressure(DBP),systolic blood pressure(SBP),fat mass,Fat％ in different serum TSH levels were found.There were positive relation between fasting plasma glucose,DBP,SBP,and serum FT4 levels,between high density lipoprotein-cholesterol,DBP,SBP,waist circumference,fat mass,Fat％,and serum FT3 levels,even after adjustment for age and sex.Serum FT3 and FT4 levels were higher in the MS group than those in the control group.
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Thyroid hormone analogues belong to a novel class of agents,which exert thyromimetic actions by selectively binding to thyroid hormone receptors,especially in the aspects of lipid lowering and calorigenesis.This review focuses on the research and application of selective thyroid hormone analogues in animal experiments and clinical trials.
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Objective To investigate the effect of treatment with levothyroxine in early maternal subclinical hypothyroidism (SCH) on the neural development of the progeny. Methods 75 thyroidectomized female Wistar rats were divided randomly into groups of hypothyroidism (CH), SCH, SCH treated with levothyroxine at embryonic day 10 (E10), E13, and E17. There were 15 sham operated controls. Body weight,thyroid function, and the development of progeny by morris water maze, immunohistochemistry, and Nissl's staining of progeny were made. Results Pups from SCH or CH group had significantly lower body weight than euthyroid group ( P＜0. 05 ). Pups from E10, E13 or E17 groups had normal body weight compared to pups of control (P＞0.05). The levels of TSH and total T4( TT4 ) of all pups were normal. The mean latencies were longer in pups from CH, SCH, and E17 group than the control (P＜0.05). The mean escape latencies did not differ between the control and E10 group pups and between the control and E13 pups (P＞0.05). There were changes in the cytoarchitecture of the barrel cortex and of the hippocampus ( toluidine blue-stained sections) in CH, SCH, and E17 pups. The barrel cortex of E10 or E13 pups was similar to that of control pups. The distribution of BrdUlabeled cells was more widespread in CH, SCH, and E17 pups than in control, E10, and E13 progeny.Conclusion Maternal SCH disturbs learning and memory performances, cytoarchitecture and cell migration of the pups. Treatment with levothyroxine in early maternal SCH before E13 improves the cell migration in the developing brain of the progeny.
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Objective To determine the factors that influence the development of abnormal thyrotropin (TSH) level in an euthyroid population.Methods We conducted a follow-up study in 3 communities with different iodine status.Of the 3403 euthyroid subjects at baseline screened in 1999,80.1% ( n = 2727 ) was visited and sampled in 2004 for measuring TSH,thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb).Results Iodine status in the 3 communities were stable.Decreased TSH level( <0.3 mU/L) developed in 2.5% (n =68) of sampled subjects,while raised TSH level( > 4.8 mU/L) in 2.4% (n = 64).A logistic analysis showed that risk factors for developing decreased TSH level included positive conversion of TPOAb (OR = 5.5 ),positive TPOAb both in 1999 and in 2004 ( OR = 4.0),positive TgAb in 2004 ( OR = 3.7) and TSH < 1.0 mU/L in 1999 ( OR = 2.6).Risk factors involved in developing raised TSH level included iodine status of Zhangwu community ( OR = 4.1 ),iodine status of Huanghua community ( OR = 3.9),positive TgAb in 2004 ( OR = 3.7 ),positive TPOAb both in 1999 and 2004 (OR =3.6),positive conversion of TPOAb (OR =2.7) and TSH > 1.9 mU/L in 1999 (OR = 2.6 ).Conclusions Exposure to long-term iodine excess imposes danger of developing hypothyroidism.The risk will be even higher when exposing to iodine adequacy after correction of iodine deficiency.An interval between 1.0 and 1.9 mU/L of TSH level was optimul with the least probability of developing abnormal TSH level.
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Objective To clarify the effect of iodine intake on serum thyroglobulin (Tg). Methods A 5-year prospective study was conducted in the 3 different iodine intake areas in China [Panshan (miht deficiency) ,Zhangwu (more than adequate) and Huanghua (excess)]. A total of 3 099 people with normal serum levels of Tg in 1999 were followed and 2 448 of these participants were feasible to be observed in 2004 and included in the present study. The serum levels of Tg, thyraglobulin antibody(TgAb), thyroid peroxidase antibody(TPOAb) and TSH, thyroid volume, family and personal histories of thyroid diseases were measured and inquried. The general linear model (GLM) was used to explore the determinants of Tg. Results Among the study population at baseline, serum Tg were significantly different in three areas [7.5 (4.4-13. 1) μg/L at Panshan, 6.8 (3.6-11.2)μg/L at Huanghua, 5.9 (3.2-10.7) μg/L at Zhangwu, P<0.01]. They were associated with age, sex and the rate of positive TgAb, abnormal thyroid volume, abnormal TSH and positive personal history of thyroid diseases, in order to control the effects of confounding factors, the data from 1856 subjects with thyroid-related indexes all in normal range and without personal history of thyroid diseases were analyzed to clarify the effect of iodine intake on Tg. The serum Tg among three areas were significantly different in both 1999 and 2004, they were all increased in 5 years with significant augment (△ Tg) among the three areas[3.1 (-0.2-8.0) μg/L at Panshan, 3.5 (0.5-9.0)μg/L at Huanghua vs 2. 5(0.3-6.1) μg/L at Zhangwu,P<0.01]. The GLM analysis revealed that age, Tg and TSH levels at baseline were the determinants of △Tg in addition to iodine intake. Conclusion Iodine intake is a dominant determinant of serum Tg. Age and TSH should also be considered while indicating iodine intake by serum Tg.
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Objective To investigate the epidemiological characteristics of non-toxic goiter and non-toxic thyroid nodules in the regions with different iodine intakes and the factors influencing the occurrence, development and outcome of goiter and thyroid nodules. Methods 3 385 subjects, who had taken part in the previous survey in 1999 with the ultrasonic examination of thyroid, were composed of individuals in Panshan with chronic mild iodine deficiency,in Zhangwu with more than adequate iodine "after iodine supplementation and in Huanghua with excessive iodine. These 3 groups of subjects were followed up in 2004. Results (1) The cumulative incidences of diffuse goiter in Panshan ,Zhangwu and Huanghua were 7.1% ,4.4% and 6.9% ,respectively ,being the lowest in Zhangwu (P<0.01) and those of nodular goiter were 5.0% ,2. 4% and 0.8%, respectively, being the highest in Panshan (P<0.01). (2) The incidences of single nodule were 4.0% ,5.7% and 5.6%, respectively, and those of multiple nodules 0.4%, 1.2% and 1.0%, respectively. (3)The result of logistic analysis showed that iodine deficiency,iodine excess and positive thyroid autoantibodies (TAA) were the independent risk factors for the occurrence of goiter. (4)In Zhangwu ,the incidence of non-toxic goiter in the group with positive TAA was higher than that in the group with negative TAA(P<0.01) ,while there were no such differences in Panshan and Huanghua. (5)In these three regions, the rates of positive TAA in the individuals with diffuse non-toxic goiter were higher than those in the healthy subjects (P<0.05). And in Huanghua,the rate of positive TAA in subjects with non-toxic nodular goiter was also higher than that in the healthy individuals (P<0.05). Conclusion Iodine deficiency and iodine excess may both induce the raising incidence of goiter. Nodular goiter is prevalent in iodine deficient district and diffuse goiter is the predominant form in places with iodine excess. Thyroid autoimmunity is associated with occurrence and maintenance of goiter, and this phenomenon is more obvious in the community with previous iodine deficiency followed then by treatment with more than adequate iodine.
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Objective To explore the trend of Th_1/Th_2 bias in Hashimoto thyroiditis(HT)and their effects on the pathogenesis of HT.Methods The proportion and mean fluorescence intensity(MFI)of CCR5 and CD30 were examined on peripheral T lymphocytes by flow cytometry in patients with Hashimoto thyroiditis(HT)(n=21)and healthy controls(n=45).Results The proportion of both CD4~+CCR5~+and CD~+4 CD30~+ cells were significantly increased in HT group(P
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Objective To analyze the relationship between different iodine intakes and epidemiological features of hyperthyroidism in 3 communities with different iodine intake levels,as well as to explore the risk factor for the pathogenesis of hyperthyroidism.Methods A cohort study was performed in 3 Chinese rural communities with long-term stable iodine nutrition status defined as mild deficient (Panshan),more than adequate (Zhangwu, previously mild iodine deficiency and salt iodization lasting 8 years until 2004) and excessive (Huanghua).A total of 3 761 (934 males,2 827 females) inhabitants aged above 13 participated in the original investigation in 1999 and 3 018(709 males,2 309 females) of them received identical examinations after 5 years.Results Median urinary iodine concentration of school-aged children was 87.61zg/L in Panshan,213.9?g/L in Zhangwu and 633.5?/L in Huanghua (P＜0.05) at fallowing up,and no statistic significance was found when comparing the corresponding data from original survey (83.5?g/L,242.9?g/L and 650.9?g/L).The accumulative incidence of hyperthyroidism was 13.6/1 000,9.4/1 000 and 8.1/1 000 (P＞0.05),being 16.4/1 000,11.2/1 000 and 9.1/1 000 (P＞0.05) in female,respectively in Panshan,Zhangwu and Huanghua.In original healthy subjects (without history of thyroid disease and overt thyroid dysfunction) merely with either positive thyroid peroxidase antibody (TPOAb＞50 IU/ml) or thyroglobulin antibody (TgAb＞40 IU/ml),the accumulative incidence of newly diagnosed hyperthyroidism was not significantly different among 3 communities in follow-up survey.TSH＜0.3 mIU/L,positive TPOAb or goiter in original healthy participants were associated with the occurrence of overt hyperthyroidism in 5 years [ Logistic Regression,OR = 5.7 (95% CI 2.1-15 ),OR = 3.8 (95% CI 1.7-8.7 ) and OR = 3.1 (95% CI 1.4-6.8) respectively].Conclusion Iodine supplementation in mild iodine deficient area does not increase the incidence of overt hyperthyroidism ultimately.Long-term excessive iodine intake does not affect the incidence and pattern of hyperthyroidism.TSH＜0.3 mIU/L,positive TPOAb and goiter in healthy individuals are the risk factors for hyperthyroidism.