Iodine nutritional status of children in North East India

Association of perchlorate, thiocyanate, and nitrate with dyslexic risk

Perchlorate, thiocyanate, and nitrate are sodium iodide symporter (NIS) inhibitors that disturb iodide uptake into the thyroid and have been implicated in child development. However, no data are available on the association between exposure to/related with them and dyslexia. Here, we examined the association of exposure to/related with the three NIS inhibitors with the risk of dyslexia in a case-control study. The three chemicals were detected in urine samples of 355 children with dyslexia and 390 children without dyslexia from three cities in China. The adjusted odds ratios for dyslexia were examined using logistic regression models. The detection frequencies of all the targeted compounds were 100%. After adjusting for multiple covariates, urinary thiocyanate was significantly associated with the risk of dyslexia (P-trend = 0.02). Compared with the lowest quartile, children within the highest quartile had a 2.66-fold risk of dyslexia (95% confidence interval: 1.32, 5.36]. Stratified analyses showed that the association between urinary thiocyanate level and the risk of dyslexia was more pronounced among boys, children with fixed reading time, and those without maternal depression or anxiety during pregnancy. Urinary perchlorate and nitrate levels were not associated with the risk of dyslexia. This study suggests the possible neurotoxicity of thiocyanate or its parent compounds in dyslexia. Further investigation is warranted to confirm our findings and clarify the potential mechanisms.

Assessment of Iodine Deficiency among School-Going Children of Age Group 6 to 12 Years in Kachchh District, Gujarat State: Cross-Sectional Hospital-Based Study

Aim Iodine deficiency disorder (IDD) is the cause of preventable brain damage, mental retardation, and stunted growth and development in children. This study aimed to detect the prevalence of IDD in Kachchh district, Gujarat, by testing urinary iodine excretion levels and iodine intake of salts in school-going children. Methods A cross-sectional study was conducted and the level of iodine deficiency was assessed in 223 school children of both sexes, aged 6 to 12 years from four taluka s, that is, subdivisions, of the Kachchh district by estimating urinary iodine using Sandell-Kolthoff reaction along with iodine content in edible salt samples by MBI kit (STK-Spot testing kit, MBI Kits International, Chennai, TN, India). Results The median urinary iodine level was found to be 194 μg/L, indicating no biochemical iodine deficiency in the region. In the study areas, 1% of the population showed a level of urinary iodine excretion < 50 μg/L. About 83% salt samples had iodine level more than 15 ppm and the iodine content in salt samples less than 15 ppm was only about 17%, indicating the salt samples at households contain iodine in adequate level. Conclusion There is a need of periodic surveys to assess the change in magnitude of IDD with respect to impact of iodized salt intervention. Furthermore, to strengthen National Iodine Deficiency Disorders Control Program, factors should be identified. There is also a need to prevent and reimpose the ban on the sale of noniodized salts in Gujarat.

Thiocyanate in excess develops goiter followed by auto immune thyroid diseases even after effective salt iodization in a rural community of north east India

PURPOSE

Salt iodization in Manipur of north-east India failed to prevent endemic goiter, therefore an in depth study carried out to evaluate thyroid functions of goitrous subjects in a randomly selected region.

METHODS

Goiter survey conducted in children and women of reproductive ages by palpation followed by measurement of urinary iodine, thiocyanate and house-hold salt iodine to evaluate iodine nutritional status and consumption pattern of bamboo-shoots (BS). In all grade-2 goitrous subjects, free thyroxine, triiodothyronine, TSH, TPO and Tg antibodies, thyroid volume and echogenecity by ultrasonography and cytomorphology of thyroid by FNAC studied.

RESULTS

Study population was 2486 children and 1506 women, goiter prevalence was 12.59% and 16.27% respectively; median urinary iodine and mean thiocyanate were 166 µg/l and 0.729 ± 0.408 mg/dl while salt iodine was ≥30 ppm. Serum thyroid hormones and TSH profiles of all grade-2 goitrous subjects showed 16.21% were subclinically hypothyroid, 2.16% overt hypothyroid, 4.86% subclinically hyperthyroid and 6.48% overt hyperthyroid, serum TPO- and Tg-antibodies found positive in 41.62%. Ultrasonographic results showed 24% had enlarged thyroid and 86.4% hypoechoic. Cytomorphological studies showed prevalence of colloid goiter (41.08%), lymphocytic thyroiditis (37.83%), Hashimoto's thyroiditis (8.10%), autoimmune thyroiditis (4.32%), sub-acute thyroiditis (2.16%) and 1.62% each papillary, medullary carcinoma, simple diffused hyperplasia and adenomoid nodular goiter.

CONCLUSIONS

Grade-2 goitrous individuals in this mild goiter endemic region were affected by hypo- and hyperthyroidism with hypoechoic thyroid and thyroiditis. Thiocyanate that originates from BS even in presence of adequate iodine developed goiter and led goitrous population towards such diseases.

Socioeconomic status of the population - a prime determinant in evaluating iodine nutritional status even in a post salt iodization scenario

Background To compare the state of iodine nutrition among school age children (SAC) in high- (HSGs) and low-socioeconomic groups (LSGs) during a post iodation scenario in Kolkata. Methods Clinical examinations of the goiter, median urinary iodine (MUI), mean urinary thiocyanate (MUSCN) in SAC (6-12 years) from both sexes in the different socioeconomic groups were carried out and the iodine content of edible salt was measured. Results A total of 5315 SAC, of which 2875 SAC were from a HSG and another 2440 SAC from an LSG were clinically examined for goiter. In the HSGs the total goiter prevalence (TGP) was 3.2% and in the LSGs the TGP was 9.1% and the difference was statistically significant (p<0.001). The MUI of the HSGs was 242 μg/L as compared to 155 μg/L in the LSGs (p<0.001). MUSCN of the HSGs was 0.77±0.45 mg/dL while in the LSGs it was 0.94±0.44 mg/dL and the difference was statistically significant (p<0.01). In the HSGs 19.4% salt samples had 15-30 ppm iodine and 80.6% salt samples were above 30 ppm as compared to 26.3% salt samples which were below 15 ppm, 37.1% salt samples which were between 15 and 30 ppm and 36.6% salt samples which were above 30 ppm in the LSGs. Conclusions The population of the LSGs was clinically mildly iodine deficient having no biochemical iodine deficiency while in the HSGs it was more than the adequate requirement and the HSG children are possibly at risk of excess iodine induced thyroid diseases. Existing goiter prevalence in the LSGs was from their relatively high consumption of dietary goitrogens. Therefore, socioeconomic status plays a pivotal role in the management of iodine nutrition even in a post salt iodation scenario.

Assessment of Iodine Nutritional Status of School-Age Children in Kolkata District of West Bengal State in Post-Iodation Scenario

To evaluate the state of iodine nutrition in post-iodation scenario, 3500 children were examined clinically for endemic goitre. Iodine and thiocyanate were measured in 240 urine samples; iodine content in 210 salt samples was measured. Total goitre prevalence was 6.1%. Median urinary iodine level was 21.80 µg/dl, and mean (±SD) urinary thiocyanate was 0.89 ± 0.49 mg/dl. Iodine content of only 11.9% salt samples was below recommended level of 15 ppm, 25.2% was between 15 and 30 ppm and 62.9% was >30 ppm. Iodine deficiency disorders are thus clinically mild public health problem of the studied population; however, they have no biochemical iodine deficiency. Studied population found exposed to thiocyanate load that might be the possible cause for persistence of endemic goitre. People of Kolkata should be advised to eat commonly consumed goitrogenic foods after boiling and decanting the water. Periodical monitoring and evaluation of iodine status should be mandatory.

Role of bamboo-shoot in the pathogenesis of endemic goiter in manipur, north East India

OBJECTIVE

Endemic goiter is prevalent in the iodine-sufficient region of Manipur, India. Bamboo shoot (BS), a goitrogenic plant food, are consumed regularly in the area. The objective of this study was to examine the role of BS in the pathogenesis of endemic goiter.

METHODS

Goiter prevalence, urinary iodine, and thiocyanate (SCN) excretion in school children, iodine content in drinking water, and the household consumption of salt fortified with iodine were measured. To confirm the goitrogenic potential of BS, its progoitrogenic constituents were fed to rats as part of an iodine-sufficient diet, after which the animals' thyroid gland morphology and functional status were assessed.

RESULTS

Goiter prevalence was 31% in 4852 children, and the median urinary I and SCN levels were 176.3 μg/L and 0.962 ± 0.190 mg/dL, respectively. Of the households assessed, 90% consumed salt fortified with adequate iodine. Progoitrogenic constituents were high in BS from Manipur. Increased thyroid weight, hypertrophy and hyperplasia of follicular cells, decreased thyroid peroxidase activity, and low serum thyroxine (T4) and triiodothyronine (T3) levels were observed in BS-fed rats.

CONCLUSION

Nearly one third of the studied participants had palpable goiter, despite a successful salt iodine fortification program. SCN from BS causes goiter in iodine-sufficient experimental animals. Similar ingestion in study participants was confirmed and is the likely cause for the persistence of endemic goiter in the Manipur region.

Thyromegaly and iodine nutritional status in a tertiary care hospital in South India

AIM AND OBJECTIVES

1. To assess the iodine nutritional status in patients with goiter by measuring urinary iodine excretion. 2. To compare the iodine nutritional status with the thyroid function and correlate with the type of thyroid disease.

STUDY DESIGN

Case control study.

MATERIALS AND METHODS

Three hundred patients with goiter and one hundred euthyroid healthy non-goitrous volunteers were included in this study.

RESULTS AND CONCLUSIONS

All patients had elevated urinary iodine suggesting excess iodine intake and absence of iodine deficiency. Complications known to be associated with excess iodine, viz., benign goiter (35%), iodine-induced hyperthyroidism or thyrotoxicosis (34%), thyroiditis (16%) and cancer of thyroid (15%) have been observed in this study. Therefore, continued supplementation of edible salt fortified with iodine should be monitored carefully, and supplementation programs should be tailored to the particular region.

Iodine deficiency disorders in 6-12 years old rural primary school children in Kutch district, Gujarat

OBJECTIVE

To compare prevalence of goitre in primary school children; to determine median urinary iodine concentration in children; and, to assess level of salt iodization at retail trader level.

DESIGN

30 cluster survey study.

SETTINGS

Primary schools of Kutch district, Gujarat, India.

METHODS

Total 70 students including five boys and five girls from 1st to 7th standard, present in class on the day of visit were selected randomly for Goitre examination (n=2100). Urine sample was collected from one boy and one girl from each standard in each cluster. From the community, 28 children, including two boys and two girls from each standard in the same age group were examined, and salt samples were tested from their households. From each village, one retail shop was visited and various salts available were purchased and tested for iodine on the spot with spot kit.

RESULTS

Goitre prevalence of 11.2% was found among primary school children (grade 1- 8.6% and grade 2-2.6%). As the age increased, the Goitre prevalence also increased except in age group of 8 years. Median urinary iodine excretion level was 110 µg/L. Iodine level more than 15 ppm was found in 92.3% salts samples tested at the household level.

CONCLUSION

Present study showed mild goitre prevalence in primary school children in Kutch district of Gujarat.

Iodine nutritional status and goiter prevalence in 6-12 years primary school children of Saurashtra region, India

BACKGROUND

Iodine deficiency disorder (IDD) or goiter is the cause of preventable brain damage, mental retardation, and stunted growth and development in children. This study aimed to detect the prevalence of IDD in Rajkot district, India by testing urinary iodine excretion levels and iodine salt intake of school children.

METHODS

A cross-sectional study was conducted in 2940 school children of both sexes aged 6-12 years from 14 talukas subdivisions of the district. Thirty clusters were selected by using cluster sampling technique. Goiter was assessed in all the studied children along with biochemical analysis of iodine in 420 urine samples and iodine content in 840 edible salt samples in the studied area.

RESULTS

Goiter was reported from all talukas subdivisions of the studied area. Goiter prevalence ranged from 1% to 35%, and the overall prevalence was 8.8% (grade 1: 7.6%; grade 2: 1.2%), indicating a mild public health problem. In the study areas, 18.1% of the population showed a level of urinary iodine excretion <50 microg/L. The median level of urinary iodine in the studied areas was 110 microg/L (range 10-415 microg/L). The iodine level of more than 15 ppm was found in 81% of salt samples tested at the household level.

CONCLUSION

There is mild goiter prevalence in primary school children of Rajkot district, which is due to the inadequate iodine intake or content from salt at the household level.

Urinary iodine concentrations in the high background radiation areas of Kanyakumari district, Tamilnadu, India

We screened urinary iodine (UI) concentrations in high background radiation areas of the Kanyakumari district of Tamilnadu, India. We collected 331 urine samples from three villages in the district: Chinna-Villai, Kadiyapatinam, and Pallam-Annai nagar. The median UI concentrations were 257, 262, and 454 microg/L in Chinna-Villai, Kadiyapatinam, and Pallam-Annai nagar, respectively. Only 27 samples showed mild or moderate iodine deficiency (<100 microg/L) and none showed severe deficiency (<20 microg/L). These findings indicate that iodine supplementation in the villages is sufficient, probably as a result of appropriate fortification of iodized salt in the region. Further screening, including morphological and functional analysis of the thyroid gland, will be needed to clarify the health effects of chronic low-dose radiation exposure attributable to residing in a high background radiation area.