BACKGROUND: Before iodination of Swedish table salt in 1936, iodine deficiency resulting in goitre and hypothyroidism was common. Sweden has become iodine sufficient, as shown in a national survey in 2007, proving its iodination fortification programme effective for the general population. The objective of this study was to collect drinking water from water treatment plants nationally and test if water iodine concentration (WIC) correlated to urinary iodine concentration (UIC) of school-aged children in a national survey 2007 to former goitre frequency in 1929 and to thyroid volume data in 2007. METHODS: In 2012, 166 treatment plants, located in 57% (166 of 290) of all Swedish municipalities, were asked to collect drinking water samples of approximately 10 ml. In 2007, tap water samples of the same volume were collected from 30 randomly selected schools for the national survey. Analysis of WIC was done in both treatment plants in 2012 (n = 166) and tap water in 2007 (n = 30). The correlation of WIC to the children's UIC and thyroid volume after iodination was tested based on data from the national survey in 2007. The association of WIC to former goitre frequency was tested based on pre-iodination data, derived from a map of goitre frequency drawn in 1929. RESULTS: The median WIC from water treatment plants was 4.0 μg/L (range 0-27 μg/L). WIC was similar in coastal and inland areas, for both ground and surface water. WIC correlated with historical goitre areas and was lower in the goitre areas than in non-goitre areas (p < 0.001). WIC in the same municipalities as the schools correlated with the UIC of children (p < 0.01), but not with their thyroid volume. CONCLUSIONS WIC still contributes to iodine nutrition in Sweden, but iodination overrides the goitre effect.
Adolescent ; Child ; Drinking Water ; chemistry ; Female ; Food, Fortified ; analysis ; Goiter ; epidemiology ; history ; History, 20th Century ; History, 21st Century ; Humans ; Iodine ; analysis ; urine ; Male ; Sodium Chloride, Dietary ; analysis ; Sweden ; epidemiology ; Thyroid Gland ; anatomy & histology

OBJECTIVEWe aimed to evaluate goiter prevalence and iodine nutritional status in areas with high levels of water iodine; to monitor the prevalence of iodine deficiency disorders (IDD) in areas at high risk of IDD; and to compare the prevalence of goiter and urine iodine (UI) concentrations between children living in the two areas.

METHODSBased on surveillance from 2012-2014, we analyzed the concentration of UI and prevalence of goiter in 8-10-year-old children from 12 high-risk IDD provinces, and from 8 provinces and municipalities with excessive water iodine. We calculated goiter prevalence for each UI level according to World Health Organization (WHO) standards and constructed predictive prevalence curves.

RESULTSThe goiter prevalence and median UI of children from areas with high water iodine were not optimal, being above the WHO standards (5% and 100-199 μg/L, respectively), whereas those in high-risk areas fell within the standard. UI and goiter prevalence exhibited a U-shaped relationship in high-risk endemic areas and a parabolic relationship in areas of iodine excess.

CONCLUSIONIodine surplus in high-iodine areas leads to high goiter prevalence and UI. However, in high-risk areas, UI was optimal and goiter prevalence met the national criteria for IDD elimination.

Child ; China ; epidemiology ; Dose-Response Relationship, Drug ; Female ; Goiter ; epidemiology ; Humans ; Iodine ; administration & dosage ; deficiency ; urine ; Male ; Prevalence ; Risk Factors

OBJECTIVETo study the changes in the constituent ratio of patients received surgical therapy for their thyroid diseases in Peking Union Medical College Hospital from 1986 to 2012.

METHODSThe clinical data of patients received surgical therapy with pathologically confirmed findings from 1986 to 2012 were collected, and a corresponding database was established. The constituent ratios of thyroid diseases and thyroid malignant tumor among different population groups in different years were analyzed.

RESULTSThe number of patients with thyroid diseases admitted to our hospital had significantly increased in the past 27 years, particularly those with nodular goiter or thyroid cancer. The composition ratios of thyroid cancer and nodular goiter increased significantly, and among malignancies the papillary thyroid carcinoma increased obviously. The detection rate of papillary thyroid micro-carcinoma had continuously increased since 2008.

CONCLUSIONThyroid diseases and malignant tumor pathological types had dramatically changed in hospitalized patients in our hospital in the past 27 years.

Adult ; Female ; Goiter, Nodular ; epidemiology ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Thyroid Diseases ; epidemiology ; surgery ; Thyroid Neoplasms ; epidemiology ; pathology

Child ; China ; epidemiology ; Goiter, Endemic ; epidemiology ; Humans ; Iodine ; deficiency ; Students

OBJECTIVETo evaluate the status of diffuse goiter of population in Zhejiang Province and to analyze the relevant influencing factors.

METHODSA total of 18 188 subjects were recruited in the cross sectional survey, by multistage stratified cluster random sampling method. B ultrasound measurement were carried among the subjects to detect the thyroid volume, and the basic information and life styles were interviewed by questionnaires. Then, we analyzed the distribution and its influencing factors of diffuse goiter.

RESULTSThe ratio of diffuse goiter among the surveyed population was 2.2% (403/18 188), the difference showed statistical significance (χ(2) = 267.11, P < 0.05). The ratio among the group aged 6-7 years old and 8-10 years old was comparatively high, separately 10.3% (27/262) and 9.8% (51/519). The ratio among women (2.9%, 305/10 470) was higher than it among men (1.3%, 97/7672) (χ(2) = 55.55, P < 0.05). The residents from inland areas had the highest prevalence (3.2%, 138/4374), followed by residents from sub-coastal areas (2.0%, 131/6411), coastal areas minimum (1.8%, 138/4374) (χ(2) = 24.31, P < 0.05). The content of water iodine and salt iodine among people with symptoms of goiter had statistical difference with it among ordinary population (water iodine:χ(2) = 4.95, P = 0.026; salt iodine: χ(2) = 11.03, P < 0.01). The median(quartile) of water iodine in ordinary population was 2.41 (1.96-6.15) µg/L and among people with symptoms of goiter was 1.88 (1.49-5.15) µg/L. The median(quartile) of salt iodine in ordinary population was 30.18 (24.69-32.65) mg/kg and among people with symptoms of goiter was 29.1 (24.70-31.95) mg/kg. The influential factors of goiter were as follows: the family income, the education degree, the job and profession status, the diet character, the habitual sea food consumption, the alcohol intake status (χ(2) were separately 8.08, 37.85, 98.78, 68.69, 10.91, 12.21, 26.94, P < 0.05). Multi-factor analysis showed the results as follows: female (OR = 0.27 95%CI:0.18-0.39), school students (OR = 8.05, 95%CI:3.87-16.73), vegetarian (OR = 1.60, 95%CI:1.15-2.22) took a higher risk of getting pathogenic goiter; while the group of those who had university degree or above (OR = 0.84, 95%CI: 0.73-0.97), ate sea food frequently (OR = 0.62, 95%CI:0.44-0.88) took a lower risk.

CONCLUSIONSThe ratio of diffuse goiter in the group aged among 6-7 years old and 8-10 years old was comparatively high. The ratio was influenced by many factors.

Adolescent ; Adult ; Aged ; Child ; China ; epidemiology ; Cross-Sectional Studies ; Feeding Behavior ; Female ; Goiter ; epidemiology ; prevention & control ; Humans ; Male ; Middle Aged ; Prevalence ; Surveys and Questionnaires ; Young Adult

OBJECTIVETo evaluate the iodine nutrition level of population in Zhejiang province and to analyze the relevant influencing factors from 2009 to 2011.

METHODSFrom October 2009 to October 2011, a total of 19 517 subjects were recruited in this cross sectional survey, by multistage stratified cluster random sampling method. The subjects were all living over three years in Zhejiang province. The basic information and life styles were interviewed by questionnaires; and the samples of drinking water, edible salt and urines were separately collected from the subjects to test the content of iodine. In total, 16 228 subjects answered the questionnaire, and 265 samples of drinking water, 7811 samples of edible salt and 19 517 samples of urine were collected. Then, we analyzed the distribution of iodine in water, edible salt and urine samples, as well as the relevance.

RESULTSThe median (25% - 75% percentile) of water iodine was 2.42 (1.17 - 6.28) µg/L in drinking water among Zhejiang residents; while separately 2.79 (1.60 - 6.87) µg/L in city and 2.04 (1.03 - 5.29) µg/L in country side (Z = 2.07, P < 0.05). The figures turned out to be 2.17 (1.22 - 5.73) µg/L, 2.77 (1.88 - 6.87) µg/L, and 1.40 (0.77 - 5.65) µg/L, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 11.16, P < 0.05). The median (25% - 75% percentile) of salt iodine was 28.80 (22.93 - 32.40) mg/kg; while separately 29.00 (24.50 - 32.60) mg/kg and 28.50 (13.90 - 32.29) mg/kg in city and country side (Z = 6.32, P < 0.05). The figures turned out to be 25.19 (0.00 - 30.20) mg/kg, 29.00 (26.60 - 31.70) mg/kg and 32.40 (28.94 - 36.30) mg/kg, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 1581.62, P < 0.05). The coverage rate of iodized salt was 79.54% (6213/7811) in all province. The urinary iodine median was 160.74(97.20 - 247.00) µg/L, while the urinary iodine median in pregnant women was 137.99 (82.40 - 215.30) µg/L, lower than the recommended optimal levels, which was 150 - 249 µg/L. The figures turned out to be 153.45(92.00 - 237.50) µg/L in city and 168.00 (102.18 - 257.00) µg/L in country side (Z = -9.25, P < 0.05); while in coastal, coastal periphery place and inland areas, the median were separately 156.00 (94.29 - 242.80) µg/L, 150.14 (94.70 - 227.00) µg/L and 187.70 (109.00 - 276.80) µg/L (χ(2) = 194.12, P < 0.05). The analysis of relevance between urine iodine, water iodine and iodized salt showed that the urine iodine would increase as long as the iodized salt increased; and the difference had statistical significance (χ(2) = 440.88, P < 0.01). And there were no relevance between urine iodine level and the water iodine level (χ(2)cmh = 0.57, P = 0.45). The analysis of the influencing factors showed that education background (χ(2) = 14.17, P < 0.05), different styles of career (χ(2) = 16.15, P < 0.01) and diet habits (χ(2) = 108.63, P < 0.01) could influence the level of urine iodine.

CONCLUSIONIodine was deficient in Zhejiang province. The nutrition level of iodine was fine in Zhejiang in 2009, however, the coverage rate of iodine was commonly low in coastal areas, especially the pregnant women suffered from iodine deficiency. In our study, the factors influencing the urine iodine level included iodized salt, age, education background and diet habits.

Adolescent ; Adult ; Aged ; China ; epidemiology ; Cross-Sectional Studies ; Drinking Water ; analysis ; Female ; Goiter, Endemic ; epidemiology ; Humans ; Iodine ; analysis ; urine ; Male ; Middle Aged ; Pregnancy ; Sodium Chloride, Dietary ; analysis ; urine ; Young Adult

OBJECTIVETo evaluate dietary iodine intake and its potential risks among the Chinese population.

METHODSIndividual dietary iodine intake was calculated using food consumption data multiplying by iodine concentration in foods, table salt and drinking water, followed by summing, and then compared with the corresponding age-specific reference values, including Upper Intake Level (UL) and Recommended Nutrient Intake (RNI).

RESULTSIn areas with water iodine concentration (WI) lower than 150 μg/L, 80.8% of residents had iodine intake between the RNI and UL, 5.8% higher than UL, and the remaining (13.4%) lower than RNI if iodized salt was consumed. However, in the uniodized salt consumption scenario, only 1.0% of residents between RNI and UL, 1.4% higher than UL, and a large part of residents (97.6%) lower than RNI. In areas with WI higher than 150 μg/L, all residents had iodine intake between RNI and UL if iodized salt was consumed, except 10.5% and 24.9% of residents higher than UL in areas with WI at 150-300 μg/L and higher than 300 μg/L respectively. However, in the uniodized salt consumption scenario, only 1.5% and 1.7% of residents had higher iodine intake than UL respectively.

CONCLUSIONThe findings suggested that in general, the dietary iodine intake by the Chinese population was appropriate and safe at the present stage. People in areas with WI lower than 150 μg/L were more likely to have iodine deficiency. While people in areas with WI higher than 150 μg/L were more likely to have excessive iodine intake if iodized salt was consumed.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Diet ; Drinking Water ; chemistry ; standards ; Female ; Goiter ; epidemiology ; prevention & control ; Humans ; Iodine ; administration & dosage ; analysis ; deficiency ; Male ; Nutritional Status ; Sodium Chloride, Dietary ; administration & dosage ; analysis

Adolescent ; Child ; China ; epidemiology ; Goiter, Endemic ; epidemiology ; Humans ; Iodine ; deficiency ; Rural Population ; Surveys and Questionnaires

OBJECTIVETo evaluate the effectiveness of universal salt iodization (USI) for the control of IDD in Hebei province since it was implemented in 1995, identify the problems currently encountered in the implementation of USI and provide practical proposals for addressing these problems.

METHODSProbability proportionate to size sampling (PPS) was employed in the surveillance of IDD, for which a total of 1200 school children aged 8-10 years were randomly selected from 30 counties around the whole province during each IDD survey. The iodine content of salt was determined quantitatively with the titration method. The iodine content of urinary samples was measured by the method of ammonium persulfate oxidation.

RESULTSThe coverage of iodized salt increased from 65.0% in 1995 to 98.0% in 1999, then decreased to 88.1% in 2005 which was below the national standard of 90%. The median urinary iodine of children aged 8-10 years varied between 160.1 microg/L and 307.4 microg/L, which was above the national standard. The proportion of urinary samples with iodine content above 300 microg/L was over 30% in 2005, implying exorbitant iodine nutrition among the children. The goiter rate (TGR) among children aged 8-10 years dropped from 11.8% in 1995 to 2.7% in 2005, indicating that the spread of endemic goiter was under control.

CONCLUSIONPreliminary elimination of IDD was achieved by USI in Hebei province. Nevertheless, some problems still existed in USI such as non-iodized salt competition, over iodization and un-standardized iodization. In order to address these problems, the management and supervision of salt market needs to be strengthened to prevent non-iodized salt from reaching households; updating equipment and modifying techniques are also necessary to ensure the quality of iodized salt; to clarify the causes of excessive urinary iodine content, the various sources of iodine from the diet need to be investigated in the future.

Child ; China ; epidemiology ; Female ; Goiter ; epidemiology ; prevention & control ; Humans ; Hypothyroidism ; epidemiology ; prevention & control ; Iodine ; deficiency ; pharmacology ; urine ; Male ; Nutrition Policy ; Nutritional Status ; Sodium Chloride, Dietary ; pharmacology ; Time Factors

OBJECTIVETo investigate the effect of cigarette smoking on thyroid gland volume, thyroid function and thyroid autoantibodies in the areas with different iodine intakes.

METHODSA cross-sectional epidemiological study in Panshan (mild iodine-deficient area), Zhangwu (more than adequate iodine intake area) and Huanghua (iodine-excessive area) was conducted in 3761 subjects in 1999.80.2 % of them were followed up in 2004. Questionnaires, thyroid function, thyroid autoantibodies, urinary iodine concentration,and thyroid B ultrasound were performed.

RESULTSThe prevalence of goiter was higher in smokers than in non-smokers (15.1% vs. 11.5%, P< 0.05). The average thyroid volume was higher in smokers with phenomenon more obvious in Panshan and Huanghua areas. Data from logistic analysis showed that smoking cigarette was an independent risk factor of goiter. There was no difference in serum TSH and Tg level between smokers and non-smokers. The positive rate of TPOAb (>100 IU/ml) was higher in smokers than in non-smokers(10.8% vs. 9.0 % , P <0.05) and was especially obvious in Huanghua area. Smoking was a independent risk factor of increasing positive rate of TPOAb. During the prospective observation,it was found that the incidence of positive TPOAb(>,100 IU/ml) was 7.4% in the subjects that were from non-smokers turning to smokers and 2.9% in those whose smoking behavior did not change. Logistic analysis indicated that the shifting from non-smoking to smoking was independent risk factor for the increase on high incidence of positive TPOAb.

CONCLUSIONSmoking cigarette was a independent risk factor of goiter. Smoking was also a risk factor of increasing TPOAb positive rate. Shifting from not smoking to smoking was an independent risk factor of increasing high incidence of positive TPOAb.

Autoantibodies ; blood ; Cross-Sectional Studies ; Female ; Goiter ; blood ; epidemiology ; immunology ; physiopathology ; Humans ; Incidence ; Male ; Smoking ; adverse effects ; Thyroid Function Tests ; Thyroid Gland ; physiopathology ; Thyroid Hormones ; blood