scholarly journals Variations in urinary iodine excretion and thyroid function. A 1-year study in healthy men

2001 ◽  
pp. 461-465 ◽  
Author(s):  
S Andersen ◽  
KM Pedersen ◽  
IB Pedersen ◽  
P Laurberg

OBJECTIVE: The iodine intake level in a population is determined in cross-sectional studies. A fraction of samples with iodine content below a certain level, e.g. 25 microg/l, may suggest iodine deficiency in part of the population. However, urinary iodine varies considerably from day to day and the fraction of low samples caused by dispersion remains unsettled. DESIGN: A longitudinal study of 16 healthy men living in an area of mild to moderate iodine deficiency. METHODS: We measured urinary iodine and creatinine concentrations, and serum TSH, total thyroxine (T4), free T4 index and total tri-iodothyronine (T3) in samples collected monthly for 1 year. RESULTS: Average urinary iodine excretion was 57.0 microg/l (49.1 microg/24 h (corrected for creatinine excretion)) and varied from 29 to 81 microg/l (28 to 81 microg/24 h) between participants. Individual samples varied between 10 and 260 microg/l, and the variation around the mean was 2.4 times larger when calculated for the 180 individual samples compared with the 15 average annual values (1.7 times larger for estimated 24 h iodine excretion values). The fraction of individual samples below 25 microg/l was 6.7% (7.2% < 25 microg/24 h), whereas none of the participants had average iodine excretion below 25 microg/l or 25 microg/24 h. Participants with average annual iodine excretion below 50 microg/24 h had a negative correlation between iodine excretion and TSH, whereas a positive correlation was observed when average annual iodine excretion was above this level. CONCLUSIONS: Seven per cent of individual urine samples indicated severe iodine deficiency without this being present in the group studied. Dispersion was reduced by 24% when using estimated 24 h urinary iodine excretion rather than urinary iodine concentration. Participants with moderate iodine deficiency (average annual urinary iodine excretion 25-50 microg/24 h) showed clear signs of substrate deficiency for thyroid hormone synthesis while participants with mild iodine deficiency (50-100 microg/24 h) did not.

Author(s):  
Rahul Damor ◽  
Jatin Chhaya ◽  
Sukesha Gamit ◽  
Jayant Patel ◽  
J. K. Kosambiya

Background: Iodine is an essential micronutrient required for normal human growth and development as it is needed for the synthesis of thyroid hormones produced by thyroid glands. The sicknesses occurred due to deficiencies of iodine in the nutrition are termed iodine deficiency disorders. Urinary iodine concentration is the prime indicator of a person’s nutritional iodine status. So, the aim of this study was to assess the status of iodine deficiency based on median urinary iodine excretion.Methods: Community based cross sectional study was carried out among purposively selected primary schools of the Dang district. All students between the age group of 6 to 12 years who were present on the day of visit were included in the study. A total 387 urine samples were collected during the period of August 2015 to September 2016.Results: Based on median urinary iodine excretion, among total analysed samples, about 6.5% samples confirmed severe iodine deficiency, 22% samples showed moderate iodine deficiency and about 36% samples indicated mild iodine deficiency. About one third (31.3%) samples suggested optimum iodine intake. Only few samples (4.4%) revealed more than required iodine intake.Conclusions: About one third (31.3%) of the surveyed population had adequate iodine intake while majority (64.4%) of them had inadequate iodine intake. 


Author(s):  
Dinesh P. Sharma ◽  
Amitkumar Maheshwari ◽  
Chandan Chakrabarti ◽  
Darshan J. Patel

Abstract 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 talukas, 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.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Norman Blumenthal ◽  
Karen Byth ◽  
Creswell J. Eastman

Aim. The primary objective of the study was to assess the iodine nutritional status, and its effect on thyroid function, of pregnant women in a private obstetrical practice in Sydney.Methods. It was a cross-sectional study undertaken between November 2007 and March 2009. Blood samples were taken from 367 women at their first antenatal visit between 7 and 11 weeks gestation for measurement of thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels and spot urine samples for urinary iodine excretion were taken at the same time as blood collection.Results. The median urinary iodine concentration (UIC) for all women was 81 μg/l (interquartile range 41–169 μg/l). 71.9% of the women exhibited a UIC of <150 μg/l. 26% of the women had a UIC <50 μg/l, and 12% had a UIC <20 μg/l. The only detectable influences on UIC were daily milk intake and pregnancy supplements. There was no statistically significant association between UIC and thyroid function and no evidence for an effect of iodine intake on thyroid function.Conclusions. There is a high prevalence of mild to moderate iodine deficiency in women in Western Sydney but no evidence for a significant adverse effect on thyroid function. The 6.5% prevalence of subclinical hypothyroidism is unlikely to be due to iodine deficiency.


2000 ◽  
Vol 12 (2) ◽  
pp. 79-84 ◽  
Author(s):  
C. Yamada ◽  
D. Oyunchimeg ◽  
P. Enkhtuya ◽  
A. Erdenbat ◽  
A. Buttumur ◽  
...  

In 1992, the Mongolian government conducted a nationwide palpation study of the thyroid glands, and the study showed an overall goiter rate of 30%. As a result of this, the Mongolian Government launched its Iodine Deficiency Disorders (IDD) Elimination Programme in 1996 and its primary strategy was salt iodization. In 1998 and 1999, we carried out programme monitoring studies in 11 provinces. The results showed: among schoolchildren, a goiter rate was 22.8% (n=6,535), median values of urinary iodine excretion ranged from 11 μg/l to 256 μg/l (n=1,930), and usage rates of iodized salt (>20 PPM iodine content) in their households ranged from 3% to 82%. We concluded that severe iodine deficiency in 1992 was improved from moderate to mild severity a few years later by salt iodization. However, stronger official commitments and community participation are needed to improve the programme so that iodized salt will be made more widely available. Asia Pac JPublic Health 2000;12(2): 79-84


Author(s):  
Yozen Fuse ◽  
Yoshiya Ito ◽  
Yoshimasa Shishiba ◽  
Minoru Irie

Abstract Context Japan has been regarded as a long-standing iodine sufficient country without iodine fortification; however, data on nationwide iodine status is lacking. Objective This study aimed to characterize the iodine status in Japan. Methods From 2014 through 2019 a nationwide school-based survey was conducted across all districts in Japan. Urinary iodine concentration (UIC), creatinine (Cr) concentration and anthropometry were assessed in healthy school-aged children (SAC) aged 6 to 12 years. Their iodine status is regarded as generally representative of the nation's iodine status. Results A total of 32,025 children participated. The overall median UIC was 269 μg/L which was within the WHO’s adequacy range. There was a regional difference in UIC values within 14 regions, and the lowest and highest median UIC were found in Tanegashima Island (209 μg/L) and Nakashibetsu, Hokkaido (1,071 μg/L), respectively. The median UIC ≥ 300 μg/L was observed in 12 out of 46 regions. By using estimated 24-h urinary iodine excretion (UIE), the prevalence of SAC exceeding the upper tolerable limit of iodine for Japanese children was from 5.2 to 13.7%. The UIC values did not change with age, BSA and BMI percentile, while the Cr concentration simultaneously increased suggesting the effect of urinary creatinine on UI/Cr and estimated 24-h UIE values. Conclusions The iodine intake of Japanese people is adequate, but in some areas it is excessive. The incidence and prevalence of thyroid disorders associated with iodine intake should be obtained especially in the areas where high amounts of iodine are consumed.


2019 ◽  
Vol 109 (4) ◽  
pp. 1080-1087 ◽  
Author(s):  
Angelo Campanozzi ◽  
Irene Rutigliano ◽  
Paolo E Macchia ◽  
Gianpaolo De Filippo ◽  
Antonio Barbato ◽  
...  

ABSTRACTBackgroundIodine is an essential micronutrient for intellectual development in children. Information on iodine intakes based on 24-h urinary iodine excretion (UIE) is scant, because iodine status is only assessed by the measurement of urinary iodine concentration (UIC) in spot urine samples.ObjectivesThe aim of our study was to evaluate the iodine intake of school-age children and adolescents, using UIE measurement in 24-h urine collections.MethodsThe study population included 1270 healthy subjects (677 boys, 593 girls) aged 6–18 y (mean age ± SD: 10.3 ± 2.9) from 10 Italian regions. Daily iodine intake was estimated as UIE/0.92, based on the notion that $\sim$92% of the dietary iodine intake is absorbed. The adequacy of intakes was assessed according to the Dietary Reference Values for iodine of the European Food Safety Authority (EFSA). Body mass index (BMI) and UIC were also measured for each subject.ResultsBased on the scientific opinion of EFSA, 600 of 1270 subjects (47.2%) had a lower than adequate iodine intake, with a higher prevalence among girls (54.6%) compared with boys (40.2%) (P < 0.001). Although UIE and 24-h urinary volumes increased with age (P < 0.001), a progressive decrease in the percentage of subjects with iodine excretion <100 µg/24 h (P < 0.001) was observed, without any significant difference in the percentage of subjects with UIC <100 µg/L. No significant association was detected between BMI z-score and UIE (P = 0.603) or UIC (P = 0.869).ConclusionsA sizable proportion of our population, especially girls, appeared to be at risk of iodine inadequacy. The simple measurement of UIC could lead to underestimation of the occurrence of iodine deficiency in younger children, because of the age-related smaller urine volumes producing spuriously higher iodine concentrations.


1980 ◽  
Vol 33 (2) ◽  
pp. 205 ◽  
Author(s):  
GH McIntosh ◽  
GB Jones ◽  
DA Howard ◽  
GB Belling ◽  
BJ Potter ◽  
...  

A low-iodine diet has been prepared for rats, using locally available low-iodine ingredients. On analysis it has been shown to consistently contain 15-20 ng iodine/g. When fed to growing female rats, this diet produced severe iodine deficiency while not significantly affecting growth or reproduction. The deficiency was manifested by a fall in daily urinary iodine excretion (to less than 1 JIg/day) and a seven-fold increase in thyroid uptake (1311) observable within 3 months. Levels of plasma thyroxine (T 4) and thyroid stimulating hormone (TSH) continued to change for 4-5 months, T 4 falling from 69�9 to 7�5 nmol/l and TSH increasing seven-fold from a control value of 364 to 2406 ng/ml. Goitre was present in all iodine-deficient rats and iodine content in the thyroid was 10 % of the control value.


Author(s):  
Nilratan Majumder ◽  
Balaram Sutradhar ◽  
Saradindu Riang ◽  
Shib Sekhar Datta

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).


2004 ◽  
Vol 10 (6) ◽  
pp. 863-870
Author(s):  
F. A. El Mougi ◽  
S. Abdel Ghaffar ◽  
N. A. F. Fayek ◽  
M. S. Mohammed

Sufficient data relating urinary iodine excretion in children to other iodine deficiency indicators are lacking in Egypt. We assayed urinary iodine concentration and serum levels of thyroid stimulating hormone [TSH], thyroglobulin, free triiodothyronine [T3] and free tetraiodothyronine in 99 school-aged Egyptian children. Goitre was found in 25 children. Median urinary iodine concentration was 70 micro g/L. We found mild iodine deficiency [50-99 micro g/L] in 60.6% of the children and moderate to severe deficiency [< 50 micro g/L] in 31.3%. The latter showed a high frequency of goitre and elevated mean serum free T3, TSH and thyroglobulin levels. Individual urinary iodine excretion rates vary, therefore these other indicators could help in screening for iodine deficiency at an individual level, especially in moderate to severe deficiency


2006 ◽  
Vol 9 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Andrew J Seal ◽  
Paul I Creeke ◽  
Daniella Gnat ◽  
Fathia Abdalla ◽  
Zahra Mirghani

AbstractObjectiveTo assess the iodine status of long-term refugees dependent on international food aid and humanitarian assistance.DesignA series of cross-sectional two-stage cluster or systematic random sample surveys which assessed urinary iodine excretion and the prevalence of visible goitre. Salt samples were also collected and tested for iodine content by titration.SettingSix refugee camps in East, North and Southern Africa.SubjectsMale and female adolescents aged 10–19 years.Main resultsThe median urinary iodine concentration (UIC) ranged from 254 to 1200 μg l−1 and in five of the camps exceeded the recommended maximum limit of 300 μg l−1, indicating excessive iodine intake. Visible goitre was assessed in four surveys where it ranged from 0.0 to 7.1%. The camp with the highest UIC also had the highest prevalence of visible goitre. The iodine concentrations in 11 salt samples from three camps were measured by titration and six of these exceeded the production-level concentration of 20 to 40 ppm recommended by the World Health Organization (WHO), but were all less than 100 ppm.ConclusionsExcessive consumption of iodine is occurring in most of the surveyed populations. Urgent revision of the level of salt iodisation is required to meet current WHO recommendations. However, the full cause of excessive iodine excretion remains unknown and further investigation is required urgently to identify the cause, assess any health impact and identify remedial action.


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