[Recognise of iodine effect on thyroid diseases and metabolism].

Iodine is an essential trace element for human and an antioxidant. It not only participates in the synthesis of thyroid hormone, but also plays a role in metabolic diseases. Previous studies mainly focused on the effect of iodine on thyroid diseases, but ignored the effect on metabolism. After the implementation of the universal salt iodization (USI) of China, the possible consequences of excessive iodine were emphasized while the harm of iodine deficiency was forgetten. The paper re-examines the effects of iodine nutrition on thyroid diseases and metabolism. Iodine deficiency can lead to an increased risk of iodine deficiency disorders and thyroid diseases, and increase prevalence of metabolic syndrome and its components. Moderate iodine excess is beneficial to metabolism, but it can increase the risk of hyperthyroidism and subclinical hypothyroidism. The average urinary iodine concentration in 100-299 µg/L is the appropriate iodine nutrition state. According to the present iodized content of salt in China, iodized salt is an economical and effective way to ensure adequate iodine nutrition.

[Survey on the prevalence and related factors of thyroid disorders in different iodine intake regions in China in 2015-2017].

Objective: To observe the prevalence and related factors of thyroid diseases in different iodine intake areas from 2015 to 2017 after the implementation of national salt iodization policy in China for 20 years. Methods: A cross-sectional survey. Multi-stage stratified cluster random sampling was used to randomly select subjects meeting the inclusion criteria from 31 provinces, municipalities and autonomous regions in China from January 2015 to December 2017, and stratified by age and sex. The survey included questionnaire, physical examination and thyroid ultrasonography. At the same time, the concentrations of serum thyrotropin, thyroxine, thyroid peroxidase antibody (TPOAb), thyroid globulin antibody (TgAb) and urinary iodine were measured.To determine whether the patient has a certain thyroid disease according to the above results. Different iodine nutrition areas were defined according to urinary iodine concentration, and the influence of iodine nutrition status in different iodine intake areas on thyroid diseases was analyzed. Results: A total of 78 470 adults were included, including 39 893 in the area of moderate iodine, 28 779 in the area of adequate iodine, and 9 798 in the area of excessive iodine.In the above three regions, the prevalence of subclinical hyperthyroidism (hyperthyroidism) was 0.45% (95%CI: 0.39%-0.52%), 0.50%(95%CI: 0.35%-0.70%)and 0.27%(95%CI: 0.20%-0.35%), respectively, with statistical significance(χ²=6.92, P=0.003). The prevalence of subclinical hypothyroidism (hypothyroidism) was 11.36% (95%CI: 10.73%-12.02%), 13.57%(95%CI: 11.70%-15.69%) and 16.18%(95%CI: 12.41%-20.82%), respectively, with statistical significance(χ²=5.08, P=0.009). The prevalence rates of Graves' disease, TPOAb, goiter and thyroid nodule among the three regions were statistically significant (all P<0.05). There were no significant differences in the prevalence of clinical hyperthyroidism and clinical hypothyroidism and the positive rate of TgAb among the three regions (all P>0.05). Multivariate logistic regression model analysis showed that excess iodine was a risk factor for subclinical hypothyroidism (OR=1.24, 95%CI: 1.06-1.44), and a protective factor for thyroid nodules (OR=0.73, 95%CI: 0.57-0.94). Iodine overdose was a risk factor for subclinical hypothyroidism (OR=1.47, 95%CI: 1.08-2.01), while it was a protective factor for subclinical hyperthyroidism (OR=0.56, 95%CI: 0.41-0.77), and TPOAb positive (OR=0.93, 95%CI: 0.87-0.99), goiter (OR=0.33, 95%CI: 0.17-0.66) and thyroid nodule (OR=0.77, 95%CI: 0.61-0.97). Conclusions: There are significant differences in the prevalence of subclinical hyperthyroidism, subclinical hypothyroidism, positive TPOAb, thyroid nodule and goiter in different iodine intake regions. Different iodine intake levels have an effect on the incidence of thyroid diseases.

[25-hydroxyvitamin D, sex hormone levels and cardiovascular risk among men in northeast area of Henan province].

Objective: To examine associations of 25-hydroxyvitamin D [25(OH)D] concentrations with sex hormone levels and cardiovascular risk factors. Methods: A total of 697 male subjects were obtained from the thyroid disorders, lodine status and diabetes: a national epidemiological survey-2014 (TIDE) research--Henan sub-center survey through multistage stratified cluster random sampling from December 2015 to March 2016. The associations between 25(OH)D and sex hormones or cardiovascular risk factors were analyzed by linear regression analyses. Results: The age of the subjects was (46.6±15.9) years (19-85 years). Proportions of vitamin D deficient, vitamin D intermediate and vitamin D optimal were 9.3%, 13.1% and 77.6%, respectively. More subjects with vitamin D deficient were in urban area than in rural area (13.3% vs. 5.7%, P=0.001). After fully adjusting for age, residence area, economic status, education, body mass index, waist circumference, homeostasis model assessment of insulin resistance (HOMA-IR), hypertension, diabetes, triglyceride, high-density lipoproteincholesterol, total cholesterol, low-density lipoprotein cholesterol and uric acid, linear regression analyses showed that every 25 nmol/L increase in 25(OH)D levels increased lg FT(FT=free testosterone) by 0.013ng/L (ß=0.013, P=0.036), lg DHT (DHT=dihydrotestosterone) by 0.030 ng/L (ß=0.030, P=0.019), and lg AD (AD=androstenedione) by 0.019 µg/L (ß=0.019, P=0.008). After fully adjusting for age, residence area, economic status and education, every 25 nmol/L increase in 25(OH)D levels lowered glycosylated hemoglobin A1c (HbA1c) by 0.051% (ß=-0.051, P=0.027). Conclusions: Higher 25(OH)D concentrations in men were associated with higher FT, DHT, AD and lower HbA1c levels.

Effects of maternal subclinical hypothyroidism on obstetrical outcomes during early pregnancy.

BACKGROUND: Maternal hypothyroidism [overt hypothyroidism and subclinical hypothyroidism (SCH)] during early pregnancy is suspected to associate with adverse obstetrical outcomes. AIM: The aim of the present study was to investigate whether maternal SCH during the early stage of pregnancy increase obstetrical complications and whether treatment results in an improvement in these outcomes. SUBJECTS AND METHODS: A total of 756 women in the 1st trimester (≤12 weeks) of pregnancy were enrolled through 10 hospitals in Shenyang from 2007 to 2009. All participants underwent thyroid function testing in early pregnancy and their obstetrical outcomes were studied following delivery. RESULTS: The incidence of spontaneous abortions in the SCH group was higher than the normal TSH group (15.48% vs 8.86%, p=0.03). No significant association was observed between SCH and other obstetrical complications including gestational hypertension, premature delivery, anemia, post-partum hemorrhage, low neonatal Apgar scores and low birth weight. Although levo-T4 (L-T4) treatment decreased the incidence of spontaneous abortions in women with SCH, it was not statistically significant when compared to women who did not receive treatment in the SCH group. None of the 28 women who received L-T4 treatment had premature delivery, low birth weight, hemorrhage, and low Apgar score. CONCLUSIONS: The incidence of spontaneous abortion in pregnant women with SCH increases in early pregnancy.

A study for maternal thyroid hormone deficiency during the first half of pregnancy in China.

BACKGROUND: Maternal thyroid hormone deficiency is the most common disorder of thyroid function during pregnancy and can influence the outcome for mother and foetus. The purpose of this study was to investigate the prevalence of thyroid hormone deficiency during the first half of pregnancy in iodine sufficient areas of China. MATERIALS AND METHODS: Four thousand eight hundred pregnant women from 10 hospitals during the first 20 weeks of gestation were enrolled in this study. All sera obtained from pregnant women were measured for thyrotropin, free thyroxine and thyroid peroxidase antibody. Screening for thyroid hormone deficiency was performed on pregnant women using gestational age-specific reference intervals or non-pregnant population reference intervals. RESULTS: With gestational age-specific reference intervals as the criterion, the prevalence of subclinical hypothyroidism at 4, 8, 12,16 and 20 weeks of gestation was 4.59%, 6.15%, 4.68%, 4.53% and 5.96%, respectively, and the prevalence of hypothyroxinaemia was 3.69%, 1.11%, 2.92%, 1.29% and 2.29%, respectively. Different prevalence was obtained when non-pregnant population reference intervals was used as the criterion. If non-pregnant population reference intervals were used, the percentage of potentially misclassified cases of subclinical hypothyroidism were 0.18%, 2.85%, 4.1%, 3.24%, and 3.21%, respectively, and 3.45%, 0.66%, 2.34%, 1.29%, and 1.83%, respectively, in potentially misclassified cases of hypothyroxinaemia. CONCLUSIONS: The percentage of potentially misclassified cases of subclinical hypothyroidism and hypothyroxinaemia in pregnant women decreased by using the gestational age-specific reference intervals as a diagnostic criteria during the first half of pregnancy.

Exercise therapy of non-insulin dependent diabetes mellitus a report of 10 year studies. The efficacy of exercise therapy.

The effect of a physical training course of 1-2 month duration using cycloergometer with the intensity of VO2 max 60%, 30 min per day was observed in non-insulin dependent diabetes mellitus (NIDDM) patients. The results showed a decrease of plasma glucose and insulin levels, sigma PG and sigma IRI and an improvement of blood lipid constitution. These were accompanied by a decreased erythrocyte insulin receptor binding rate and a reduction of receptor binding sites of both high and low affinity receptors.

Exercise therapy of non-insulin dependent diabetes mellitus. Effects of acute exercise loading.

The dynamic changes of 15 parameters (divided into 6 sections in this study) relating to metabolism, platelet function, blood coagulation and hemorrheologic situation under acute exercise loading with the intensity of VO2 max 60% were observed in noninsulin dependent diabetes mellitus (NIDDM) patients. The advantage, safety and feasibility of exercise therapy were discussed.

Epitope binding of human thyroglobulin autoantibodies of different IgG subclasses.

Autoantibodies against thyroglobulin in patients with Hashimoto's thyroiditis are believed to recognize only three main epitopes. The possibility that antibodies of different IgG subclass recognize these separate epitopes has been suggested by preliminary studies with monoclonal antibodies against thyroglobulin. To assess whether this is a more general phenomenon, sera from 9 Hashimoto patients were fractionated into subclasses IgG1, IgG2 and IgG4 by negative selection on affinity columns. Binding of each subclass to thyroglobulin both in a competition ELISA and an assay of radiolabelled thyroglobulin immunoprecipitation was significantly inhibited by the other subclasses. These results indicate that there is no restriction of thyroglobulin epitope recognition by different IgG subclasses in unselected patients with autoimmune thyroiditis.

T cell receptor phenotypes in autoimmune thyroid disease.

We have examined T cell receptor expression by peripheral blood and thyroidal lymphocytes in Graves' disease and Hashimoto's thyroiditis, using monoclonal antibodies directed against three beta chain variable region families and against the gamma chain. There was no abnormal distribution of positive staining with the beta chain reagents (compared to normal peripheral blood) in either the thyroid or the blood. However, thyroidal lymphocytes contained an excess of gamma-chain-bearing T cells, compared to peripheral blood, in five of the seven patients in whom simultaneous samples were available. The gamma-chain-positive T cells were not altered in the blood lymphocyte population of untreated Graves' patients. These results suggest that the T cell response in autoimmune thyroid disease is polyclonal and that there may be a role (such as cytotoxicity) for T cells expressing the gamma delta type of T cell receptor in thyroiditis.

Peripheral blood T cell activation after radioiodine treatment for Graves' disease.

Radioiodine therapy for Graves' thyrotoxicosis produces a rise in thyroid autoantibodies in the first three months after treatment, but little is known of its effects on T cells. We have therefore followed the changes in T cell subsets in sequential samples from 23 patients with Graves' disease treated with radioiodine, using dual-colour flow cytometry. In the first month after treatment there was a significant rise in activated T cells, identified by the markers HLA-DR (la) and CDw26/Ta1 (p less than 0.025 in both cases). CD45RO-positive T cells, which are the primed population containing memory cells, also increased (p less than 0.025), but there was no change in CD45R-positive, resting T cells or in the CD4 to CD8 (helper to cytotoxic/suppressor) ratio. Vicia villosa-binding T cells, containing the contrasuppressor population, showed a more variable response, but the trend was to an overall increase from pre-treatment values (p less than 0.025). The changes did not appear to be related to antithyroid drug treatment, since they were seen irrespective of whether patients continued such therapy. These results suggest that T cell activation and enhanced contrasuppressor activity may in part be responsible for the rise in autoantibodies after radioiodine. The T cell changes could also contribute to the worsening of ophthalmopathy seen in some radioiodine-treated patients.

Insulin-dependent diabetes mellitus (IDDM) is associated with CTLA4 polymorphisms in multiple ethnic groups.

Linkage disequilibrium (association) analysis was used to evaluate a candidate region near the CTLA4/CD28 genes using a multi-ethnic collection of families with one or more children affected by IDDM. In the data set unique to this study (Spanish, French, Mexican-American, Chinese and Korean), the transmission/disequilibrium test (TDT) revealed a highly significant deviation for transmission of alleles at the (AT)n microsatellite marker in the 3' untranslated region (P = 0.002) and the A/G polymorphism in the first exon (P = 0.00002) of the CTLA4 gene. The overall evidence for transmission deviation of the CTLA4 A/G alleles is also highly significant (P = 0.00005) in the combined data set (669 multiplex and 357 simplex families) from this study and a previous report on families from USA, Italy, UK, Spain and Sardinia. Significant heterogeneity was observed in these data sets. The British, Sardinian and Chinese data sets did not show any deviation for the A/G polymorphism, while the Caucasian-American data set showed a weak transmission deviation. Strong deviation for transmission was seen in the three Mediterranean-European populations (Italian, Spanish and French) (P = 10(-5)), the Mexican-American population (P = 0.002) and the Korean population (P = 0.03). These results suggest that a true IDDM susceptibility locus (designated IDDM12) is located near CTLA4.