The Prevention of Iodine Deficiency: A History.

Iodine is an essential component of the hormones produced by the thyroid gland and is, therefore, essential for mammalian life. A landmark trial in the early 20th century definitively demonstrated that iodine supplementation could prevent what was then known as "endemic goiter." Subsequent studies over the next decades demonstrated that iodine deficiency causes a spectrum of disease, including not just goiter, but also cretinism, intellectual impairment, and adverse obstetric outcomes. Salt iodization, first used in Switzerland and the United States in the1920s, has become the mainstay of iodine deficiency prevention efforts. The dramatic reduction in the global prevalence of iodine deficiency disorders (IDD) over the past 30 years represents an outstanding and under-recognized public health achievement. This narrative review provides an overview of critical scientific discoveries and advances in public health nutrition related to the prevention of IDD in the United States and worldwide. This review was written to commemorate the centennial of the founding of the American Thyroid Association.

[Epidemiology of benign thyroid disorders in the adult population of the Republic of Belarus: analysis of nationwide statistics 2009 to 2019].

BACKGROUND: Nowadays, the Republic of Belarus belongs to the countries with sufficient iodine supply, which made it possible to reduce the incidence of non-toxic goiter and congenital hypothyroidism. However, even a slight change in iodine consumption influences the pattern of thyroid diseases. In addition to iodine deficiency, other environmental conditions, as well as genetic factors, play a significant role in the etiology of thyroid diseases. AIM: To analyze the dynamics of the main epidemiological indicators of benign thyroid diseases from 2009 to 2019 in the adult population of the Republic of Belarus, using the data of official state statistics. MATERIALS AND METHODS: The indicators of the incidence and prevalence of benign thyroid diseases were studied on the basis of state statistics for 2009-2019. To analyze the dynamics of the studied indicators, regression analysis was used with the construction of linear and polynomial models. RESULTS: A decrease in the incidence and prevalence of diffuse euthyroid goiter and an increase in the incidence and prevalence of nodular euthyroid goiter, thyroiditis, acquired hypothyroidism, Graves' disease, as well as the incidence of nodular toxic goiter were revealed. CONCLUSION: Obtained data indicate, that there is an increase in the prevalence of most of the studied thyroid diseases, despite the adequate iodine supply. The above justifies the need for further study of the causes of the identified trends, as well as the necessity of developing new methods of diagnosis and treatment of thyroid diseases.

Concomitant thyroid cancer in patients with primary hyperparathyroidism in an endemic goitre region.

OBJECTIVE: Primary hyperparathyroidism (pHPT) is often accompanied by underlying thyroid pathology and 1 to 36% of these thyroid pathologies are malignant. How the identification of these lesions affects patient management is unclear. We present a single-center experience with the prevalence of concomitant thyroid cancer in patients who underwent parathyroidectomy for pHPT. MATERIALS AND METHODS: This was a retrospective cohort study. Two hundred-two patients with primary hyperparathyroidism included study. Demographic data, clinical findings, and final histopathological diagnosis were recorded retrospectively. RESULTS: Preoperative cervical ultrasound examination revealed co-existent thyroid abnormalities in 117 (57.9%) patients. Mean age of these patients was 57.8 ± 12.2 years and 88% were female. Sixty-three (53.9%) of the patients with thyroid abnormalities, underwent preoperative fine needle aspiration biopsy (FNAB). Cytology result was malignant in one (1.6%) patient, benign in 47(85.7%) patients, indeterminate in six (9.5%) patients and Hurthle cell neoplasm in two (3.2%) patients. Ninety-four (80.3%) of the patients underwent simultaneous thyroid surgery. Final pathology of the thyroid specimen was malignant in 26 (12.9%) patients. Sixteen of the malignant patients had preoperative FNAB. Preoperative FNAB result of these patients was malignant in one patient, indeterminate in two patients and benign in 13 patients. CONCLUSION: By implementing a comprehensive approach to patients with pHPT who present with thyroid disease, concomitant pathology may be elucidated preoperatively. But, this approach will not facilitate the detection of otherwise unsuspected thyroid cancer in an endemic goitre region. KEY WORDS: Cancer, Parathyroid adenoma, Parathyroidectomy, Thyroid, Thyroidectomy.

Cirugía tiroidea en programas de cooperación en África subsahariana / Thyroid surgery at a volunteer program in Sub-Saharan Africa

INTRODUCCIÓN: Nuestro objetivo es describir la experiencia adquirida en un programa de cooperación dedicado a la cirugía tiroidea en Camerún. Su interés radica en la imposibilidad para seguir las guías internacionales de tratamiento en áreas de recursos imitados debido a la falta de estudios preoperatorios y a la dificultad para conseguir medicación hormonal sustitutiva de por vida. MÉTODOS: Estudio observacional de una cohorte de 16 pacientes operados de enfermedad tiroidea en Dschang (Camerún) en junio de 2015. La técnica quirúrgica empleada fue la hemitiroidectomía con istmectomía en la enfermedad unilateral y la tiroidectomía subtotal bilateral en la enfermedad bilateral. RESULTADOS: Todos los pacientes eran de raza negra, 15 mujeres y un hombre, con edad media de 41 años. Se realizaron 5tiroidectomías subtotales, 9hemitiroidectomías y 2istmectomías. Cuatro pacientes presentaban componente intratorácico. Fue necesaria la sección de músculos pretiroideos en un caso. Se visualizaron las glándulas paratiroides y los nervios laríngeos recurrentes en el 86 y el 84% de los casos, respectivamente. Se dejaron drenajes en 7 casos y la mediana de duración de la intervención fue de 75 min. Como complicaciones cabe destacar un hematoma cervical que precisó reintervención y 2infecciones de herida quirúrgica. No hubo hipocalcemias clínicas ni lesiones recurrenciales apreciables. La estancia media fue de 2,3 días. A largo plazo, los pacientes con tiroidectomías bilaterales presentaban niveles elevados de TSH. CONCLUSIONES: La cirugía tiroidea en países subdesarrollados, adaptando los protocolos y técnicas que utilizamos en nuestro medio (evitando la tiroidectomía total), tiene una tasa de complicaciones asumible. No deben realizarse tiroidectomías bilaterales salvo que se disponga de estudios funcionales y se asegure previamente la disponibilidad de la hormona tiroidea

INTRODUCTION: The aim of this study is to demonstrate our experience at a volunteer surgical program in Cameroon, which is of special interest given to the inability to adopt international treatment guidelines for thyroid surgery in areas of limited resources due to the lack of preoperative testing and to the difficulty to obtain sustitutive hormonal treatment. METHODS: This is a prospective observational study that includes 16 cases of thyroid surgery in Dschang (Cameroon) during June 2015. The patients were previously selected by a local medical team. All patients were black, 15 women and one man, with a mean age of 41 years. The surgical technique used for the removal of unilateral disease was hemithyroidectomy with isthmectomy and bilateral subtotal thyroidectomy for bilateral disease. RESULTS: Five subtotal thyroidectomies, 9hemithyroidectomies and 2isthmectomies were performed. Prethyroid muscles were divided only in one case. We visualized 86% of the parathyroid glands and 84% of the recurrent laryngeal nerves. The main complications observed were one symptomatic cervical haematoma that required reoperation and 2surgical wound infections. There were no clinical episodes of hypocalemia or recurrent nerve lesion. The mean length of stay was 2.3 days. At follow-up, all bilateral thyroidectomies developed high TSH levels. CONCLUSIONS: Thyroid surgery is safe in developing countries adopting protocols and techniques we use in our environment (avoiding total thyroidectomy). Bilateral thyroidectomies should not be performed unless functional studies are available in the follow-up and a thyroid hormone supplement stock guaranteed whenever necessary

[Imbalance of microelements and vitamins in adolescents with diffuse nontoxic goiter and biliary dyskinesia].

The purpose of the present work was to study the level of microelements and vitamins in adolescents with diffuse nontoxic goiter. It has been shown that comorbid biliary dyskinesia leads to significant dysregulation of vitamin and mineral metabolism: the level of essential elements was decreased and the level of toxic elements was increased. Comorbid biliary dyskinesia in adolescents with diffuse nontoxic goiter was accompanied by a disbalance of vitamins. The changes found in micronutrients have sex differences.

Impaired glucose metabolism is a risk factor for increased thyroid volume and nodule prevalence in a mild-to-moderate iodine deficient area.

OBJECTIVE: Insulin resistance (IR) is a key factor involved in the pathogenesis of impaired glucose metabolism. IR is associated with increased thyroid volume and nodule prevalence in patients with metabolic syndrome. Data on the association of thyroid morphology and abnormal glucose metabolism are limited. This prospective study was carried out to evaluate thyroid volume and nodule prevalence in patients with pre-diabetes and type 2 diabetes mellitus (DM) in a mild-to-moderate iodine deficient area. MATERIALS AND METHODS: Data were gathered on all newly diagnosed patients with pre-diabetes and type 2 diabetes mellitus between May 2008 and February 2010. 156 patients with pre-diabetes and 123 patients with type 2 DM were randomly matched for age, gender, and smoking habits with 114 subjects with normal glucose metabolism. Serum thyroid-stimulating hormone (TSH) and thyroid ultrasonography was performed in all participants. RESULTS: Mean TSH level in the diabetes group (1.9±0.9 mIU/L) was higher than in the control group (1.4±0.8 mIU/L) and the pre-diabetes group (1.5±0.8 mIU/L) (P<0.0001 for both). Mean thyroid volume was higher in the pre-diabetes (18.2±9.2mL) and diabetes (20.0±8.2mL) groups than in controls (11.4±3.8mL) (P<0.0001 for both). Percentage of patients with thyroid nodules was also higher in the pre-diabetes (51.3%) and diabetes groups (61.8%) than in controls (23.7%) (P<0.0001 for both). CONCLUSIONS: The results suggest that patients with impaired glucose metabolism have significantly increased thyroid volume and nodule prevalence.

Indications for surgery and significance of unrecognized cancer in endemic multinodular goiter.

BACKGROUND: The exclusion of cancer in endemic goiter is often difficult mainly because of the high number of nodules and the as-yet unclear natural history of diagnosed cancer in endemic goiter patients. In a large number of consecutive patients who were to undergo total thyroidectomy for endemic multinodular goiter, we assessed indications for surgery and thyroid cancer outcome. METHODS: All patients who were to undergo total thyroidectomy for diffuse multinodular goiter on histological examination between January 1990 and October 2008 were evaluated. RESULTS: Of the 1,161 patients included in the study, 252 were cases of thyroid cancer (21.7%). Sensitivity of thyroid ultrasound (US) and fine-needle aspiration cytology (FNAC) for cancer detection was 30.3 and 64.1%, respectively. Differentiated thyroid carcinoma accounted for most of the tumors (96%), with 54.8% of them being papillary microcarcinomas, while bilateral-multicentric cancer occurred in 20.3%. In multivariate analysis, younger age (p = 0.06), sonographic findings (p = 0.03), and presence of histological thyroiditis (p = 0.09) were independently associated with the occurrence of tumors with diameter greater than 2 cm. The percentage of transient and permanent postoperative complications were approximately 25 and below 2%, respectively. After a median follow-up time of 78.5 months, overall recurrence rate was 6.7% and disease-specific mortality was 1.2%. CONCLUSION: As US and FNAC did not consistently detect cancer in patients with diffuse multinodular goiter in our endemic area, evidence-based indications for surgery in this group of patients is needed, although radical surgery and favorable tumor histology offer favorable outcomes in commonly diagnosed thyroid cancer after total thyroidectomy for endemic multinodular goiter.

Clinicopathological profile, airway management, and outcome in huge multinodular goiters: an institutional experience from an endemic goiter region.

BACKGROUND: Huge goiters are common in iodine-deficient endemic regions. They are of concern to the surgeons because of the anticipated risk of difficult dissection and increased chances of surgical complications. Similarly, they are of concern to the anesthesiologists because of anticipated intubation-related difficulties and post-thyroidectomy tracheomalacia. In the present study we aimed to present our experience of managing goiters based on their gross weight, highlighting their clinicopathological profile, perioperative airway-related difficulties, and management of surgical morbidity. METHODS: Retrospective analysis of patients who underwent total thyroidectomy in the primary setting at our institute from 1995 to 2009 was carried out based on the gross gland weight. The patients were thus grouped into group A: ≤200 g; group B: 201 to ≤400 g; group C: 401 to ≤600 g; group D: >600 g. RESULTS: Group A (660 cases); group B (108 cases); group C (36 cases); and group D (9 cases) were included. As the goiter size increased, the mean duration of goiter, compressive symptoms, retrosternal extension (RSE), airway deformity, intubation difficulty, and tracheomalacia increased. The rate of tracheostomy, sternotomy, hemorrhage, visceral injury, and hospital stay was high with huge goiters. These features were more marked in malignant goiters compared to benign goiters. However, the postoperative complications were comparable in both of those groups. CONCLUSIONS: Long-standing huge goiters are common in iodine-deficient endemic areas. The majority of patients have symptomatic or clinicoradiological evidence of airway involvement. The incidence of RSE, airway deformity, intubation difficulty, and tracheomalacia is high with huge goiters. The surgery is technically demanding with greater associated chances of injury to native structures. Malignancy influences the presentation and outcome in smaller goiters. In centers with experienced endocrine surgeons and dedicated anesthetists, huge goiters can be successfully managed with minimal short-term and long-term morbidity.

Follicular thyroid carcinoma in an iodine-replete endemic goiter region: a prospectively collected, retrospectively analyzed clinical trial.

OBJECTIVE: To determine risk factors for presence of lymph node or distant metastases in patients with follicular thyroid cancer (FTC) at the time of diagnosis and whether there is a relationship between the type of tumor invasion and metastases. SUMMARY BACKGROUND DATA: FTC often presents distant metastases at the initial diagnosis. As distant metastases are independent prognostic factors in a patient's survival, determination of clinicopathologic characteristics for patients who are at higher risk for developing metastases is of greater clinical importance. METHODS: The prognostic significance of gender (male vs. female), age (40 mm), number of lesions (uni- vs. multifocality), type of invasion (minimally invasive vs. widely invasive), and oncocytic changes (with vs. without) were analyzed in 207 patients, according to presence of lymph node and distant metastases at the time of initial surgery. According to the type of invasion, the carcinoma-specific survival and the disease-free survival of minimally invasive (MI) and widely invasive (WI) FTC were estimated and compared. RESULTS: None of the 127 patients with MI growth presented with lymph node metastases but 9.4% distant metastases. Overall risk factors for the presence of lymph node metastases at the initial diagnosis were multifocality (P = 0.02) and widely invasion (P = 0.0001) and for distant metastases age >45 years (P = 0.007), tumor size larger than 40 mm (P = 0.03) and widely invasion (P = 0.0001).WI-FTC patients show larger tumors (P = 0.0001), older age (P = 0.0001), and are presented more frequently in recurrent goiter disease (P = 0.0001). The estimated 10 years carcinoma-specific survival and disease-free survival for MI-tumors were significantly better than for WI-tumors (P = 0.0001). CONCLUSIONS: Total thyroidectomy is recommended in all patients with FTC because of early distant metastases. Patients with WI-FTC need a more aggressive surgical treatment because of higher tendency for lymph node metastases. MI-FTC has an excellent prognosis with no sign of lymph node metastases, which emphasizes a limited need for nodal surgery.

Malignancy rates in operated patients with hyperthyroidism in an area of endemic goiter.

We aimed to evaluate the incidence of thyroid cancer in Turkish patients with hyperthyroidism who had undergone thyroid surgery. The data of 344 patients who had been operated on for hyperthyroidism between 1998 and 2006 at our center were evaluated retrospectively. Sixty-five of the subjects had single toxic adenomas, 223 had toxic multinodular goiter, and 56 had Graves' disease. In 35 of 344 patients (10.1%), papillary carcinoma was diagnosed. Other forms of thyroid carcinomas were not observed. The rate of carcinoma was found to be 11.6% in patients with toxic multinodular goiter, 7.7% in patients with single toxic adenomas, and 7.1% in patients with Graves' disease. Occult papillary carcinoma was found in 62.9% of all malignancy diagnoses. The primary aim in the surgical treatment of hyperthyroidism should be to abolish the hyperthyroid state. However, the probability of malignancy, especially occult carcinoma, should always be considered.

Thyroid cancer, thyroiditis and dietary iodine: a review based on the Salta, Argentina model.

Factors that should be considered when studying the effect of dietary iodine in the development of thyroid cancer include pathological criteria, diagnostic techniques, screening programs, radioactive fallout, and standard of medical care in the studied population. In most surveys, papillary carcinoma forms the largest group of thyroid malignancies, both before and after iodine prophylaxis where an increase in the papillary:follicular carcinoma ratio is also noted. Undifferentiated carcinomas decrease after salt prophylaxis. In Salta, Argentina, the increasing incidence of clinically significant papillary thyroid cancer and the decrease of undifferentiated carcinoma after iodine prophylaxis are probably due to better access to health centers and consequent earlier detection of differentiated precursor tumors. Autoimmune focal and diffuse or Hashimoto's thyroiditis are linked to dietary iodine. Pathological studies made in different regions indicate that these types of thyroiditis occur more frequently in areas of iodine sufficiency than in areas of iodine deficiency, and increase after iodine prophylaxis both in non-goitrous and iodine-deficient areas like Salta, Argentina. An increase of lymphocytic thyroiditis could be linked to an increased incidence of primary thyroid lymphoma, and thyroiditis is more commonly associated with papillary carcinoma than with other types of thyroid follicular or C-cell derived carcinomas regardless of iodine intake.

The goitre rate, its association with reproductive failure, and the knowledge of iodine deficiency disorders (IDD) among women in Ethiopia: cross-section community based study.

BACKGROUND: Iodine deficiency is severe public health problem in Ethiopia. Although urinary iodine excretion level (UIE) is a better indicator for IDD the goitre rate is commonly used to mark the public health significance. The range of ill effect of IDD is however beyond goitre in Ethiopia. In this study the prevalence of goitre and its association with reproductive failure, and the knowledge of women on Iodine Deficiency were investigated. METHODS: A cross-section community based study was conducted during February to May 2005 in 10998 women in child bearing age of 15 to 49 years. To assess the state of iodine deficiency in Ethiopia, a multistage "Proportional to Population Size" (PPS) sampling methods was used, and WHO/UNICEF/ICCIDD recommended method for goitre classification. RESULTS: Total goitre prevalence (weighted) was 35.8% (95% CI 34.5-37.1), 24.3% palpable and 11.5% visible goitre. This demonstrates that more than 6 million women were affected by goitre. Goitre prevalence in four regional states namely Southern Nation Nationalities and People (SNNP), Oromia, Bebshandul-Gumuz and Tigray was greater than 30%, an indication of severe iodine deficiency. In the rest of the regions except Gambella, the IDD situation was mild to moderate. According to WHO/UNICEF/ICCIDD this is a lucid indication that IDD is a major public health problem in Ethiopia. Women with goitre experience more pregnancy failure (X2 = 16.5, p < 0.001; OR = 1.26, 1.12 < OR < 1.41) than non goitrous women. Similarly reproductive failure in high goitre endemic areas was significantly higher (X2 = 67.52; p < 0.001) than in low. More than 90% of child bearing age women didn't know the cause of iodine deficiency and the importance of iodated salt. CONCLUSION: Ethiopia is at risk of iodine deficiency disorders. The findings presented in this report emphasis on a sustainable iodine intervention program targeted at population particularly reproductive age women. Nutrition education along with Universal Salt Iodization program and iodized oil capsule distribution in some peripheries where iodine deficiency is severe is urgently required.

[The influence of severe iodine insufficiency on the character of intellectual deficit].

To study mental deficit in 60 children living in the areas with marked insufficiency of iodine in the soil, water and air, pupils of 3-4 grades of secondary schools in the western regions of Tyva Republic, where researchers of the State Medical Research Institute, Siberian Department of Russian Academy of Sciences, had discovered the hotbed of severe iodine insufficiency in 1997, were examined. Authors also studied 175 children who lived in the same social and economic conditions in the areas with light and moderate degree of iodine insufficiency. Impairments of memory, mental ability, intellectual function and visual motor coordination were found in the structure of mental deficit caused by the severe iodine insufficiency. In children from areas with light and moderate iodine insufficiency these disturbances were more subtle. Disturbances of analytical synthetic function and logical thinking were determined in the intellectual sphere. Processes suggesting between sensory integration disturbances were found in the perceptual sphere.

Treatment of iodine deficiency in school-age children increases insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations and improves somatic growth.

CONTEXT: Iodine deficiency in utero impairs fetal growth, but the relationship between iodine deficiency and postnatal growth is less clear. OBJECTIVE: The objective of the study was to determine whether iodine repletion improves somatic growth in iodine-deficient children and investigate the role of IGF-I and IGF binding protein (IGFBP)-3 in this effect. DESIGN, PARTICIPANTS, AND INTERVENTIONS: Three prospective, double-blind intervention studies were done: 1) in a 10-month study, severely iodine-deficient, 7- to 10-yr-old Moroccan children (n = 71) were provided iodized salt and compared with children not using iodized salt; 2) in a 6-month study, moderately iodine-deficient, 10- to 12-yr-old Albanian children (n = 310) were given 400 mg iodine as oral iodized oil or placebo; 3) in a 6-month study, mildly iodine-deficient 5- to 14-yr-old South African children (n = 188) were given two doses of 200 mg iodine as oral iodized oil or placebo. At baseline and follow-up, height, weight, urinary iodine (UI), total T4 (TT4), TSH, and IGF-I were measured; in Albania and South Africa, IGFBP-3 was also measured. RESULTS: In all three studies, iodine treatment increased median UI to more than 100 microg/liter, whereas median UI in the controls remained unchanged. In South Africa, iodine repletion modestly increased IGF-I but did not have a significant effect on IGFBP-3, TT4, or growth. In Albania and Morocco, iodine repletion significantly increased TT4, IGF-I, IGFBP-3, weight-for-age z scores, and height-for-age z scores. CONCLUSION: This is the first controlled study to clearly demonstrate that iodine repletion in school-age children increases IGF-I and IGFBP-3 concentrations and improves somatic growth.

[Goiter transformation as a risk factor of the development of bronchial asthma in children under the influence of natural and technogenic factors of the environment].

The paper deals with the comparative characterization of the prevalence of goiter transformation in children with bronchial asthma (BA) in relation to the level of a technogenic load and natural iodine deficiency in case of the Perm Region. There was a wide distribution of goiter transformation in children, which did not correspond to natural iodine supply in the Perm Region, suggesting the contribution of anthropogenic strumogenic factors to the formation of goiter endemia. There was a high prevalence of thyromegaly in children with BA as compared with those with another disease and its high the incidence as man-made pollution increased particularly in the areas exposed to a combination of natural and technogenic factors as compared in relatively pure areas. The findings suggest that goiter transformation is a marker of ecological ill-being and an additional serious risk factor of the development and prolonged course of BA in predisposed children.

Thyroid cancer with skull enlargement: a lesson learned?

A case of endemic goitre associated with thyroid cancer and huge enlargement of the scalp is reported in a Brazilian mulatto from an iodine deficient Central west region of the country. On admission, osteolytic metastases of follicular thyroid carcinoma were found scattered in the parietal bones. Impressive images from old files could illustrate and emphasize the hurdle-like role of poverty and inadequate social and cultural attitudes before the fight against cancer in regions with limited resources. Even in developed countries, goitres still occur in areas with iodine prophylaxis. Another concern is insufficiency of reliable data on the incidence and pattern of head and neck tumours in developing countries.