Areas Of Mild Iodine Deficiency Research Articles

Association of obesity and diabetes with thyroid nodules

There are conflicting data concerning the possibility that obesity and diabetes raise the risk of thyroid nodules. The incidence of thyroid nodules is increasing, as is that of obesity and diabetes; therefore, understanding whether these metabolic and nutritional disorders influence nodular thyroid disease is important for organizing prevention strategies. This study investigated the association between thyroid nodules, obesity, diabetes, and dietary habits. A cohort of randomly selected adults (455 males, 746 females; age: 18-90 years) living in Palermo (Italy), a mild iodine deficiency area, was cross-sectionally investigated. Participants underwent high-resolution ultrasonographic evaluation of the thyroid, and answered a food frequency questionnaire. Laboratory blood measurements were obtained in 587 participants. Thyroid nodules were detected in 475 (39.5%) participants. The number of thyroid nodules was correlated with age (r = 0.19; P < 0.001), gender (r = 0.08; P = 0.005), and body mass index (r = 0.07; P = 0.02). No significant correlation was observed between the number of nodules and glycated hemoglobin, serum insulin concentrations, and homeostasis model assessment of insulin resistance. Age-adjusted and gender-adjusted prevalence of both overweight/obesity and type 2 diabetes of each group of participants divided according to the number of nodules significantly increased with the number of nodules (P < 0.05 in both cases). The group of participants with nodules exhibited a significantly lower age-adjusted and gender-adjusted habitual intake of milk (P = 0.02). Multivariate regression analysis showed that age, gender, body mass index, diabetes, and habitual consumption of milk were independently correlated with presence of thyroid nodules. This study seems to indicate that an association exists between obesity, diabetes, and thyroid nodules.

Impact of thyroid autoimmunity in euthyroid women on live birth rate after IUI.

Does thyroid autoimmunity (TAI) predict live birth rate in euthyroid women after one treatment cycle in IUI patients? TAI as such does not influence pregnancy outcome after IUI treatment. The role of TAI on pregnancy outcome in the case of IVF/ICSI is largely debated in the literature. This is the first study to address this issue in the case of IUI. This was a retrospective cohort study. A two-armed study design was performed: patients anti-thyroid peroxidase (TPO)+ and patients anti-TPO-. All patients who started their first IUI cycle in our fertility center between 1 January 2010 and 31 December 2014 were included. After exclusion of those patients with or being treated for thyroid dysfunction, 3143 patients were finally included in the study. After approval by the institutional review board we retrospectively included all patients who started their first IUI cycle in our center between 1 January 2010 and 31 December 2014 with follow-up of outcome until 31 December 2015. Patients with clinical thyroid dysfunction were excluded (thyroid-stimulating hormone (TSH) <0.01 mIU/l; TSH >5 mIU/l) as were patients under treatment with levothyroxine or anti-thyroid drugs. These patients were then divided into two main groups: patients anti-TPO+ and patients anti-TPO- (= control group). Live birth delivery after 25 weeks of gestation was taken as the primary endpoint of our study. As a secondary endpoint, we evaluated differences in live birth delivery after IUI according to different upper limits of preconception TSH thresholds (<2.5 and <5.0 mIU/l). Furthermore, the influence of thyroid function (TSH, free thyroxine (fT4)), anti-TPO status, age, smoking, BMI, parity, ovarian reserve (anti-mullerian hormone (AMH) and FSH), IUI indication and IUI stimulation on live birth rate was analyzed. Between-group comparison did not show any significant difference between the anti-TPO+ and anti-TPO- group with respect to live birth delivery-, pregnancy- or miscarriage rate with odds ratio at 1.04 (95% CI: 0.63; 1.69), 0.98 (95% CI: 0.62; 1.55) and 0.74 (95% CI: 0.23; 2.39), respectively. In addition, there were no significant differences in live birth delivery-, pregnancy- or miscarriage rate when comparing subgroups according to TSH level (TSH ≥2.5 mIU/l vs. TSH <2.5 mIU/l) with an odds ratio at 1.05 (95% CI: 0.76; 1.47), 1.04 (95% CI: 0.77; 1.41) and 0.95 (95% CI: 0.47; 1.94), respectively. This study was powered for the primary aim, live birth rate. The limitations of this study are the absence of region-specific reference ranges for thyroid hormones and the absence of follow-up of TSH values during ART and subsequent pregnancy. Moreover, there was a time difference of 5 months between thyroid assessment and the start of stimulation. The area where the study was conducted corresponds to a mild iodine deficient area and data should be translated with caution to areas with different iodine backgrounds. Our findings indicate comparable pregnancy-, abortion- and delivery rates in women with and without TAI undergoing IUI. Moreover, we were unable to confirm a negative effect of TSH level above 2.5 mIU/l on live birth delivery rate. We therefore believe that advocating Levothyroxine treatment at TSH levels between 2.5 and 4 mIU/l needs to be considered with caution and requires further analysis in a prospective cohort study. No external funding was used for this study. No conflicts of interest are declared.

Iodine nutritional status and thyroid effects of exposure to ethylenebisdithiocarbamates

IntroductionItaly is still characterized by a mild iodine deficiency and is among the most intensive users of chemical products for agriculture in Europe. The aim of this study was i) to evaluate thyroid effects of exposure to mancozeb, a fungicide widely used in agriculture, in a sample of Italian grapevine workers, and ii) to verify whether the iodine intake may modulate the risk of thyroid disruption due to the mancozeb metabolite ethylenthiourea (ETU). MethodsOne hundred seventy-seven occupationally exposed male workers (29 from Chianti, a mild iodine deficient area, and 148 from Bolzano an iodine sufficient province) and 74 non-occupationally exposed male controls (34 from Chianti and 40 from Bolzano) were enrolled in the study. Serum biomarkers of thyroid function, as well as urinary iodine and ETU concentrations were assessed. Moreover all the recruited subjects underwent clinical examination and thyroid ultrasound. ResultsMultivariate comparisons showed lower mean serum levels of FT4 in Chianti-workers as compared to Bolzano-workers. Moreover, an increased urinary iodine excretion (>250µg/L) was more frequently found among more exposed workers (ETU>20µg/L) than among less exposed ones and this effect was more pronounced in Chianti- than in Bolzano-workers. Chianti-workers also showed a significantly higher frequency of very low thyroid volume (≤6.0ml) as compared to controls. ConclusionsThese findings showed a mild thyroid disrupting effect due to occupational exposure to mancozeb, more pronounced in workers residing in an area characterized by a mild to moderate iodine deficiency as compared to workers residing in an area covered by a long-lasting iodine prophylaxis program.

Population Survey of Iodine Deficiency and Environmental Disruptors of Thyroid Function in Young Children in Haiti.

Iodine deficiency is the leading cause of preventable neurodevelopmental delay in children worldwide and a possible public health concern in Haiti. To determine the prevalence of iodine deficiency in Haitian young children and its influence by environmental factors. Cross-sectional study, March through June 2015. Community churches in 3 geographical regions in Haiti. 299 healthy Haitian children aged 9 months to 6 years; one-third each enrolled in a coastal, mountainous, and urban region. Urinary iodide, serum thyrotropin (TSH), goiter assessment, and urinary perchlorate and thiocyanate. Mean age was 3.3±1.6 years, with 51% female, median family income USD 30/week, and 16% malnutrition. Median urinary iodide levels were normal in coastal (145 μg/L, interquartile range [IQR] 97 to 241) and urban regions (187 μg/L, IQR 92 to 316), but revealed mild iodine deficiency in a mountainous region (89 μg/L, IQR 56 to 129), P < 0.0001. Grade 1 goiters were palpated in 2 children, but TSH values were normal. Urinary thiocyanate and perchlorate concentrations were not elevated. Predictors of higher urinary iodide included higher urinary thiocyanate and perchlorate, breastfeeding, and not living in a mountainous region. Areas of mild iodine deficiency persist in Haiti's mountainous regions. Exposure to two well-understood environmental thyroid function disruptors is limited.

Early detection of biochemically occult autonomous thyroid nodules.

Autonomously functioning thyroid areas may be associated with subclinical or overt hyperthyroidism, but may exist even in the presence of normal TSH. This study was aimed at comparing the rate of autonomously functioning areas and their cardiac sequelae in patients with nodular goitre studied with the usual and a novel approach. In total 490 adult outpatients with thyroid nodular goitre, living in a mild iodine-deficient area, were selected in our referral centre for thyroid diseases from 2009 to 2014 on the basis of a suspicion of thyroid functional autonomy. They were divided in three groups according to a non-conventional approach (excessive response to thyroxine treatment: group 1) or conventional approach (low/normal TSH with clinical suspicion or low TSH: groups 2 and 3). All patients of the study with the suspicion of thyroid functional autonomy underwent thyroid scan with radioactive iodine (I131) uptake (RAIU). The percentage of confirmed thyroid functional autonomy was 319/490, being significantly higher in group 3 than in groups 1 and 2 (81.5 vs 64.7 vs 52.6%; chi-square P < 0.0001). However, the diagnosis with non-conventional approach was made at a significant earlier age (P < 0.0001). Cardiac arrhythmias as well as atrial fibrillation were similarly detected by conventional and non-conventional approaches (chi-square test: P = 0.2537; P = 0.8425). The hyper-responsiveness to thyroxine treatment should induce the suspicion of thyroid functional autonomy at an early stage, allowing to detect autonomous functioning areas in apparently euthyroid patients.

Parathyroid Hormone Determination in Ultrasound-Guided Fine Needle Aspirates Allows the Differentiation between Thyroid and Parathyroid Lesions: Our Experience and Review of the Literature

In many cases, it is difficult or even impossible to distinguish parathyroid lesions from thyroid ones at ultrasound as well as at scintiscan and even at cytology, because they often share common features. The aim of this study was to evaluate the role of Parathyroid Hormone (PTH) determination in the aspirates in the differential diagnosis of parathyroid from thyroid lesions in an area of mild iodine deficiency and high prevalence of thyroid nodules. Forty-six consecutive patients were suspected to have one or more nodule(s) of parathyroid origin because of their position in the posterior aspect of thyroid lobes and/or their shape and echo-pattern at ultrasound examination. In 13 cases, there were also laboratory findings suggestive for primary hyperparathyroidism, with clinical evidence in 6 of these patients. A total of 55 lesions suspected to be of parathyroid origin were selected. After obtaining cytological preparations, the needle used to perform the fine-needle aspirate (FNA) was washed using 1 ml of normal saline. Intact PTH determination in the washout was done whereas the evaluation was performed directly in the aspirated fluid in case of cystic lesions. The values of PTH in the aspirates ranged from 6.7 to 16640 pg/ml. Sixteen patients underwent surgical intervention and the histological examination of the 23 operated lesions previously submitted to FNA-PTH showed 11 parathyroid adenomas, 5 hyperplasic parathyroid lesions and 7 benign thyroid nodules. A strong positive correlation between high levels of PTH in the aspirate and the histological findings of parathyroid lesions was found. A value over 245 pg/ml was constantly associated to the parathyroid lesions. Our results confirmed the high accuracy of FNA-PTH determination in differentiating parathyroid lesions from thyroid nodules and this is of special value in an area of mild iodine deficiency with a high prevalence of thyroid nodules.

Iodine supplementation for lactation: time for tailoring treatments targeted to specific subgroups

27 March 2012 We completely agree with the main point brought forth by Emder and Jack.1 They emphasise that although most attention has recently focused on the inadequacy of iodine in Australian diets, the reverse situation should not be overlooked and that the recent national recommendation for routine supplementation of pregnant women with iodine may result in an increased number of cases of iodine toxicity in infants of women with high dietary iodine intakes. We work in Spain's eastern, Mediterranean coast. We are antipodal to New Zealand but, nevertheless, we face the same problem. This is an area of mild iodine deficiency.2 Living near the sea may confer advantages for iodine intake. Iodine gas released from seaweeds may, through respiration, supply a significant fraction of daily iodine requirements. The medical panel recommends since 2006 a daily supplement of 250 μg. of iodine for all Spanish lactating women.3 We perform routine urine iodine determination (UIC) to all lactating women newly enrolled in our well baby practice since 2009. We collected samples from 72 participants (median UIC 110.5 μg/L, range 9–875 μg/L). According to the WHO/ICCIDD/UNICEF classification, 4.2%, 8.3%, 31.9%, 29.2%, 12.5%, and 10% of participants had UIC <20, 20–49, 50–99, 100–199, 200–299 and >300 μg/L, respectively. This evaluation of the nutritional status of iodine in our Consultation rooms shows an iodine deficiency within iodine sufficiency. Moreover, a cross-sectional study of 1844 pregnant women carried out in three areas in Spain, during the period 2004–2008 reported that iodine supplement intake in the first half of pregnancy may lead to maternal thyroid dysfunction in iodine-sufficient or mildly iodine-deficient populations.4 We hypothesise that detrimental results are to be expected from the indiscriminate supplementation of iodine for women with the highest median urinary iodine, i.e. 22.5% of our patients. A challenge for any provider in treating a patient is tailoring a treatment plan to fit his level of disease. It applies to malignancy and asthma, and it ought to apply to iodine nutritional status. We are grateful to Emder and Jack because their clinical cases illustrate the problems clinicians may encounter when working in these controversial areas. We are very grateful to Berta Verd for editorial assistance.

Relative Impact of Iodine Supplementation and Maternal Smoking on Cord Blood Thyroglobulin in Pregnant Women with Normal Thyroid Function

Objective: To assess the impact on cord blood (CB) thyroglobulin (Tg) of early iodine supplementation during pregnancy. Methods: A total of 111 healthy pregnant women with normal thyroid function were included in a prospective randomized study and divided into two groups with (150 µg/day) or without iodine supplementation started during the first trimester. Maternal smoking was assessed qualitatively by self-reported statements and quantitatively by cotininuria. Exhaustive thyroid tests were performed at delivery in the mother and in CB. Results: Third-trimester ioduria documented compliance with iodine supplementation (160 vs. 76 µg/l in controls). CB Tg was not different between the iodine and control groups (median 77 vs. 79.5 ng/ml, respectively) and did not correlate with maternal ioduria. CB Tg was higher in newborns from smoking mothers (114 vs. 64.7 ng/ml) and correlated with self-reported smoking status more than with maternal cotininuria. Nonsmokers had no difference in CB Tg whether they took iodine supplementation or not, as opposed to smokers, who tended to benefit from supplementation. Conclusions: Iodine supplementation does not significantly impact CB Tg in healthy nonsmoker pregnant women selected for normal thyroid function, as opposed to maternal smoking. CB Tg appears to be a marker of in utero tobacco exposure. In areas of mild iodine deficiency, iodine supplementation could especially benefit the fetuses of smokers.

Iodine supplementation in pregnancy and its effect on child cognition

Maternal hypothyroidism and hypothyroxenemia due to iodine deficiency have been shown to affect development of the newborn negatively. Maternal iodine supplementation may therefore improve cognitive performance of the offspring, even in areas of mild-to-moderate iodine deficiency (ID). Several iodine supplementation studies have been performed in mildly ID pregnant women in Europe. These studies have shown that iodine supplementation increases maternal urinary iodine (UI) excretion and reduces thyroid volume, as well as prevents increases in infant thyroid volume and thyroglobuline. However, randomized controlled studies with long-term outcomes are lacking. Therefore, two trials were started in 2008 in areas of low iodine status; one in Bangalore, India (n=325), and another in Bangkok, Thailand (n=514). Pregnant women were recruited <14 weeks gestational age and randomized to either receive a daily dose of 200μg I (as KI) or an identical placebo throughout pregnancy. Both trials are ongoing, and women are followed up during pregnancy and at delivery. UI, thyroid hormones, and thyroid size are measured. Birth outcomes are recorded, such as gestational age at delivery, height, weight, and APGAR scores, and cord blood and heel stick blood (<72h) is collected from the child. Child development is assessed at 6 weeks of age using the Neonatal Behavioral Assessment Scale (NBAS), and at 12 and 24 months of age using the Bayley Scales of Infant Development. The outcomes of these trials will contribute importantly to the evidence base for iodine supplementation of pregnant women living in areas of mild iodine deficiency.

Dietary Iodine and Thyroid Cancer Risk in French Polynesia: A Case–Control Study

French Polynesia has one of the world's highest thyroid cancer incidence rates. Iodine is suspected to play a role in this high incidence. The objective of this study was to assess whether low dietary iodine is related to a higher risk of thyroid cancer in the French Polynesian population. A case-control study was performed among native residents of French Polynesia. It included 229 cases of differentiated thyroid cancer diagnosed between 1979 and 2004 (203 women, 26 men) matched with 371 population controls (324 women, 47 men) on the date of birth. The current study is focused on dietary iodine intake and fish consumption (food rich in iodine) and analyzed by conditional logistic regression. Daily dietary iodine intake was insufficient (<150 μg/day) in 60% of both cases and controls. A decreased risk of thyroid cancer was observed with a higher consumption of fish (p(trend)=0.008) and shellfish (p(trend)=0.002), and also with a higher dietary iodine intake (p(trend)=0.03). There was no significant interaction between the effects of the thyroid radiation dose and the dietary iodine intake (p=0.2). French Polynesia is a mild iodine deficiency area in which a higher consumption of food from the sea and a higher dietary iodine intake are significantly associated with a decreased risk of thyroid cancer. The quantification of this reduction requires specific investigation of iodine intake in traditional Polynesian food.

Iodine supplementation in Saint-Petersburg

Problem of iodine insufficiency is still actual as well as 75% of Russian population is living in the area of mild iodine deficiency. To compare iodine supplementation of Saint-Petersburg population in 1999 and 2010. We examined 704 schoolchildren (420 girls and 284 boys) from 6 up to 11 years old, living in Saint-Petersburg. We had took day samples of urine (50 ml) for measuring of iodineurea by well known reaction of Sandell-Kolthoff. All children were examined by endocrinologist, palpation of thyroid gland was performed for revealing of enlargement and nodules. Such examination was made in 1999 and 2010 years. Study which was performed in Saint-Petersburg in 1999 has not revealed severe iodine deficiency and iodineuria mediana was 105 μg/l but nearly half of examined children had iodineuria less than 100 μg/l as mild iodine deficiency. In 2010 iodineuria mediana was 148 μg/l and it was significantly higher than in 1999. In 2010 samples with iodineuria less than 100 μg/l were revealed three times rare (in15.8% of cases) than in 1999 (49%). Goiter by palpation was found in 3% of schoolchildren in 1999 and in 1.6% in 2010. It was shown that during last ten years iodine supplementation in Saint-Petersburg was significantly improved.

Iodine status assessment in Campania (Italy) as determined by urinary iodine excretion

Objective Mild iodine deficiency was first documented in Campania in the 1990s. We assessed the urinary iodine nutritional status of schoolchildren in Campania before the introduction of legislation for salt iodization and compared the findings with previous results to evaluate to what extent “silent” iodine prophylaxis, which accompanies socioeconomic advances, affects iodine status. Methods We examined 10552 schoolchildren aged 9–13 y from the five Campania provinces. The study was conducted from April 1999 to October 2002. Urinary iodine excretion was measured in morning urine samples with the AutoAnalyzer 3, an automated system based on the Sandell-Kolthoff reaction. Data were interpreted according to World Health Organization criteria. Results The median urinary iodine excretion level in Campania was less than 100 μμg/L, which indicates insufficient iodine intake. Mild iodine deficiency was identified in all provinces, namely Napoli, Salerno, Caserta, Avellino, and Benevento, with median urinary iodine excretions of 87, 81, 72, 64, and 61 μg/L, respectively. Overall, the analysis of frequency distribution showed values below 50 and 100 μg/L in 32% and 61% of children, respectively. These values were lower than those previously reported for Campania. Conclusion This study confirms that Campania is a mild iodine deficiency area. The decrease in iodine deficiency versus previous studies indicates that silent prophylaxis plays a relevant role in this condition, but it is not sufficient to eradicate it. Our data will serve as a basis for future evaluations of iodine status in Campania.

Референтные значения тиреотропного гормона и распространенность субклинических нарушений функции щитовидной железы у подростков в регионе легкого йодного дефицита

The present study was undertaken to determine the reference values of thyroid-stimulating hormone (TSU) in a representative sample of healthy adolescents and to establish the prevalence of subclinical thyroid dysfunction in a mild Iodine-deficiency area (median Ioduria 53 mg/l). An integrated study, involving thyroid ultrasonography, determination of TSH and thyroid peroxidase Ab, was conducted in 1179 children (637 girls and 542 boys) aged 13-16 years in 23 localities of the Sverdlovsk Region. By taking into account the criteria recommended for the determination of the reference ranges of thyroid hormones, the authors formed a sample of 561 adolescents (271 boys and 290 females). The upper TSH range was 5.2 and 4.7 mIU/l for boys and girls, respectively. The established reference values of TSH show it inexpedient to reduce its upper range under the existing conditions of inadequate iodine intake, the prevalence of subclinical hypothyroidism in adolescents prevails over the incidence of subclinical thyrotoxicosis.

Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate

Background: Vitamin A (VA) deficiency (VAD) and iodine deficiency (ID) often coexist in children in Africa. VAD may affect thyroid function and the response to iodine prophylaxis.Objective: The aim was to investigate the effects of supplementation with iodine or VA alone, and in combination, in children with concurrent VAD and ID.Design: A 6-mo randomized, double-blind, 2 × 2 intervention trial was conducted in 5–14 y-old South African children (n = 404), who, on average, had mild-to-moderate VAD and ID. At baseline and after 3 mo, children received 1) iodine (191 mg I as oral iodized oil) + placebo (IS group), 2) VA (200000 IU VA as retinyl palmitate) + placebo (VAS group), 3) both iodine and VA (IS+VAS group), or 4) placebo. At baseline, 3 mo, and 6 mo, urinary iodine (UI), thyroid volume, thyrotropin (thyroid-stimulating hormone; TSH), total thyroxine (TT4), thyroglobulin, serum retinol (SR), and retinol-binding protein (RBP) were measured.Results: SR and RBP increased significantly with VA supplementation (P < 0.05). For UI, SR, and RBP, there were no significant treatment interactions between iodine and vitamin A. The 3-factor and all three 2-factor interactions were significant for thyroid volume, TSH, and thyroglobulin (P < 0.001), whereas none of these interactions were significant for TT4. There was a clear effect of VAS without IS on TSH, thyroglobulin, and thyroid volume; all 3 variables decreased significantly (P < 0.05).Conclusions: Iodine prophylaxis is effective in controlling ID in areas of poor vitamin A status. VA supplements are effective in treating VAD in areas of mild ID and have an additional benefit—through suppression of the pituitary TSHβ gene, VAS can decrease excess TSH stimulation of the thyroid and thereby reduce the risk of goiter and its sequelae.

The Prevalence of Thyroid Disease in the Children and Teenagers in Iodine-Deficient Region

To indicate iodine intake and the prevalence of thyroid disease in the iodine-deficient area we perform complex investigation of 2332 children and teenagers in 23 settlements of Sverdlovsk region. Studying population consisted of1153 7—8 years old children (599 girls and 554 boys) and 1179 14—15 years old teenagers (637 girls and 542 boys). Study protocol includes thyroid ultrasound for all children and urinary iodine excretion for younger group and, serum TSH, AT-TG and AT-TPO in older group. The incidence of diffuse goiter was 22.8% and median of urinary iodine excretion was 53 μg/l. We found that Sverdlovsk region is a mild iodine-deficient area. The incidence of significant thyroid diseases is relatively low (thyroid cancer, functional autonomy and overt hypothyroidism — in 0.04%, nodular goiter — 0.26%, autoimmune thyroiditis with subclinical hypothyroidism — 0.6%). There is no significant difference in the prevalence of thyroid disease among children and teenagers. We found that thyroid ultrasound is not a reasonable screening strategy for thyroid cancer and nodular goiter in pediatric population of the iodine-deficient region. We consider that the most reasonable screening strategy is the palpation technique.

Efficiency of iodine prophylaxis in pregnant women with nontoxic diffuse goiter in a mild iodine-deficiency area

Thirty-four pregnant women with nontoxic diffuse goiter (NDG), living in a mild iodine-deficiency area, were examined. The absence of iodine prophylaxis causes a higher than normal increase in thyroid-stimulating hormone levels by the end of pregnancy and a high frequency (87.5%) of hypothyroxinemia In the second half of pregnancy. These unfavorable events are prevented by the administration of iodine in a daily dose of 150-200 g; the early initiation of iodine prophylaxis is most effective. In women with NDG, pregnancy is most commonly complicated as threatening miscarriage, particularly in those who have not received iodine prophylaxis. Smoking during pregnancy enlarges the thyroid, which is not prevented by iodine prophylaxis.

Goiter prevalence and urinary iodine status in urban and rural/mountain areas of Piedmont region

Piedmont region was reported in the 70s as a mild iodine-deficient area with a goiter prevalence > 10%. This study aimed at characterizing the current status of iodine deficiency in Piedmont, with special attention to putative differences between urban and rural/mountain areas. A cross-sectional, observational study was performed according to the surveillance methods for iodine deficiency disorders recommended by the World Health Organization (WHO). Ultrasound local thyroid volume reference values and median urinary iodine concentration were obtained in 2178 schoolchildren aged 11-15 yr, resident in Piedmont region for more than 5 yr to assess both goiter prevalence and iodine intake. Anamnestic and anthropometric data, thyroid volume by both bimanual palpation and ultrasound were assessed, and spot urinary iodine samples were collected. The median urinary iodine concentration was 115.8 microg/l and the prevalence of goiter 3.1%, indicating this area as iodine-sufficient. Nevertheless, 39% of the schoolchild population had urinary iodine levels < 100 microg/l and 6.8% < 50 microg/l. No differences in goiter prevalence and median urinary iodine excretion were observed between urban and rural/ mountain populations. In conclusion, Piedmont is now an iodine-sufficient region. As no programs of salt iodization have been carried out in the last 30 yr, a silent iodine replacement has occurred. Despite a sufficient median urinary iodine excretion, a program of iodine prophylaxis is strongly recommended due to a large part of iodine-deficient population.

The incidence of recurrence and hypothyroidism after radioiodine treatment in patients with hyperthyroidism in Trakya, a mild iodine deficiency area, during the period 1991–2003

The purpose of this retrospective study was to evaluate the incidence of recurrence and the success of radioiodine treatment (RIT) in the Trakya region of Turkey, an area with mild iodine deficiency, and to compare the effect of dose regimen selection (fixed (FD) or calculated dose (CD)) on treatment success. The study sample included 148 patients (40 male, median age 50) treated with radioiodine between the years 1991-2003. Patients were categorized into three diagnostic groups: Graves' disease (GD) (n = 65), solitary toxic adenoma (TA) (n = 29), and toxic multinodular hyperthyroidism (TMH) (n = 54), and each divided into two subgroups according to treatment method; the first group was treated with a FD of 370 MBq (10 mCi), and the second with CD. The largest group was GD (44%), followed by TMH (36%). Median duration of follow-up was 28 months (range 6-147). FD was given to 52.7% of all patients and CD was given to 47.3%. There was a partial difference in the dose regimen between all groups, but did not reach statistically significant levels (FD vs. CD: 65%-35%; 38%-62%; 46%-54%; GD, TA, TMH respectively, p > 0.05). Total cure rate in FD and CD was 46 (59%) and 37 (52.9%), respectively. The rates of hypothyroidism for GD, TA, and TMH groups were 28 (43.1%), 6 (20.7%) and 16 (29.6%), respectively. The incidence of hypothyroidism did not vary significantly between any groups (p > 0.05). At the end of the follow-up period, a total of 104 patients (70.3%) were treated successfully. There was no significant difference in the cure rate between any groups (p > 0.05). The treatment success in all groups and subgroups did not differ significantly between FD and CD. Our lower cure rate than in previous studies may be related to iodine deficiency. Higher doses of radioiodine may be required to increase final treatment success in endemic goiter areas. If this true, dosimetry and calculated dose regimen would be required in all groups of patients instead of an FD concept. However, our findings should be verified in larger series of patients, with longer follow-up period, and urinary iodine concentration measurements.

Thyroid structural changes: results of a screening ultrasound study of a Moscow population

То assess the prevalence and pattern of thyroid disease in Moscow, a mild iodine-deficiency area, the authors examined a random sample of 1103 individuals (1004 females and 99 males) during 14 months. The examinees' age ranged from 17 to 80 years; the mean age was 36.7±14.05; median was 37 years. The survey involved a physical examination with thyroid palpation, brief history data collection, and thyroid ultrasound study on a "Mysono"portable apparatus with a 7.5-MHz linear transducer, operating on a real-time basis. Among the examinees the echographic signs of these or those thyroid changes were found in 36% of cases. The most common abnormalities were focal thyroid tissue changes, whose prevalence was 12.4%. Thyroid nodular masses were encountered at a slightly less frequency (10.5%). Of them, nodular and multinodular goiter accounted for 6 and 4.5%, respectively. The third group of changes is presented by a diffuse decrease in thyroid tissue echogenicity (9%). Diffuse goiter was less frequently identified; its frequency was 5%. A minor proportion (0.1%) of the examinees had a history of operations for this or that thyroid disease.

Prevalence of thyroid nodules in an occupationally radiation exposed group: a cross sectional study in an area with mild iodine deficiency

BackgroundThyroid nodules and thyroid cancer occur more frequently in people exposed to radiation for therapeutic purposes, and to nuclear fallout. Furthermore, it is known that a moderate degree of iodine deficiency may be responsible for an increased prevalence of thyroid nodules, while it is suspected that radiation exposure could induce changes in thyroid autoimmunity. The iodine intake of people resident in Bari, S. Italy, is mildly deficient, which could be presumed to cause a higher prevalence of thyroid pathology. This study was conducted to evaluate the prevalence of thyroid nodules in a population occupationally exposed to radiation, in an area of mild iodine deficiency.MethodsA cross-sectional study was designed to evaluate the prevalence of thyroid nodules in radiation exposed workers, compared with a stratified sample of non exposed workers. After giving written consent to participate in the study, all the recruited subjects (304 exposed and 419 non exposed volunteers) were interviewed to fill in an anamnestic questionnaire, and underwent a physical examination, ultrasound thyroid scan, serum determinations of fT3, fT4 and TSH, fine needle aspiration biopsy. The sample was subdivided into one group exposed to a determined quantity of radiation (detected by counter), one group exposed to an undetectable quantity of radiation, and the non exposed control group.ResultsThe prevalence of thyroid nodules <1 cm in diameter, defined as incidentalomas, in the exposed group with detected doses, was 11.28% in males and 9.68% in females, while in the exposed group with undetectable dose the prevalence was 10.39% in males and 16.67% in females. In the non exposed group the prevalence of incidentalomas was 9.34% in males and 13.20% in females. These prevalences were not statistically different when analysed by a multiple test comparison with the bootstrap method and stratification for sex.Instead, the prevalence of thyroid nodules > 1 cm in diameter resulted statistically different in exposed and non exposed health staff: 18.68% in non exposed males vs exposed: 3.76% (determined dose) and 9.09% (undetectable dose) in males, and 20.30% in non exposed females versus 3.23% (detected dose) and 9.52% (undetectable dose) in exposed females.There was a higher proportion of healthy staff in the exposed group than in the non exposed: (80.45% vs 68.68% in males; 80.65% vs 57.87% in females).ConclusionIn our study, occupational exposure to radiation combined with mild iodine deficiency did not increase the risk of developing thyroid nodules. The statistically significant higher prevalence of thyroid nodules in the non exposed group could be explained by the high percentage (22%) of people with a familial history of, and hence a greater predisposition to, thyroid disease.The endemic condition of mild iodine deficiency, demonstrated in other studies, played a major role in determining the thyroid pathology in our study groups.