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Objective To investigate the effects of high iodine intake on thyroid function in pregnant and lactating women.Methods A cross sectional epidemiological study was conducted among 130 pregnant women and 220 lactating women aged 19-40 years in areas with high environment iodine level (＞300 μg/L) or proper environment iodine level (50-100 tg/L) in Shanxi in 2014.The general information,urine samples and blood samples of the women surveyed and water samples were collected.The water and urine iodine levels were detected with arsenic and cerium catalysis spectrophotometric method,the blood TSH level was detected with electrochemiluminescence immunoassay,and thyroid stimulating hormone (FT4),antithyroid peroxidase autoantibody (TPOAb)and anti-thyroglobulin antibodies (TGAb) were detected with chemiluminescence immunoassay.Results The median urine iodine levels of the four groups were 221.9,282.5,814.1 and 818.6 μg/L,respectively.The median serum FT4 of lactating women in high iodine area and proper iodine area were 12.96 and 13.22 pmol/L,and the median serum TSH was 2.45 and 2.17 mIU/L,respectively.The median serum FT4 of pregnant women in high iodine area and proper iodine area were 14.66 and 16.16 pmol/L,and the median serum TSH was 2.13 and 1.82 mIU/L,respectively.The serum FT4 levels were lower and the abnormal rates of serum TSH were higher in lactating women than in pregnant women in both high iodine area and proper iodine area,the difference was statistically significant (FT4:Z=-6.677,-4.041,P＜0.01;TSH:Z=8.797,8.910,P＜0.01).In high iodine area,the abnormal rate of serum FT4 in lactating women was higher than that in pregnant women,the difference was statistically significant (Z=7.338,P=0.007).The serum FT4 level of lactating women in high iodine area was lower than that in proper iodine area,the difference was statistically significant (Z=-4.687,P=0.000).In high iodine area,the median serum FT4 in early pregnancy,mid-pregnancy and late pregnancy was 16.26,14.22 and 14.80 pmol/L,respectively,and the median serum TSH was 1.74,1.91 and 2.38 mIU/L,respectively.In high iodine area,the serum FT4 level in early pregnancy was higher than that in mid-pregnancy and late pregnancy,and the serum TSH level was lower than that in mid-pregnancy and late pregnancy,the difference was statistically significant (FT4:Z=-2.174,-2.238,P＜0.05;TSH:Z=-2.985,-1.978,P＜0.05).There were no significant differences in the positive rates of serum thyroid autoantibodies among the four groups of women and women in different periods of pregnancy (P＞0.05).The morbidity rates of subclinical hyperthyroidism in pregnant women and lactating women in high iodine area were obviously higher than those in proper iodine areas,the difference was statistically significant (x2=5.363,5.007,P＜0.05).Conclusions Excessive iodine intake might increase the risk of subclinical hypothyroidism in pregnant women and lactating women.It is suggested to strengthen the iodine nutrition and thyroid function monitoring in women,pregnant women and lactating women in areas with high environmental iodine.
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Objective To investigate the effects of high iodine intake on thyroid function in pregnant and lactating women.Methods A cross sectional epidemiological study was conducted among 130 pregnant women and 220 lactating women aged 19-40 years in areas with high environment iodine level (＞300 μg/L) or proper environment iodine level (50-100 tg/L) in Shanxi in 2014.The general information,urine samples and blood samples of the women surveyed and water samples were collected.The water and urine iodine levels were detected with arsenic and cerium catalysis spectrophotometric method,the blood TSH level was detected with electrochemiluminescence immunoassay,and thyroid stimulating hormone (FT4),antithyroid peroxidase autoantibody (TPOAb)and anti-thyroglobulin antibodies (TGAb) were detected with chemiluminescence immunoassay.Results The median urine iodine levels of the four groups were 221.9,282.5,814.1 and 818.6 μg/L,respectively.The median serum FT4 of lactating women in high iodine area and proper iodine area were 12.96 and 13.22 pmol/L,and the median serum TSH was 2.45 and 2.17 mIU/L,respectively.The median serum FT4 of pregnant women in high iodine area and proper iodine area were 14.66 and 16.16 pmol/L,and the median serum TSH was 2.13 and 1.82 mIU/L,respectively.The serum FT4 levels were lower and the abnormal rates of serum TSH were higher in lactating women than in pregnant women in both high iodine area and proper iodine area,the difference was statistically significant (FT4:Z=-6.677,-4.041,P＜0.01;TSH:Z=8.797,8.910,P＜0.01).In high iodine area,the abnormal rate of serum FT4 in lactating women was higher than that in pregnant women,the difference was statistically significant (Z=7.338,P=0.007).The serum FT4 level of lactating women in high iodine area was lower than that in proper iodine area,the difference was statistically significant (Z=-4.687,P=0.000).In high iodine area,the median serum FT4 in early pregnancy,mid-pregnancy and late pregnancy was 16.26,14.22 and 14.80 pmol/L,respectively,and the median serum TSH was 1.74,1.91 and 2.38 mIU/L,respectively.In high iodine area,the serum FT4 level in early pregnancy was higher than that in mid-pregnancy and late pregnancy,and the serum TSH level was lower than that in mid-pregnancy and late pregnancy,the difference was statistically significant (FT4:Z=-2.174,-2.238,P＜0.05;TSH:Z=-2.985,-1.978,P＜0.05).There were no significant differences in the positive rates of serum thyroid autoantibodies among the four groups of women and women in different periods of pregnancy (P＞0.05).The morbidity rates of subclinical hyperthyroidism in pregnant women and lactating women in high iodine area were obviously higher than those in proper iodine areas,the difference was statistically significant (x2=5.363,5.007,P＜0.05).Conclusions Excessive iodine intake might increase the risk of subclinical hypothyroidism in pregnant women and lactating women.It is suggested to strengthen the iodine nutrition and thyroid function monitoring in women,pregnant women and lactating women in areas with high environmental iodine.
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Objective To study the nutritional status of pregnant women in Shanxi Province before and after the implementation of the new standards of iodized salt content,provide the basis for scientific supplementation of iodine for pregnant women.Methods According to the method of population proportion sampling,30 county-level monitoring sites were selected,a primary school was selected from each county (city,district) by the method of simple random sampling and 40 students in 2011 or 50 students in 2014 aged 8-10 years were selected in each school,direct titration was used to detect salt iodine;at the same time,20 pregnant women were selected from each town where the primary school was located and urinary iodine was determined using arsenic cerium catalytic spectrophotometry (WS/T 107-2006).Results A total of 1 182 and 1 437 salt samples was detected in Shanxi Province in 2011 and 2014,the median of salt iodine was 30.5 and 24.1 mg/kg,respectively,and the difference was statistically significant (H =567.45,P ＜ 0.01);it was 95.41％,80.31％,76.62％ of the coverage rate of iodized salt,qualified rate of iodized salt,qualified iodized salt consumption rate in 2014,respectively;which were compared with those in 2011 (97.63％,97.49％,95.18％),the differences were statistically significant (x2 =9.27,232.40,166.25,P ＜ 0.01).A total of 440 and 630 urinary samples of pregnant women were tested in 2011 and 2014,the median of urinary iodine was 279.6 and 177.1 μg/L,respectively,iodine nutrition of pregnant women was more than adequate in 2011,and iodine nutrition was suitable in 2014.The difference was statistically significant (H =153.89,P ＜ 0.01).The proportion of pregnant women's median of urinary iodine less than 150 μg/L in 2014 [41.11％ (259/ 630)] was significantly higher than that in 2011 [8.18％ (36/440),x2 =140.68,P ＜ 0.01].The constituent ratio of 250 to 500 μg/L was significantly decreased [23.65％ (149/630) vs 54.77％ (241/440),x2 =108.33,P ＜ 0.01).Conclusion It is at a reasonable level of iodine nutrition level of pregnant women in Shanxi after the adjustment of iodized salt content,but the ratio of ＜ 150 μg/L is increasing,which needs to be paid attention to.
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Objective To understand the distribution of water iodine in the external environment of Shanxi Province, and to provide a basis for redefining and implementation of scientific iodine supplementation in iodine deficiency, iodine adequate or iodine high areas. Methods In 2012 - 2016, administrative villages (neighborhood committees)in 119 counties(cities,districts)in 11 cities of Shanxi Province were selected as the investigation units, and 1 to 5 drinking water samples were collected. Water iodine content was detected using arsenic-cerium catalytic spectrophotometry. Areas standard was designated: water iodine content < 10 μg/L as iodine deficiency areas, > 100 μg/L as iodine high areas. Results A total of 26 213 administrative villages (neighborhood committees) of 1 362 townships (towns) of 119 counties (cities, districts) were surveyed, covering 2 850.94 ten thousand people. A total of 32 766 water samples were collected and the median iodine was 5.2 μg/L. There were 18 199 villages with water iodine < 10 μg/L, accounting for 69.4% (covering 1 812.17 ten thousand people, accounting for 63.6%), 6 471 villages with water iodine 10-<50 μg/L,accounting for 24.7%(covering 787.44 ten thousand people,accounting for 27.6 %),1 166 villages with water iodine 50 - < 100 μg/L,accounting for 4.4% (covering 181.46 ten thousand people, accounting for 6.4%), 377 villages with water iodine ≥100 μg/L, accounting for 1.4%(covering 69.87 ten thousand people, accounting for 2.5%).In 1 362 townships (towns), 71.1% (969)water iodine median was<10 μg/L,24.2%(330)water iodine median was in 10-<50 μg/L,3.4%(46)water iodine median was in 50-<100 μg/L,and 1.2%(17) water iodine median was ≥100 μg/L. In 119 counties(cities,districts),there were 90 counties(accounting for 75.6%) with the water median < 10 μg/L, there were 26 counties (accounting for 21.8%) with the water median 10 - < 50 μg/L. Conclusions Most parts of Shanxi Province(or the resident population) are iodine deficiency areas, the external environment water iodine contents in the rest of the regions are different, we should adopt different iodine supplement or iodine reduction measures in regions with different water iodine levels.
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Objective To establish a arsenic cerium catalytic rate method for determination of urinary iodine,and increase the linear range of urinary iodine determination.Methods Standard series and urine samples after digestion treatment,were tested using dynamics function of spectrophotometer to record the curve of absorbance value (A) change with time (t) during arsenic cerium catalytic reaction for each measurement system,choice (A1,t1) and (A 2,t2) on this curve and calculating the reaction rate (v),v =(lgA1-lgA2)/(t2-t1).Through the determination of the standard series it could calculate regression equation of iodine concentration (C) with X:C =a ± bX,X =1 000 (v-v0),and the v0 is the reaction rate of reagent blank.Results (① C and X were positively correlated.The standard series linear range was 0-1 200 pμg/L and correlation coefficient r was higher than 0.999 1.The minimum detection limit was 3.9 μg/L (0.25 ml urine).②)Precision:5 urine samples (A,B,C,D,E) were selected within the range of 0-1 200 μg/L and the measured value were (72.3 ± 2.7),(148.2 ± 5.2),(210.5 ± 4.4),(562.7 ± 6.8),and (899.3 ± 8.0) μg/L.The relative standard deviation (RSD) was between 0.9％-3.8％.(③)Accuracy:4 samples (A,B,C,D) were measured for standard addition recovery test,recovery was between 94.2％-107.2％;urinary iodine standard material [the given values were (67.9 ± 9.0),(142.0 ± 10.0),(195.0 ± 10.0),(558.0 ± 17.0),(885.0 ± 28.0) μg/L] were determined and the results were in the range of uncertainty of the standard material.④Method contrast:with the national health standard method (method for determination of iodine in urine by arsenic cerium catalytic spectrophotometry) to determinate 120 urine samples,the results showed that there were 60 urine samples within 0-300 μg/L,60 urine samples were more than 300 μg/L.Then rate method was used to test the 120 urine samples.For the 60 samples within the scope of 0-300 μg/L,the determination results of the two methods were positively correlated (r =0.994,P ＜ 0.01);the results of the rate method were lower than those of the standard method and the difference was statistically significant (t =2.047,P ＜ 0.05).But the average deviation was only 2.1 μg/L,for the determination of urine iodine there was no practical significance;for the 60 samples higher than 300 μg/L,the determination results of the two methods were positively correlated (r =0.993,P ＜ 0.01) and the difference was not statistically significant (t =-1.092,P ＞ 0.05).Conclusions Arsenic cerium catalytic rate method has increased the linear range of urinary iodine determination.Using this method,the vast majority samples can be tested directly without dilution,thereby reducing the workload for determination of urine iodine.
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Objective To establish a method for determination of arsenic in urine,using hydrogen peroxide as the main digestion reagent to digest urine,and using hydride generation atomic fluorescence spectrometry (HG-AFS) to determine arsenic (this method was referred to below),the feasibility of the application in the monitoring of endemic arsenic poisoning was discussed.Methods Temperature control instrument (60 holes) and supporting special calibration tube were used to digest urine.Digestion reagents was mainly hydrogen peroxide plus a small amount of nitric acid and sulfuric acid,HG-AFS was used to determinate.Based on standard curve to calculate linear relationship.Using this method to determinate detection limit,precision,accuracy and stability of samples,this method was compared with the national hygienic standard method (DDCAg method,WS/T 28-1996).Results The detection limit was 0.8 μg/L (1 ml of urine was tested),the correlation coefficient was larger than 0.999 5.Precision:3 samples were determined,the arsenic contents were (11.0 ± 0.6),(39.2 ± 1.0),(174.4 ± 3.8) μg/L and the relative standard deviations were 5.03％,2.59％ and 2.17％,respectively.Recovery rate:3 samples were determined for standard addition recovery test,the average recovery rate was 99.4％ and the recovery rate ranged between 94.0％-104.3％.Methods contrast:this method [(125.9 ± 61.6) μg/L] and DDCAg method [(121.3 ± 52.5) μg/L] were used to determinate 20 samples from endemic arsenic poisoning areas,respectively,the determination results of the two methods were not significantly different (t =1.22,P ＞ 0.05).Conclusions This method is built successfully,it has good precision and accuracy,it needs small amount of sample and reagent,the amount of harmful gases generated is greatly reduced,and it is easy to operate and beneficial to operator's health.Therefore,it is a good method to determine arsenic in urine,and it can be applied in prevention of endemic arsenism.
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Objective To study the efficacy of L-3,5-diiodotyrosine (DIT) and inorganic iodine (KIO3) in iodine-deficiency Wistar rats.Methods Sixty Wistar rats,weighting about 160-180 g,were divided into two groups according to body weight by the random number table method:iodine-deficiency model (40 rats) was fed with low-iodine food (the iodine content was 35.9 μg/kg);optimal-iodine model (20 rats) was fed with low-iodine food and given with KIO3 water (the iodine content was 18 mg/L) 0.5 ml by intragastric once a day.Model was established for 3 months.Iodine-deficiency model was subdivided into low iodine (LI) group,KIO3 group and DIT group,eight,nine,ten rats in each group;from optimal-iodine model,nine rats were randomly selected as optimal iodine (NI) group.LI group was fed with low-iodine food;KIO3 group was fed with low-iodine food and given with KIO3 water (the iodine content was 18 mg/L) 0.5 ml by intragastric once a day;DIT group was fed with low-iodine food and given with DIT water (the iodine content was 18 mg/L) 0.5 ml by intragastric once a day;NI group was fed with low-iodine food and given with KIO3 water (the iodine content was 18 mg/L) 0.5 ml by intragastric once a day.After 3 months,24-hour urine of the rats was collected.According to the method for determination of iodine in urine by As3 +-Ce4+ catalytic spectrophotometry (WS/T 107-2006),iodine content in urine was detected.Rats were anesthetized intraperitoneally with 25％ urethane,blood from abdominal aortic was collected to determinate the serum thyroid hormone [total triiodothyronine (TT3),total thyroxine (TT4),free triiodothyronine (FT3),free thyroxine (FT4)] level in rats by automatic electrochemical luminescence immunoassay.All the rats were sacrificed to analyze the thyroid weight.Results ① The urine iodine showed significant differences in the four groups (x2 =25.24,P ＜ 0.05).The median of urine iodine concentration in the LI,NI,KIO3 and DIT groups were 3.00,286.14,223.37,214.33 μg/L,respectively.The urine iodine concentration in LI group was significantly lower than those of other three groups (all P ＜ 0.05).② The serum TT3,TT4,FT3,FT4 levels showed significant differences in the four groups (F =63.48,140.73,130.20,365.27,all P ＜ 0.05).And the hormone levels in KIO3 group were lower than those of the DIT group [TT3:(1.57 ± 0.20) vs.(1.97 ± 0.18) mmol/L,TT4:(51.23 ± 4.90) vs.(71.94 ± 5.27) mmol/L,FT3:(5.34 ± 0.45) vs.(6.98 ± 0.33) pmol/L,FT4:(26.18 ± 2.30) vs.(35.47 ± 2.28) pmol/L,all P ＜ 0.05].③The color of thyroid in KIO3 and DIT groups became pale pink.The absolute and relative thyroid weight showed significant differences in the four groups (F =225.05,345.40,all P ＜ 0.05).The absolute thyroid weight [(31.76 ± 1.75) mg] and relative thyroid weight [(11.69 ± 3.47) mg/100 g] in DIT group was lower than that of the KIO3 group [(36.31 ± 5.23) mg,(12.83 ± 4.38) mg/100 g,all P ＜ 0.05].Conclusion Animal experimental results show that DIT has a better iodine-supplementing efficacy than that of KIO3.
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Objective To master the iodine nutritional status of residents and to evaluate the effect of iodine nutrition improvement on residents health after the adjustment of salt iodine concentration. Methods According to the method of population proportion sampling, 30 county-level monitoring sites were selected in 2014, a primary school was selected from each county (city, district) by the method of simple random sampling and 50 students aged 8 - 10 (half males and half females) were selected in each school, B ultrasound was used to detect thyroid volume, arsenic cerium catalytic spectrophotometry (WS/T 107-2006) was used to detect urinary iodine, direct titration was used to detect salt iodine; At the same time, 20 pregnant women were selected from each town and urinary iodine was determined. All results were compared with the results of 2011 to evaluate the effect of iodine nutrition improvement on resident's health after the adjustment of salt iodine concentration. Results A total of 1 437 edible salt samples were tested, the median of salt iodine concentration was 24.1 mg/kg. Based on the new standard (18 - 33 mg/kg), the coverage rate of iodized salt was 95.4%(1 371/1 437), the qualified rate of iodized salt was 80.3%(1 101/1 371), the consumption rate of qualified iodized salt was 76.6% (1 101/1 437). A total of 1 496 urine samples of children and 630 urine samples of pregnant women were tested, the median of urinary iodine of children and pregnant women was 224.6 and 177.1 μg/L, respectively, which were significantly lower than those of 2011 (274.6, 279.6μg/L), the differences were statistically significant (H=70.10, 153.50, all P<0.05). The proportion of counties which iodine nutrition of children and pregnant women in suitable range was 36.7% (11/30) and 56.7% (17/30), which were higher than those of 2011 [6.5%(2/31), 25.8%(8/31)], the differences were statistically significant (χ2 = 7.88, 5.00, all P < 0.05). Totally 1 552 children were examined thyroid in Shanxi Province, the rate of goiter was 4.4% (69/1 552). Conclusion The new standard of iodine concentration makes it possible to maintain a sustainable elimination of iodine deficiency disorders, and it can improve the iodine nutrition of children aged 8-10 years and pregnant women to more reasonable level.
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Objective To investigate the distribution of endemic arsenism and to provide a scientific basis for control and prevention of the disease.Methods According to previous investigation,in the high-arsenic water areas,the arsenic diseased areas and the surrounding lands,35 counties were investigated.Water arsenic was screened in all the survey sites,villages with water arsenic exceeding the standard were quantitative surveyed of water arsenic and the disease conditions.Screening of arsenic content in drinking water was done by the method of half-quantitative fast reagent kit.Quantitative determination of arsenic in water was done by hydride generationatomic fluorescence spectrometry (HG-AFS).Patients of endemic arsenism were diagnosed by the Standard of Diagnosis for Endemic Arsenism (WS/T 211-2001).Identification of area was done by Definition and Division Standard for Endemic Arsenism (WS 277-2007).The data were analyzed using SPSS 13.0 for windows.Results Water arsenic of 151 villages in 15 counties among 1 771 villages were higher than the national drinking water quality level(0.05 mg/L).Exposure population of high arsenic was 177 018 people.The census results of high arsenic water sources indicated that the ratio of drinking water arsenic levels higher than the national standard was 35.10％ (2 355/6 709) and the highest contents of arsenic was 1.733 0 mg/L.The disease census indicated that there were 33 latency arsenism districts and 118 arsenism districts.There was totally 39 757 patients with latency arsenism.Totally 137 261 people lived in arsenism districts.Light,moderate and severe arsenism districts was 82,29 and 7,respectively.Totally 1 244 suspicious patients with endemic arsenism were discovered,and 3 473 light and more severe patients were discovered and the detected rate of light and more severe patients was 2.54％ (3 473/136 924).Most patient were not serious.Conclusions High arsenic areas and endemic arsenism areas are distributed in 15 counties of Shanxi Province.In the future primary task in prevention and control of endemic arsenism is comprehensive prevention and control measures.
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Objective To know the drinking water quality in the rural areas in Shanxi province in order to enhance the management of drinking water and provide the scientific basis for water improvement in the rural areas. Methods 11 counties were selected based on the geographical condition in Shanxi province and 10 investigation sites were selected in each county based on the population proportion of different drinking-water types. 14 indicators were determined for every water sample. Results In the rural areas, most drinking water sources were ground water and the type of water supply was mainly non-central water supply. The indexes that exceeded the related standard limit were fluoride,arsenic and bacteria indicators. The hygienic state of central water supply was much better(?2=4.13, P