The impact of dietary iodine intake on lipid metabolism in experimental hypothyroid mice / 中国地方病学杂志

Objective To observe the effects of iodine deficiency and iodine excess on the lipid metabolism in an experimental hypothyroid model of mice and to explore the roles of iodine independent of its role in thyroid hormones. Methods Female Balb/c mice were randomly divided into 6 groups: control, severe iodine deficiency (SID), mild iodine deficiency(MID), normal iodine (NI), 10-fold high iodine (10HI) and 50-fold high iodine(50HI), 10 in each group. The mice in control group were fed with low iodine forage, other mice were fed with low iodine forage containing 0.2% methylthiouracilum. All mice drank deionic water containing different concentrations of potassium iodide(KI). The iodine content in water was 326.79, 0, 196.08,326.79, 385621, 19 542.50 μg/L, respectively. After three months, thyroid hormones in the serum were determined by radioimmunoassay.Also, the blood samples were analyzed for total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesteiol (HDL-C) and low density lipoprotein cholesterol (LDL-C) and measured enzymatically by automatic analyzer. Results①The levels of Tr4 in SID[(21.27 ± 9.63)μg/L], MID[(23.41 ± 3.93)μg/L], NI[(22.57 ±4.66)μg/L], 10HI [(21.07 ± 5.03) μg/L] and 50HI groups [(21.46 ± 5.90) μg/L] were distinctively decreased compared with control group[(42.15 ± 8.26)μg/L, all P ＜ 0.01]. There were no statistical significant differences of TT3 between different groups (F = 0.99, P > 0.05 ). ②The level of TG in 10HI group [ ( 1.17 ± 0.16)mmol/L ] was obviously decreased compared with control [(1.39 ± 0.22 )mmol/L] and NI groups[(151 ± 0.22)mmol/L, all P＜ 0.05].Both TG and TC in 50HI group[(1.18 ± 0.22), (1.78 ± 0.15)mmol/L] were significantly decreased compared with control [( 1.39 ± 0.22), (2.14 ± 0.37)mmol/L] and NI groups [(1.51 ± 0.22), (2.00 ± 0.15)mmol/L, all P ＜ 0.05].The difference of serum HDL-C and LDL-C between the groups was not significant(F = 0.55,0.54, all P ＞ 0.05 ).Conclusions Dietary iodine plays a role in the metabolism of serum lipids independent of thyroid hormones.Thus, monitoring the amount of iodine intake during sodium restriction should also be taken extremely important for effectively prevention and cure of cardiovascular disease.

The impact of dietary iodine/sodium intake on blood lipid metabolism in mice / 中国地方病学杂志

Objective The present study has been designed to investigate the impact of dietary iodine/sodium intake on blood lipid metabolism in mice. Methods According to body weight and gender, two hundred and sixty Balb/c mice were randomly divided into 2 groups including normal sodium group(Na) and low sodium group(LNa), with 130 animals per group. Each group were then randomly further divided into 5 sub-groups according to the amount of iodine intake: ① severe iodine deficiency(SID); ② mild iodine deficiency(MID); (③normal iodine (NI); ④ 10-fold high iodine ( 10HI ); (⑤ 50-fold high iodine (50HI), 10 groups in total, 26 per group.Eight months later, the body weight and the levels of urinary iodine, thyroid hormones and total cholesterol (TC),Results In Na group, the levels of TG and TC in male mice of SID group[ (1.64 ± 0.35), (3.88 ± 0.35 )mmol/L]and MID group[ ( 1.67 ± 0.31 ), (3.41 ± 0.66)mmol/L] were significantly higher than that of NI group[ ( 1.49 ± 0.42), (3.25 ± 0.47)mmol/L] and the levels of TG in female mice of SID group[(1.52 ± 0.22)mmol/L] were significantly higher than that of NI group[ (1.23 ± 0.22)mmol/L]. In addition, the levels of TG in male mice of 10HI and 50HI groups [ ( 1.16 ± 0.23 ), ( 1.21 ± 0.27 ) mmol/L ] were significantly lower than that of NI group [ ( 1.49 ± 0.42)mmol/L, all P ＜ 0.05], the levels of TC in female mice of 10HI and 50HI groups[(2.37 ± 0.49), (2.48 ± 0.37)mmol/L] were significantly lower than that of NI group[ (2.84 ± 0.37) mmol/L, all P ＜ 0.05 ]. In LNa group,the levels of TG and TC in male mice of SID group[ (1.39 ± 0.40), (3.33 ± 0.46 )mmol/L] were significantly lower than that of NI group [(1.30 ± 0.28), (3.00 ± 0.53) mmol/L, all P ＜ 0.05], the levels of TG, TC and LDL in female mice of SID group[ (1.48 ± 0.26), (2.76 ± 0.43), (0.62 ± 0.22)mmol/L], the levels of LDL in female mice of MID group[ (0.60 ± 0.17 )mmol/L] were significantly lower than that of NI group[(l.22 ± 0.36), (2.51 ± 0.38),(0.48 ± 0.08), (0.48 ± 0.08)mmol/L, all P ＜ 0.05], the levels of TG in male mice of 10HI and 50HI group [ (1.12 ± 0.22), (0.90 ± 0.11 )mmol/L] were significantly lower than that of NI group (all P ＜ 0.05 ), the levels of TC in female mice of 10HI and 50HI groups[ (2.35 ± 0.34), (2.37 ± 0.37)mmol/L], the levels of LDL in female mice of 50HI group[(0.65 ± 0.18)mmol/L], were significantly lower than that of NI group(all P ＜ 0.05). In Na group, the levels of thyroid hormones were distinctively decreased in SID group[TT4(0.00 ± 0.00)nmol/L, FT4 (0.93 ± 0.42)pmol/L, TT3(0.49 ± 0.07)nmol/L, FT3(2.86 ± 0.37)pmol/L] and MID group [TT4 (17.15 ± 15.26)nmol/L, FT4( 18.46 ± 4.31 )pmol/L, TT3(0.67 ± 0. 10)nmol/L, FT3(3.18 ± 0.24)pmol/L] compared with that of the NI group [TT4 (37.15 ± 15.26)nmol/L, FT4(28.46 ± 4.31)pmol/L, TT3(0.85 ± 0.10)pmol/L, FT3(3.87 ± 0.24)pmol/L, all P ＜ 0.05 ]. In LNa group, the levels of thyroid hormones were distinctively decreased in SID group [TT4 (0.00 ± 0.00) nmol/L,FT4(1.03 ± 0.78)pmol/L, TT3(0.51 ± 0.05)nmol/L, FT3(3.01 ± 0.17)pmol/L] and MID group[TT4(19.76 ± 12.22)nmol/L, FT4(21.46 ± 5.37)pmol/L, TT3(0.71 ± 0.21)nmol/L, FT3(3.56 ± 0.23)pmol/L] compared with that of the NI group[TT4(36.23 ± 14.72)nmol/L, FT4(30.96 ± 6.33)pmol/L, TT3(0.89 ± 0.20)nmol/L, FT3(4.05 ± 0.24)pmol/L, all P ＜ 0.05]. Conclusions Dietary iodine intake plays an important role in the blood lipid metabolism. Iodine deficiency could increase while iodine excess could decrease the levels of serum TG, TC or LDL in mice. Monitoring the amount of iodine intake during sodium restriction should have an important role in effective prevention and treatment of cardiovascular disease.

Effect of iodine on the pathogenesis of postpartum thyroiditis / 中国地方病学杂志

Objective To explore the effect of iodine on the pathogenesis of postpartum thymiditis.Methods Forty-four female C57BL/6J mice,8-week old,fed by low iodine dietary(the concentration of iodine≤35 μg/kg),were randomly divided into 4 groups:non-pregnancy experimental autoimmune thymiditis(non-pregnancy EAT)group with 8 mice,EAT of mice was induced by immunization with pig's thyroglobulin(Tg)in the presence of complete Freund's adjuvant.Six mice in non-pregnancy EAT group survived at the end of experiment;normal iodine-PPT(NI-PPT)group,10-fold high iodine-PPT(10HI-PPT)group and 50-fold high iodine-PPT(50HI-PPT)group with 12 mice in each group.The last 3 groups mice,who received the same immunization schedule as the above,were mated with adult male mice followed by induction of EAT.In the end,7,6 and 6 mice were noticed to be pregnant in each group.All animals were killed 4 weeks after postpartum.Histological severity of thyroid specimens was evaluated.The serum level of thyroglobulin antibody(Tg-Ab),thyroid pomxidase antibody(TPO-Ab),TT3 and TT4 were measured by radioimmunoassay(RIA).The expression level of IFN-γ/IL-4 mRNA in spleenwere assayed by RT-PCR.Results Pathological examination showed the infiltration of inflammatory cells.epithelial cell applanation,follicle atrophy or destruction.The severity of inflammation in non-pregnancy EAT bgroup.NI-PPT group and 10HI-PPT group was less serious than that in the 50HI-PPT group,the difference has bstatistical significance(P＜0.05).The level of TPO-Ab in non-pregnancy EAT group,NI-PPI-group,10HI-PPTgroup and 50HI-PPT group wag(14.32±8.85)%,(64.45±10.52)%,(38.46±5.57)%and(90.09±9.98)%.respectively the difference being statistically significant between any two groups(P＜0.05).There was no statisticaldifference(F＝0.484,P＞0.05)of Tg-Ab among non-pregnancy EAT group[(33.74±3.71)%],NI-PPT group [(29.65±2.06)%],10HI-PPT group[(37.21±3.87)%]and 50HI-PPT group[(33.87±4.17)%].There was no statistical difference(F＝1.596,P＞0.05)of TT3 among non-pregnancy EAT group (2.47±0.69)%,NI-PPT group(1.57±0.25)%,10HI-PPT group[(1.60±0.28)%]and 50HI-PPT group[(1.82±0.75)%].The level of TT4 in 50HI-PPT group[(66.68±5.47)%]was lower than that in non-pregnancy group,NI-PPT group and 10HI-PPTgroup[(99.87±5.97)%,(89.13±7.64)%and(91.05±5.82)%],the difference being statistically significant(P＜0.05).The expression level of IFN-γ mRNA was increasing,being 1.02±0.10,1.37±0.10,1.39±0.12 and 1.68±0.06 in non-pregnancy EAT group,NI-PPT group,10HI-PPT group and 50HI-PPT group.The difference had a statistical significance between any two groups except for NI-PPT group and 10HI-PPT group(P＜0.05).The expression level of IL-4 mRNA in 10HI-PPT group(0.49±0.04)and 50HI-PPT group(0.53±0.06)were all higher than non-pregnancy EAT group(0.24±0.05)and NI-PPT group(0.35±O.05),the differences being statistically significant (P＜0.05).Conclusions Adequate iodine supplementation during pregnancy and postpartum period is necessary,but iodine excess could induce postpartum thyroiditis.So iodine supplementation during pregnancy and postpartum should be adequate and reasonable.

Detection of serum fibrosis markers in patients with autoimmune thyroid diseases / 中国地方病学杂志

Obecfive To study the clinical significance of detecting serum proeollagen type Ⅲ(PCⅢ) and hyaluronie acid(HA)in patients with autoimmune thyroid diseases(AITD).Methods According to the thyroid function,the 114 patients with AITD were divided into hyperthyroidism group(38),hypothyroidism group(35),and sub-hypothyroidism group(41).In addition,40 healthy persons were served as controls.The level of serum PCⅢ was determined with ELISA and that of serum HA with RIA.The level of FT3,FT4 and sTSH were detected by immumnofluorometric assay.Results Serum FT3(18.35±6.19)pmol/L]and FT4[(76.28±23.49)pmol/L]level of patients with hyperthyroidism were obviously higher than those of the controls[(4.75±0.31),(16.12±3.27) pmol/L],but serum sTSH[(0.15±0.07)mU/L]was obviously lower than that of the control[(3.78±0.15)mU/L],the differences were statically significant(P＜0.01).Serum FT3[(3.36±0.26)pmol/L]and FT4 [(6.37±2.19) pmol/L]level of patients with hypothyroidism were both lower than those of the controls(P＜0.05).but serum sTSH[(44.58±13.29)mU/L]was obviously higher than that of the control(P＜0.01).Serum FT3 [(4.86±0.45)pmol/L]and FT4[(15.26±2.78)pmol/L]level of patients with sub-hypothyroidism had no statistical difference compared with those of the controls(P＞0.05),but serum sTSH[(14.26±4.73)mU/L] was obviously higher than that of the controls(P＜0.01).The level of sernm PCⅢ[(4.63±1.22)μg/L]in pafients with hyperthyroidism was significantly higher than that of any other group(P＜0.05).There waB no statistical significant difference in PCⅢ among the patients with hypothyroidism,the patients with sub-hypothyroidism and controls [(3.64±1.12),(3.54±1.17)and(3.56±1.07)μg/L],respectively(P＞0.05).The level of serum HA [(31.13±10.28)μg/L]in patients with hypothyroidism was significantly higher than that of any other group(P＜0.05).There was no statistical significant difference in HA among the patients with hyperthyroidism,the patients with sub-hypothyroidism and controls[(22.24±7.22),(22.43±7.99)and(23.09±9.19)μg/L,respectively,P＞0.05].Conclusions It is very significant to understand myocardial fibrosis early through detecting sernm PCⅢ in patients with hyperthyroidism.Measurement of serum PCⅢ and HA will be useful to discovery hepatic fibrosisearly in patients with a long course of hyperthyroidism.

Levels of serum leptin in the autoimmune thyroid diseases / 中国地方病学杂志

Objective To observe the levels of serum leptin in Gaves disease(GD)and thyroiditis(HT)Datients and to discuss the immunological role of leptin in the pathogenesis of autoimmune thyroid disease(AITD).Methods 102 newly diagnosed female AITD patients were divided into 3 groups:GD hyperthyroid group,HT hypothyroid group and subclinical hypothyroid group.Age,sex and BMI-matched 27 euthyroid,healthy subjects served as controis.The levels of FT3,FT4 and sTSH were determined by immunofluorometrie assay.ELISA kit was aDplied to measure the levels of serum leptin.Results Serum FT3 and FT4[(19.74±15.39),(78.25±58.68)pmol/L]levels of GD hyperthyroid patients were obviously higher than those of the controls[(4.87±0.25),(15.96±3.15)pmol/L,P＜0.01],but serum sTSH and leptin levels[(0.15±0.08)mU/L,(8.73±1.92)μg/L]were obviously lower than those of the controls[(3.81±0.19)mU/L,(12.38±3.51)μg/L,P＜0.01or＜0.05].Serum FT3 and FT4[(3.36±0.26),(6.95±3.29)pmol/L]levels of HT hypothyroid patients were obviously lower than those of the controls(P＜0.05),but serum sTSH and leptin levels[(45.48±35.83)mU/L,(17.17±3.82)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Serum FT3 and FT4[(4.67±0.60),(14.87±2.14)pmol/L]levels of subclinical hypothyroid patients had not statistical difference comparing with those of the controls(P＞0.05),but serum sTSH and leptin levels[(13.67±8.66)mU/L,(16.25±3.67)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Conclusions Leptin might have an immuoregulation role in the pathogenesis of AITD.In addition,serum levels of leptin in AITD is also influenced by many other related hormones.

The effects of iodine/selenium on the function of antigen presentation of peritoneal macrophages in rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effects of iodine/selenium on the function of antigen presentation of peritoneal macrophages in rats and explore the immunological mechanisms of iodine/ selenium's role in pathogenesis of autoimmune thyroid diseases (AITD).</p><p><b>METHODS</b>Female Lewis rats were randomly divided into four groups including (1) low selenium and normal iodine group (L(sE)N(I)) (2) low selenium and high iodine group (L(Se)H(I)) (3) normal selenium and normal iodine group (N(Se)N(I) ) (4) normal selenium and high iodine group (N(Se)H(I)). All rats were fed by a special diet with lower selenium and iodine in it and drunk ion-free water containing different levels of iodine and selenium for 3 months. Peritoneal macrophages of each group and OVA allergized T cells were prepared and cultured together. Then the function of antigen presentation were estimated by detecting the levels of IL-2 in the culture supernatant. The levels of the expression of co-stimulator CD86 in the spleen of each group were determined by RT-PCR.</p><p><b>RESULTS</b>The level of IL-2 in the supernatant in N(Se)H(I) (43.22 +/- 3.27) pg/ml was much stronger than N(Se)N(I) [the level of IL-2 was (25.74 +/- 2.45) pg/ml, P < 0.05]. The level of IL-2 in L(Se)N(I) (15.79 +/- 2.13) pg/ml was significantly lower than N(Se)N(I) (P < 0.05). The expression of CD86 mRNA in N(Se)H(I) (CD86/beta-actin: 0.52 +/- 0.10) were higher than N(Se)N(I) (CD86/beta-actin: 0.35 +/- 0.04), P < 0.05.</p><p><b>CONCLUSIONS</b>High iodine could promote the presentation function of macrophages to a higher state than normal. Therefore, high iodine intake might become an importantly inducing factor in thyroid autoimmunity. Low selenium could weaken the ability of recognizing and presenting OVA antigen of peritoneal macrophages which might destroy immunological homeostasis and thus the low selenium intake might also become an inducer of AITD.</p>

Experimental study on effects of iodine deficiency and excess on thyroid autoimmunity / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the effects of iodine on the level of CD4/CD8 cells and the production of thyroglobulin autoantibody (TGAb) and thyroid peroxidase autoantibody (TPOAb) in Wistar rats and to investigate the role of iodine in thyroid autoimmunity.</p><p><b>METHODS</b>Rat models with different iodine intakes including low iodine (LI,), normal iodine (NI,), 5 times normal iodine (5HI), 10 times normal iodine (10HI), 50 times normal iodine (50HI) and 100 times normal iodine (100HI) were established. The amount of iodine intake per rat per day in every group was about < 1, 6.15, 30.75, 61.50, 307.50, 615.00 microg separately. The levels of CD4 and CD8 immune cells in peripheral blood were measured by using flow cytometry. Radioimmunoassay (RIA) was used to determine the titers of TGAb and TPOAb in the serum.</p><p><b>RESULTS</b>In peripheral blood, the level of CD4 cells in LI group was (57.9 +/- 4.3)%, being much higher than in NI group (51.2 +/- 4.9)%. When the level of CD8 cells in 100HI group was (18.4 +/- 3.1)% showing significantly lower than in NI group (26.5 +/- 4.1)%, thus making the ratio of CD4/CD8 cells in the above two groups (LI: 2.4 +/- 0.40 and 100 HI: 2.7 +/- 0.4) higher than in NI group (1.9 +/- 0.3). As comparing with NI group (2099 +/- 220) CPM, the level of TGAb in LI group (1510 +/- 221) CPM was significantly decreased; while in 50HI group (3986 +/- 286) and 100HI group (3550 +/- 378) CPM, the levels of TGAb were both increased, and the levels of TPOAb in 10HI group (2066 +/- 184) CPM and in 50HI group (2141 +/- 163) CPM were both distinctly lower than in NI group (2372 +/- 245) CPM.</p><p><b>CONCLUSIONS</b>Iodine might exert influence on the level of CD4/CD8, and thus the production of thyroid antibodies might directly or indirectly take part in the process of thyroid autoimmunity. Both low iodine and 100 times normal iodine intakes might activate the immune state on some degrees. The effects of iodine on immune responses of TG and TPO antigen in thyroid autoimmunity might not be completely the same.</p>

Thyroid peroxidase antibody in autoimmune thyroid diseases / 中华内分泌代谢杂志

In hyperthyroid,hypothyroid and subclinical hypothyroid patients,the positive rate and level of the thyroid autoantibodies were all remarkably higher than those in the control group.The positive rate of thyroid peroxidase antibody (TPOAb) was higher than those of thyroglobulin antibody and thyroid microsome antibody in each group.In the group with restored thyroid function,the average level of TPOAb was significantly decreased, suggesting that TPOAb could be taken as an important indicator in evaluating the treatment and prognosis of autoimmune thyroid diseases.