Iodine status in children with intestinal failure.

OBJECTIVES: Children on long-term parenteral nutrition (PN) are at high risk of iodine deficiency (ID). However, most available information comes from cross-sectional studies. We investigated the iodine status, associated factors, and prevalence of hypothyroidism in children with intestinal failure (IF) who were followed up longitudinally. METHODS: This was a cohort study of children with IF monitored for urine iodine concentration (UIC), iodine intake, serum selenium concentration, and thyroid function in an intestinal rehabilitation program. The outcome variable ID was defined as a UIC value < 100 µg/L. Adjusted generalized estimating equations were used to assess the effects of the exposure variables on the UIC. RESULTS: Twenty-four patients aged 62.7 (39.1; 79.7) months who received PN for 46.5 (21.5) months were included. The average energy supply was 81.2 kcal/kg/day, 77.6% of which was provided by PN. An average of 5.2 UIC measurements per patient were performed. ID prevalence decreased from baseline (83.3%) to the last assessment (45.8%). Three patients had hypothyroidism secondary to iodine and selenium combined severe deficiency. Iodine intake from enteral or oral nutritional formulas was positively associated with UIC (ß = 0.71 [0.35, 1.07]; p < 0.001). Meeting approximately 80% of the estimated average requirement for iodine from nutritional formulas resulted in a greater probability of normal UIC values. CONCLUSION: ID is highly prevalent in children with IF who receive long-term PN and its frequency decreases with iodine intake from nutritional formulas. Severe combined iodine and selenium deficiencies are associated with the development of hypothyroidism in these patients.

Computer-Assisted Levothyroxine Dose Selection for the Treatment of Postoperative Hypothyroidism.

Background: Thyroid hormone replacement with levothyroxine (LT4) is a recommended treatment for patients undergoing thyroidectomy. The starting LT4 dose is frequently calculated based on the patient's weight. However, the weight-based LT4 dosing performs poorly in clinical practice, with only ∼30% of patients achieving target thyrotropin (TSH) levels at the first thyroid function testing after treatment initiation. A better way to calculate the LT4 dose for patients with postoperative hypothyroidism is needed. Methods: In this retrospective cohort study we used demographic, clinical, and laboratory data for 951 patients after thyroidectomy and several regression and classification machine learning methods to develop an LT4 dose calculator for treating postoperative hypothyroidism targeting the desired TSH level. We compared the accuracy with the current standard-of-care practice and other published algorithms and evaluated generalizability with fivefold cross-validation and out-of-sample testing. Results: The retrospective clinical chart review showed that only 285/951 (30%) patients met their postoperative TSH goal. Obese patients were overtreated with LT4. An ordinary least squares regression based on weight, height, age, sex, calcium supplementation, and height:sex interaction predicted prescribed LT4 dose in 43.5% of all patients and 45.3% of patients with normal postoperative TSH (0.45-4.5 mIU/L). The ordinal logistic regression, artificial neural networks regression/classification, and random forest methods achieved comparable performance. LT4 calculator recommended lower LT4 doses to obese patients. Conclusions: The standard-of-care LT4 dosing does not achieve the target TSH in most thyroidectomy patients. Computer-assisted LT4 dose calculation performs better by considering multiple relevant patient characteristics and providing personalized and equitable care to patients with postoperative hypothyroidism. Prospective validation of LT4 calculator performance in patients with various TSH goals is needed.

Prevalence of thyroid dysfunction in neonates receiving parenteral nutrition in the intensive care unit.

OBJECTIVE: The use of parenteral nutrition (PN) formulations that do not contain iodine can contribute to the deficiency of this mineral, potentially leading to hypothyroidism and, ultimately, neurocognitive impairments. This study aimed to evaluate TSH alterations in newborns receiving PN. METHODS: Retrospective study of neonatal intensive care unit patients receiving PN for > 15 days. Nutritional, anthropometric, and biochemical variables (TSH, T4, CRP) were analyzed. Hypothyroidism was defined by TSH > 10 mU/L. RESULTS: Two hundred newborns were evaluated [156 (78%) preterm, 31±5 weeks of gestational age, 112 (56%) with very or extremely low birth weight]. The median (IQR) hospital stay was 68 (42-110) days, PN duration was 31 (21-47) days, and 188 (94%) patients also received enteral nutrition. Overall, 143 (71.5%) newborns underwent at least one TSH measurement. The prevalence of hypothyroidism was 10.5%. The Median PN duration in this group was 51 (34-109) days. Among those with hypothyroidism, 10 received Lugol's solution and six levothyroxine. Thirteen patients received prophylactic Lugol's solution with a median PN duration of 63 (48-197) days. TSH levels correlated positively with PN duration (r = 0.19, p = .02). CONCLUSIONS: The present data suggest that changes in TSH and T4 levels are present in neonates receiving PN for > 15 days, suggesting this population may be at risk for developing hypothyroidism. Therefore, the authors suggest that TSH and T4 measurements should be included as routine in neonatal patients receiving PN for > 15 days if PN formulations are not supplemented with iodine, and that iodine supplementation be provided as necessary.

Impact of photobiomodulation therapy on the morphological aspects of submandibular gland submitted to excretory duct ligation and hypothyroidism: an animal study.

The aim of this study was to evaluate the impact of photobiomodulation therapy (PBMT) on histomorphological aspects of submandibular gland (SMG) submitted to salivary gland duct obstruction in hypothyroid rats. Fifty-six male Wistar rats (250 to 300 g) were divided into 4 groups (n = 14): euthyroid (EU), EU + PBMT, hypothyroid (HYPO), and HYPO + PBMT. Duct obstruction of the left submandibular gland (LSMG) was performed in all animals by a ligature procedure. For the induction of hypothyroidism, total thyroidectomy was performed. PBMT groups received irradiation with AlGaInP diode laser (808 nm, 0.04 W, 0.04cm2 spot size, 60 s, 2.4 J per point, 60 J/cm2, 1 W/cm2). Irradiation was performed immediately, 24 h, and 48 h after the obstruction of the salivary gland duct, in one point, extra oral and perpendicular to the gland. Animals were sacrificed after 24 h and 72 h after duct ligature. Our results indicated that salivary duct obstruction and hypothyroidism caused negative modifications on the salivary glands' histomorphology, especially acinar atrophy, after 24 h and 72 h. HYPO + PBMT showed a significant reduction of the inflammatory infiltrate, congested blood vessels, and acinar atrophy in the SMG submandibular salivary gland in 72 h compared to 24 h (p < 0.05). In conclusion, obstruction of the salivary gland excretory duct and hypothyroidism causes severe sialoadenitis with expressive atrophy of the glandular parenchyma. However, PBMT was able to modulate the inflammatory process and delaying acinar atrophy. This study provided insights to better understand the role of the PBMT on the altered salivary gland by duct ligation and associate hypothyroidism.

Endocrinal Complications in Children and Adolescents with Thalassemia Major in Central India: An Observational Study.

OBJECTIVE: To determine the prevalence of short stature, delayed puberty, hypothyroidism, and diabetes mellitus in multiply transfused patients of beta thalassemia major and their correlation with serum ferritin. METHODS: A descriptive observational study was conducted in a tertiary care center in Indore, Madhya Pradesh from 2014 to 2016. All children with thalassemia major of the age group 8 to 18 y attending outpatient department or admitted in ward were included in the study. Detailed clinical history, demographic data, compliance to transfusion and chelation therapy, and growth parameters were recorded. Blood samples to look for endocrinopathies and serum ferritin were assessed. Tanner staging was done to assess for delayed puberty. RESULTS: Mean age of study participants (n = 50) was 15.98 ± 3.4 y. Short stature (n = 44; 88%), delayed puberty (n = 33; 71.7%), hypothyroidism (n = 6; 16%), and diabetes mellitus (n = 5; 10%) were the endocrinal abnormalities found. Mean serum ferritin level was 3122 ± 2117 ng/mL. Serum ferritin had significant positive correlation with serum TSH (thyroid stimulating hormone), fasting blood sugars, postprandial blood sugar, and delayed puberty. CONCLUSION: Evaluation of endocrinopatines must be carried out in thalassemia major patients regularly by pediatricians to detect and treat endocrinal complications. Importance of chelation therapy must be emphasized frequently to parents and patients.

High prevalence of central hypothyroidism among patients with transfusion dependent thalassemia in Hospital Pulau Pinang: A cross sectional study.

INTRODUCTION: Thalassemia is the most common heritable haematological disorder in Malaysia. Hypothyroidism is one of the complications of the transfusion dependent thalassemia (TDT) patients as a result of iron overload. MATERIALS AND METHODS: All registered TDT patients attending Haematology day care, Hospital Pulau Pinang from January 2019 to January 2020 were included in the study. Hypothyroidism was defined according to TSH and FT4, or based on the history of treatment for diagnosed hypothyroidism. RESULTS: There were 51 TDT patients, with 24 (47%) males and 27 (53%) females. Most of the patients were Malays (27, 53%) followed with Chinese (23, 45%) and Indonesian (1, 2%). Beta thalassemia major and HbE beta thalassaemia accounted for 35 (68.8%) and 14 (27.5%) TDT patients respectively, while two (3.9%) were HbH Constant Spring. Eleven (21.6%) had hypothyroidism; of which seven (63.6%) had central hypothyroidism, three (27.3%) had subclinical hypothyroidism, the remaining one (9.1%) had primary hypothyroidism. Three (27.3%) had concomitant hypogonadism, one (9.1%) had hypocortisolism and another (9.1%) had both diabetes mellitus and hypogonadism. There was no statistical relationship between the prevalence of hypothyroidism and age, serum ferritin, splenectomy history and iron chelation therapy. CONCLUSION: High prevalence of central hypothyroidism is reported. Measurement of both TSH and FT4 is recommended as initial screening for thyroid dysfunction among patient with TDT.

High-dose radiation exposure and hypothyroidism: aetiology, prevention and replacement therapy.

Without any doubt, high dose radiation exposure can induce hypothyroidism. However, there are open questions related to the mechanisms of its induction, corresponding dose thresholds and possible countermeasures. Therefore, this review addresses the aetiology, prevention and therapy of radiation induced hypothyroidism. External beam radiotherapy with several 10 Gy to the head and neck region and radioiodine therapy with several 100 Gy thyroid absorbed dose can destroy the thyroid gland and can induce autoantibodies against thyroid tissue. According to recent literature, clinical hypothyroidism is observed at threshold doses of ∼10 Gy after external beam radiotherapy and of ∼50 Gy after radioiodine therapy, children being more sensitive than adults. In children and adolescents exposed by the Chernobyl accident with mean thyroid absorbed doses of 500-800 mGy, subclinical hypothyroidism has been detected in 3%-6% of the cases with significant correlation to thyroid absorbed doses above 2.5 Gy. In case of nuclear emergencies, iodine thyroid blocking (ITB) is the method of choice to keep thyroid absorbed doses low. Large doses of stable iodine affect two different steps of internalization of radioiodine (transport and organification); perchlorate affecting the transport only may be an alternative to iodine. Administered before radioiodine incorporation, the effect of 100 mg iodide or more is still about 90% after 1 days, 80% after 2 days, and 50% or less after 3 days. If administered (too) late after exposure to radioiodine, the theoretically expected protective effect of ITB is about 50% after 6 h, 25% after 12 h, and about 6% after 24 h. In case of repeated or continuous exposure, repeated administration of 50 mg of iodide daily is indicated. If radiation-induced hypothyroidism cannot be avoided, thyroid hormone replacement therapy with individualized dosing and regular monitoring in order to maintain thyroid-stimulating hormone levels within the normal range ensures normal life expectancy.

Plant constituents and thyroid: A revision of the main phytochemicals that interfere with thyroid function.

In the past few decades, there has been a lot of interest in plant constituents for their antioxidant, anti-inflammatory, anti-microbial and anti-proliferative properties. However, concerns have been raised on their potential toxic effects particularly when consumed at high dose. The anti-thyroid effects of some plant constituents have been known for some time. Indeed, epidemiological observations have shown the causal association between staple food based on brassicaceae or soybeans and the development of goiter and/or hypothyroidism. Herein, we review the main plant constituents that interfere with normal thyroid function such as cyanogenic glucosides, polyphenols, phenolic acids, and alkaloids. In detail, we summarize the in vitro and in vivo studies present in the literature, focusing on the compounds that are more abundant in foods or that are available as dietary supplements. We highlight the mechanism of action of these compounds on thyroid cells by giving a particular emphasis to the experimental studies that can be significant for human health. Furthermore, we reveal that the anti-thyroid effects of these plant constituents are clinically evident only when they are consumed in very large amounts or when their ingestion is associated with other conditions that impair thyroid function.

Thyroxine replacement modifies changes in deiodinase and thyroid hormone transporter expression induced by subclinical hypothyroidism in rats.

PURPOSE: The potential benefits of treating subclinical hypothyroidism (SCH) are unclear and still controversial. Thus, we surgically induced SCH in rats and evaluated the effects of thyroxine (T4) replacement on the gene expression levels of deiodinases and thyroid hormone (TH) transporters in different tissues. METHODS: SCH was induced by hemithyroid electrocauterization. The control animals underwent the same surgical procedure but were not subjected to electrocauterization (sham). After 14 days, half of the SCH animals were treated with T4 (SCH + T4). At the end of the experimental protocol, all of the rats were euthanized, serum hormone concentrations were measured, and RNA analyses were performed on different tissues and organs. RESULTS: Consistent with previous studies, we observed increased TSH levels, normal TH levels, and reduced hypothalamic TRH expression in the SCH group. Additionally, Dio2 mRNA expression was downregulated in the hippocampus and pituitary, and Dio1 was upregulated in the kidney and pituitary of the SCH animals. The changes in Dio3 expression were tissue-specific. Concerning TH transporters, Mct10 expression was upregulated in the pituitary, kidney, hypothalamus, and hippocampus, and Mct8 expression was downregulated in the kidney of the SCH group. Crym expression was upregulated in the kidney and pituitary. Notably, T4 replacement significantly attenuated serum TSH levels and reverted Dio1, Dio2, Mct10, and Crym expression in the pituitary, hippocampus, and kidney to levels that were similar to the sham group. Tissue-specific responses were also observed in the liver and hypothalamus. CONCLUSION: Our results indicate that treatment of SCH should be considered before the appearance of clinical symptoms of hypothyroidism.

Thyroid Hormone Supplementation Therapy for Differentiated Thyroid Cancer After Lobectomy: 5 Years of Follow-Up.

Background: Lobectomy with preservation of the contralateral lobe has already become the most preferred surgical method for patients with low-risk thyroid cancer. The incidence of and risk factors for the development of hypothyroidism after lobectomy for thyroid cancer remains unclear. The previous practice of levothyroxine supplementation post-thyroidectomy, to bring about thyroid stimulating hormone (TSH) suppression, had some serious side effects. This study aimed to evaluate the incidence of hypothyroidism and to identify the factors associated with hypothyroidism requiring thyroid hormone replacement. Methods: We retrospectively reviewed the charts of 256 consecutive patients with differentiated thyroid cancer treated with lobectomy at the Gangnam Severance Hospital between April and December 2014 who were followed-up for more than 5 years. Patients were evaluated using a thyroid function test at the time of outpatient visit every 6 months for the 1st year, with an annual follow-up thereafter. Results: After 5 years, 66.0% (169) of the patients needed levothyroxine supplementation to maintain euthyroid status. The incidence of hypothyroidism requiring levothyroxine supplementation increased until 3 years but showed no significant change in the 4 and 5th year. Recurrence showed no difference between the group with and without levothyroxine supplementation. The presence of thyroiditis and preoperative TSH levels were correlated with postoperative levothyroxine supplementation to maintain euthyroid status, in univariate and multivariate analyses. Conclusion: High preoperative TSH levels and/or thyroiditis indicate a significantly increased likelihood of developing hypothyroidism requiring thyroid hormone supplementation after a thyroid lobectomy. Patients with an increased risk of postoperative hypothyroidism must be aware of their risk factors and should undergo more intensive follow-ups.

Risk of Iodine Deficiency in Extremely Low Gestational Age Newborns on Parenteral Nutrition.

Iodine is an essential component of thyroid hormones, which play a critical role in neurodevelopment. The iodine status of pregnant women and their newborns is not checked routinely. Extremely Low Gestational Age Newborns do not receive Iodine supplementation while on parenteral nutrition (PN). We measured urine iodine levels and thyroid function tests in 50 mother-infant dyads at birth, at 1 week, 1, 2, 3 months and near discharge. We correlated maternal and neonatal urine iodine levels with thyroid functions and measured iodine levels in milk and PN. In our study, 64% of mothers were iodine deficient at the time of delivery, their free T4 levels were 0.48 (0.41-0.54) ng/dL with normal thyroid-stimulating hormone (TSH). Iodine levels were thirty-fold higher in extremely low gestational age newborns (ELGAN) exposed to iodine comparing to full terms (p < 0.001), but this effect lasted <1 week. At 1 month of age, ELGAN on PN developed iodine deficiency (p = 0.017) and had high thyroglobulin levels of 187 (156-271) ng/mL. Iodine levels improved with enteral feeds by 2 months of age (p = 0.01). Iodine deficiency is prevalent among pregnant women and ELGAN; in particular, those on PN are at risk of hypothyroidism. Iodine supplementation during pregnancy and postnatally should be considered to avoid iodine deficiency.

Combined mutations of NKX2-1 and surfactant protein C genes for refractory low oxyhemoglobin saturation and interstitial pneumonia: A case report.

RATIONALE: Mutations of the NKX2-1 gene are associated with brain-lung-thyroid syndrome, which is characterized by benign hereditary chorea, hypothyroidism, and pulmonary disease with variable presentation. Surfactant protein C (SFTPC) gene mutations result in chronic interstitial lung disease in adults or severe neonatal respiratory distress syndrome. PATIENT CONCERNS: Recurrent hypoxemia was observed shortly after birth in a baby at a gestational age of 40 weeks and birth weight of 3150 g. The need for respiratory support gradually increased. He had hypothyroidism and experienced feeding difficulties and irritability. DIAGNOSIS: Genetic examination of the peripheral blood revealed combined mutations of the NKX2-1 and SFTPC genes. INTERVENTIONS: The patient was administered respiratory support, antibiotics, low-dose dexamethasone, supplementary thyroxine, venous nutrition, and other supportive measures. OUTCOMES: The patient's guardian stopped treatment 3 months after commencement of treatment, due to the seriousness of his condition and the patient died. LESSONS: Combined mutations of NKX2-1 and SFTPC genes are very rare. Thus, idiopathic interstitial pneumonia with hypothyroidism and neurological disorders require special attention.

Prevalence of endocrine complications in transfusion dependent thalassemia in Hospital Pulau Pinang: A pilot study.

INTRODUCTION: Frequent blood transfusions results in iron overload and lead to multiple endocrine complications. In spite of improvements in iron chelation therapy, a significant number of transfusion dependent thalassaemia (TDT) patients still develop endocrine complications. The aim of this study is to evaluate the prevalence of various endocrine complications in our adult TDT patients and to study the correlation with serum ferritin and liver iron concentration (LIC). METHODS: A retrospective review of all TDT patients treated in Haematology Unit, Hospital Pulau Pinang (HPP) was conducted. RESULTS: Of the 45 adult TDT patients, 22 were males and 23 were females with mean age of 28.8±6.9 years old. Majority of TDT in HPP were beta thalassemia major (71.1%), followed by E-Beta thalassemia (24.4%) and HbH-Constant Spring (4.4%). Frequency of transfusion was 3-4 weekly. 40.0% of adult TDT suffered from at least one endocrine complication. Among the adult TDT patients with endocrine complication, 50% have one endocrinopathy, 38.9% with two types of endocrinopathies and 11.1% of them have three or more types of endocrinopathies. Hypogonadism (22.2%) was the commonest endocrine complication, followed by osteoporosis (20%), hypothyroidism (13.3%), diabetes mellitus (6.7%) and hypocortisolism (4.4%). Patients with endocrine complications were significantly older. Mean serum ferritin level and LIC was higher among patients with endocrine complications but both were not statistically significant. CONCLUSION: Endocrinopathy is still prevalent in 40% of adult TDT patients. This leads to higher health-care resource utilization, cost and significant morbidities among patients with TDT. Therefore, regular monitoring and early detection with intensification of chelation therapy is essential.

Oncological impact of hypothyroidism and levothyroxine supplementation following hemithyroidectomy in patients with papillary thyroid carcinoma.

BACKGROUND: We aimed to evaluate the oncological impact of hypothyroidism and levothyroxine (LT) supplementation after hemithyroidectomy in patients with papillary thyroid carcinoma (PTC). METHODS: We retrospectively examined 401 patients who underwent hemithyroidectomy for classic PTC and who were postoperatively followed-up with ≥3 thyroid function measurements for ≥24 months. RESULTS: During 77.4 months of follow-up, 268/401 patients (66.8%) developed hypothyroidism and 19/401 patients (4.7%) showed recurrence. Recurrence rates did not differ between the euthyroidism and hypothyroidism development groups. Recurrence rates were significantly lower in the LT group than in the no-LT group, although mean postoperative thyroid-stimulating hormone (TSH) levels were not different between the two groups. Univariate and multivariate analysis showed that tumors sized >1 cm and lack of LT supplementation were significantly associated with recurrence. CONCLUSIONS: Postoperative hypothyroidism development was not a risk factor for PTC recurrence after hemithyroidectomy. Nevertheless, LT supplementation reduced recurrence risk without suppressing TSH.

The Relationship Between Thyroid Antibodies and Vitamin D Level in Primary Hypothyroidism.

INTRODUCTION: Vitamin D deficiency is a global health problem. Its deficiency has been reported to be associated with different autoimmune diseases. AIM: The aim of this study was to evaluate the relationship between vitamin D level and thyroid antibodies in autoimmune hypothyroidism. METHODS: A total number of 150 individuals were enrolled in this study. They were divided into the fallowing groups: group I included 50 patients with autoimmune thyroid disease (AITD), group II included 50 patients without autoimmune thyroid disease. Group III included 50 apparently healthy participants representing a control group. All participants underwent a detailed clinical examination and laboratory tests including, 25 (OH) vitamin D, thyroid-stimulating hormone (TSH) and thyroid autoantibodies assessment, including anti-thyroid peroxidase antibodies (anti-TPO) and anti-thyroglobulin antibodies (anti-TG). RESULTS: Serum levels of 25 (OH) vitamin D recorded a highly significant difference between the studies groups (20,76±6,31 ng/ml in group I vs. 24,37±9,05ng/ml in group II vs. 24,57±6,45ng/ml in group III, p<0,01). Moreover, there was a highly significant difference between patients with AITD and patients without AITD (20,76±6,31ng/ml vs. 24,37±9,05ng/ml, respectively; p<0,01). The concentration of anti-TPO and anti-TG antibodies were statistically significant higher in patients with vitamin D deficiency (p< 0,001). Serum TSH were significantly higher in group I (p< 0,001). CONCLUSION: Significantly low levels of vitamin D were documented in patients with AITD that were related to the presence of anti-thyroid antibodies and higher level thyroid-stimulation hormone (TSH), suggesting the involvement of vitamin D in the pathogenesis of AITD and the advisability of supplementation.

Selenium supplementation in patients with subclinical hypothyroidism affected by autoimmune thyroiditis: Results of the SETI study.

OBJECTIVE: The purpose of this prospective study was to assess the effects of selenium supplementation on TSH and interferon-γ inducible chemokines (CXCL9, CXCL10 and CXCL11) levels in patients with subclinical hypothyroidism due to Hashimoto's thyroiditis. PATIENTS AND METHODS: Patients with subclinical hypothyroidism due to Hashimoto thyroiditis were prospectively enrolled in the SETI study. They received 83mcg of selenomethionine/day orally in a soft gel capsule for 4 months with water after a meal. No further treatment was given. All patients were measured thyroid hormone, TPOAb, CXCL9, CXCL10, CXCL11, iodine, and selenium levels at baseline and at study end. RESULTS: 50 patients (43/7 female/male, median age 43.9±11.8 years) were enrolled, of which five withdrew from the study. At the end of the study, euthyroidism was restored in 22/45 (48.9%) participants (responders), while 23 patients remained hypothyroid (non-responders). There were no significant changes in TPOAb, CXCL9, CXCL10, CXCL11, and iodine levels from baseline to the end of the study in both responders and non-responders. TSH levels were re-tested six months after selenomethionine withdrawal: 83.3% of responding patients remained euthyroid, while only 14.2% of non-responders became euthyroid. CONCLUSIONS: The SETI study shows that short-course supplementation with selenomethionine is associated to a normalization of serum TSH levels which is maintained 6 months after selenium withdrawal in 50% of patients with subclinical hypothyroidism due to chronic autoimmune thyroiditis. This TSH-lowering effect of selenium supplementation is unlikely to be related to changes in humoral markers of autoimmunity and/or circulating CXCL9.

Compliance with Deferoxamine Therapy and Thyroid Dysfunction of Patients with ß-Thalassemia Major in Syria.

Hypothyroidism is one of the common endocrine complications described in patients with ß-thalassemia major (ß-TM). Studies have reported its incidence and severity depending on the region, quality of management and treatment protocols. The reported thyroid dysfunction includes overt hypothyroidism, subclinical hypothyroidism and rarely, central hypothyroidism. The main aims of this study were to identify the incidence of hypothyroidism in 82 patients with ß-TM in Syria, and also to evaluate the effect of compliance with deferoxamine (DFO) therapy on the patients' thyroid function. Out of the 82 patients included in this study, 24 had subclinical hypothyroidism (29.27%) and one patient had overt hypothyroidism (1.22%). It was demonstrated by this study that noncompliance with DFO therapy increases the risk of thyroid dysfunction 6.38-times compared to compliance with DFO [risk ratio (RR) = 6.385; 95% confidence interval (95% CI) 2.40-16.95)]. These results emphasize the importance of compliance with chelation therapy to minimize the burden of thyropathy on patients' quality of life, and also augment the rationale for a routine follow-up and endocrine evaluation for early detection and management of these complications.

Identifying Predictors of Prolonged Levothyroxine Dose Adjustment After Thyroidectomy.

BACKGROUND: Levothyroxine (LT4) is one of the most prescribed drugs in the United States; however, many patients started on LT4 after thyroidectomy suffer from symptoms of hyper- or hypo-thyroidism before achieving euthyroidism. This study aims to describe the time required for dose adjustment before achieving euthyroidism and identify predictors of prolonged dose adjustment (PDA+) after thyroidectomy. METHODS: This is a single institution retrospective cohort study of patients who achieved euthyroidism with LT4 therapy between 2008 and 2017 after total or completion thyroidectomy for benign disease. Patients who needed at least three dose adjustments (top quartile) were considered PDA+. Binomial logistic regression was used to identify predictors of PDA+. RESULTS: The 605 patients in this study achieved euthyroidism in a median of 116 d (standard deviation 124.9) and one dose adjustment (standard deviation 1.3). The 508 PDA- patients achieved euthyroidism in a median of 101 d and one dose adjustment. The 97 PDA+ patients achieved euthyroidism in a median of 271 d and three dose adjustments. Iron supplementation (odds ratio = 4.4, 95% confidence interval = 1.4-13.5, P = 0.010) and multivitamin with mineral supplementation (odds ratio = 2.4, 95% confidence interval = 1.3-4.3, P = 0.004) were independently associated with PDA+. Age, gender, preoperative thyroid disease, and comorbidities did not independently predict PDA+. CONCLUSIONS: After thyroidectomy, achieving euthyroidism can take nearly 4 mo. Iron and mineral supplementation are associated with PDA+. This information can inform the preoperative counseling of patients and suggests that this may expedite achieving euthyroidism.

Excess iodine intake: sources, assessment, and effects on thyroid function.

Iodine is essential for thyroid hormone synthesis. High iodine intakes are well tolerated by most healthy individuals, but in some people, excess iodine intakes may precipitate hyperthyroidism, hypothyroidism, goiter, and/or thyroid autoimmunity. Individuals with preexisting thyroid disease or those previously exposed to iodine deficiency may be more susceptible to thyroid disorders due to an increase in iodine intake, in some cases at intakes only slightly above physiological needs. Thyroid dysfunction due to excess iodine intake is usually mild and transient, but iodine-induced hyperthyroidism can be life-threatening in some individuals. At the population level, excess iodine intakes may arise from consumption of overiodized salt, drinking water, animal milk rich in iodine, certain seaweeds, iodine-containing dietary supplements, and from a combination of these sources. The median urinary iodine concentration (UIC) of a population reflects the total iodine intake from all sources and can accurately identify populations with excessive iodine intakes. Our review describes the association between excess iodine intake and thyroid function. We outline potential sources of excess iodine intake and the physiological responses and consequences of excess iodine intakes. We provide guidance on choice of biomarkers to assess iodine intake, with an emphasis on the UIC and thyroglobulin.