A cross-sectional study on iodine status among pregnant and non-pregnant women of Tripura: a North-Eastern state of India

Background: Due to excess metabolic demand of iodine in pregnancy, pregnant women and lactating mother and their neonates are most vulnerable of iodine deficiency disorder. Urinary iodine excretion is a good marker of recent dietary iodine intake. Thus, present study was conducted to assess the iodine status and median urinary iodine excretion (UIE μg/lit) among pregnant and non-pregnant women of Tripura.Methods: Tribal and Bengali pregnant and non-pregnant women from Bokafa and Jolaibari Block of South Tripura district were included in the study. Urinary iodine excretion was done using simple micro plate method. Salt iodine was estimated using iodometric titration. All the tests were performed at CNRT Lab, ICMR, India.Results: Total number of subjects included in this study was 1071. Total number of urine samples collected from pregnant and non-pregnant women was 538 and 533 respectively. Median value of UIE in pregnant and non-pregnant women of Tripura was 155.0µg/L and 130.0µg/L. In pregnant women percentage prevalence of severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-149µg/L) was found in 4.1%, 15.1% and 29.6% subjects. In case of non-pregnant women severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-99µg/L) was found in 0.6%, 9.6%, 27.8% subjects respectively. The overall prevalence of iodine deficiency was found in 48.8% pregnant women, compared to 38.0% non-pregnant subjects.Conclusions: Efforts towards universal salt iodization need to be stepped-up in Sub-Himalayan region (NE part of India) and pregnant and lactating mothers may be targeted with alternate iodine supplements (Colloidal Iodine).

Iodine Deficiency and Toxicity Among School Children in Damoh District, Madhya Pradesh, India

Objective: To estimate the prevalence of Iodine Deficiency Disorders, and householdconsumption of adequately iodized salt in Damoh district, Madhya Pradesh in 2016.Methods: Cross-sectional study with cluster sampling method was used among school-going children. 30 clusters, each with 90 children were selected to access Total Goiter rate(TGR). 540 salt samples were collected to estimate salt iodine content from their householdand 270 on the spot urine samples were collected to estimate Urine Iodine Excretion level.Results: TGR was 2.08%. The prevalence of iodine deficiency, adequate iodine nutrition,and either more than adequate or toxic level of Iodine was 26%, 28% and 46 %, respectively.72.4% people were consuming adequately iodized salt. Conclusions: Damoh district is nomore an endemic area for iodine deficiency. We recommend continuous monitoring toassess IDDs as well Iodine-induced toxicity in future

Iodine Deficiency in School Children in Aligarh District, India.

We carried out this study to assess iodine deficiency disorders among school children of 6-12 years age group in Aligarh district of India. The prevalence of goiter was 5.2%. Median Urinary Iodine Excretion level was 150 µg/L; 22.5% of students had biochemical iodine deficiency. 50.4% households were consuming adequately iodized salt.

Breast Milk Iodine and Iodine Status of Breast-Fed Infants.

Background: Breast milk is the only source of iodine for exclusively breast-fed infants. Iodine status of breast-fed infants depends on iodine in breast milk and also number of feeding in 24 hours. Iodine deficiency and iodine excess both have bad impact on infant’s health. Objective: To measure the iodine in breast milk and to evaluate iodine status of their breast-fed infants. Materials and method: This observational analytical study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Women’s Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. Urinary iodine was used as indicator for assessing iodine status. All statistical analyses were done by using SPSS (statistical programme for social science) 12 version software package for Windows. Results: The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.25 μg/L (61.50-530.00) and 225.75 μg/L (100.50-526.00) respectively. The median (range) breast-milk iodine concentration was 157 μg/L (54.50-431.50) which was more than three times of recommended minimum concentration (50 μg/L). Only 2 (4%) lactating mothers had mild biochemical iodine deficiency (UIE, 50-99 μg/L). There was no biochemical iodine deficiency of breast-fed infants. Iodine in breast milk of lactating mothers was positively correlated with their urinary iodine excretion (p<0.01). Infant’s urinary iodine was positively correlated with iodine concentration in breast milk (p<0.01) and with urinary iodine of lactating mothers (p<0.01). Conclusion: Lactating mothers and their breast-fed infants in this study were iodine sufficient. If iodine content of breast-milk is within normal range, 10-12 numbers of feeding in 24 hours for infants is enough to get sufficient iodine from their mother’s milk.

Iodine Status among School Children of remote Hilly regions of Nepal.

A cross-sectional study was conducted in remote hilly areas (Shree Antu and Ranke) of eastern Nepal to assess iodine status among school children aged 6-12 years. Urinary iodine excretion was estimated in 292 urine samples. The median urinary iodine excretion was 187.52 μg/L, and 33.6% children have insufficient urinary iodine excretion.

Iodine Deficiency Disorder in Children Aged 6-12 Years of Ambala, Haryana.

We conducted this study to assess the prevalence of goitre among 2700 children (6-12 yr) of district Ambala in Haryana. Children were examined as per standards laid by National iodine deficiency disorder control programme (NIDDCP). Multi stage cluster sampling method was used. Urine and salt samples were also studied for iodine concentration. The overall prevalence of goitre in the studied subjects was 12.6%. The median urinary iodine excretion in the study sample was more than 100μg/L Iodine content was found to be adequate in 88% of salt samples. We conclude that there was a high prevalence of goitre in young children despite iodine repletion. This calls for identification of factors to strengthen NIDDCP and the need to emphasize use of iodized salt in Haryana.

Nutrición de yodo en escolares de Calama, Chile: persitencia de niveles elevados de yodo urinario / Iodine nutrition in school children of Calama city, Chile: persistence of high urinary iodine levels

Introducción: El año 2000 se determinó que la mediana de la concentración urinaria de yodo (CUI) en escolares de educación básica de Calama estaba en 2600 ug/L, valor muy elevado, el que descendió a 487 ug/L el año 2004 después de reducir los niveles oficiales de yodación de la sal de 100 ppm a 40 ppm el año 2000. Objetivo: Investigar la nutrición de yodo en escolares de Calama, 12 años después del cambio de legislación. Sujetos y métodos: 332 escolares de ambos sexos de una escuela municipal de educación básica de Calama fueron evaluados sobre la prevalencia de bocio mediante la palpación de la glándula tiroides; al 22% de los mismos (72) se les evaluó la nutrición de yodo mediante la determinación de CUI en muestras casuales de orina por espectrofotometría. Se recolectaron 58 muestras de sal de consumo humano, seleccionadas aleatoriamente en locales comerciales, comedores de la escuela y en los hogares de los escolares, para determinar su contenido de yodo por la técnica de almidón. Adicionalmente, en todos los escolares se registró peso, talla e IMC. Resultados: Se encontró una prevalencia de bocio de 8.2%, todos del grado 1. La mediana de la concentración urinaria de yodo fue 448 ug/L. La concentración de yodo en la sal fue 31,4 ± 17.8 ppm, valor dentro de los estándares oficiales establecidos en el Reglamento Sanitario de los Alimentos (RSA) del Ministerio de Salud de Chile. Comentarios y conclusiones: Los resultados muestran un leve aumento en la prevalencia de bocio y que persiste una alta CUI en escolares de Calama, probablemente debido a una excesiva ingesta de yodo, no obstante que el promedio de contenido de yodo en la sal para consumo humano estuvo dentro del rango recomendado por OMS-UNICEF-ICCIDD (20-40 ppm). Estos hallazgos plantean la necesidad de investigar otras probables fuentes de ingesta de yodo, como causa del exceso de yodo que persiste en Calama.

Introduction: In the year2000 it was determined that the median of the urinary iodine concentration (UIE) in primary school children from Calama was 2600 ug/L, a very high level which went down to 487 ugI/L in 2004, after the standards of the Food Sanitary Regulation were scaled down from 100 ppm to 40 ppm in the year 2000. Objective: To search the current iodine nutrition in school children of Calama, 12 years after the change in the legislation. Subjects and methods: 332 primary school children from Municipal School D-48 ofthe City ofCalama were assessed in relation to their prevalence of goiter determined through palpation of the thyroid gland. In 22% ofthem (72 children), UIE was determined by spectrophotometry. 58 samples ofsalt for human consumption saltwere randomly collected from local shops, school canteens and from the children's homes to determine their iodine concentration through the starch technique. In addition, the school children were measured and weighed to determine the adequacy of their height and Body Mass Index (BMI). Results: An 8.2% prevalence ofgoiter was found; all were grade 1. The iodine concentration in the salt was 31.4 ± 17.8 in the 58 samples analyzed, the average met the adequate range of the current Food Sanitary Regulation (FSR) of Health Ministry of Chile. Conclusion and comments: A non significant increase in the prevalence ofgoiter was found, the average of UIE continue being high, possible due to an excessive intake ofiodine, nevertheless average iodine concentration in the salt for human consumption is within de recommended range by WHO-UNICEF-ICCIDD (20-40 ppm). These findings prompt to search another sources of iodine intake, as an explanation of the persistent elevation of UIE in these children.

Urinary Iodine Excretion in Urine Samples Among Children in Dahod District, Gujarat.

Aim: To measure urinary iodine excretion level and to assess the iodine level in salt sample. Study design: Cross-sectional study done in 30 randomly selected wards/villages of Dahod district. Materials and method: The IDD survey at the Dahod district was conducted by population proportionate to size (PPS) cluster sampling. A sample of 90 children (45 boys and 45 girls) of age group of 6-12 years from the school was taken. In each cluster, seven urine samples of boys and seven samples of girls were collected and sent to the public health laboratories. From each cluster, salt samples were collected from a minimum of 10 houses and tested with the use of spot salt testing kit for the presence of iodine. Results: The median urinary iodine level was 115 μg/dl. Age-wise distribution of urinary iodine showed that the proportion of children with urinary iodine excretion <100 μg/dl was lowest in the 6-year age group, whereas the highest proportion was in the 10-year age group. Out of 300 salt samples, 207 samples (69%) had >15 ppm (parts per million) iodine; four samples (1.3%) had <15 ppm iodine. This means that the use of iodized salt was 70.3%. Conclusion: The lowest urinary iodine excretion was seen in age group of six years whereas highest urinary iodine excretion was seen in age group of 10 years. In 69%, salt samples had >15 ppm iodine present and in 1.3%, samples had <15 ppm iodine present. Thirty percent of salt samples were noniodized.

Low Iodine Diet for Preparation for Radioactive Iodine Therapy in Differentiated Thyroid Carcinoma in Korea

Preparation for radioactive iodine (RAI) therapy includes an increased serum thyroid stimulating hormone level and a low iodine diet (LID). Because of extremely high iodine intake, some physicians have advocated a more stringent LID for greater than 2 weeks in Korean patients with thyroid cancer prior to RAI therapy; however, it is very difficult to maintain a stringent LID for a longer period of time. According to recent reports in Korea, a nonstringent, simple LID for only 1 week might be enough prior to RAI therapy, if the patients can be educated intensively by specially trained staff. The measurement of simple urinary iodine concentration (UIC; microg/L) may underestimate daily iodine excretion in patients with a urinary volume of more than 1 L/day and can also be affected by dilution status. Simple UIC had a weaker correlation than the iodine/creatinine (I/Cr) ratio. Therefore, the urinary I/Cr ratio can replace 24-hour urine iodine excretion instead of simple UIC, although it may overestimate iodine intake in patients with malnutrition or poor muscle mass. The measurement of serum iodine level might be useful as an adjunct parameter for assessing LID preparation, but its sensitivity and specificity were relatively low compared to the urinary I/Cr ratio.

Thyroid Function and Urinary Iodine Status in Primary School Age Children of the Hills and the Plains of Eastern Nepal.

The aim of this study is to find out the iodine nutrition and thyroid function status of the school age children of Sunsari and Dhankuta districts. A total of 386 urine and 142 blood samples were randomly collected from four schools of above districts to estimate urinary iodine and thyroid hormones, respectively. Median UIE of Dhankuta and Sunsari were 238.00 μg/L and 294.96 μg/L respectively. Relatively higher percentage (31.8%) of subclinical hypothyroid cases was found in Sunsari than Dhankuta (29.59%).

Urinary Iodine Excretion of Lactating Mothers Predicts the Iodine Content of Their Breast Milk.

Background: Iodine is essential for normal growth, mental development and survival of infants. Bangladesh is an iodine deficient region. Breast milk is the only source of iodine for exclusively breast-fed infants. Routine measurement of breast milk iodine concentration is very difficult in our country due to some social and religious barriers. So, we designed this study in our population using urinary iodine as the indicator for assessing iodine status. Objectives: To assess the iodine status of lactating mothers and their breast-fed infants and to propose a method on how to predict the iodine concentration in breast milk. Materials and Methods: This observational analytical study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Women’s Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. All statistical analyses were done by using SPSS (Statistical Programme for Social Science) 12 version software package for windows. Results: The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.25 μg/L (61.50-530.00) and 225.75 μg/L (100.50-526.50). 96% (48) mothers had no biochemical iodine deficiency (UIE ≥100μg/L), only 4% (2) mothers had mild biochemical iodine deficiency (UIE 50-99μg/L). There was no biochemical deficiency of breast-fed infants. The median (range) breast-milk iodine concentration was 157 μg/L (54.50-431.50) which was more than three times of recommended minimum concentration (50 μg/L). Iodine in breast milk of lactating mothers positively correlated with their urinary iodine excretion (P<0.01). Infant’s urinary iodine positively correlated with iodine concentration in breast milk (P<0.01) and also positively correlated with urinary iodine excretion of lactating mothers. Conclusion: Lactating mothers and their breast-fed infants in this study were found iodine sufficient. Urinary iodine concentration of lactating mothers predicts the iodine content of their breast milk.

Iodine Intake and Tolerable Upper Intake Level of Iodine for Koreans

The present study reviewed the effects of excess iodine intake on thyroid function and the incidence of thyroid disease and discussed the scientific basis for establishing a tolerable upper intake level (UL) of iodine for Koreans. ULs are defined as "the highest level of daily nutrient intake that is likely to pose no risk of adverse effects to almost all individuals in the general population." Koreans consume excess iodine from seaweed, and iodine intake is strongly influenced by seaweed consumption. However, no dose-response data derived from subjects consuming excess iodine frequently but not continuously during a lifetime are available. Therefore, the Korean DRI committee set the iodine UL to reduce the risk of adverse health effects by excess iodine intake for Koreans with distinctive seaweed-eating habits.

A review of tracking progress towards elimination of Iodine deficiency disorders in Tamil Nadu, India.

Background : Iodine deficiency disorders (IDD) are significant health problem in India. But there is dearth of regional/state level information for the same. Objective: This study was designed to study the current status of IDD in Tamil Nadu. Materials and Methods: A cross-sectional community-based survey was conducted in the state of Tamil Nadu. The study population was children in the age group of 6-12 years and the probability proportional to size 30 cluster methodology was used for sample selection. The parameters studied were prevalence of goiter, urinary iodine excretion, and iodine content in salt at the household level. Results: A total of 1230 children aged between 6 and 12 years were studied. The total goiter rate was 13.5% (95% CI: 11.1-14.9). The median urinary iodine excretion was found to be 89.5 μg/L (range, 10.2-378 μg/L). The 56% of the urinary iodine excretion values were <100 μg/L. The proportion of households consuming adequately iodized salt (iodine content ≥ 15 parts per million) was 18.2% (95% CI: 16.1-20.5). Conclusion: The total goiter rate of 13.5% and median urinary iodine excretion of 89.5 μg/L is indicative of iodine deficiency in Tamil Nadu.

Iodine Nutrition in Upper Socioeconomic School Children of Delhi.

We assessed the iodine nutrition of upper socioeconomic strata school children from Delhi to identify its association with goiter, thyroid autoimmunity or thyroid function. After informed consent of parents, all assenting students (n=997) from one randomly selected section of each class from five private schools representing all the zones of Delhi) were evaluated for goiter, urinary iodine excretion, thyroid function and antibody status. Median urinary iodine was 35.28μg/dL. Goiter was present in 123 (12.3%) and positive anti-TPO antibodies in 17 (2.6%). Increased urinary iodine was associated with thyroid dysfunction, though not with goiter.

Iodine deficiency disorders after a decade of universal salt iodization in a severe iodine deficiency region in China.

Background & objectives: Universal salt iodization (USI) was implemented in all counties of China in 1995. This study was undertaken to assess the status of iodine deficiency disorders control and prevention after 10 years of implementation of USI in a severe iodine deficiency region in China. Methods: Thirty primary school were selected in Gansu province utilizing cluster sampling methodology for the years 1995 and 2005. In each selected school, 40 children aged 8-10 yr were randomly selected for thyroid and IQ examination, and urinary samples were collected from 12. On the spot casual urine samples and salt samples were collected from a subset of children included in the study. In 2005, casual urine samples were also collected from 50 pregnant and lactating women in each cluster. Effect of health education was studied by a combination method of giving questionnaires to and observing students and families. Results: The total goiter rates (TGR) were found to be 13.5 and 38.7 per cent in 2005 and 1995 respectively. The medians urinary iodine excretion levels of children were 191.8 and 119.9 μg/l in 2005 and 1995. The median urinary iodine excretion level of women was 161.9 μg/l. The mean intelligence quotient (IQ) was 96.9 in 2005 significantly more than that in 1997 (P<0.05). The health education pass rate of children and women were 21.1 and 51.1 per cent respectively. Interpretation & conclusion: After ten years of universal salt iodization (USI), iodine nutrition of people improved and the current iodine nutrition status of population was adequate. Decrease in TGR and increase in IQ showed that IDD control and prevention had made great progress through ten years USI, salt iodization played the key role in IDD control and prevention for sustained elimination of IDD, the programme of USI and other measures like health education should be persisted and enforced.

Dietary iodine intake and urinary iodine excretion in patients with thyroid diseases

This study was conducted to examine the usual iodine intake in patients with thyroid diseases and to compare iodine status with normal subjects. The dietary iodine intake was assessed using a semi-quantitative food frequency questionnaire, and urinary iodine excretion was measured in 184 patients diagnosed with thyroid diseases and 207 normal subjects. The average usual iodine intake of patients with thyroid diseases was 673.8 +/- 794.9 ug/day and that of normal subjects was 468.9 +/- 481.9 ug/day. Among the patients with thyroid diseases, higher values were found in the patients with thyroid cancer (1460.6 +/- 1044.8 ug/day) and lower values were found in patients with simple goiter (443.5 +/- 470.4 ug/day). The urinary iodine excretions of patients and normal subjects were 4.33 +/- 5.70 mg/L and 2.11 +/- 0.69 mg/L, respectively. The iodine intake and urinary iodine excretion of patients with thyroid diseases were significantly higher than those of normal subjects (p < 0.05). The dietary iodine intake and urinary excretion of patients with thyroid cancer were significantly higher than other patients with thyroid diseases and normal subjects because of the use of seaweed or seaweed-containing dietary supplements (p < 0.01). This study suggests that the habitual ingestion of seaweed-containing dietary supplements in addition to dietary iodine intake will have adverse effects due to its excessive iodine intake.

A Study on the Urinary Iodine Excretion in Normal subjects and Patients with Thyroid disease / 대한내분비학회지

An adequate supply of dietary iodine is essential for the synthesis of the thyroid hormons. The measurement of dietary iodine intake is important for the clinical assessment of thyroid disease, especially in areas where iodine intake is excessive or deficient.To evaluate dietary iodine intake in Korean and its effects on thyroid function, we measured urinary iodine excretion with morning urine by electrode method in 184 normal subjects, 96 postpartum women and 181 patients with thyroid disease from October 1994 to February 1995. The results were as follows;1) In normal control, the mean value of urinary iodine excretion was 3.8+-2.7mg/L (range 0.1-15.0mg/L). However, there was no sex and age differences in the urinary iodine excretion.2) In postpartum women, the urinary iodine excretion was 9.0+-10.8mg/L who were not taken high iodine diet(Miyok-Guk), the mean value was statistically higher than normal control(p<0.01) and significant increased the urinary iodine excretion after eating of high iodine diet(p<0.01).3) In volunteer, there were increase of urinary iodine excretion more than 10 folds after high iodine diet and medication.4) The urinary iodine excretion in patients with thyroid diseases was not different from normal control, and there were no significant differences of urinary iodine excretion among the patient groups. The urinary iodine excretion in the acute stage of patients with subactue thyroiditis or painless thyroiditis was significantly increased compared to the recovery stage. However, it was not significantly different from that of normal control.In conclusion, urinary iodine excretion in Korean population is very high comparing to the reported data in Western population but similar with Japanese. The urinary iodine excretion is significant increase( more than 10-folds of basal level) after high iodine diet or high iodine containing medication in postpartum women or healthy persons. As a clue of destruction induced thyrotoxicosis, the urinary iodine excretion measurement is not valid in area where iodine intake is excessive like Korea.