Increase In Thyroid Volume Research Articles

The relationship between maternal thyroid volume, TSH levels, and Healthy Eating Index scores in BMI-matched pregnant women with hyperemesis gravidarum

Objective The aim is to investigate the relationship between thyroid volume measurement and healthy nutrition questionnaire scoring in pregnant women diagnosed with hyperemesis gravidarum (HEG). Methods One hundred and fifty pregnant women with a BMI of 15–25 kg/m2 and between the ages of 17 and 42 who were diagnosed with HEG at 11–14 weeks of gestation were included in the study. Patients with a history of any disease, drug use, and previously diagnosed eating disorders were excluded. All patients were subjected to the Healthy Eating Index (HEI) questionnaire. The cutoff value for HEI score was determined as 80 points. Patients were evaluated in two groups: group 1 (HEI <80 score) and group 2 (HEI ≥80 score). Complete urine analysis including ketonuria, and thyroid function tests including TSH, T3, and T4 levels were performed for all patients. In addition, the thyroid gland volume of every patient was measured by the same radiologist. Results Increased thyroid gland volume was significantly associated with lower TSH levels (p = .02) and lower HEI scores (p < .001). On the other hand, it was not significantly associated with ketonuria (p = .47), and parity status (p = .82). Conclusions In our study, we found that there may be an increase in thyroid volume in pregnant women with HEG with lower TSH levels and eating scores. Thyroid volume may predict the patients with probable eating disorders and further studies on thyroid volume in patients with HEG may contribute to the literature.

Iatrogenic endocrine complications of lithium therapy

Lithium is a cation, similar to sodium and potassium, affecting ion transport. It is used in the medical field as a treatment of bipolar disorders. The main endocrine complications of lithium treatment affect thyroid and parathyroid glands, in association with renal complications. Thyroid adverse effects, which are more frequent in women, comprise hypothyroidism, goiter, or sometimes hyperthyroidism, through interference with the iodine symporter. The increase in thyroid volume is early. Prevalence of goiter is 4 times higher than in the general population and hypothyroidism (8–20%) more frequent in case of pre-existing thyroid autoimmunity. Hyperthyroidism likely to worsen mood is reported in 5% of cases but the causal link to lithium is unproven. An increase in serum calcium and PTH occurs in 30% of cases, as lithium stimulates parathyroid cell proliferation by activating the Wnt pathway. The risk of hyperparathyroidism, by adenoma and especially by hyperplasia, is 5 times higher than in the general population, with the particularity of frequent low urine calcium by action on the calcium-sensing receptor (CaSR). Renal complications include risk of acute or chronic renal failure and nephrogenic diabetes insipidus, which is a factor for hypernatremia and hypercalcemia through dehydration. Nephrogenic diabetes insipidus is not always reversible after lithium therapy discontinuation. Metabolically, weight gain can be observed, but rather less than with other psychotropic drugs, and lithium does not in itself induce diabetes. At pituitary level, corticotropic activation is frequent, but implicating the disease rather than lithium. Lithium treatment induces little or no hyperprolactinemia. Regular monitoring of serum calcium, the ionogram, creatinine and TSH is recommended in lithium treatment.

A prospective follow-up of thyroid volume and thyroiditis features on ultrasonography among survivors of predominantly mild to moderate COVID-19.

We previously showed that higher SARS-CoV-2 viral load correlated with smaller thyroid volumes among COVID-19 survivors at 2 months after acute COVID-19. Our current follow-up study evaluated the evolution of thyroid volumes and thyroiditis features within the same group of patients 6 months later. Adult COVID-19 survivors who underwent thyroid ultrasonography 2 months after infection (USG1) were recruited for follow-up USG 6 months later (USG2). The primary outcome was the change in thyroid volume. We also reassessed thyroiditis features on USG, thyroid function and anti-thyroid antibodies. Fifty-four patients were recruited (mean age 48.1 years; 63% men). The mean thyroid volume increased from USG1 to USG2 (11.9 ± 4.8 to 14.5 ± 6.2 mL, p<0.001). Thirty-two patients (59.3%) had significant increase in thyroid volume by ≥15%, and they had a median increase of +33.3% (IQR: +20.0% to +45.0%). Multivariable logistic regression analysis showed that only higher baseline SARS-CoV-2 viral load independently correlated with significant thyroid volume increase on USG2 (p=0.022). Among the seven patients with thyroiditis features on USG1, six (85.7%) had the features resolved on USG2. None had new thyroiditis features on USG2. All abnormal thyroid function during acute COVID-19 resolved upon USG1 and USG2. Most COVID-19 survivors had an increase in thyroid volume from early convalescent phase to later convalescent phase. This increase correlated with high initial SARS-CoV-2 viral load. Together with the resolution of thyroiditis features, these may suggest a transient direct atrophic effect of SARS-CoV-2 on the thyroid gland with subsequent recovery of thyroid volume and thyroiditis features.

Ultrasonographic Evaluation of Thyroid Gland Volume and Nodularity in Pregnant versus Non Pregnant Females: A Cross-sectional Study

Introduction: Continuous stimulation of thyroid gland occurs during pregnancy in order to meet the demands of growing foetus. This might result in variations in thyroid gland morphology which may be misdiagnosed if not assessed accurately. Ultrasonography can measure these variations during pregnancy in the form of change in volume, echotexture, nodularity etc. Aim: To compare the thyroid volume and nodules using ultrasound, amongst different trimesters of pregnancy and with non pregnant women of similar age and find the correlation with different factors. Materials and Methods: A time-bound, hospital-based, crosssectional observational study was done in the Department of Radiodiagnosis, Maharaja Yeshwantrao (MY) Hospital, Indore, Madhya Pradesh, India, from April 2021 to August 2022 on 240 patients. All subjects were divided into groups of 60 women each, which included non pregnant women in group 1 and pregnant women during each trimester in rest three groups, as group 2, 3 and 4, respectively. Thyroid volume and nodules were measured in each group. The descriptive data was calculated using mean and standard deviation and then compared using Analysis of Variance (ANOVA) test. Linear regression analysis was also used to assess the correlation. Results: Most 125 (52%) of the women belonged to the younger age group i.e., 21-25 years. Majority i.e., 114 (47.5%) of pregnant women were primigravida. Mean total thyroid volume in non pregnant group, 1st trimester group, 2nd trimester group and in 3rd trimester group were 5.44±0.82 mL, 5.85±0.64 mL, 6.25±0.67 mL and 7.24±1.16 mL, respectively, with up to 24% increase of thyroid volume during the course of pregnancy (p-value=0.001). Thyroid nodule incidence was 12.2% in pregnant women and 5% in non pregnant women. Conclusion: With pregnancy, there is an increase in thyroid gland size along with a small increase in thyroid nodularity. Also, the interplay of a few factors such as Body Mass Index (BMI), parity, age etc., was noted.

Association between exposure to radioactive iodine after the Chernobyl accident and thyroid volume in Belarus 10-15\u2009years later

BackgroundWhile there is a robust literature on environmental exposure to iodine-131 (131I) in childhood and adolescence and the risk of thyroid cancer and benign nodules, little is known about its effects on thyroid volume.MethodsTo assess the effect of 131I dose to the thyroid on the volume of the thyroid gland, we examined the data from the baseline screening of the Belarusian-American Cohort Study of residents of Belarus who were exposed to the Chernobyl fallout at ages ≤18 years. Thyroid dose estimates were based on individual thyroid activity measurements made shortly after the accident and dosimetric data from questionnaires obtained 10-15 years later at baseline screening. During baseline screening, thyroid gland volume was assessed from thyroid ultrasound measurements. The association between radiation dose and thyroid volume was modeled using linear regression where radiation dose was expressed with power terms to address non-linearity. The model was adjusted for attained age, sex, and place of residence, and their modifying effects were examined.ResultsThe analysis was based on 10,703 subjects. We found a statistically significant positive association between radiation dose and thyroid volume (P < 0.001). Heterogeneity of association was observed by attained age (P < 0.001) with statistically significant association remaining only in the subgroup of ≥18 years at screening (P < 0.001). For this group, increase in dose from 0.0005 to 0.15 Gy was associated with a 1.27 ml (95% CI: 0.46, 2.07) increase in thyroid volume. The estimated effect did not change with increasing doses above 0.15 Gy.ConclusionsThis is the first study to examine the association between 131I dose to the thyroid gland and thyroid volume in a population of individuals exposed during childhood and systematically screened 10-15 years later. It provides evidence for a moderate statistically significant increase in thyroid volume among those who were ≥ 18 years at screening. Given that this effect was observed at very low doses and was restricted to a narrow dose range, further studies are necessary to better understand the effect.

Risk Factors for Subacute Thyroiditis Recurrence: A Systematic Review and Meta-Analysis of Cohort Studies.

BackgroundSubacute thyroiditis (SAT) is a self-limited inflammatory thyroid disease with recurring episodes. However, the results regarding the recurrence rate and risk factors for SAT are inconsistent. This meta-analysis aimed to summarize the evidence of the recurrence rate and the risk factors for SAT.MethodsThe present study involved the performance of a systematic literature search of all English studies published in PubMed, Embase, Web of Science, and The Cochrane Library from inception to August 20, 2021. Cohort studies that reported the SAT recurrence rate and risk factors for recurrence were included. Two independent investigators extracted relevant information. Fixed- and random-effects models were used to pool effect sizes based on study heterogeneity.ResultsEighteen cohort studies were identified. The pooled findings showed that the recurrence rate was 12.0% (95% CI: 8.2%, 17.1%). The risk of recurrence in the glucocorticoids group was higher than that in the NSAIDs group (RR = 1.84, 95% CI: 1.04, 3.24). However, there was no significant difference in age or sex between the recurrence group and the non-recurrence group. Findings from one or two cohort studies also indicated that the copresence of HLA-B*18:01 and -B*35, the number of days required to taper prednisolone (PSL) to 5 mg/day, the duration of disease before treatment less than 30 days, the sialic acid level, or the TSH level at the termination of treatment and further extension of the hypoechoic area and increase in thyroid volume were related to the recurrence of SAT.ConclusionRecurrence was common in SAT patients. The present study indicated that glucocorticoid treatment was associated with a higher recurrence rate of SAT than NSAIDs treatment. The clinical implications of this association should be interpreted with caution, and further clinical trials on the long-term effects of different treatment strategies are needed.

DNA methylation at a nutritionally sensitive region of the PAX8 gene is associated with thyroid volume and function in Gambian children.

PAX8 is a key thyroid transcription factor implicated in thyroid gland differentiation and function, and PAX8 gene methylation is reported to be sensitive to the periconceptional environment. Using a novel recall-by-epigenotype study in Gambian children, we found that PAX8 hypomethylation at age 2 years is associated with a 21% increase in thyroid volume and an increase in free thyroxine (T4) at 5 to 8 years, the latter equivalent to 8.4% of the normal range. Free T4 was associated with a decrease in DXA-derived body fat and bone mineral density. Furthermore, offspring PAX8 methylation was associated with periconceptional maternal nutrition, and methylation variability was influenced by genotype, suggesting that sensitivity to environmental exposures may be under partial genetic control. Together, our results demonstrate a possible link between early environment, PAX8 gene methylation and thyroid gland development and function, with potential implications for early embryonic programming of thyroid-related health and disease.

Вивчення йодної забезпеченості школярів м. Києва та шляхи корекції виявлених порушень

Актуальність. Нестача йоду в довкіллі є однією з актуальних медико-соціальних проблем у багатьох країнах світу. Дефіцит йоду є важливим чинником ризику відставання у фізичному розвитку, зниження пам’яті, здатності до аналізу та абстрактного мислення. Традиційно в Україні проблема йодної недостатності була актуальною в західних регіонах, але дослідження останніх років свідчать про існування помірного йододефициту на всій території. Метою нашого дослідження була оцінка стану йодного забезпечення школярів молодших класів м. Києва. Матеріали та методи. Проведено обстеження 52 дітей віком 6–12 років, яке передбачало анкетування родини з питань поінформованості щодо наслідків йодного дефіциту та частоти вживання продуктів харчування, що містять йод, об’єктивне та ультразвукове дослідження щитоподібної залози, визначення йодурії у разових порціях сечі. Результати. Йодна недостатність виявлена у 87 % школярів, переважно легкого ступеня. Дифузний зоб 1-го ступеня діагностований у 23 % обстежених. З метою корекції йододефіциту використовувався продукт нового покоління — йодис-концентрат у вигляді водного розчину. Висновки. Дослідження йодної забезпеченості школярів віком 6–12 років м. Києва показало наявність йододефіциту легкого та середнього ступеня у 87 % дітей (відповідно у 68 та 19 %). У 12 (23 %) дітей діагностовано збільшення об’єму щитоподібної залози за нормальної ехогенності та однорідної ехоструктури. Недостатня забезпеченість йодом зумовлена нераціональним харчуванням, відсутністю масової, групової та індивідуальної йодної профілактики, низькою санітарно-гігієнічною культурою населення. Школярам із йододефіцитом призначалась індивідуальна дотація йоду у вигляді водного розчину йодис-концентрату протягом 12 місяців, що дозволило суттєво покращити стан йодного забезпечення дітей, нормалізувати рівень йодурії. Раннє виявлення йодного дефіциту та його корекція є перспективним напрямком сучасної педіатрії щодо профілактики захворювань щитоподібної залози та зниження ризиків реалізації інфекційно-респіраторної, алергічної та метаболічної патології.

Association Between 131I Exposure After the Chernobyl Accident and Thyroid Volume in Children in Belarus

Thyroid enlargement can cause problems with swallowing or breathing and a decrease in accuracy of screening for thyroid cancer. Exposure to radioactive iodines after the 1986 Chernobyl accident is known to increase risk of thyroid cancer in those exposed at a young age, but little is known about its effects on thyroid volume, which could have important clinical implications. The objective of this study is to characterize the dose-response association between iodine-131 (131I) exposure and thyroid volume using data from a Belarusian-American cohort study of residents of Belarus exposed during childhood. Persons exposed to Chernobyl fallout in Belarus at the age of 18 years or younger had individual 131I doses to the thyroid gland estimated from direct thyroid activity measurements, radioecological and biokinetic models, and interview data on whereabouts and dietary habits collected during baseline screening in 1996-2001 (N=11,970; median age 21 years). Thyroid volume was estimated from thyroid ultrasound measurements during screening. Individuals with diagnoses of benign or malignant tumors of thyroid gland, any thyroid surgery or aplasia, and missing thyroid volume measurements were excluded (n=1,104). Dose and thyroid volume were log-transformed due to right-skewed distributions. We used a multivariable linear regression to estimate the dose-response association between 131I dose to the thyroid and thyroid volume accounting for confounding effects of sex, age at screening, and place of residence at the time of screening, a proxy for endemic iodine deficiency. To examine nonlinear effects, we added a quadratic term for the log-transformed dose. Among 10,866 participants, dose to thyroid ranged from 0.0005 to 39 gray (Gy) (median=0.3 Gy). In a linear regression model adjusted for confounders, log thyroid volume was best described by a linear-quadratic function of log dose (p<0.001 for log dose and log dose-squared coefficients). The largest effect was observed for doses 0.3-0.6 Gy (14%), then gradually decreased. Subjects with thyroid dose of 1 Gy had an average thyroid volume 13.6% (95% CI 8-19.2%) higher compared to those with dose 1 mGy. Thyroid volume increased with age and was significantly higher for males compared to females and for those from Minsk city and area compared to other regions (both p<0.001). The adjusted R2-value was 30%, suggesting unaccounted factors that might better explain this association. This is the first study to assess the dose-response association between exposure to 131I and thyroid volume. Although statistically significant, the observed increase in thyroid volume with dose was small. Availability of measurements of iodine deficiency and dietary habits around the time of an accident in the future studies of nuclear accidents will be essential for understanding the mechanism of association between radiation dose and thyroid volume in young people.

A study on evaluation of foetal thyroid volume in aborted foetus by ellipsoid method in relation to gestational age

Introduction: Thyroid volume measurement is a better reflection of thyroid gland growth than any other linear dimension of the organ. Foetal thyroid volume is significantly correlated with gestational age and foetal weight. Aim: To evaluate the foetal thyroid volume in relation to the gestational weeks. Materials and Methods: A total of 22 (Male - 9; Female - 13) aborted foetuses were collected from the department of Anatomy, ESIC Medical College & PGIMSR, Chennai. Results: We have observed there was significant increase in thyroid volume with the correction factor (CF-0.479) by ellipsoid method in relation to gestational weeks. Thyroid volume with correction factor was noted to be more in males as compared to females in all gestational age groups. There was a gradual increase in thyroid weight in relation to thyroid volume in all groups of gestational ages in our study. Conclusion: The present study evaluated the foetal thyroid volume in relation to the gestational age in aborted foetuses and also suggested the volume related changes of the thyroid gland in foetal life and its abnormalities. Keywords: Evaluation, Gestation, Thyroid, Volume.

Decrease in Acromegaly-Associated Thyroid Enlargement after Normalization of IGF-1 Levels: A Prospective Observation and in Vitro Study

Objective: Goiter occurs at high frequency in acromegaly patients. Whether normalization of insulin-like growth factor 1 (IGF-1) levels could decrease goiter and thyroid volume remains unclear. Methods: Thyroid hormone levels and ultrasound measurements were assessed in 101 acromegaly patients, compared with 108 patients with nonfunctioning pituitary adenoma (NFPA) and 55 healthy controls. Thirty-four acromegaly patients underwent repeat evaluation 1 year post-transsphenoidal surgery. The effect of IGF-1 on thyroid cell proliferation, cell cycle, and apoptosis was evaluated in vitro. Results: Acromegaly patients showed larger thyroid volume than those with NFPAs (18.32 mL vs. 9.91 mL; P<.001) and healthy controls (18.32 mL vs. 9.63 mL; P<.001). Duration of acromegaly was shown to be independently associated with thyroid volume enlargement (B = 0.259; 95% confidence interval, 0.162 to 0.357) in multivariate analysis. At follow-up, the median thyroid volume decreased from 22.74 to 17.87 mL in the cured group (n = 20; P = .003), but the number of nodular goiters showed no significant change. Serum free thyroxine levels decreased from 13.76 to 10.08 pmol/L in the cured group (P = .006) but increased from 9.28 to 12.09 pmol/L in the active group (P = .013). Change in thyroid volume was significantly correlated with IGF-1 level (r = 0.37; P = .029). In vitro, IGF-1 time- and dose-dependently promoted proliferation and secretory function of thyroid cells by enhancing cell cycle shift from the G1/S to G2/M phase and suppressing apoptosis. Conclusion: Acromegaly-associated thyroid volume increase, but not nodular goiter, could be reversed in cured acromegaly. IGF-1 time- and dose-dependently promoted the proliferation and secretory function of thyroid cells. Abbreviations: CCK-8 = Cell Counting Kit-8; fT3 = free triiodothyronine; fT4 = free thyroxine; GH = growth hormone; IGF-1 = insulin-like growth factor 1; MRI = magnetic resonance imaging; NFPA = nonfunctioning pituitary adenoma; qRT-PCR = quantitative real-time-polymerase chain reaction; TSH = thyroid-stimulating hormone.

Comparison of Iodine Concentrations in Kitchen Salt and Urine with the Thyroid Volume of Schoolchildren from Ribeirão Preto, São Paulo, Brazil: Warning of Worsening After 10 Years of Study

Background: In 2007 and 2015, two studies were conducted in Ribeirão Preto, São Paulo, Brazil, on schoolchildren of both sexes attending schools of three different socioeconomic levels (school 1: low; school 2: middle; school 3: high). Methods: Iodine concentrations were measured in samples of kitchen salt from the home provided by the schoolchildren and in urine samples, and these levels were compared to the thyroid volume by clinical assessment. Results: In 2007, a marked discrepancy in iodine concentrations was found in salt samples in 300 schoolchildren of both sexes (age range 8-10 years). Urinary iodine excretion >100 μg/L was detected in all cases, and 55.2% had concentrations of >300 μg/L (considered to be the upper limit by the World Health Organization). There was no increase in thyroid volume among the schoolchildren. In 2015, after a change in the norms for salt iodination from 20-60 to 15-45 mg/kg, the study was repeated in 295 schoolchildren (age range 8-10 years) from the same three schools studied previously. An improved standardization of iodine concentration was observed in the salt samples provided by the children, as well as a significant reduction in ioduria, with 10.9% of the samples showing an iodine concentration of <100 μg/L and with a reduction to 30.5% of samples with >300 μg/L. An increase in thyroid volume was also observed in a greater proportion of children from school 1, with a 7.92%, 5.19%, and 0.85% prevalence of goiter at schools 1, 2, and 3, respectively. Conclusions: Despite the limitations of the present study, which include sample size and thyroid evaluation by palpation, it is inferred that the iodination of the Ribeirão Preto schoolchildren studied is adequate. However, the individual iodine intake of some students was <100 μg/L, and some students also had an increased thyroid volume, raising the possibility of a deterioration of iodine intake in 2015 compared to 2007.

Relationship between metabolic syndrome and nodular thyroid diseases

Nodular thyroid diseases are common in Turkey. Insulin resistance (IR) is considered as the most important component of metabolic syndrome (MetS), and it is thought to directly affect thyroid diseases, together with other components of MetS. The aim of this study was to evaluate potential factors associated with thyroid nodularity. This study was part of the prospective MELEN study. In total, randomly selected 2233 subjects were evaluated. A euthyroid subgroup of participants (n = 1432) was selected and 421 of them had MetS. Both goitres and multinodular goitres (MNGs) were significantly more common in the MetS (+) group (p < .001). Older age was the only factor that significantly affected the presence of a nodular goitre (NG) (p < .001). The presence of a MNG was associated with older age (p < .001), systolic blood pressure level (p < .008) and MetS (p < .001). There was no difference in the thyroid volume or presence of nodular thyroid diseases between the IR (+) and (−) groups. Both the thyroid volume and the presence of MNGs were significantly associated with MetS, independent of thyroid-stimulating hormone (TSH) and IR. We suggest that the individual components of MetS may influence thyroid nodularity to some degree and that together they exert a cumulative effect on the thyroid gland. As a result, in the absence of MetS, we further suggest that IR alone does not explain the increase in thyroid volume and thyroid nodule formation.

Large multinodular goiter--outpatient radioiodine treatment.

131-I treatment of nodular, especially nontoxic, goitre is still reserved mainly for elderly patients, whose numerous concomitant diseases disqualify them from surgery. Therapy often involves isolation and is available only in selected centres, which may be located far from some patients' places of residence, which is inconvenient for elderly people. The aim of the study was to assess the effectiveness of outpatient fractionated 131-I treatment of patients with large nodular goitres, as well as to evaluate complications and the factors affecting treatment results. The study included 35 patients with a large nodular goitre. Thyroid volume and treatment results were evaluated using US and CT neck examination. Mean thyroid volume prior to treatment was 104.36 mL (range 36.23-301.09 mL). An average administered 131-I activity was 1806 MBq (range 800-4000). The average reduction of goitre volume was 43.18% (range -17.23-89.66%). Final treatment results correlated with the thyroid size reduction obtained three months after treatment (r = 0.74; p = 0.001). Symptoms of transient hyperthyroidism were observed in 8.57% of patients, in 5.4% Graves disease was induced (including severe Graves' orbitopathy in 2.7%), and in 2.86% TRAb increase without development of hyperthyroidism was observed. The treatment results were not influenced by initial thyroid volume (r = -0.01; p = 0.95). An increase in thyroid volume during the treatment was reported in 20% of patients, with a mean increase of 22.3% (range 0.63-55.03%). Post-treatment hypothyroidism was diagnosed in 42.9% of patients. One patient was diagnosed with salivary gland damage. Fractionated 131-I treatment of large nodular goitres is an effective method, the results of which are comparable to those obtained from the administration of one-time high doses of radioiodine.

Effects of GH replacement therapy on thyroid volume and nodule development in GH deficient adults: a retrospective cohort study.

Despite the well-known effects of GH/IGF1 signaling on the thyroid, few data are available on the risk of developing nodular goiter in hypopituitary subjects during GH replacement therapy (GHRT). We aimed to define the effects of GH therapy on thyroid volume (TV) and nodular growth. The records of 96 subjects (47 males and 49 females, median age 48 years) with GH deficit (GHD) were investigated. Seventy also had central hypothyroidism (CH). At the time of our retrospective evaluation, median treatment duration was 5 years. Pre-treatment TV was smaller in GHD patients than in healthy subjects (P=0.030). During GH treatment, TV significantly increased (P=0.016 for the entire group and P=0.014 in euthyroid GHD patients). Before starting GH therapy, 17 patients harbored thyroid nodules. During GH therapy, nodule size increased slightly in seven patients, and new thyroid nodules occurred in nine patients. Among the 79 patients without pre-existing thyroid nodules, 17 developed one or more nodules. There was no difference in the prevalence of CH in GHD patients with or without thyroid nodules (P=0.915; P=0.841, when patients with pre-therapy nodular goiter were excluded), the main predictor for nodule development being serum IGF1 (P=0.038). GHRT is associated with TV's increase in GHD patients. Thyroid nodules developed in 27% of patients, mainly in relation to pre-therapy IGF1 levels, independently of normal or impaired TSH stimulation.

Iodine fortification may influence the age-related change in thyroid volume: a longitudinal population-based study (DanThyr)

To assess the individuals' thyroid volume changes after the mandatory nationwide iodine fortification (IF) program in two Danish areas with different iodine intake at baseline (Copenhagen, mild iodine deficiency (ID) and Aalborg, moderate ID). A longitudinal population-based study (DanThyr). We examined 2465 adults before (1997) and after (2008) the Danish IF of salt (2000). Ultrasonography was carried out by the same sonographers using the same equipment, after controlling performances. Participants treated for thyroid disease were excluded from analyses. Overall, median thyroid volume had increased in Copenhagen (11.8-12.2 ml, P=0.001) and decreased in Aalborg, although not significantly (13.3-13.1 ml, P=0.07) during the 11 years of follow-up. In both regions, there was an age-related trend in individual changes in thyroid volume from baseline to follow-up; thyroid volume increased in women <40 years of age and decreased in women >40 years of age. IN A MULTIVARIATE REGRESSION MODEL, HIGHER AGE AT ENTRY WAS A PREDICTOR (P0.05) FOR THYROID VOLUME DECREASE 20% DURING THE FOLLOW-UP PERIOD (WOMEN AGED 4045 YEARS: odds ratio (OR) 4.3 (95% CI, 2.2-8.2); women aged 60-65 years: 5.8 (2.9-11.6)) and individuals of higher age were also less likely to have an increase in thyroid volume (women aged 40-45 years: OR 0.2 (0.1-0.3); women aged 60-65: OR 0.3 (0.2-0.4)). Age-dependent differences in thyroid volume and enlargement had leveled out after the Danish iodization program. Thus, the previously observed increase in thyroid volume with age may have been caused by ID.

SU‐GG‐J‐120: Silver Nanoparticle Added to Nuclear Medicine: A Preliminary Evaluation of Dose Increase in Iodine Therapy Assessed by Monte Carlo

Purpose: Investigate physical aspects of silver nanoparticle (AgNp) application in iodine therapy aiming increase dose conformality in Nuclear Medicine treatments of thyroid disease. Material and Methods: AgNp (2–3nm size) were considered uniformly embedded in thyroid tissue in 1% mass concentration. PENELOPE‐2008 Monte Carlo code was used to perform the simulations. A faithful neck geometry was described in PENGEOM‐2008 code, considering air cavity, spinal cord and all relevant tissues present in clinical cases. Iodine‐131 radioactive events inside thyroid volume were simulated considering beta and photon energy spectrums. Monte Carlo spectrometry was applied inside thyroid volume to identify components with high probability of interaction with silver atoms that increase dose locally due to AgNP presence. Dose increase in thyroid volume was calculated as the ratio between total dose deposited with and without AgNp (DEF = Dwithout AgNp/Dwith AgNp) and comparing total doses deposited in studied volumes. Dose conformality increase was evaluated from changes in dose‐profiles and isodose curves inside the neck. Results: The DEF was 1.19 to thyroid volume (target) and 0.40, 0.56, 0.77 and 0.63 to spinal cord, spinal bone, parotids and sublingual base, respectively. In non‐target regions, DEF lower than 1 indicate that the dose decrease, resultant from high absorptions of fluency that occurs locally in target volume. Total dose in thyroid volume increases from 32.43Gy to 38.40Gy due to AgNp presence, representing 18.4%. In axial and longitudinal profiles is possible to observe that the doses not only increase in target region, but also decrease in healthy volumes, contributing to more conformai treatment. Conclusions: Silver nanoparticle added to Iodine therapy can contribute to dose increase changing dose conformality in benefic therapeutic levels. Monte Carlo simulation is a powerful tool to investigate metal nanoparticle applications in Nuclear Medicine cases. Future investigations will asses nanoparticle atomic number and concentration variations.

SHORT-TERM EFFECT OF RECOMBINANT HUMAN THYROID-STIMULATING HORMONE ON THYROID VOLUME AND ECHOGENICITY IN HEALTHY BEAGLES

In humans, administration of recombinant human thyroid stimulating hormone (rhTSH) allows radioactive iodine dose reduction and higher efficacy in the treatment of multinodular goiter and thyroid cancer. A similar effect might be expected in dogs with thyroid carcinoma. However, if rhTSH leads to an increase in thyroid volume, it must be used carefully in dogs with large thyroid tumors to avoid compression of key anatomical structures. The aim of this study was to determine the short-term effect of rhTSH on thyroid volume and echogenicity, measured by ultrasonography, in healthy Beagles. Seven beagles were divided randomly in two groups in a prospective placebo-controlled blinded cross-over study. On day 1, one group received 100 microg of rhTSH intravenously and the other group received placebo. After a wash-out period of 3 weeks, the groups were crossed over. Evaluation of thyroid echogenicity, homogeneity, shape, capsule delineation, and measurement of thyroid length, width, and height were performed by the same observer at baseline, and at 6, 24, and 48h after injection of rhTSH and placebo. There was no significant difference between the effect of rhTSH and placebo on thyroid volume (P = 0.397), echogenicity, homogeneity, or capsule delineation. Time had a significant effect on thyroid volume (P = 0.027). No adverse effects after rhTSH administration were noticed. The effect of rhTSH on thyroid volume in dogs with thyroid carcinoma needs to be assessed.

Metabolic syndrome and its components are associated with increased thyroid volume and nodule prevalence in a mild-to-moderate iodine-deficient area

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities with insulin resistance (IR) as a major component. It has been recently questioned whether MetS and its related components are associated with functional and morphological alterations of the thyroid gland. The aim of our study is to examine thyroid volume and nodule prevalence in a case-control study of patients with MetS in a mild-to-moderate iodine-deficient area. Two hundred and seventy-eight patients with MetS were randomly matched for age, gender, and smoking habits with 261 subjects without MetS. Serum TSH, free tri-iodothyronine and thyroxine, and the level of IR, which was estimated by the homeostasis model assessment for IR, as well as other MetS parameters were evaluated. Thyroid ultrasonography was performed in all subjects. All subjects with thyroid nodules >1 cm were offered to undergo thyroid fine needle aspiration biopsy. TSH was significantly positively correlated with the presence of MetS diagnosis. There was no association between free thyroid hormone levels and MetS and its related components. Mean thyroid volume was significantly higher in patients with MetS than in controls (17.5 + or - 5.5 vs 12.2 + or - 4.2 ml, P<0.0001). Also the percentage of patients with thyroid nodules was significantly higher in patients with MetS (50.4 vs 14.6%, P<0.0001). Subjects were also divided into two groups according to the presence of IR. The group of subjects with IR had increased thyroid volume and nodule formation. The odds ratio for the development of thyroid nodule in the presence of IR was 3.2. TSH as well as all MetS components were found to be independent predictors for thyroid volume increase. IR but not TSH was found to be correlated with thyroid nodule formation. Thyroid cancer was diagnosed in 3 out of 38 patients with MetS who agreed to have a biopsy (7.9%). None of the subjects in the control group was diagnosed to have thyroid cancer. The results suggest that patients with MetS have significantly increased thyroid volume and nodule prevalence. Multivariate regression analysis model demonstrated that the presence of IR contributed substantially to this increased risk. Our data provide the first evidence that IR is an independent risk factor for nodule formation in an iodine-deficient environment.

Preoperative Administration of Excess Iodide Increases Thyroid Volume of Patients with Graves' Disease

Preoperative excess iodide administration for patients with Graves' disease has been widely adopted by surgeons to perform surgery safely, because it decreases blood flow in the thyroid. However, surgeons often encounter the enlargement of thyroid volume after iodide administration, which makes surgery even more difficult. In this study, we retrospectively investigated the change in thyroid volume in Graves' disease that was evaluated on ultrasonography between before and after iodide administration. Eighty-nine patients who received iodide administered (KI(+) patients) and 24 in whom iodide was not administrated (KI(-) patients) before surgery for Graves' disease were enrolled in the study. The level of free T4 (FT4) significantly decreased and that of thyroid stimulating hormone (TSH) significantly increased after iodide administration. Average thyroid volume also significantly increased for KI(+) patients after iodide administration and 17% of these patients showed a 30% or more increase in thyroid volume. In KI(-) patients who were preoperatively treated only by anti-thyroid drugs, thyroid volume did not change before surgery. Preoperative TSH levels remained below measurement sensitivity in 37 of KI(+) patients, but the average thyroid volume also significantly increased after iodide administration. These findings suggest that thyroid volume in Graves' disease can increase with iodide administration not only due to TSH stimulation but also due to reasons other than TSH. Surgeons should be careful when preoperatively iodide administering to patients with Graves' disease, especially when the goiter is large.