Adult ; Child ; China ; epidemiology ; Female ; Humans ; Iodine ; deficiency ; urine ; Male ; Thyroid Diseases ; epidemiology ; etiology

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 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 evaluate the influence of different salt iodine concentration on urinary iodine excrition among the target population and to determine the appropriate level of salt iodization to the local people.

METHODSIn the 31-day random control trial, 1099 subjects from 399 families were randomly distributed into four groups and were supplied with iodized-salt with different iodine concentration of (6 +/- 2)mg/kg, (15 +/- 2)mg/kg, (24 +/- 2)mg/kg and (34 +/- 2)mg/kg, respectively. The original family salt was retrieved, whose iodine content was determined in those subjects' families with single-blind method. Baseline survey was conducted including salt and urinary iodine of the subjects. From the 27th day after the intervention, the urinary samples of the subjects were continuously collected for 5 days and urinary iodine was tesed respectively. Meanwhile, daily meal investigation was conducted to evaluate the influences originated from food.

RESULTSThe median of local water iodine content was 3.05 microg/L and the average salt iodine concentration was (36.4 +/- 5.4)mg/kg while 98.8% of the household consumed sufficient iodized-salt. The medians of baseline urinary iodine of the subjects were 293.6 microg/L in city, and 508.8 microg/L in the countryside. The urinary iodine medians of four groups in the day of 28th after intervention were 97.2 microg/L, 198.6 microg/L, 249.4 microg/L, and 330.7 microg/L respectively in the city group, while they were 100.5 microg/L, 193.0 microg/L, 246.3 microg/L and 308.3 microg/L seperately in the countryside group. There was no statistically significant differences among the medians of urine iodine in the 27th, 28th, 29th, 30th and 31st day after intervention (P > 0.05).

CONCLUSIONSThe target areas were with iodine deficiency which possessed high coverage of qualified iodized-salt at household level. The average urinary iodine level of the subjects was slightly higher than the standard level, according to the baseline survey. The intervetion trail showed that the salt iodine concentration of 15-24 mg/kg was sufficient to the local people.

Adolescent ; Adult ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Female ; Housing ; Humans ; Iodine ; deficiency ; pharmacology ; urine ; Male ; Pregnancy ; Sodium Chloride, Dietary ; pharmacology ; Time Factors

OBJECTIVETo measure the iodine nutritional status on adult islanders and to evaluate the advantages and disadvantages of iodized salt prophylactic programs.

METHODSA comparative study was carried out in 8 rural townships selected from Dinghai (iodized salt district) and Daishan (non-iodized salt district) of Zhoushan islands by random sampling method. Mann-Whitney test was used to compare the urinary iodine concentration and dietary iodine intake of the two groups. Spearman correlation test was used to look for the correlation of urinary iodine concentration and dietary iodine intake in the two groups respectively.

RESULTSThe amounts of daily iodine intake excluding the iodine intake from iodized salt in the two groups were 128 micro g and 147 micro g respectively but the difference was not statistically significant (u = 1.847, P = 0.065). The urinary iodine concentration of non-iodized salt group was 90 micro g/L, lower than 194 micro g/L in iodized salt group (u = 14.673, P = 0.000). There was no significant correlation between daily iodine intake and urinary iodine concentration (r(s) = 0.052, P = 0.095).

CONCLUSIONSIn Zhoushan islands, the daily iodine intake did not meet the daily need (150 micro g/day) suggesting that iodized salt supplement was necessary. However, side effect due to overdose should be brought into attention.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Goiter ; epidemiology ; Humans ; Infant ; Iodine ; administration & dosage ; adverse effects ; deficiency ; urine ; Male ; Middle Aged ; Sodium Chloride, Dietary ; administration & dosage ; adverse effects

OBJECTIVETo investigate the prevalence of thyroid diseases in a community which did not use iodized salt.

METHODSThe survey was conducted in Panshan, Liaoning Province. 1 103 inhabitants aged 14 years or more attended the examinations, which included questionnaire, physical examination and serum analysis. Iodine in the urine and thyroid B ultrasound examination were also conducted.

RESULTSThe prevalence of overt hyperthyroidism and hypothyroidism was 16.3 per thousand and 2.7 per thousand, respectively. Subclinical hyperthyroidism and hypothyroidism were detected in 37.2 per thousand and 9.1 per thousand of the subjects, respectively. Serum autoantibodies to thyroid were detected in 10.9% of the entire population. The prevalence of goiter was 20.7% (diffuse goiter 16.8% and nodular goiter 3.9%).

CONCLUSIONIn the iodine deficient areas, perhaps autoimmununization is not only related to the development of goiter but is also the main cause of subclinical hyperthyroidism and hypothyroidism.

Adolescent ; Adult ; Aged ; Autoantibodies ; analysis ; China ; epidemiology ; Female ; Goiter ; epidemiology ; Health Surveys ; Humans ; Hyperthyroidism ; epidemiology ; Hypothyroidism ; epidemiology ; Iodine ; deficiency ; urine ; Male ; Middle Aged ; Prevalence ; Residence Characteristics ; Sodium Chloride, Dietary ; Thyroid Diseases ; epidemiology ; immunology ; metabolism ; Thyroid Nodule ; epidemiology

Thyroid tumors display diverse spectrum of histopathological groups with geographic variation in its prevalence. Influence of iodine deficiency (a major causative factor) in its etiology, prevalence, or aggressiveness is debatable which reflects the existence of various genetic events in pathogenesis. The present study was undertaken to study the role of Microsatellite instability (MSI) or LOH (loss of heterozygosity), an indicator of defective mismatch repair system as a genetic change and to explore it as a prognostic marker in thyroid tumors. Tumor tissues from total thyroidectomy surgical specimens and blood (matched control) of 36 patients from iodine deficient areas (10 benign; 26 malignant) were obtained after their consent. Urinary iodine analysis was done by alkali ash method for which 10 ml of urine was collected from 18 patients before surgery. Genomic DNA, isolated from tumor tissue and blood was amplified by polymerase chain reaction (PCR) using mono and dinucleotide markers - BAT-26, BAT-40, TGF(RII, IGFIIR, hMSH3, BAX, D2S123, D9S283, D9S851 and D18S58. PCR products were analysed on 8% denaturing polyacrylamide gel followed by autoradiography. Of total, 66.6% of tumors [70% (7/10) benign and 65.4% malignant cases (17/26)] showed MSI/LOH. Strong association of MSI/LOH with low iodine (P=0.01) and with AMES risk groups i.e. age (P=0.02), tumor size (P=0.04) and metastases (P=0.002) in thyroid tumors was observed. This may help in predicting the biological behaviour and strengthening the hypothesis that iodine deficiency has influence on MSI in thyroid tumors. Our results further substantiate the risk group classification and help in deciding the treatment modality in particular patient.
Adult ; Aged ; DNA, Neoplasm/*genetics ; Female ; Genomic Instability/*genetics ; Humans ; Iodine/*deficiency/urine ; Loss of Heterozygosity/genetics ; Male ; Microsatellite Repeats/*genetics ; Middle Aged ; Predictive Value of Tests ; Prevalence ; Research Support, Non-U.S. Gov't ; Risk Factors ; Thyroid Neoplasms/epidemiology/etiology/*genetics/pathology/therapy/urine ; Thyroidectomy ; Tumor Markers, Biological/*genetics