Rapeseed glucosinolates and iodine in sows affect the milk iodine concentration and the iodine status of piglets.

I in the chain sow diet --> blood serum of sow --> sow milk --> piglet serum was investigated in two experiments with a total of eighty-one sows and their piglets. In experiments conducted during the last trimester of gravidity and the 28 d of lactation, diets with glucosinolates (1.9 mmol/kg diet via 100 g ground rapeseed/kg diet (Expt 1) and 2.1 and 4.2 mmol/kg diet via 75 and 150 g rapeseed press cake/kg diet (Expt 2)) were compared with control groups without rapeseed products. From 0 to 600 microg I/kg was added to sow diets during lactation. Diets without supplementary I decreased the I concentration particularly in milk and piglet serum. The presence of rapeseed and rapeseed press cake were indicated by a thiocyanate concentration increase, mainly in sow serum. The diets with glucosinolates decreased the milk and piglet serum I concentration. Spot urine and faeces samples from sows eating the rapeseed-press cake diets had increased I concentration. The sows' serum I and thyroxine did not respond to glucosinolates (Expt 1) or these diets caused an increase in concentration (Expt 2). Both these criteria seem unsuitable for the diagnosis of I status of adult animals. Glucosinolates and their degradation compounds may affect the thyroid and the mammary glands resulting in lower I milk transfer and higher renal and intestinal I excretion.     

Influencing factors on iodine content of cow milk

Purpose

Iodine is an essential trace element for humans and animals, and it is incorporated into the thyroid hormones such as thyroxine and triiodothyronine, which have multiple functions in energy metabolism and growth, but also as transmitter of nervous stimuli and as an important factor for brain development. Because of the small range between iodine requirements and the upper level for humans (between 1:2.5 and 3), the requirements should be met, but excesses should be avoided. One of the most important iodine sources for humans is milk of ruminants. Therefore, various influencing factors on the iodine content of milk of ruminants should be analyzed in the paper.

Results

The iodine content of milk depends on many factors, such as iodine content and level of iodine supplementation of feed, iodine source, iodine antagonists such as glucosinolates in the feed, farm management, teat dipping with iodine-containing substances, and milk processing in the dairy. The effects of some factors on the iodine content of milk are demonstrated and discussed. Feed iodine supplementation has the main effect on milk iodine. However, the iodine content of milk may vary considerably depending on many other influencing factors.

Conclusions

As a consequence of preventive consumer protection, the European Food Safety Authority proposed a reduction in the iodine upper level for lactating ruminants from 5 to 2 mg/kg complete feed.     

Dietary low-glucosinolate rapeseed meal affects thyroid status and nutrient utilization in rainbow trout (Oncorhynchus mykiss)

Two rapeseed (Brassica napus) meals, RM1 and RM2, with two levels of glucosinolates (GLS; 5 and 41 mumol/g DM respectively) were incorporated at the levels of 300 and 500 g/kg of the diets of juvenile rainbow trout (Oncorhynchus mykiss) in replacement of fish meal, and compared with a fish-meal-based diet. A decrease in the digestibility of the DM, protein, gross energy and P was observed with high-rapeseed meal (RM) incorporation. In trout fed on RM-based diets, growth performance was reduced even after only 3 weeks of feeding. Feed efficiency was adversely affected by RM and GLS intake. Protein and energy retention coefficients were significantly lower in fish fed on the diet containing the higher level of GLS. P retention was significantly lower with all the RM-based diets than with the fish-meal diet. Irrespective of the degree of growth inhibition, fish fed on RM-based diets exhibited similar typical features of hypothyroid condition due to GLS intake, expressed by lower plasma levels of triiodothyronine and especially thyroxine and a hyperactivity of the thyroid follicles. This hypothyroidal condition led to a strong adjustment of the deiodinase activities in the liver, the kidney and the brain. A significant increase of the outer ring deiodinase activities (deiodinases type I and II respectively) and a decrease of the inner ring deiodinase activity (deiodinase type III) were observed. It is concluded that the observed growth depression could be attributed to the concomitant presence of GLS, depressing the thyroid function, and of other antinutritional factors affecting digestibility and the metabolic utilization of dietary nutrients and energy.     

应用全自动碘分析仪测定鲜奶及奶粉中碘含量的方法学评价

目的 建立全自动碘分析仪测定鲜奶及奶粉中碘含量的分析方法。方法 用碱灰化处理样品后,应用全自动碘分析仪测定鲜奶及奶粉内碘离子含量,进行方法学评价。结果 该方法检测范围为0～500μg/L碘,标准曲线的平均相关系数为0.999 9,检测限为5μg/kg,样品加标回收率为96.0%～101.8%,精密度（RSD,n=6）为1.55%～3.04%。全自动碘分析仪法和砷铈催化分光光度法对低、中、高3种浓度样品的碘含量检测的结果差异无统计学意义（t=0.424、0.607、0.073,P均>0.05）。两种方法对低（t=0.902,P=0.388）、中（t=0.318,P=0.757）、高（t=1.783,P=0.105）浓度样品加标后的碘含量检测的结果差异无统计学意义。两种方法测定30份鲜奶及奶制品中碘含量检测的结果差异无统计学意义（t=0.396,P>0.05）。结论 应用全自动碘分析仪测定鲜奶及奶粉中碘的精密度、准确度均可达到标准方法水平,样品试剂用量少、程序简单、操作容易,适用于鲜奶及奶粉中总碘的检测。     

Urinary iodine and thyroid status of New Zealand residents

OBJECTIVES: The aim of this project was to assess the clinical significance of our low iodine excretions in terms of thyroid hormone status and thyroid volume in an adult population in a low soil iodine area of the South Island of New Zealand. DESIGN AND SETTING: Two-hundred and thirty-three residents of Otago, New Zealand collected two 24 h urine samples for assessment of iodine status. Thyroid status was determined from serum total T(4), TSH and thyroglobulin, and thyroid volumes. Relationships between urinary iodide excretion and measures of thyroid status were determined and subjects were allocated to one of three groups according to low, medium and high iodide excretion, for comparison of thyroid hormones and thyroid volumes. RESULTS: Significant correlations were found for relationships between measures of urinary iodide excretion and thyroid volume and thyroglobulin. Multiple regression analysis of data for subjects divided into three groups according to 24 h urinary iodide excretion (<60, 60-90; >90 microg iodide/day) or iodide/creatinine ratio (<40; 40-60; >60 microg/g Cr) showed significant differences in thyroid volume (P=0.029; P=0.035, respectively) and thyroglobulin (P=0.019; P=0.005, respectively) among the groups. CONCLUSIONS: The results of this study confirm the low iodide excretions of Otago residents, and indicate that the fall in iodine status is being reflected in clinical measures of thyroid status, including enlarged thyroid glands and elevated thyroglobulin. Our observations suggest the possible re-emergence of mild iodine deficiency and goitres in New Zealand. This situation is likely to worsen should iodine intakes continue to fall and continued monitoring of the situation is imperative.     

重庆城区儿童青春期发动时相现况及与肥胖的相关研究

目的调查重庆主城区8～19岁学生青春期发育现状及与肥胖的相关关系。方法采用多阶段分层整群抽样,对3046名中小学生进行青春期发育调查,内容包括青春期发动问卷(PDS)调查;体格检查包括身高、体重,男童外生殖器、阴毛、睾丸容积,女童乳房、阴毛发育检查;并运用概率单位回归法计算各分期年龄,采用Spearman秩相关分析青春期发动时相提前与肥胖的关系。结果女童乳房B2期平均年龄为11.51岁,阴毛FP2期平均年龄为13.93岁,月经初潮平均年龄为12.29岁;男童外生殖器G2期平均年龄为13.13岁,阴毛MP2期平均年龄13.62岁,睾丸容积达4ml平均年龄为11.67岁,男生首次遗精平均年龄为13.57岁;女生青春期发动提前组超重、肥胖比例大于发育正常组,且存在秩相关(P<0.01)。结论重庆城区女生青春期发动和性发育明显提前,且与肥胖存在相关关系。     

武威市妊娠妇女碘营养水平及甲状腺功能状态分析

目的了解不同妊娠期妇女碘营养水平及甲状腺功能状态。方法于2009年4月-2010年1月采用横断面调查方法随机抽取甘肃省武威市90名(城市49人,农村41人)妊娠期妇女。采集样本人群空腹晨起血样及任意一次尿样,检测血清促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺激素(FT4)、甲状腺球蛋白抗体(TGAb)、甲状腺微粒体抗体(TMAb)及尿碘。结果孕早、中、晚期妇女尿碘中位数分别为231.49、158.25和328.35μg/L,尿碘低于150μg/L的比率分别为39.29%、45.16%、25.81%。孕早期FT3、FT4水平高于孕晚期(P﹤0.05),TSH水平呈增高趋势,组间比较差异无显著性(P>0.05)。不同妊娠期妇女TGAb、TMAb抗体阳性率比较差异无显著性(P>0.05)。孕早、中、晚期妇女甲状腺功能紊乱发生率比较差异有显著性(P<0.05)。结论妊娠妇女碘营养状况良好,部分孕妇存在甲状腺功能减退倾向。     

Studies on iodine content in daily diets,particularly elderly people's diets

Poland represents moderate degree of severity of iodine deficiency. In 1997 a national program has been introduced of obligatory iodine prophylaxis including the iodination of household salt. In order to assess the extent of iodine consumption, the assessment were carried out on iodine content in average Polish diets with regard elderly people's diets. The aim of the study was also to analyse the composition of supplements allowed for trade in Poland, with regard to iodine content in these products. The assessment of iodine content in Polish diets was performed on the basis of the data of the household budgets and the data of iodine content in food products (without kitchen salt). The calculated iodine content in average Polish daily diets (adults and children) ranged from 40.4 microg to 50.7 microg. The iodine content in elderly people's diets was 75.5 microg/daily diets. In all studied diets the amount of iodine coming from food products, not taking into account iodinated salt, was insufficient for the realization of Polish RDA for this element. It shows that iodination of kitchen salt in Poland is necessary. Moreover on the Polish market exist supplements including iodine (20-200 microg iodine in tablet).     

Urinary iodine concentrations and thyroid function in adult Zimbabweans during a period of transition in iodine status.

BACKGROUND: In 1993 the compulsory iodization of salt was introduced in Zimbabwe, a country that was previously an area of severe iodine deficiency. OBJECTIVE: The objective of this study was to document urinary iodine excretion and biochemical thyroid function in seemingly healthy, community-dwelling adults after the introduction of iodization. DESIGN: A multistage, random sampling method was used in rural and urban settings to identify households from which the senior household member (aged >35 y) was recruited (alternating male and female recruits). Demographic data were collected for each subject and urinary and venous blood samples were taken. Urinary iodine excretion and serum thyroid hormone status (thyrotropin and total thyroxin) were evaluated according to age, sex, and area of residence. RESULTS: A total of 736 adults were recruited (253 men; mean age: 64 y). Urinary iodine concentrations were high [median (first and third quartiles): 4.41 (2.84, 6.78) micromol/L, or 560 (360, 860) microgram/L] and were significantly higher in rural areas than in urban areas [4.73 (3.07, 7.14) micromol/L, or 600 (390, 906) microgram/L, compared with 3.47 (2.05, 4.73) micromol/L, or 440 (260, 600) microgram/L; P < 0.001]. Urinary iodine excretion declined significantly with increasing age (r = -0.29, P < 0.001). Serum thyroid status suggested that the prevalence of biochemical hyperthyroidism in the study was 3%, with 13 of 415 cases in rural and 3 of 149 cases in urban subjects. CONCLUSION: This study reaffirms the need to continuously monitor iodine replacement programs to ensure efficacy.     

硒碘对大鼠谷胱甘肽过氧化物酶活力及甲状腺激素代谢的影响──Ⅱ．硒碘营养状态对大鼠甲状腺激素代谢的影响

用四种硒水平饲料和两种碘含量饮水饲养大鼠观察了其甲状腺激素（ＴＨ）代谢。硒组间肝脏、肾脏Ⅰ型脱碘酶（ＩＤⅠ）活力、血清Ｔａ含量差异显著；两碘组间甲状腺重量、甲状腺过氧化物酶（ＴＰＯ）活力。甲状腺碘含量、肾脏ＩＤⅠ及大脑Ⅱ型脱碘酶（ＩＤⅡ）活力差异明显；Ⅰ－（不加碘）组中甲状腺ＩＤⅠ活力与血清三碘甲腺原氨酸（Ｔａ）含量呈显著正相关。提示硒缺乏通过ＩＤⅠ影响ＴＨ代谢继而影响大脑ＩＤⅡ活力并可加重碘缺乏的效应；低碘时甲状腺ＩＤⅠ在维持循环Ｔａ含量中起重要作用；碘缺乏有可能增加硒缺乏的效应；硒、碘对ＴＨ代谢的影响可能在一定程度上取决于自身和对方的营养状态。     

The effect of selenium on thyroid status in a population with marginal selenium and iodine status

The effects of Se on thyroid metabolism in a New Zealand population are investigated, including (a) the relationship between Se and thyroid status, and (b) the effect of Se supplementation on thyroid status. The data used come from two cross-sectional studies of Se, I, thyroid hormones and thyroid volume (studies 1 and 4), and three Se intervention studies in which thyroid hormones, Se and glutathione peroxidase (GPx) activities were measured (studies 2, 3 and 5). There were no significant correlations between Se status and measures of thyroid status after controlling for sex at baseline or after supplementation in any of the studies. When data from study 4 were divided into two groups according to plasma Se, plasma thyroxine (T4) was lower in males with higher plasma Se levels (P=0.009). Se supplementation increased plasma Se and GPx activity, but produced only small changes in plasma T4 and triiodothyronine (T3):T4 ratio. In study 2, there was a significant reduction in plasma T4 (P=0.0045). In studies 3 and 5 there were small decreases in plasma T4 and a small increase in the T3:T4 ratio, which were not significantly different from placebo groups. Lack of significant associations between plasma Se and thyroid status, and only small changes in T4 suggest that Se status in New Zealand is close to adequate for the optimal function of deiodinases. Adequate plasma Se may be approximately 0.82-0.90 micromol/l, compared with 1.00-1.14 micromol/l for maximal GPx activities.     

Effect of thiocyanate levels in milk on thyroid function in iodine deficient subjects

To utilize the antibacterial effect of the lactoperoxidase system to prevent bacterial spoilage of raw milk it is necessary to increase the thiocyanate concentration of the milk. Thiocyanate has, however, a potent antithyroid effect which is enhanced by iodine deficiency. In this study the thyroid function has been studied, before and after 4 weeks daily administration of 250 ml of such treated milk, in 55 goitrous subjects living in an endemic goiter region of western Sudan. The iodine content was 0.1 mg/l and the thiocyanate content was either 3.6 mg/l (n 19) or 19 mg/l (n 36) in the milk. At the start of the experiment all subjects were iodine deficient with a urinary excretion of 40-50 micrograms/g creatinine. After 4 weeks daily intake of 4.75 mg of thiocyanate by way of milk the serum thiocyanate level increased by approximately 1.7 mg/l. Both at the beginning and at the end of the experimental period the serum levels of thyroxine, triiodothyronine and TSH were in the normal range for all subjects. After 4 weeks the TSH levels had decreased significantly, (from 2.6 +/- 0.2 to 2.1 +/- 0.2 mU/l, p less than 0.001) probably as an effect of the supplementary intake of iodine. The thyroid hormone levels remained unchanged during the experimental period. In conclusion, the intake of milk with an iodine concentration of 0.1 mg/l and a thiocyanate concentration of 19 mg/l does not have a negative effect on the thyroid function in iodine deficient subjects.     

碘缺乏和碘过量对甲状腺自身免疫影响的实验研究

目的观察碘对大鼠免疫细胞(CD4/CD8)、甲状腺球蛋白抗体(thyroglobulin autoanti-body,TGAb)、甲状腺过氧化物酶抗体(thyroid peroxidase autoantibody,TPOAb)的作用,探讨碘对甲状腺自身免疫应答的影响。方法将Wistar大鼠分为6组(1)低碘组(LI)摄碘量<1μg/d;(2)适碘组(NI)摄碘量为6.15μg/d;(3)5倍碘组(5HI)摄碘量为30.75μg/d;(4)10倍碘组(10HI)摄碘量为61.50μg/d;(5)50倍碘组(50HI)摄碘量为307.50μg/d;(6)100倍碘(100HI)摄碘量为615.00μg/d。采用流式细胞仪检测外周血CD4和CD8免疫细胞数量,应用放射免疫分析法(RIA)检测血清中TGAb和TPOAb水平。结果LI组大鼠外周血CD4细胞为(57.9±4.3)%,NI组为(51.2±4.9)%,两组比较,差异有统计学意义。100HI组CD8细胞为(18.4±3.1)%,NI组为(26.5±4.1)%,两组比较,差异有统计学意义。LI组CD4/CD8比值为2.4±0.40,100HI组为2.7±0.4,均高于NI组的1.9±0.3。LI组TGAb含量为(1510±221)CPM,明显低于NI组的(2099±220)CPM;50HI组和100HI组的TGAb含量分别为(3986±286)和(3550±378)CPM,较NI组明显升高。TPOAb含量在10HI组和50HI组分别为(2066±184)和(2141±163)CPM,均明显低于NI组的(2372±245)CPM。结论碘会直接或间接影响CD4/CD8细胞数量和甲状腺自身抗体(TGAb、TPOAb)生成水平,参与甲状腺自身免疫反应。低碘或100倍高碘的摄入,可不同程度地激活Wistar大鼠的免疫状态。在甲状腺自身免疫应答中,碘对甲状腺球蛋白和甲状腺过氧化物酶抗原的影响不相同。     

Effect of iodine source and dose on growth and iodine content in tissue and plasma thyroid hormones in fattening pigs

Purpose

The aim of the present feeding trial with iodine was to assess pigs’ growth performance and carcass characteristics, the iodine accumulation in tissues, and their influences on the thyroid hormones in plasma.

Methods

Eighty pigs (33–115?kg body weight) were allotted to 5 dietary treatments: a control group (150?μg I/kg), two potassium iodide [KI] groups (4,000 and 10,000?μg I/kg), and two potassium iodate [KIO₃] groups (4,000 and 10,000?μg I/kg). Iodine concentration was determined in thyroid gland, liver, kidney, muscle, fat, and skin by ICP-MS. Furthermore, thyroxine (T₄) and triiodothyronine (T₃) in plasma were evaluated.

Results

High dietary iodine tended to have a negative effect on younger animals' growth (average daily gain, ADG). However, during the entire growth period, the growth performance and carcass characteristics were not influenced by iodine dosages or sources. Irrespective of iodine source, higher iodine doses of diets affected higher iodine stores in all tested tissues except for abdominal fat. Thus, iodine supplementation with 10,000?μg I/kg feed significantly increased iodine content in thyroid gland (+122%), liver (+260%), kidney (+522%), muscle (+131%), and skin (+321%) compared to the control group. However, there was no significance of thyroid hormones in plasma.

Conclusions

As a result, pork and fat of pigs showed only low iodine accumulation even in the high-iodine groups. Thus, there should be no risk of an iodine excess in human nutrition and animal health, and the EU-upper level for iodine in pig feed can be maintained.     

舟山群岛居民碘营养状况及甲状腺癌现患调查

目的调查舟山群岛居民碘营养状况、甲状腺癌患病情况及致甲状腺癌的相关影响因素。方法以整群阻随机抽样法对舟山群岛城镇居民、农民、岱山盐民、嵊泗渔民及普陀山僧侣进行流行病学问卷调查、甲状腺B超检查、甲状腺功能和尿碘测定,对甲状腺癌疑似病人行术后病理切片诊断。结果舟山群岛城镇居民、农民、岱山盐民、嵊泗渔民及普陀山僧侣的尿碘中位数(MUI)为分别为320.7、188.9、122.2、193.6和271.7μg/L,甲状腺癌累积患病率分别为215/10万(3/1 389)、398/10万(2/502)、407/10万(3/737)、829/10万(3/362)和340/10万(1/294);年龄、血清人促甲状腺激素(hTSH)是预测甲状腺癌的独立危险因素(P<0.05)。结论舟山群岛居民碘营养充足,居民甲状腺癌累积患病率较高,血清hTSH检测可预测甲状腺癌患病风险。     

30例正常产妇初乳与成熟乳碘含量的分析

报道了３０例正常产妇的初乳和成熟乳的碘含量分别为１３５．６５±５８．２８×１０－ ２ μｍ ｏｌ／Ｌ和５４．８８±２９．２１×１０－ ２ μｍ ｏｌ／Ｌ，经ｔ检验表明初乳与成熟乳的碘含量有极显著性差异，从碘含量的角度再次提示母乳特别是初乳喂养的重要性。