Mean Urinary Iodine Excretion Research Articles

The correlation between iodine nutrition and autoimmunity among hyperthyroid goiter patients in tertiary care hospital of Tamil Nadu

Background: Iodine is a trace element that is essential for the formation of thyroid hormones. It is essential for the human life’s growth and development. The thyroid gland size and functions affected by deficient or excessive intake of iodine. Iodine excess intake was found to associating with iodine-induced hyperthyroidism (IIH) and autoimmune thyroiditis. Aims and Objectives: The present study was to find the hyperthyroid goiter patient nutritional status by urinary iodine excretion (UIE) measurement and correlate them with thyroid hormone and thyroid autoantibodies. Materials and Methods: In this study, 100 adult hyperthyroid goiter ssubjects and 100 apparently normal adult subjects were conveniently recruited in this study.Urinary iodine estimation and serum TSH, fT4, fT3, AMA, and ATG were estimated,which were estimated for case and control groups. Results: The hyperthyroid goiter patient mean UIE concentration was 278.98 μg/L and 68% of excess UIE which was found. There was significant difference in the UIE between the hyperthyroid goiter patient and control (P<0.001). The following types of goiter, based on palpation, were identified among the 100 hyperthyroid patients: Grade I – 4 %, Grade II – 63%, and Grade III – 33%. There were elevated serum AMA levelswith positive correlation of excess iodine for hyperthyroid goiter patient. Conclusion: In this study, there were excess UIEs among patients; hence, these associated complications, namely, benign goiter (14%), thyroiditis (43%), cancer of thyroid (4%), and thyrotoxicosis (39%) were observed.

Study the correlation of iodine nutrition and autoimmunity among Euthyroid goiter patient in a tertiary care hospital in Tamil Nadu

Background: Iodine is an essential micronutrient for the thyroid hormone synthesis. It is crucial for the growth and development of human life. Deficient or excessive iodine intake may affect thyroid gland size and functions. Despite the intake of iodized salt, the increasing occurrence of thyroid disorders in India.
 Aim and Objective: Aim of the present study is to analyse the nutritional status of iodine among Euthyroid goiter patient by measuring urinary excretion and correlate with thyroid hormone and auto antibodies
 Materials and Methods: one hundred and fifty Euthyroid goiter patients and one hundred and fifty age-matched normal adult were included in study. Urinary Iodine level and serum TSH, freeT4, freeT3, AMA and ATG were estimated both case and control groups.
 Results: The mean urinary iodine excretion concentration (UIC) in Euthyroid goiter patient was 244.39 µg/L and excess urinary iodine excretion was found in 48%. There were elevated serum AMA levels in Euthyroid goiter patient and that positive correlated with excess iodine.
 Conclusion: In this study we found that excess urinary iodine excretion among patients. This study we observed iodine excess associated complications, viz., benign goiter (49%), thyroiditis (24%), cancer of thyroid (21%) and thyrotoxicosis (6%).

Food sources of iodine in schoolchildren and relationship with 24-h urinary iodine excretion in Victoria, Australia.

Dietary recalls have been used previously to identify food sources of iodine in Australian schoolchildren. Dietary assessment can provide information on the relative contributions of individual food groups which can be related to a robust objective measure of daily intake (24-h urinary iodine excretion (UIE)). In Australia, the government has mandated the use of iodised salt in breadmaking to address iodine deficiency. The aim of this study was to determine the dietary intake and food sources of iodine to assess their contribution to iodine excretion (UIE) in a sample of Australian schoolchildren. In 2011-2013, UIE was assessed using a single 24-h urine sample and dietary intake was assessed using one 24-h dietary recall in a convenience sample of primary schoolchildren from schools in Victoria, Australia. Of the 454 children with a valid recall and urine sample, 55 % were male (average age 10·1 (1·3 (sd) years). Mean UIE and dietary iodine intake were 108 (sd 54) and 172 (sd 74) μg/d, respectively. Dietary assessment indicated that bread and milk were the main food sources of iodine, contributing 27 and 25 %, respectively, to dietary iodine. Milk but not bread intake was positively associated with UIE. Multiple regression (adjusted for school cluster, age and sex) indicated that for every 100 g increase in milk consumption, there was a 3 μg/d increase in UIE (β = 4·0 (se 0·9), P < 0·001). In conclusion, both bread and milk were important contributors to dietary iodine intake; however, consumption of bread was not associated with daily iodine excretion in this group of Australian schoolchildren.

Study of iodine nutrition level in pregnant south Indian subjects in third trimester

Objective: Aim of the present study is to analyse the nutritional status of iodine among pregnant women by measuring urinary excretion and do the correlation with thyroid hormone and auto antibodies. Materials and Methods: one hundred pregnant women with third trimester gestation and one hundred age-matched non-pregnant were included in study. Results: Urinary Iodine excretion and serum TSH, fT4, fT3, AMA and ATG were estimated were estimated for case and control groups. The mean urinary iodine excretion concentration (UIC) in pregnant women was 290.17±91.71 µg/L. Excess urinary iodine excretion was found in 69%. There were elevated serum AMA levels in 36 pregnant women and that positive correlated with excess iodine. Conclusion: The pregnant women had no iodine deficiency, rather had high urinary iodine concentrations indicating more than adequate iodine intake. The excess urinary iodine level may tiger the thyroid auto antibody. Keywords: Urinary iodine excretion (UIE), thyroid stimulating hormone (TSH), free thyroxine (fT4), free tri-iodothyronine (fT3), anti-microsomal antibody (AMA), anti-thyroglobulin antibody (ATA), pregnancy, iodine excess.

Study of iodine nutrition level in pregnant south Indian subjects in third trimester

Objective: Aim of the present study is to analyse the nutritional status of iodine among pregnant women by measuring urinary excretion and do the correlation with thyroid hormone and auto antibodies Materials and Methods:one hundred pregnant women with third trimester gestation and one hundred age-matched non-pregnant were included in study. Results:Urinary Iodine excretion and serum TSH, fT4, fT3, AMA and ATG were estimated were estimated for case and control groups. The mean urinary iodine excretion concentration (UIC) in pregnant women was 290.17±91.71 µg/L. Excess urinary iodine excretion was found in 69%. There were elevated serum AMA levels in 36 pregnant women and that positive correlated with excess iodine. Conclusion:The pregnant women had no iodine deficiency, rather had high urinary iodine concentrations indicating more than adequate iodine intake. The excess urinary iodine level may tiger the thyroid auto antibody. Keywords: Urinary iodine excretion (UIE), Thyroid stimulating hormone (TSH), Free thyroxine (fT4), Free tri-iodothyronine (fT3), Anti-microsomal antibody (AMA), Anti-thyroglobulin antibody (ATA), pregnancy, Iodine excess

Adequately iodized salt is an important strategy to prevent iodine insufficiency in pregnant women living in Central Java, Indonesia.

Iodine is an essential micronutrient for cognitive development and growth. Optimal intakes are critical during pregnancy. We report the iodine status and thyroid function of pregnant women living in areas previously affected by severe iodine deficiency and in longstanding iodine sufficient areas in Java, Indonesia. This cross-sectional study was conducted in Magelang, Java, from July to November 2015, in four sub-districts; two previously affected by severe iodine deficiency (area 1) and two that were iodine-sufficient (area 2). Iodine intake was estimated using median urinary iodine concentration in spot samples and mean urinary iodine excretion in 3 x 24-hour samples, thyroid hormones (thyroid-stimulating hormone and free thyroxine) were measured in venous blood samples, and iodine content of household salt samples was estimated by titration. We recruited a total of 244 pregnant women, 123 in area 1 and 121 in area 2. Urinary iodine results suggested adequate habitual iodine intakes in both areas (median urinary iodine concentration in area 1: 222 μg/l (interquartile range 189, 276 μg/l), area 2: 264 μg/l (interquartile range 172, 284 μg/l), however, the risk of inadequate intakes increased with advancing trimester (Odds Ratio = 2.59 (95% CI 1.19–5.67) and 3.85 (95% CI 1.64–9.02) at second and third trimesters, respectively). Estimated prevalence of thyroid function disorders was generally low. Salt was iodized to approximately 40 ppm and foods rich in native iodine did not contribute significantly to dietary intakes. Adequately iodized salt continues to prevent iodine insufficiency in pregnant women living in areas previously affected by severe iodine deficiency in Java, Indonesia. Monitoring and surveillance, particularly in vulnerable groups, should be emphasized to ensure iodine sufficiency prevails.

Assessment of Iodine Status in Iranian Students Aged 8-10 Years: Monitoring the National Program for the Prevention and Control of Iodine Deficiency Disorders in 2016

Iodine is a key element in the synthesis of thyroid hormones. The deficiency of the secretion of them will Reduce IQ, disturbance in the psychomotor growth and shortened height. Urinary iodine is a good indicator of iodine intake status. Urinary iodine status in at-risk groups is one of the most important indicators of community status. All 56 universities/medical faculties in Iran should determine and report median urinary iodine and its relative distribution in school children aged 8 to 10 yr, to determine the status of urine output. The sample size in each university/college is 240 students and the cluster sampling method (48 clusters in each area in 2016) and based on probability Measurement. The amount of urinary iodine was measured quantitatively by acid digestion. The mean urinary iodine excretion was estimated at 18.61 μg/dl. The median urinary iodine concentration in 52 universities was sufficient, and the national mean of urinary iodine excretion rate was 19.3 μg/dl. The iodine status was estimated in the optimal range in 65.6% of the students and in only 4.7% in the range of moderate and severe deficits, based on the urinary iodine index. Iodine is sufficient in most parts of the country. The implementation of the country's national program for the prevention and control of iodine deficiency disorders has made more important the quality control of the collaborative laboratories of this program than before. Moreover, it is absolutely essential to avoid excessive iodine in order to prevent possible side effects.

Trimester-Specific Reference Intervals for Thyroid Function Parameters in Indian Pregnant Women during Final Phase of Transition to Iodine Sufficiency.

Background:Interpretation of thyroid function tests during pregnancy depends on gestational age, method, and population-specific reference intervals. Therefore, there is a worldwide trend to establish trimester-specific levels for different populations. The aim of this study was to establish a trimester-specific reference range for thyroid function parameters during pregnancy in Indian women.Materials and Methods:Thyroid function tests (TSH, FT4, TT4, TT3) of 80, 76, and 73 women at 1st, 2nd, and 3rd trimester, respectively, and 168 nonpregnant women were analyzed after exclusion of low UIC(<150 μg/L) and anti-TPO positivity(>35 IU/ml). Urinary iodine excretion (UIC) was assessed in all. The 2.5th and 97.5th percentile values were used to determine the reference ranges for thyrotropin (TSH), free thyroxine (FT4), total thyroxine (TT4), and total triiodothyronine (TT3) for each trimester of pregnancy.Results:The reference range for TSH for first trimester was 0.19–4.34 μIU/ml, for second trimester 0.46–4.57 μIU/ml, and for third trimester 0.61–4.62 μIU/ml. The reference range during three trimesters for FT4 (ng/dl) was 0.88–1.32, 0.89–1.60, and 0.87–1.54, for total T4 (μg/dl) was 5.9–12.9, 7.4–15.2, and 7.9–14.9. In nonpregnant women, FT4 was 0.83–1.34, total T4 was 5.3–11.8, and TSH was 0.79–4.29. The mean UIC in nonpregnant women was 176 ± 15.7 μg/L suggesting iodine-sufficiency in the cohort.Conclusion:The trimester-specific TSH range in pregnant women in this study is not significantly different from nonpregnant reference range in the final phase of transition to iodine sufficiency in India.

Goitre and urinary iodine excretion survey in schoolchildren of Kashmir Valley

An extensive survey on schoolchildren in Kashmir Valley in 1995 showed a high prevalence of goitre, making it imperative to have a relook at our iodine status, 15 years postiodization. To study the total prevalence of goitre and urinary iodine excretion (UIE) in Kashmiri schoolchildren, 15 years postiodization. A cross-sectional survey, covering 9576 schoolchildren, aged 5-15 years (5988 in 6-12 year age group) was conducted. Goitres were graded as per WHO/UNICEF/ICCIDD. UIE was measured by the arsenic acid reduction in ceric ions method and was estimated in 208 subsampled children. Results were compared with that of 1995 survey. The overall prevalence of goitre in the present study was 3·8% (95% CI: 3·4-4·2) and 3·7% (95% CI: 3·2-4·2) in those aged 6-12 years. No significant difference in prevalence of goitre was observed between boys and girls overall (3·6% vs 4·1%. P > 0·2), nor in the 6-12 year age group (3·3% vs 4·0%, P > 0·1). There was a significant trend of increasing prevalence of goitre with age (P < 0·005). UIE ranged from 12 to 397 μg/g.creatinine (median, 104); 11% subjects had UIE of <50 μg/g.creatinine. Overall, prevalence of goitre was significantly lower (3·8% vs 45·2%, P < 0·001), and mean UIE was significantly higher (123·6 ± 5·3 vs 49·60 ± 3·55 μg/g.creatinine, P < 0·001), compared to that in the 1995 survey. The marked improvement in overall iodine nutrition in Kashmir Valley- one and a half decades after implementation of salt iodization should encourage healthcare providers to make tangible efforts for implementation of iodization programmes in areas with iodine deficiency.

Iodine Deficiency in Northern Paris Area: Impact on Fetal Thyroid Mensuration

IntroductionIodine is essential for normal fetal and neonatal development. We studied the prevalence and impact on fetal thyroid development of iodine deficiency in pregnant women in the northern part of the Paris conurbation.Materials and Methods110 patients underwent several determinations of urinary iodine excretion (UIE) and of serum FT4, FT3, and TSH. Fetal thyroid gland size was assessed using ultrasonography.ResultsWe found evidence of widespread iodine deficiency (mean UIE, 49.8 µg/L [standard deviation, 2.11]). Iodine deficiency did not correlate significantly with maternal thyroid parameters but showed a significant negative correlation with fetal thyroid gland size (rho = 0.25, P = 0.02).ConclusionIodine deficiency during pregnancy is still a problem in our geographical area and affects the fetal thyroid gland.Clinical Trials.gov NCT00162539

Assessment of current iodine status of pregnant women in a suburban area of Imo State Nigeria, twelve years after universal salt iodization

Three hundred and two pregnant women participated in this study. Our results showed that the range, mean and median urinary iodine excretion (UIE) were 28.1 to 218.1, 152.09 ± 41.65 and 163.1 µg/l, respectively. The range, mean and median TSH concentration were 0.7 - 5.9, 1.4 ± 0.7 and 1.3 µIU/ml, respectively. Our results showed that none of the women have severe iodine deficiency, 2% had moderate iodine deficiency, 12% had mild iodine deficiency, while 80% had optimal iodine nutrition and 6% have more than adequate. We observed a progressive and significant (P = 0.0009) decrease in the mean UIE from the 1st to the 3rd trimester. We observed also that 95% of the pregnant women had TSH concentration within the normal range. The TSH values between the three trimesters showed no significant difference (P = 1.20). The Urinary Iodine Excretion and Thyroid Stimulating Hormone concentration values suggest that iodine deficiency has been eliminated as a public health problem in Orlu. The progressive decrease in the median UIE from the 1st to the 3rd trimester should be addressed to meet the increased demand of iodine as a result of the pregnancy. Key words: Urinary iodine, thyroid stimulating hormone, iodine deficiency, hyperthyroidism, pregnant women, Orlu, Nigeria.

Lack of Association between Urinary Iodine Excretion and Successful Thyroid Ablation in Thyroid Cancer Patients

Low-iodine diet is prescribed before (131)I administration in patients with differentiated thyroid cancer, although no study has properly quantified its clinical benefit. Our study aimed to evaluate the association between urinary iodine excretion (UIE) and (131)I ablation by correlating UIE with the rate of successful ablation. We retrospectively studied 201 differentiated thyroid cancer patients who had received (131)I therapy and posttherapy whole-body scan (WBS) for remnant ablation after either thyroid hormone withdrawal (THW group, n = 125) or recombinant human TSH (rhTSH group, n = 76). The outcome of thyroid ablation was assessed using two different criteria: no visible uptake at control WBS 8-12 months after ablation or no visible uptake plus undetectable stimulated serum thyroglobulin (Tg). According to the criterion of no visible uptake, 84.6% of the patients were successfully ablated, with no significant difference between THW and rhTSH groups. Mean UIE at the time of ablation was 132 +/- 160 microg/liter, not significantly different between patients of the THW and rhTSH groups. There was no significant difference in UIE between ablated or nonablated patients both in the whole group and the rhTSH or THW groups. According to the criterion of no visible uptake plus undetectable stimulated serum Tg (in anti-Tg negative patients) at control WBS 8-12 months after ablation, UIE was not significantly different in ablated and nonablated patients. Our study indicates that the body iodine content is not an important determinant of thyroid ablation, when preparing the patients with either THW or rhTSH.

Thyroid volume, selenium levels and nutritional habits in a rural region in Albania

Environmental factors are involved in goiter development. An increased number of goitrous patients were identified among outpatients in Gyrocaster, a mountainous region in Southwestern Albania. We examined possible associations of thyroid enlargement with nutritional factors. 112 consecutive patients, 104 females, aged 52.8 +/-12.1 (mean+/-SD), who either were taking thyroxine (n=27) or were suspected to have thyroid disease were examined. Thyroid parameters and nutritional habits were recorded and serum selenium and urine iodine levels were determined; thyroid ultrasound was performed. The median thyroid volume (TV) was 20.4 ml (range 4.4-97.6). All consumed food was home-produced. TV correlated negatively with the frequency of lamb-goat meat and vegetables consumption (p=0.05 and p=0.03, respectively). Mean TV was significantly lower in those eating lamb-goat >1 times/week (21.4+/-13.3 vs 31.9+/-23 ml, p<0.01). The association of TV with lamb meat consumption was independent of sex, education or occupation (p < 0.009). Selenium levels ranged from 30.6-138 microg/L (reference range 43-190). There was no association between selenium levels and TV. 43% of the subjects had TSH < 0.3 mU/L (those on thyroxine were excluded). Log TSH correlated negatively with TV and fT4 levels (p < 0.007), indicating the presence of autonomy (TSHRab positive in two subjects). Mean urinary iodine excretion was 99.8+/-35.3 microg/gr creatinine (normal >100). Nutritional factors may be involved in the development of goiter in Southwestern Albania. No role of selenium was found. The higher consumption of lamb-goat meat and vegetables, all non-industrialized, appeared to be protective. This finding may reflect better socioeconomic status, although this was not identified. Unrecognized subclinical hyperthyroidism, probably due to thyroid autonomy, was quite common.

Iodine deficiency in children 7–19 years old in Eastern Province of Cameroon

To determine the prevalence of iodine deficiency in children in Eastern Province, Cameroon. Urinary iodine (I) and thiocyanate (SCN) excretion levels were assessed in 158 children (62 boys and 96 girls) aged 7-19 years. Mean urinary iodine excretion was 4.49 microg/dl for girls and 4.71 microg/dl for boys, lower than the 5.0 microg/dl minimal value defined by WHO. Overall 64.42% of subjects had urinary iodine excretion below the minimum, more than three times the population percentage (20%) at which a zone is declared endemic. Mean urine SCN concentration and mean I/SCN ratios of the study population were 2.57 +/- 1.43 mg/dl and 2.21 +/- 1.35 microg/mg for boys and 2.91 +/- 1.57 mg/dl and 1.91 +/- 1.1 microg/mg for girls. Iodine deficiency remains a problem in Eastern Province of Cameroon.

Goiter Persistence After Iodine Replenishment, the Potential Role of Selenium Deficiency in Goitrous Schoolchildren of Semirom, Iran

Despite long-standing iodine supplementation in Iran, the prevalence of goiter remains high in some areas. This suggests other nutritional deficiencies may be considered as responsible factors of goiter persistence. Therefore, we assessed the prevalence of selenium deficiency in children living in a mountainous area in Iran to evaluate its correlation with goiter. In this cross-sectional study, 1828 students from the 108 primary schools of urban and rural areas of Semirom in central Iran were selected by multistage random cluster sampling. After obtaining written consent from their parents, the children were examined for goiter grading. Grade 2 goitrous children (108 cases) were compared with non-goitrous children (111 children) as control group for serum selenium concentration. Overall, 36.7% of 1828 students had goiter. The mean and median urinary iodine excretion level was 19.3 and 18.5 mug/dl respectively. This was within normal limits. Of 219 evaluated cases, 109 children had selenium deficiency. Mean serum levels of selenium in the goitrous and control groups were 62.7 mug/l and 60.8 mug/l, respectively (p=0.42). There was a borderline significant difference of the goiter prevalence in selenium deficient and selenium sufficient subjects (40.8% vs. 54.3%, p=0.037). Twelve children had clinical or subclinical hypothyroidism. The mean (SD) serum selenium concentration of euthyroid and hypothyroid students were 61.9 (17.2) mug/l and 66.4 (11.9) mug/l respectively (p=0.35). In the area studied, selenium deficiency cannot explain high prevalence of goiter and other responsible factors should be investigated. Selenium deficiency may also have mild borderline significant protective effects on thyroid function and goiter.

Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals

The iodine intake level in a population is determined in cross-sectional studies. Urinary iodine varies considerably and the reliability of studies of iodine nutrition and the number of samples needed is unsettled. We performed a longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency. Iodine and creatinine concentrations were measured in spot urine samples collected monthly for 13 months. From these data we calculated the number of urine samples needed to determine the iodine excretion level for crude urinary iodine and for 24 h iodine excretion estimated from age- and gender-specific creatinine excretions. We found that mean urinary iodine excretion varied from 30 to 87 microg/l (31 to 91 microg/24 h). Sample iodine varied from 10 to 260 microg/l (20 to 161 microg/24 h). Crude urinary iodine varied more than estimated 24 h iodine excretion (population standard deviation 32 v. 26; individual standard deviation 29 v. 21; Bartlett's test, P < 0.01 for both). The number of spot urine samples needed to estimate the iodine level in a population with 95 % confidence within a precision range of +/- 10 % was about 125 (100 when using estimated 24 h iodine excretions), and within a precision range of +/- 5 % was about 500 (400). A precision range of +/- 20 % in an individual required twelve urine samples or more (seven when using estimated 24 h iodine excretions). In conclusion, estimating population iodine excretion requires 100-500 spot urine samples for each group or subgroup. Less than ten urine samples in an individual may be misleading.

High prevalence of goiter in an iodine replete area: do thyroid auto-antibodies play a role?

Despite long standing iodine supplementation in Iran the prevalence of goiter remains high in some areas. This may suggest that causes other than iodine deficiency, such as autoimmune thyroid diseases, should also be considered. We therefore assessed the prevalence of anti-thyroid antibodies in children living in an inland area in Iran and correlated these findings with prevalence of goiter within this region. In a cross-sectional study, 1948 students were selected by multistage random cluster sampling from the 108 primary schools (age, 7-13 year-old) of the urban and rural areas of Semirom. After obtaining written consent from their parents, the children were examined by endocrinologists for goiter grading. Grade 2 goitrous children (108 cases) were compared with non-goitrous children (111 children as control group) for anti-thyroid antibodies. Overall, 36.7% of 1948 students had goiter. The mean urinary iodine excretion level was 1.49+/-0.7 micromol/L. This was within normal limits. Of 219 children studied, 4.3% presented with subclinical hypothyroidism, and 7.3% had positive anti-thyroid antibodies. There was non-significant difference of positive thyroperoxidase antibody (anti-TPO) (Odds Ratio= 3.2, p= 0.13) but significant difference of anti Tg between goitrous and non goitrous children (Odds Ratio: 5.6, 95% CI: 1.18-26.0, p: 0.015). This study suggests that autoimmunity may be one of the mechanisms responsible for goiter persistence after iodine replenishment in this iodine deficient region, but the role of other factors should also be considered.

Bocio endémico y déficit de yodo: ¿sigue siendo una realidad en España?

To estimate the prevalence of goiter and iodine deficiency in a health district in the Autonomous Community of Valencia, given the absence of data in this region of Spain. We conducted a descriptive, epidemiologic, cross-sectional study, stratified by age and sex, in four interior regions of the province of Valencia. We selected students aged from 6 to 14 years old in 20 centers. Thyroid examination was performed by means of palpation and inspection (goiter > or = 0B). Urinary iodine excretion was analyzed in a routine urine sample. Sociodemographic and anthropometric data, as well as nutritional iodine status, were recorded in a standardized survey. In children with goiter, thyroid-stimulating hormone (TSH), free T4, and antithyroid antibodies were determined. We studied 928 children (478 boys and 450 girls). The prevalence of goiter was 33.7 % (95 % CI: 30.7-36.9 %). There were no significant differences in the prevalence of goiter by age or sex, but an inverse correlation was detected between the prevalence of goiter and parental socioeconomic position. Mean urinary iodine excretion was 155 .g/l, with no significant correlation with the prevalence of goiter. In children with goiter, 13 had positive antithyroid antibodies, 18 had high TSH (subclinical hypothyroidism), and one had suppressed TSH (subclinical hyperthyroidism). There is endemic goiter in the region studied. Urinary iodine levels were in the normal range and could be interpreted as indicating a transition phase to an improvement in iodine deficiency. Autoimmune diseases would only explain 4 % of cases of goiter.

Iodine Nutrition, Nodular Thyroid Disease, and Urinary Iodine Excretion in a German University Study Population

We determined the influence of different nutritional factors on the urinary iodine excretion in an East German university population. First, we assessed iodine excretion in spot urine samples. Second, we measured iodine content in the university canteen meals, where approximately 20% of the probands had regular meals. Third, we used a special food questionnaire to assess for other sources of nutritional iodine intake, namely iodine tablets, fish consumption, etc. Fourth, we determined the actual prevalence of goiter and thyroid nodules in our probands by high-resolution ultrasonography. The mean urinary iodine excretion in our cohort was 109 +/- 81 microg/g level indicating a borderline adequate iodine intake (100-200). The frequency of thyroid nodules was 30% and the frequency of goiter 11%. Thyroid volumes greater than 18 mL and 25 mL were considered to be enlarged in adult women and men respectively. Urinary iodine excretion was not related to the presence of goiter or thyroid nodules. In addition urinary iodine excretion did not vary with regular consumption of canteen meals, which contained approximately 50% of the daily recommended iodine intake. In contrast probands with regular supplementary intake of iodine tablets had significantly higher values of urinary iodine excretion (169 +/- 130 microg/g) compared to participants without (103 +/- 87 microg/g). No other single nutritional factor (e.g., salt, milk, or bread) had a statistically significant impact on urinary iodine excretion or was able to raise the urinary iodine excretion above the level of marginal iodine deficiency. In summary, the nutritional iodine intake in a Saxonian study population was found to be close to the margin of iodine deficiency. This shows insufficient supplementation of iodine through iodized salt/industrialized food production.

Reevaluation of Stringent Low Iodine Diet in Outpatient Preparation for Radioiodine Examination and Therapy

To decrease total body iodine is a key point in preparation for radioiodine study and therapy. We introduced a stringent self-managed low iodine diet (LID) and compared the outcome to that of the conventional restricted iodine diet (RID) for outpatients. We measured urine iodine to creatinine ratios (I/Cr) in patients prepared with RID for one week, LID for one week, or LID for two weeks. Mean urinary iodine excretion after RID for one week (n = 210) was 182.2 microg/gCr (range, 13-986 microg/gCr; standard deviation (SD) = 158.5) not reaching below the recommended level (I/Cr<100 microg/gCr). Urinary iodine excretion after LID for one week (n = 15) showed a lower mean urinary iodine level (I/Cr 119.4 microg/gCr; range, 23-218 microg/gCr; SD = 55.9) than RID for one-week, and two-week LID (n = 17) showed an even lower mean level (I/Cr 63.1 microg/gCr; range, 7-134 microg/gCr; SD = 38.7). The one-week LID period adequately (recommended level of I/Cr being less than 100 microg/gCr) prepared 26% of the patients, while two-weeks on the diet adequately prepared 70% of the patients. Furthermore, none of the two-week LID patients had I/Cr>150 microg/gCr, although a significantly greater number of one-week LID patients (19%) did. Our self-managed, outpatient LID successfully induced iodine deficiency, and two-week LID may be recommended for preparation in radioiodine study and therapy for thyroid cancer.