Large differences in incidences of overt hyper- and hypothyroidism associated with a small difference in iodine intake: a prospective comparative register-based population survey

Around 3-4 billion people in the world are covered by iodine supplementation programs to prevent developmental brain damage and other iodine deficiency (ID) disorders. Mild ID is associated with more hyperthyroidism and less hypothyroidism in the population than a high iodine intake. Knowledge of the iodine intake levels where the shifts in incidences occur is important for planning of iodine supplementation programs. A computer-based register linked to thyroid diagnostic laboratories was used to continuously identify all new cases of overt hyper- and hypothyroidism in two population cohorts with moderate and mild ID, respectively (Aalborg, n = 310,124; urinary iodine, 45 micro g/liter; and Copenhagen, n = 225,707; urinary iodine, 61 micro g/liter). The investigation was initiated before iodization of salt in Denmark and was part of the monitoring program. In 1997-1998, the incidence rate of overt hyperthyroidism was high in the area with the lowest iodine intake (92.9/100,000 per year) compared with the area with only mild ID (65.4/100,000 per year). Standardized rate ratio was 1.49, and 95% confidence interval was 1.22-1.81. The opposite relationship was present for overt hypothyroidism (moderate ID, 26.5/100,000 per year; mild ID, 40.1/100,000 per year; standardized rate ratio, 0.73; 95% confidence interval, 0.55-0.97). The different incidence rates were confirmed during each of the two following years. The results of this prospective investigation of the incidence of overt hyper- and hypothyroidism suggest that iodine supplementation of a population may increase the incidence of overt hypothyroidism, even if the population is moderately iodine-deficient. In such a population, the increase in risk of hypothyroidism should be weighed against the risk of ID disorders such as hyperthyroidism due to multinodular toxic goiter. The optimal level of iodine intake to prevent thyroid disease may be a relatively narrow range around the recommended daily iodine intake of 150 micro g.     

河北某水源性高碘地区成人甲状腺疾病的流行病学调查

目的：调查水源性高碘地区－河北省黄骅市歧口村、高头村≥14岁人群甲状腺疾病的流行状况,方法：入户问卷调查4230人的基础上,采样调查1074人,所有采样调查对象均详细填与甲状腺疾病调查表,接受体检查和B超检查,测定血清促甲状腺激素（TSH）、甲状腺自身抗体（TAA）和甲状腺球蛋白（TG）,留取空腹尿样测量尿碘、TSH异常者测定甲状腺激素和TSH受体抗体（TRAb）。结果：采样人群的尿碘中位数为614．61μg/L。临床甲状腺功能亢进症（甲亢）和亚临床甲亢的患病率分别为1．21％和1．12％;临床甲亢中92．3％为Graves病所致,亚临床甲亢中75％TRAb阳性;回顾性分析普遍食盐碘化前后临床甲亢平均年发病率差异无显著性,临床甲状腺功能减低症（甲减）和亚临床甲减的患病率分别为1．96％和6．05％,患者TAA阳性率分别为85．71％和29．23％。采样人群甲状腺过氧化物酶抗体（TPOAb）和甲状腺球蛋白抗体（TGAb）阳性率分别为11．6％和9．3％。弥漫性甲状腺肿,结节性甲状腺肿、单发结节和多发结节的患病率分别为3．26％、2．61％、1．77％和6．4％。甲状腺癌病率为91．58／10万,结论：在尿磺中位数为614．61μg/L的碘营养状态下,甲状腺功能减退症和甲状腺癌患病率显著增高,提示这一碘摄入量并不安全。     

The prevalence of thyroid dysfunction in a population with borderline iodine deficiency

OBJECTIVE: We lack information on the influence of borderline iodine deficiency on the occurrence of thyroid dysfunction. Iodine deficiency has been reported to facilitate the development of toxic nodular goitre, whereas a high iodine intake may increase the prevalence of autoimmune hypothyroidism. SUBJECTS AND METHODS: In a cross-sectional study of a random sample of the general population in our region with borderline iodine deficiency 2656 (65%) of 4073 men and women aged 41 to 71 years participated. Records were made of previous thyroidal illness. Blood samples were drawn for thyroid parameters and TPO Ab values. Iodine and creatinine was assessed in casual urine samples. RESULTS: Previous or present hyperthyroidism was reported by 1.4% of the participants whereas 0.6% had unknown biochemical hyperthyroidism. All cases of undiagnosed hyperthyroidism were among women. Previously diagnosed and treated hypothyroidism was reported by 1.0% and undiagnosed hypothyroidism was found in 0.4%. Subclinical hyperthyroidism was found in 1.3% and subclinical hypothyroidism in 0.7%. TPO Ab titres >200 kU/l were found in 16.9% of the women and 6.6% of the men, and 83% of participants with TSH >5 mU/l had TPO Ab titres >200 kU/l. Participants with TPO Ab titres between 100 and 200 kU/l had no increased frequency of thyroid dysfunction. The median iodine excretion rate was estimated as 103 microg/day. Serum TSH values were higher in women than in men and showed higher dispersion in women as well as in old age. Serum free T3 was found to be higher in women than in men and increased with age. Serum free T4 showed no sex difference but values increased with increasing age. CONCLUSION: In our region with borderline iodine deficiency more than 5% of the general population has clinical or subclinical thyroid dysfunction. We found a relatively high prevalence of hyperthyroidism, especially previously undiagnosed disease, but a low prevalence of hypothyroidism as would be expected in an area of iodine deficiency. Hypothyroidism was related to TPO Ab titres of >200 kU/l. Thyroid hormone levels varied with age and sex.     

Epidemiological survey on the relationship between different iodine intakes and the prevalence of hyperthyroidism

OBJECTIVE: To investigate the effect of different levels of iodine intake on the prevalence of hyperthyroidism and the impact of universal salt iodization on the incidence of hyperthyroidism. DESIGN: A comparative cross-sectional and longitudinal survey was conducted in three areas with borderline iodine deficiency, mild iodine excess (previously mild iodine deficiency) and severe iodine excess. Universal salt iodization had been introduced 3 years previously except in the area with borderline iodine deficiency. METHODS: In total 16 287 inhabitants from three areas answered a questionnaire concerning the history of thyroid disease. Among them 3761 unselected subjects received further investigations including thyroid function, thyroid autoantibodies, thyroid ultrasonography and urinary iodine excretion. RESULTS: Among areas with median urinary iodine excretion of 103 microg/l, 375 microg/l and 615 microg/l (P<0.05), the prevalence of hyperthyroidism did not differ significantly (1.6%, 2% and 1.2%). The prevalence of subclinical hyperthyroidism was higher in areas with borderline iodine deficiency and mild iodine excess than in the area with severe excess iodine intake (3.7%, 3.9% and 1.1%, P<0.001). The prevalence of Graves' disease and its proportion in hyperthyroidism did not differ among areas. The incidence of hyperthyroidism did not significantly increase after the introduction of universal salt iodization. CONCLUSION: Different iodine intakes under a certain range do not affect the prevalence and type of hyperthyroidism. Subclinical hyperthyroidism is more prevalent in the iodine deficient area than in the severe iodine excessive area. In the area with mild iodine deficiency, the introduction of universal salt iodization may not be accompanied by an increased incidence of hyperthyroidism.     

海岛居民甲状腺疾病和碘营养状况的关系

目的 调查舟山海岛地区居民甲状腺疾病和碘营养状况,分析二者的相互关系.方法 通过整群随机抽样的方法选取了3284名舟山成年居民进行了尿碘检测,并进行流行病学问卷调查、甲状腺B超检查、甲状腺功能测定.结果 舟山海岛地区成年居民尿碘中位数为226.0μg/L,其中城镇居民320.7 μg/L、盐民122.2 μg/L、农民188.9 μg/L、渔民193.6 μg/L、僧侣271.7 μg/L.舟山地区3284名居民弥漫性甲状腺肿、结节性甲状腺肿、胶质性甲状腺肿、甲状腺腺瘤、甲状腺癌、甲状腺功能亢进(甲亢)、亚临床甲亢、甲状腺功能减退(甲减)、亚临床甲减的患病率分别为1.7%、25.3%、8.7%、0.2%、0.4%、0.5%、0.8%、0.03%和1.0%,甲状腺过氧化物酶抗体(TPOAb)阳性率为9.5%.甲状腺疾病患病率女性明显高于男性(P＜0.05),且随年龄的增长而增高(P＜0.05).经logistic回归模型分析甲状腺疾病患病率与年收入、食用海产品、吸烟史、饮酒史、饮茶史、尿碘值等均无明显相关性(P＞0.05).结论 舟山地区居民碘摄入充足,是否实施全民食盐加碘值得商榷;舟山海岛地区甲状腺疾病的患病率较高可能与碘过量有关.

Abstract：

Objective To investigate iodine nutrition and thyroid health status among residents in Zhoushan archipelago, and to analyse their relationship.Methods A total of 3 284 residents in Zhoushan archipelago were surveyed by questionnaire and their thyroids were examined by B-mode ultrasound.The levels of urinary iodine and thyroid function were detected.Results The median level of urinary iodine in 3 284 residents was 226.0 μg/L, being 320.7 μg/L in citizens, 188.9 μg/L in farmers, 122.2 μg/L in salt-makers, 193.6 μg/L in fishers, and 271.7 μg/L in buddhist.The prevalence of diffuse goiter, nodular goiter, colloid goiter, thyroid adenoma, thyroid carcinoma, hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, and positve rate of TPOAb were 1.7% ,25.3% ,8.7% ,0.2% ,0.4% ,0.5% ,0.8% ,0.03%,1.0% ,and 9.5% repectively.The prevalence of thyroid diseases was increasing with aging, and higher in women than in men (P＜0.05).There was no significant relationship of the thyroid diseases with seafood, smoking,drinking, and tea (P＞0.05).Conclusions The citizens of Zhoushan archipelago have adequate iodine intake.It is pertinent to discuss Universal Salt Iodization.Excessive iodine intake may contribute to the high prevalence rate of thyroid diseases in Zhoushan.     

Thyroid Dysfunction during Late Gestation Is Associated with Excessive Iodine Intake in Pregnant Women

Context: Adequate iodine intake during pregnancy is essential for both the synthesis of maternal thyroid hormones and the maintenance of normal fetal brain development. Scant evidence is available on the effects of excessive iodine intake during pregnancy. Objective: The study assesses the relationship between iodine nutritional status and thyroid function of pregnant women with excessive iodine intake during late gestation. Design and Participants: A cross-sectional study of 384 pregnant women was carried out in Tianjin and Haixing from April to October in 2010. Main Outcome Measures: Morning urine samples and blood samples were obtained from all subjects. Serum levels of free T(3), free T(4), and sensitive TSH and urinary iodine concentration were measured. Results: The median urinary iodine concentration of pregnant women with excessive iodine intake was significantly higher than those with adequate iodine intake (P < 0.001). The prevalence of thyroid disease, especially subclinical hypothyroidism, in pregnant women with excessive iodine intake was significantly higher than in those with adequate iodine intake (P < 0.05). Subclinical hypothyroidism was the most frequent pattern of thyroid disease for pregnant women and those with positive or negative thyroid autoantibodies. Living with high water iodine content and having urinary iodine concentration higher than 250 μg/liter are associated risk factors for subclinical hypothyroidism in pregnant women (OR(1) = 41.822, OR(2) = 6.202; P < 0.05, where OR(1) is the odds ratio for living with high water iodine content and hypothyroidism and OR(2) is the odds ratio for urinary iodine concentration >250 μg/liter and hypothyroidism). Conclusions: Excessive iodine intake during late pregnancy may lead to maternal thyroid dysfunction, particularly subclinical hypothyroidism. The appropriate measurements should be performed to monitor the onset of hypothyroidism in pregnant women with excessive iodine intake.     

The thyroid epidemiology, audit, and research study: thyroid dysfunction in the general population

The objective of this study was to define the level of treated thyroid dysfunction in a complete and representative population base in an area of sufficient dietary iodine intake. We used record-linkage technology to retrospectively identify subjects treated for hyperthyroidism or hypothyroidism in the general population of Tayside, Scotland from 1 January 1993 to 30 April 1997. Thyroid status was ascertained by record linkage of patient-level datasets containing details of treatments for hyperthyroidism and hypothyroidism.We identified 620 incident cases of hyperthyroidism, an incidence rate of 0.77/1000 x yr [95% confidence interval (CI), 0.70-0.84] in females and 0.14/1000 x yr (95% CI, 0.12-0.18) in males. There were 3,486 incident cases of diagnosed primary hypothyroidism, an incidence rate of 4.98/1000 x yr (95% CI, 4.81-5.17) in females and 0.88/1000 x yr (95% CI, 0.80-0.96) in males. For both hyperthyroidism and hypothyroidism, the incidence increased with age, and females were affected two to eight times more than males across the age range. The midyear point prevalence of all-cause hypothyroidism rose from 2.2% in 1993 to 3.0% in 1996.The level of thyroid dysfunction in Tayside, Scotland is higher than previously reported, and it increased from 1993 to 1996.     

Epidemiology of subtypes of hypothyroidism in Denmark

OBJECTIVE: Studies of hypothyroidism are often based on referred patients, and limited information is available on the incidence rates of subtypes of hypothyroidism in the general population. We therefore studied incidences of subtypes of primary, overt hypothyroidism in a Danish population cohort and compared incidences in two subcohorts with different levels of iodine intake. DESIGN: A prospective population-based study, monitoring a well-defined cohort representative of the Danish population. METHODS: The Danish Investigation of Iodine Intake and Thyroid Diseases registry of hyper- and hypothyroidism was established as part of the monitoring of the iodine fortification of salt in Denmark. A computer-based system linked to laboratory databases identified all patients diagnosed with new, biochemically overt hypothyroidism in populations living in Aalborg (moderate iodine deficiency, n = 311,102) and Copenhagen (mild iodine deficiency, n = 227,632). We subsequently evaluated all identified patients to verify incident thyroid disease, and subclassified hypothyroidism into nosological types. RESULTS: During a 4-year period (2,027,208 person-years) 685 new cases of overt hypothyroidism were diagnosed in the cohort; the incidence rate was 32.8 per 100,000 person-years (standardised to the Danish population). Nosological types of hypothyroidism were: spontaneous (presumably autoimmune) 84.4%, post-partum 4.7%, amiodarone-associated 4.0%, subacute thyroiditis 1.8%, previous radiation or surgery 1.8%, congenital 1.6% and lithium-associated 1.6%. Crude incidence rates were 29.0 around Aalborg and 40.6 in an area of Copenhagen. The higher incidence rate of hypothyroidism in the area with higher iodine intake was caused solely by more cases of spontaneous (presumably autoimmune) hypothyroidism, whereas the incidence of non-spontaneous hypothyroidism (all types combined) was significantly lower in the area with higher iodine intake. CONCLUSION: In a population-based study we observed a higher incidence of hypothyroidism with higher iodine intake. This was due solely to the entity of spontaneous hypothyroidism. The occurrence of overt hypothyroidism was relatively low in Denmark.     

The Danish investigation on iodine intake and thyroid disease, DanThyr: status and perspectives

OBJECTIVE: Denmark was an area of iodine deficiency, and mandatory iodine fortification of table salt and salt in bread (13 p.p.m. iodine) was initiated in 2000/2001. The Danish investigation on iodine intake and thyroid disease (DanThyr) is the monitoring of the iodine fortification program. DESIGN AND METHODS: DanThyr consists of three main parts: a study of population cohorts initialized before (n=4649) and after (n=3570) iodization of salt, a prospective identification of incident cases of overt hyper- and hypothyroidism in a population of around 550,000 people since 1997, and compilation of data from the national registers on the use of thyroid medication, thyroid surgery, and radioiodine therapy. Studies were carried-out in parallel in subcohorts living in areas with differences in iodine content of ground water. RESULTS: The study showed profound effects of even small differences in iodine intake level on the prevalence of goiter, nodules, and thyroid dysfunction. Mild and moderate iodine deficiency was associated with a decrease in serum TSH with age. Other environmental factors were also important for goiter development (increase in risk, smoking and pregnancy; decrease in risk, oral contraception and alcohol consumption), and the individual risk depended on the genetic background. Environmental factors had only a minor influence on the prevalence of thyroid autoantibodies in the population. There were more cases of overt hypothyroidism in mild than in moderate iodine deficiency caused by a 53% higher incidence of spontaneous (presumably autoimmune) hypothyroidism. On the other hand, there were 49% more cases of overt hyperthyroidism in the area with moderate iodine deficiency. The cautious iodine fortification program, aiming at an average increase in iodine intake of 50 mug/day has been associated with a 50% increase in incidence of hyperthyroidism in the area with the most severe iodine deficiency. The incidence is expected to decrease in the future, but there may be more cases of Graves' hyperthyroidism in young people. CONCLUSION: A number of environmental factors influence the epidemiology of thyroid disorders, and even relatively small abnormalities and differences in the level of iodine intake of a population have profound effects on the occurrence of thyroid abnormalities. Monitoring and adjustment of iodine intake in the population is an important part of preventive medicine.     

轻度碘缺乏城市食盐加碘后甲状腺疾病流行病学调查研究

 目的 评价轻度碘缺乏城市贵阳食盐加碘25年后的碘营养状态及各种甲状腺疾病的患病情况。
方法 采用分层整群抽样方法,抽取贵阳市云岩区宅吉社区20岁及以上居民1509人,测定其血清促甲状腺素（TSH）、游离T₃、游离T₄、甲状腺过氧化物酶抗体（TPOAb）、甲状腺球蛋白抗体（TgAb）水平、尿碘水平及甲状腺B超检查;同时抽取8~10岁学龄儿童80名,测定其尿碘水平。
结果 8~10岁儿童尿碘中位数为228.7 μg/L。成人临床甲状腺功能减退症（甲减）、亚临床甲减、临床甲状腺功能亢进症（甲亢）及亚临床甲亢的患病率分别为1.79%、14.12%、1.52%及1.06%,亚临床甲减的患病率显著高于临床甲减（P < 0.05）;TPOAb及TgAb的阳性率分别为14.38%及 13.59%,自身免疫性甲状腺炎的患病率为4.44%。甲状腺肿大患病率为1.06%,其中,弥漫性甲状腺肿（0.86%）较结节性甲状腺肿（0.20%）多见（P < 0.05）。
结论 食盐加碘25年后,贵阳市处于碘超足量状态,成人临床甲减、亚临床甲减、甲状腺自身抗体阳性及自身免疫性甲状腺炎的患病率均较高。     

115例亚临床甲状腺功能亢进症的流行病学研究

对3个不同碘摄入量地区流行病学调查中发现115例亚临床甲状腺功能亢进症(甲亢)，其发病率为高碘地区低于低碘和适碘地区，与自身免疫有关，但在随访的1～2年中未发现碘摄入量对亚临床甲亢的转归有影响。     

Screening for thyroid diseases in an iodine sufficient area with sensitive thyrotrophin assays, and serum thyroid autoantibody and urinary iodide determinations

OBJECTIVE The present study was designed to investigate the prevalence of thyroid dysfunction and Its relation to thyroid autoantibodies and urine iodide concentration in apparently healthy people residing in Sapporo, a city of northern Japan, where the iodine intake is high. DESIGN AND SUBJECTS Serum TSH and thyroid autoantibodies, and urine iodide were measured in 4110 people (2931 men and 1179 women) (age 456 ± 103 years (mean ± SD)) who were recruited at the hospital for medical examinations. RESULTS The thyroid autoantibodies were positive in 6.4% of males and 13.8% of females with an age-related increase. Of the people with positive antibodies, 87.2% had normal TSH values (0.15–5.0 mU/l) as measured by a sensitive assay. The prevalence of unsuspected hyperthyroidism as defined by suppressed TSH values was 0.61%, of which 64% was diagnosed as Graves' disease based on positive thyrotrophin receptor antibody results. The prevalence of unsuspected hypothyroidism, as evidenced by supranormal TSH, was 0.68% for males and 3.13% for females with an age-related increase. Of those with hypothyroidism, 45.5% were autoantibody positive. The overall prevalence of Hashimoto's thyroiditis was 13.11% for females and 6.15% for males. The urine iodide levels of hypothyroidism with a positive autoantibody of 38.5 (17.7–83.9)μmol/l and a negative autoantibody of 34.9 (17.9–67.9) μmol/l were both significantly higher than that of normal subjects (26.9 (14.6–49.6) μmol/l) (P <0.01). When iodine intake was restricted for 6–8 weeks for hypothyroid subjects, the elevated TSH and thyroglobulin and low free T4 levels were reversed in the autoantibody negative but not in the positive group. CONCLUSIONS This study provides further information on the prevalence of thyroid dysfunction and autoimmune thyroid diseases in an iodine sufficient area. In addition, it suggests that more than half of the patients with unsuspected hypothyroidism were negative for autoantibodies and that the excessive iodine intake may be involved in causing latent hypothyroidism.     

高碘地区妊娠晚期妇女与育龄妇女甲状腺功能的比较

探讨妊娠和高碘对妇女甲状腺功能及甲状腺自身免疫功能的影响.选择高碘地区(27.69±4.73)岁孕妇210例和(30.62±6.01)岁育龄妇女290例;采集空腹晨尿及静脉血,砷-铈催化分光光度法测定尿碘浓度,化学发光法测定血清游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)及灵敏促甲状腺激素(sTSH),放射免疫法测定血清甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TGAb).孕妇和育龄妇女尿碘中位数分别为1 240.70μg/L和949.21μg/L,有94.3%的孕妇和81.0%的育龄妇女碘过量.孕妇和育龄妇女甲状腺疾病总患病率为22.9%和30.3%,孕妇甲状腺功能亢进症(甲亢)、亚临床甲亢、甲状腺功能减退症(甲减)、亚临床甲减的患病率分别为0.5%、1.9%、0.5%和20.0%.育龄妇女的甲亢、亚临床甲亢、甲减及亚临床甲减的患病率分别为2.8%、0.3%、0.3%和26.9%.孕妇的FT3、FT4水平低于育龄妇女[(4.03±0.59对4.71±1.04)pmol/L,(13.35±1.59对14.27±3.63)pmol/L,均P＜0.01],TGAb阳性率低于育龄妇女(7.1%对14.1%,P=0.014).高碘地区妇女甲状腺疾病患病率及甲状腺自身抗体阳性率较高,妊娠使孕妇甲状腺激素水平及TGAb阳性率较育龄妇女降低,建议育龄妇女及孕妇控制碘摄入,并加强甲状腺功能和甲状腺自身抗体的监测.

Abstract：

To explore the influences of pregnancy and iodine intake on thyroid function and immune functions, 210 pregnant women and 290 fertile women were chosen from iodine excess area, and the average ages of them were (27. 69±4. 73 )and (30. 62±6. 01 )years respectively. Fasting blood and urine were collected in the morning. The urinary iodine level was determined by arsenic-cerium catalytic contact. Serum free triiodothyronine ( FT3 ), free thyroxine ( FT4 ), and sensitive thyroid-stimulating hormone ( sTSH ) levels were measured by chemiluminescence.Thyroid peroxidase antibody (TPOAb)and thyroglobulin antibody (TGAb)were measured by radioimmunoassay. The median urinary iodine in the pregnant and fertile women were I 240. 70 and 949. 21 μg/L, respectively. There were 84. 3% pregnant women and 81.0% fertile women admitting excess iodine intake. The prevalence of overall thyroid diseases was 22. 9% in the pregnant women and 30. 3% in the fertile women. The prevalence of hyperthyroidism,subclinical hyperthyroidism, hypothyroidism, and subclinical hypothyroidism was0. 5%, 1.9%, 0. 5%, and 20. 0% in the former group, and 2. 8%, 0. 3%, 0. 3%, and 26. 9% in the latter. Both FT3 and FT4 levels of the pregnant women were lower than those of fertile women [(4. 03±0. 59 vs 4. 71 ± 1.04)pmol/L, ( 13. 35 ± 1.59 vs 14. 27 ±3.63 )pmol/L,both P＜0. 01], and the positive rate of TGAb of pregnant women was also lower than that of fertile women (7. 1% vs14. 1%, P=0. 014). The prevalence of thyroid diseases and positive rate of thyroid autoantibodies is high in women with excess iodine intake. Compared with fertile women, pregnancy may lead to decreas~s in level of thyroid hormones and positive rate of TGAb. Their iodine intake should be controlled, and the thyroid function and autoimmunity antibodies should be monitored.     

93例亚临床甲状腺功能减退症的随访研究

目的 研究不同碘摄入量地区亚临床甲状腺功能减退症(甲减)的流行病学特点和影响转归的因素。方法 选择盘山、彰武和黄骅3个农村社区(分别为低碘、适碘和高碘地区)，在入户调查的基础上行采样调查。测定血清TSH、甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TGAb)、尿碘浓度及进行甲状腺B超检查，TSH异常者测定FT3、FT4，筛选出118例亚临床甲减患者。盘山和彰武社区于2年后、黄骅社区于1年后进行随访，再次进行以上检查。结果 盘山、彰武和黄骅社区亚临床甲减的患病率分别为0．73％、2．90％和5．96％。亚临床甲减的病因33．1％是自身免疫性甲状腺疾病。在随访到的93例亚临床甲减患者中有4例女性进展为临床甲减。结论 随着碘摄入量的增加亚临床甲减的患病率增加，但无明显性别差异。随访研究证实女性、甲状腺自身抗体阳性是亚临床甲减患者进展至临床甲减的危险因素，碘摄入量与亚临床甲减的转归无关。     

Graves病多发家系成员甲状腺自身免疫状况及碘摄入量对其发病率的影响

目的：确定在Graves病（GD）多发家系成员中,甲状腺自身免疫及甲状腺功能异常的发生情况,并研究碘摄入量对GD发病率的影响。方法：对全部家系成员做甲状腺疾病病史询问,体格检查,甲状腺功能及甲状腺自身抗体测定,并测定空腹尿碘含量。结果：GD患者一级亲属的亚临床甲亢,临床甲状,亚临床甲状的患病率分别为5．2％,1．0％和1．4％,这三种疾病患者的甲状腺自身抗体均为阳性,甲状腺功能正常一级亲属的甲状腺自身抗体阳性率为68．6％,尿碘水平500－599ug/L时,GD的发病率显著增高（P＜0．05）,。结论：在GD多发家系中,GD患者一级亲属发生甲状腺功能异常的原因均为自身免疫甲状腺病,尿碘水平500－599ug/L是GD发病率增高的危险因素。     

Iodine supplementation in Austria: methods and results.

Until 1963 Austria was an extremely iodine-deficient area with low iodine intake and high goiter prevalence. Therefore, for the first time in 1963, salt iodination with 10 mg of potassium iodide per kilogram of salt was introduced by federal law. Twenty years after this salt iodination, however, investigations in schoolchildren demonstrated iodine deficiency grade I to II according to the World Health Organization (WHO) (urinary iodine excretion, 42-75 microg/g Crea) and goiter prevalence of far more than 10%. In 1990, salt iodination was increased to 20 mg of potassium iodide per kilogram of salt. In 1994, further investigations in schoolchildren demonstrated an increase of urinary iodine excretion (121 microg/g Crea) and a reduction of goiter prevalence below 5%, with the exception of pupils ages 14-19 (12%). In the year 2000, 10 years after the increase of salt iodination in Austria, 430 nonselected adult inhabitants of three communities in Carinthia (a county of Austria) were investigated for iodine excretion, goiter prevalence, and prevalence of thyroid autoantibodies. This study demonstrated that although iodine supply is sufficient now in Austria (males, 163.7 microg of Crea; females, 183.3 microg of iodine per gram of Crea), goiter prevalence is still high in the elderly, who lived for a longer period of iodine deficiency (34.3% in women and 21.3% in men), whereas goiter prevalence in younger people up to age 40 years is below 5%. It could also be shown that the percentage of thyroid autoantibodies is now as high as in other countries with sufficient iodine supply (3.19% in males, 5.17% in females). In addition to the changes of urinary iodine excretion and goiter prevalence because of salt iodination, changes of incidence in hyperthyroidism and histologic types of thyroid cancer are discussed in this paper. In conclusion, the introduction of salt iodination led to an improvement in iodine supply with a marked reduction of goiter prevalence in people who were born after 1963, but also to an increase in hyperthyroidism and autoimmune thyroid diseases as well as changes in histologic types of thyroid cancer.     

High prevalence of thyroid autoimmunity and hypothyroidism in patients with psoriatic arthritis

OBJECTIVE:To evaluate the prevalence of thyroid disorders in a group of patients with psoriatic arthritis (PsA). METHODS: A complete thyroid investigation was carried out in 80 patients with PsA, in gender- and age-matched subjects (1:5) drawn from the general population (controls), and in 112 patients with rheumatoid arthrtitis (RA) with similar iodine intake. RESULTS: Anti-thyroid peroxidase antibodies (AbTPO), a hypoechoic thyroid, and subclinical hypothyroidism were significantly more frequent in women with PsA than in control women, and their frequency was similar to that in patients with RA (positive AbTPO titer 28%, 12%, and 31%; hypoechoic thyroid 31%, 16%, and 36%; subclinical hypothyroidism 25%, 8%, and 12%, respectively). Among men, positive AbTPO titers and a hypoechoic thyroid were found more frequently in the patients with PsA and RA than in controls (positive AbTPO titer 14%, 5%, and 2%; hypoechoic thyroid 16%, 10%, and 3%, respectively). All patients with PsA with subclinical hypothyroidism had polyarticular involvement (p 相似文献   

The prevalence of undiagnosed thyroid disorders in a previously iodine-deficient area.

OBJECTIVE: The aim of the present study was to analyze the current status of morphologic and functional thyroid abnormalities in a previously iodine-deficient area. METHODS: The population based Study of Health in Pomerania (SHIP) comprised 4310 participants, aged 20-79 years. Thyroid function (thyrotropin [TSH] free triiodothyronine [FT(3)], and free thyroxine [FT(4)]) and serum autoantibodies to thyroperoxidase (TPOAb) were evaluated from blood samples. Thyroid structure and size were measured by ultrasound. Data from 3941 participants with no known thyroid disorders were analyzed. RESULTS: The median iodine urine excretion was 12.4 microg/dL. The rate of decreased serum TSH levels (<0.3 mIU/L) was 11.3%; 2.2% of participants had suppressed serum TSH levels (<0.1 mIU/L). The prevalence of subclinical hyperthyroidism was 1.8%, the prevalence of overt hyperthyroidism 0.4%. Elevated TSH levels were found in 1.2% of individuals. Subclinical hypothyroidism was observed in 0.5%, overt hypothyroidism in 0.7% of the sample. Elevated TPOAb were detected in 7% of subjects, 4.1% of participants had TPOAb greater than 200 IU/mL. The prevalence of goiter was 35.9%. An inhomogeneous echo pattern was detected in 35.2% and nodules in 20.2% of participants. Diffuse autoimmune thyroiditis was diagnosed in 47 subjects (1.2%). CONCLUSION: There are a number of thyroid disorders in this previously iodine-deficient region. Further studies are required to investigate the change of thyroid disorders during iodine supplementation programs.     

糖尿病住院患者434例甲状腺疾病患病率分析

目的 探讨江苏地区糖尿病患者中甲状腺疾病的现患情况.方法 横向断面调查2006年10月至2007年6月于南京医科大学第一附属医院就诊的长期居住于江苏地区的434例糖尿病患者的甲状腺功能,其中109例患者作了甲状腺超声检查.结果 (1)糖尿病患者合并甲状腺疾病的患病率为23.27%,女性多见(P＜0.05),其中甲状腺功能减退者占16.36%(临床甲减4.15%,亚临床甲减12.21%),明显高于甲状腺功能亢进者6.91%(临床甲亢4.61%,亚临床甲亢2.30%),两者差异有统计学意义.(2)糖尿病患者中,甲状腺功能减退的患病率随患者年龄和糖尿病病程的增加而增加(P＜0.01);甲状腺功能亢进的患病率随糖尿病痛程的增加而降低(P＜0.05),随年龄的增加患病率改变无统计学意义.(3)糖尿病患者中甲状腺结节患病率为40.37%,性别差异无统计学意义,患病率随年龄的增加而增加(P＜0.05),不随糖尿病痛程的增加而增加.结论 糖尿病患者合并甲状腺疾病较常见,可能影响糖尿病患者的病情和预后,筛查和随访糖尿病患者的甲状腺功能及形态学状态具有重要的临床意义.     

OUTCOME OF SUB-TOTAL THYROIDECTOMY FOR THYROTOXICOSISIN ICELAND AND NORTHEAST SCOTLAND

A comparative study of the outcome of surgical treatment for thyrotoxicosis was carried out in two countries with dissimilar dietary iodine levels. In the area with a high iodine level (Iceland) the prevalence of post-operative hypothyroidism was five times lower, but recurrent hyperthyroidism was five times higher, than in the area with lower iodine levels (northeast Scotland). The total morbidity reached comparable levels in the two samples. The prevalence of positive thyroid antibody tests and serum thyrotrophin levels was lower and the functional capacity of the thyroid remnant higher in the area with the higher dietary iodine intake. The study provides further evidence that there are important regional differences in the prevalence of factors known to influence the response to surgical treatment of thyrotoxicosis which should be taken into account when planning treatment services.