Determination of iodine concentration in urine by isotope dilution analysis and thyroid volume of school children in the west coast of Turkey after mandatory salt iodization

Study on influential factors and reference values for thyroid volume in Chinese children aged 6-12 years

The purpose of the current study was to research the factors influencing thyroid volume (TVOL) in 6-12-year-old children and update the reference values. A cross-sectional study was carried out in iodine-sufficient areas of four provinces in China. Urine, edible salt and drinking water samples were collected from children. Children's height, weight and TVOL were measured. Ridge regression was used to screen variables for solving the multicollinearity problem. Quantile regression was used to analyse the relationship between the quantiles of TVOL and other variables. In total, 5653 children aged 6-12 years were enrolled in this study, including 2838 boys and 2815 girls. There was no significant difference in TVOL between boys and girls (P > 0·05). Spearman correlation analysis showed that total TVOL was positively correlated with age, height, weight, body surface area (BSA) and BMI, and the correlation coefficients were 0·616, 0·663, 0·669, 0·685 and 0·479, respectively. Among them, the correlation between TVOL and BSA was the strongest. According to the ridge regression results, age and BSA influenced TVOL, and the ridge regression coefficients were 0·13 and 0·94, respectively. Quantile regression further showed that age and BSA had significant influences on the whole TVOL distribution (P < 0·001). Therefore, the TVOL of children aged 6-12 years in China was mainly influenced by age and BSA, and reference values for TVOL of different genders based on age and BSA were established.

Ultrasonographic determination of thyroid volume in infants and children from Aegean region of Turkey and comparison with national and international references

OBJECTIVES

Accurate diagnosis and follow-up of pediatric patients with thyroid disorders, depends on the availability of appropriate data for normal thyroid volume (TV). The aim of this study was to determine the TV by ultrasonography (US) in subjects from the newborn period up to 18 years of age from the Aegean region of Turkey.

METHODS

We measured the thyroid volumes in 513 children using US and compared them with the children's age, gender, standard deviation score (SDS) of body height (BH-SDS), body weight (BW-SDS), body mass index (BMI-SDS), and body surface area (BSA-SDS). The 3rd, 50th, and 97th percentiles of the age-dependent distribution of the TV were calculated and compared with national and international references.

RESULTS

The BH, BW, BMI, and BSA of all the participants were within the normal ranges for Turkish children. The TV was significantly positively correlated with age, gender, BH-SDS, BW-SDS, BMI-SDS, and BSA-SDS in all subjects (r=0.748, r=0.267, r=0.730, r=0.735, r=0.664 and r=0.735, respectively; p<0.0001 for all). The most important predictors for TV were age and BW-SDS, followed by BSA-SDS and BH-SDS. In multivariate regression, age and BW-SDS were the only significant independent predictors for TV. Our results were nearly similar to the corresponding data reported by the World Health Organisation in 2004.

CONCLUSIONS

The present study provides updated values for TV that can serve as a potential tool in differentiating the normal from the abnormal size of the thyroid gland in children aged 0-18 years from the Aegean region of Turkey.

Larger Thyroid Volume and Adequate Iodine Nutrition in Chinese Schoolchildren: Local Normative Reference Values Compared with WHO/IGN

Objective. Thyroid volume measured by ultrasound to define goiter needs reliable local thyroid volume reference from iodine-sufficient populations. The aim of this study is to explore the reference interval for normal thyroid volume in schoolchildren aged 8-10 years from Zhejiang Province, China. Methods. A probability-proportionate-to-size sampling method was applied to select a representative sample of 1213 children aged 8-10 years in Zhejiang Province to detect the thyroid volume, salt iodine, and urine iodine. Results. Median urinary iodine concentration in involved schoolchildren was 178.30 (125.00) μg l^-1, with the percentage of samples less than 100 μg l^-1 as 12.69% and more than 300 μg l^-1 as 15.25%. Thyroid volume was significantly correlated with age and anthropometric measurements independently of each other. The 97th percentile of thyroid volume in our study was larger generally than the new international reference. Conclusions. The iodine nutritional status in Zhejiang Province was at an adequate level. Despite some limitations in this study, we initially established the reference values for thyroid volume in 8-10-year-old schoolchildren in Zhejiang Province, China, as a local reference to be used for monitoring iodine deficiency disorders.

Determination of thyroid volume by ultrasonography among schoolchildren in Philippines

OBJECTIVE

Iodine deficiency is defined by the goiter and the urinary iodine concentration. However, a lack of local thyroid volume reference data resulted in the vague definition of goiter, especially in school-aged children. The aim of this paper was to determine the thyroid volumes by ultrasonography in schoolchildren aged 6 to 12 years living in Cagayan areas in Philippine.

METHODS

Cross-sectional thyroid ultrasonographic data of 158 schoolchildren aged 6-12 years from Tuguegarao and Lagum in Cagayan valley, Philippine were used. Thyroid volumes were compared based on logistic issue and urban and rural area and compared with other previously reported data.

RESULTS

The mean values of thyroid volume in Tuguerago and Lagum were 2.99 ± 1.34 mL and 2.42 ± 0.92 mL. The thyroid size was significantly in association with age (P < 0.00), weight (P < 0.00), height (P < 0.00), and BSA (P < 0.00) by Pearson's correlation. The median thyroid volumes of schoolchildren investigated in this study were generally low compared to international reference data by age group but not by BSA.

CONCLUSIONS

We propose for the first time local reference ultrasound values for thyroid volumes in 6-12 aged schoolchildren that should be used for monitoring iodine deficiency disorders.

Demographic, clinical, laboratory, ultrasonographic, and cytological features of patients with Hashimoto's thyroiditis: results of a university hospital of 769 patients in Turkey

We investigated the demographic and clinical features of patients with Hashimoto's thyroiditis who had been diagnosed and treated in Ege University, the main referral center in the Aegean region of Turkey. Medical records of patients who had been followed in the endocrinology clinic of Ege University were retrospectively evaluated. Patients who had been diagnosed as having any thyroid disorder were determined. Patients with Hashimoto's thyroiditis were selected among those patients. Seven hundred and sixty-nine patients fulfilled diagnostic criteria for Hashimoto's thyroiditis (725 females, 44 males; mean age 41.76 ± 12.49 years). 62.7% of patients were between 30 and 50 years of age. 53.3% of females and 63.6% of males had diffuse enlargement of the thyroid gland. TSH level was above 4.0 IU/l in 25.6% of females and 27.4% of males. Anti-tyroglobulin antibody was positive in 92% of females and 93.2 % of males. Anti-thyroid peroxidase antibody was positive in 98.4 % of females (713 patients) and 100% of males. Thyroid ultrasonography demonstrated single nodule in 52.2% and multiple nodules in 11.3% of female patients; and single nodule 32% and multiple nodules in 20% of male patients. Fine-needle aspirations of the nodules were performed in 207 patients, and none of those biopsies was diagnosed as malignant. Women with suspicious biopsis were operated. After surgery, we found that, 2% (n = 4) of patients with FNAC diagnosis of suspicious biopsies were papillary carcinoma and the other patients (3% (n = 6)) were lymphocytic thyroiditis. Age and sex distribution and laboratory findings of our patients were comparable to the previous reports. Nodule formation was the most common ultrasonographic finding in our patients, probably due to pseudonodularity. We found four women patients with thyroid cancer in our population.

Current iodine status in Turkey

OBJECTIVES

To evaluate the current nationwide iodine status in Turkey by determining urinary iodine concentrations (UIC) and household salt iodine content. A follow- up monitoring study was also conducted in 30 urban areas.

METHODS

A school-based survey was conducted in 2007 by using multistage 'proportionate to population size' (PPS) cluster sampling method. The study population was composed of 900 school-age children (SAC) from different urban, suburban, and rural areas. UIC and iodine content of the table salt used at home were analyzed.

RESULTS

Median UIC was 107 microg/l (147 in urban, 42 in suburban and rural areas, p<0.001). There were severe iodine deficiency (ID) in 7.2%, moderate and mild ID in 20.6% and 19.3%, of the SAC, respectively. UIC was sufficient (>100 microg/l) in 50% of the study population, whereas it was excessive (>300 microg/l) in 10.5% of them. Of the 900 salt samples, 662 (73.5%) were iodized and 508 samples (56.5%) contained adequately iodized salt (iodine content >15 ppm). UIC of the study population and salt iodine levels correlated well (r=0.42, p<0.001).

CONCLUSIONS

Moderate to severe ID still exists in 27.8% of the Turkish population, which is much better compared to 1997 and 2002 surveys (i.e. 58%, 38.9%, respectively). The follow-up monitoring study (in 2007) demonstrated that ID has been eliminated in 20 of 30 cities surveyed, and median UIC was 130 microg/l. ID has been eliminated in most of the urban population, however, it is still an important problem in rural areas and in particular geographical regions, which should be the target of future programs.

Trace elements in growth: iodine and selenium status of Turkish children

Starting from the fetal life and increasing the need throughout the childhood, adequate intake of micronutrients is of great importance for the proper development of structure and function of the body, and the well being. However, micronutrient deficiency is widespread in many populations of the world mainly due to nutritional insufficiencies and/or inadequate and unbalanced nutrition. While iodine and selenium (Se) are inadequately available for men and live stock in many parts of the world, Turkey is one of those countries where iodine deficiency (ID) is widespread, Se levels are marginal. In this communication, importance of adequate iodine and Se nutrition and status of Turkish children is summarized.