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Background: Altered thyroid function has been linked to insulin resistance (IR), but its relationship with the Metabolic Score for Insulin Resistance (METS-IR), a novel non-insulin-based index of IR, remains unclear. This study aimed to investigate the association between thyroid function status and METS-IR in a U.S. population. Methods: This cross-sectional study utilized data from 6,507 adults (aged ≥ 20 years) participating in the National Health and Nutrition Examination Survey from 2007 to 2012. Thyroid function status was categorized into five groups based on thyroid-stimulating hormone and free thyroxine levels. METS-IR was calculated from measures of fasting glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI). Multivariate regression analyzed the relationship between thyroid status and METS-IR after adjusting for potential confounders. Results: Higher thyroid-stimulating hormone levels were positively associated with METS-IR (β = 0.003, 95% CI 0.001–0.004, p = 0.021). Subclinical hypothyroidism in males and subclinical hyperthyroidism in females showed significant correlations with higher METS-IR. Thyroid peroxidase antibodies (TPO Ab) positivity strengthened the association between overt hypothyroidism and METS-IR. Conclusions: This study demonstrates significant associations between thyroid function status, particularly subclinical thyroid dysfunction, and insulin resistance as measured by METS-IR in a U.S. population. Thyroid status may serve as an early marker of insulin resistance risk. [ABSTRACT FROM AUTHOR]

Introduction: Increasing incidence of fragility fractures has spurred development of protocols, largely focused on peri-operative care, with numerous proven benefits. The purpose of this investigation was to evaluate outcomes of our hip fracture treatment program regarding successful protocol implementation, compliance, effect on subsequent fracture rates, and mortality during the first decade of adoption. Methods: A retrospective review identified patients >65 years old with fragility hip fractures between 2010 and 2022. The HiROC (+) cohort consisted of patients who received a "High-Risk Osteoporosis Clinic" (HiROC) referral for bone health evaluation and bisphosphonate initiation as indicated. Additional fracture rates and mortality at 3 years were calculated. Protocol implementation and compliance over the first 10 years was analyzed in the four identified cohorts. Results: A total of 1671 fragility hip fractures were identified, with 386 excluded due to insufficient follow-up, with an average age of 81.6 years and a median follow-up of 36.4 months. Of the 1280 included cases, 56% (n = 717) had a HiROC referral placed. HiROC(+) groups had lower subsequent fracture rates at two years, compared to those without referral (28% vs 13%, P < 0.0001) and those completing more steps of the protocol had lower subsequent fracture rates (28% vs 15% vs 13% vs 5%, P < 0.0001). No statistically significant difference was observed between the cohorts for anatomic site of subsequent fractures. Discussion: Greater than half of all eligible patients were successfully captured by the protocol. Patients completing more steps of the protocol had lower subsequent fracture rates. Captured patients demonstrated reduced mortality rates when compared to current literature. Conclusion: Successful implementation of this geriatric hip fracture protocol was associated with reduced additional fractures and mortality rates. Identifying steps of process failures in the protocol can provide opportunities for increased compliance and reduction in future fracture occurrences. [ABSTRACT FROM AUTHOR]

Context: Thyroid-stimulating hormone (TSH) is one of the most ordered laboratory tests. Objective: Determine trends of TSH testing rates and components of thyroid function testing. Methods: This was a retrospective analysis of adults 18-64 years old without evidence of thyroid disease with at least 365 days of continuous enrollment between 2006 and 2020 in the IBM MarketScan Claims Database. The main outcome measures were trends of TSH tests/1000 eligible patient-months stratified by age, sex, and region and composition of thyroid function testing. Results: Among 67 353 280 patients meeting eligibility criteria, we identified 25 606 518 TSH tests and 15 138 211 patients with ≥1 TSH test. Patients contributing an episode of TSH testing were most commonly 45-54 years old (29.8%) and female (63.6%). TSH testing rates remained consistent throughout the study period with 11.4 and 11.7 TSH tests/1000 person-months in the first and last study months, respectively (mean 12.2 TSH tests/1000 person-months). TSH testing rates dropped sharply in the spring of 2020 (4.2 TSH tests/1000 person-months). Females showed a nearly 2-fold higher rate of TSH testing than males (16.1 TSH tests/1000 person-months vs 8.6 TSH tests/1000 person-months). TSH testing rates increased with age (8.2 TSH tests/1000 person-months among individuals 18-34 years old vs 15.4 TSH tests/1000 personmonths among individuals 55-64 years old). No difference in TSH testing rates was noted between regions. Thyroid function testing episodes included only TSH in most cases (70.8%). Conclusion: TSH testing rates among commercially insured individuals without known thyroid disease appears stable over time, with higher frequency in females and with increasing age. [ABSTRACT FROM AUTHOR]

Background: There are conflicting results in the existing studies regarding the association between depression and subclinical hypothyroidism in adolescents. Subclinical hypothyroidism is defined as elevated thyroid stimulating hormone (TSH) levels above the reference range without signs or symptoms of hypothyroidism. Objectives: The focus of this study is to determine whether there is any association between depression and subclinical hypothyroidism, (as defined by the serum TSH levels) in a population of healthy adolescents. Design: Quantitative-based cross-sectional study of a representative subset of the adolescent population. Methods: We carried out a cross-sectional study to determine the association between major depressive disorder (MDD) and subclinical hypothyroidism, in adolescents presenting for annual physical examinations during the peak period of the COVID-19 pandemic in the USA, a period deemed high for adolescent depression. All the adolescents were screened for depression by the PHQ-9 screening tool and had their TSH measured. Results: Of the 304 subjects analyzed, 179 (58.88%) were minimally or not depressed according to the Patient Health Questionnaire (PHQ-9) screening tool (mean PHQ 1.80 ± 1.49). 70 (23.03%) had mild depression (mean PHQ 6.59 ± 1.46), 50 (16.45%) had moderate depression (mean PHQ 13.70 ± 2.75), and 5 (1.64%) had severe depression (mean PHQ 21.40 ± 1.67). Mean TSH values were 1.93 ± 0.99, 1.77 ± 1.05, 2.10 ± 0.98, and 1.57 ± 0.32 mIU/L, respectively in the four groups. All values were within the recommended range of 0.50 to 4.30 mIU/L, without statistically significant inter-group differences. Conclusion: We conclude that there is no statistically significant association between depression and subclinical hypothyroidism, in a population of adolescents presenting for physical examinations, and if the screening for depression by the PHQ-9 tool indicates depression, a screening TSH test for subclinical hypothyroidism is not justified. [ABSTRACT FROM AUTHOR]

The majority of patients with hypothyroidism feel better when levothyroxine treatment restores thyroid‐stimulating hormone (TSH) concentrations to normal. Increasingly, a significant minority of patients remain symptomatic and are dissatisfied with their treatment. Overzealous treatment of symptomatic patients with subclinical hypothyroidism may contribute to dissatisfaction among hypothyroidism patients, as potential hypothyroid symptoms in patients with minimal hypothyroidism rarely respond to treatment. Thyroid hormone prescriptions have increased by 30% in the United States in the last decade. The diagnosis of subclinical hypothyroidism should be confirmed by repeat thyroid function tests ideally obtained at least 2 months later, as 62% of elevated TSH levels may revert to normal spontaneously. Generally, treatment is not necessary unless the TSH exceeds 7.0–10 mIU/L. In double‐blinded randomized controlled trials, treatment does not improve symptoms or cognitive function if the TSH is less than 10 mIU/L. While cardiovascular events may be reduced in patients under age 65 with subclinical hypothyroidism who are treated with levothyroxine, treatment may be harmful in elderly patients with subclinical hypothyroidism. TSH goals are age dependent, with a 97.5 percentile (upper limit of normal) of 3.6 mIU/L for patients under age 40, and 7.5 mIU/L for patients over age 80. In some hypothyroid patients who are dissatisfied with treatment, especially those with a polymorphism in type 2 deiodinase, combined treatment with levothyroxine and liothyronine may be preferred. [ABSTRACT FROM AUTHOR]

Objectives: Thyroid dysfunction in pregnancy is associated with increased risk of adverse outcomes to mother and child. Trimester-specific reference intervals for thyroid function tests are not routinely provided by clinical laboratories. In this study, we present first- and second-trimester-specific reference intervals in a US population for thyroid-stimulating hormone (TSH), free thyroxine (FT4), total thyroxine (T4), and total triiodothyronine (T3) measured on Roche analyzers.Methods: We used patient samples from first- and second-trimester prenatal screening. Samples were limited to singleton pregnancies and negative screening results for thyroid peroxidase and thyroglobulin antibodies. Analytes (TSH, FT4, T4, and T3) were measured on a Roche Modular e170 then verified on a Roche cobas e801.Results: The reference intervals established on the e170 and verified on the e801 for the first trimester were 0.16 to 2.82 mIU/L for TSH, 12.0 to 18.5 pmol/L for FT4, 62.8 to 177.9 nmol/L for T4, and 1.5 to 3.4 nmol/L for T3. The reference intervals for the second trimester were 0.40 to 3.62 mIU/L for TSH, 10.2 to 16.6 pmol/L for FT4, 66.6 to 176.0 nmol/L for T4, and 1.56 to 3.6 nmol/L for T3.Conclusions: This is the first report of trimester-specific reference intervals for thyroid function tests on Roche analyzers in the United States, and it is consistent with worldwide reports. [ABSTRACT FROM AUTHOR]

Subclinical hypothyroidism affects 4.3% of the US population. Despite this prevalence, whether to treat or to observe patients with subclinical hypothyroidism remains controversial. Guidelines for overt hypothyroidism strongly favor treatment for symptomatic benefi ts, but the same benefi ts of levothyroxine treatment have not been proven for patients with subclinical hypothyroidism--most likely due to the asymptomatic nature of the condition. Additionally, a connection between subclinical hypothyroidism and cardiovascular complications has not been defi nitively established, although the evidence favors a relationship. This article describes the background, presentation, and diagnostics of subclinical hypothyroidism, treatment, and potential cardiovascular complications, so clinicians can decide if initiating treatment is best for their patients with subclinical hypothyroidism. [ABSTRACT FROM AUTHOR]

Background: Data on osteoporosis and fractures in patients with thyroid cancer, especially men, are conflicting. Our objective was to determine osteoporosis and fracture risk in U.S. veterans with thyroid cancer. Materials and Methods: This is a case‐control study using the Veterans Health Administration Corporate Data Warehouse (2004–2013). Patients with thyroid cancer (n = 10,370) and controls (n = 10,370) were matched by age, sex, weight, and steroid use. Generalized linear mixed‐effects regression model was used to compare the two groups in terms of osteoporosis and fracture risk. Next, subgroup analysis of the patients with thyroid cancer using longitudinal thyroid‐stimulating hormone (TSH) was performed to determine its effect on risk of osteoporosis and fractures. Other covariates included patient age, sex, median household income, comorbidities, and steroid and androgen use. Results: Compared with controls, osteoporosis, but not fractures, was more frequent in patients with thyroid cancer (7.3% vs. 5.3%; odds ratio [OR], 1.33; 95% confidence interval [CI], 1.18–1.49) when controlling for median household income, Charlson/Deyo comorbidity score, and androgen use. Subgroup analysis of patients with thyroid cancer demonstrated that lower TSH (OR, 0.93; 95% CI, 0.90–0.97), female sex (OR, 4.24; 95% CI, 3.53–5.10), older age (e.g., ≥85 years: OR, 17.18; 95% CI, 11.12–26.54 compared with <50 years), and androgen use (OR, 1.63; 95% CI, 1.18–2.23) were associated with osteoporosis. Serum TSH was not associated with fractures (OR, 1.01; 95% CI, 0.96–1.07). Conclusion: Osteoporosis, but not fractures, was more common in U.S. veterans with thyroid cancer than controls. Multiple factors may be contributory, with low TSH playing a small role. Implications for Practice: Data on osteoporosis and fragility fractures in patients with thyroid cancer, especially in men, are limited and conflicting. Because of excellent survival rates, the number of thyroid cancer survivors is growing and more individuals may experience long‐term effects from the cancer itself and its treatments, such as osteoporosis and fractures. The present study offers unique insight on the risk for osteoporosis and fractures in a largely male thyroid cancer cohort. Physicians who participate in the long‐term care of patients with thyroid cancer should take into consideration a variety of factors in addition to TSH level when considering risk for osteoporosis. Thyroid stimulating hormone suppression therapy may contribute to bone loss in patients with thyroid cancer, especially in postmenopausal women. The link between thyroid cancer treatment and osteoporosis and fractures in men is less certain. This article reports results of a study designed to address this knowledge gap. [ABSTRACT FROM AUTHOR]

Objectives: Blood tests for endocrinological derangements are frequently requested in general medical inpatients, in particular those in the older age group. Interrogation of these tests may present opportunities for healthcare savings., Methods: This multicentre retrospective study over a 2.5-year period examined the frequency with which three common endocrinological investigations [thyroid stimulating hormone (TSH), HbA1c, 25-hydroxy Vitamin D3] were performed in this population, including the frequency of duplicate tests within a given admission, and the frequency of abnormal test results. The Medicare Benefits Schedule was used to calculate the cost associated with these tests., Results: There were 28,564 individual admissions included in the study. Individuals ≥65 years old were the majority of inpatients in whom the selected tests were performed (80% of tests). TSH was performed in 6730 admissions, HbA1c was performed in 2259 admissions, and vitamin D levels were performed in 5632 admissions. There were 6114 vitamin D tests performed during the study period, of which 2911 (48%) returned outside the normal range. The cost associated with vitamin D level testing was $183,726. Over the study period, 8% of tests for TSH, HbA1c, and Vitamin D were duplicates (where a second test was performed within a single admission), which was associated with a cost of $32,134., Conclusions: Tests for common endocrinological abnormalities are associated with significant healthcare costs. Avenues by which future savings may be pursued include the investigation of strategies to reduce duplicate ordering and examining the rationale and guidelines associated with ordering tests such as vitamin D levels., (© 2023 The Authors. Australasian Journal on Ageing published by John Wiley & Sons Australia, Ltd on behalf of AJA Inc’.)

Context: Hypothyroidism is a common yet under-recognized condition in patients with chronic kidney disease (CKD), which may lead to end-organ complications if left untreated., Objective: We developed a prediction tool to identify CKD patients at risk for incident hypothyroidism., Methods: Among 15 642 patients with stages 4 to 5 CKD without evidence of pre-existing thyroid disease, we developed and validated a risk prediction tool for the development of incident hypothyroidism (defined as thyrotropin [TSH] > 5.0 mIU/L) using the Optum Labs Data Warehouse, which contains de-identified administrative claims, including medical and pharmacy claims and enrollment records for commercial and Medicare Advantage enrollees as well as electronic health record data. Patients were divided into a two-thirds development set and a one-third validation set. Prediction models were developed using Cox models to estimate probability of incident hypothyroidism., Results: There were 1650 (11%) cases of incident hypothyroidism during a median follow-up of 3.4 years. Characteristics associated with hypothyroidism included older age, White race, higher body mass index, low serum albumin, higher baseline TSH, hypertension, congestive heart failure, exposure to iodinated contrast via angiogram or computed tomography scan, and amiodarone use. Model discrimination was good with similar C-statistics in the development and validation datasets: 0.77 (95% CI 0.75-0.78) and 0.76 (95% CI 0.74-0.78), respectively. Model goodness-of-fit tests showed adequate fit in the overall cohort (P = .47) as well as in a subcohort of patients with stage 5 CKD (P = .33)., Conclusion: In a national cohort of CKD patients, we developed a clinical prediction tool identifying those at risk for incident hypothyroidism to inform prioritized screening, monitoring, and treatment in this population., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The objective of this study was to evaluate the association between thyroid function and exposure to selected polycyclic aromatic hydrocarbons (PAH) among those aged ≥ 20 years. Thyroid variables considered for evaluation were thyroid-stimulating hormone, free and total serum thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin. PAH metabolites in urine for which data were analyzed were 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene. Using data from 2007 to 2008 National Health and Nutrition Examination Survey, regression models with logs of thyroid variables as dependent variables and PAH exposure, age, race/ethnicity, iodine sufficiency, smoking status, and others as independent variables were fitted. For females, increased levels of 2-hydroxynapthalene, 2-hydroxyphenanthrene, and 1-hydroxypyrene were associated with elevated levels of TT3. For males, increased levels of 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, and 9-hydroxypyrene were associated with decreased levels of FT4. [ABSTRACT FROM AUTHOR]

Interacting effects of blood levels of manganese (Mn), selenium, cadmium (Cd), lead (Pb), and mercury, and serum levels of iron (Fe), zinc (Zn), and copper (Cu) on thyroid function in general US population were evaluated. Data from the National Health and Nutrition Examination Survey for 2011–2012 were used for this evaluation. The variables used to evaluate thyroid function were as follows: thyroid-stimulating hormone, free and total triiodothyronine (FT3, TT3), free and total thyroxine (FT4, TT4), and thyroglobulin (Tg). Levels of FT4 were positively associated with the levels of copper and negatively associated with the levels of Fe for males only. Elevated levels of Mn and Fe were associated with increased levels of FT3 for both males and females. TT4 had a positive association with the levels of Cu and a negative association with the levels of Fe for both males and females. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between hypothyroidism and glaucomatous disease. Methods: This cross-sectional study included all subjects above the age of 40 years from two nationwide surveys: the 2008 National Health Interview Survey (NHIS) as well as the 2007 and 2008 National Health and Nutrition Examination Survey (NHANES). The presence or absence of glaucoma, thyroid disease and other demographic and health-related information including comorbidities was ascertained via interview. Blood samples were collected from NHANES subjects and analyzed for thyrotropin (TSH). Results: A total of 13,599 and 3,839 NHIS and NHANES participants respectively were analyzed to assess for a possible relationship between self-reported glaucoma, and self-reported hypothyroidism as well as self-reported thyroid disease. The unadjusted odds ratio (OR) for NHIS showed a significant association between self-reported glaucoma and self-reported hypothyroidism (OR 1.46, 95% confidence interval [CI] 1.07-1.99). Multivariate logistic regression analysis adjusted for age, gender, race, comorbidities, and health-related behavior, however, showed no association between self-reported glaucoma and hypothyroidism or thyroid disease in both surveys (OR 1.60, 95%CI 0.87-2.95 for NHIS; OR 1.05, 95%CI 0.59-1.88 for NHANES). Conclusion: A previously reported association between hypothyroidism and glaucomatous disease was not confirmed in two large U.S. health survey populations. While such an association was noted in the univariate analysis for the NHIS survey, such a relationship was not found in the multivariate analysis after adjustment for potential confounding variables. [ABSTRACT FROM AUTHOR]

Background: Iodine-induced thyroid dysfunction is a potential risk among susceptible individuals. Iodinated contrast media is a common source of an acute iodine load used in the health care setting and is frequently required for diagnostic computed tomography scans, coronary angiograms, and other radiologic studies. However, the epidemiologic risks of iodine-thyroid dysfunction have not been fully established in the United States. Methods: This population-based retrospective cohort study used the U.S. Veterans Health Administration database between 1998 and 2021 and included adults aged ≥18 years with a serum thyrotropin (TSH) measurement. Multivariable logistic regression was used to ascertain the risk of incident thyroid dysfunction (defined by repeated measurements of serum thyroid function) following iodine exposure, adjusting for age, sex, race/ethnicity, baseline serum TSH concentration, and duration between baseline and follow-up TSH concentration. Results: The cohort was composed of N  = 4,253,119 veterans (mean ± SD = 63.5 ± 14.3 years; 92.9% men; 65.6% non-Hispanic Whites) with 8,729,155 corresponding pairs of serum TSH measurements, from which there were 499,897 TSH pairs with intervening iodine exposure. Thyroid dysfunction occurred in 4.8% of those pairs who had received iodine contrast and 3.6% of those without iodine exposure. Iodinated exposure was associated with an increased risk of thyroid dysfunction (odds ratio [OR] = 1.39, 95% confidence intervals [CI] = 1.37-1.41, p  < 0.001) and consistent for all types of serum thyroid dysfunction (overt or subclinical hypo-/hyperthyroidism). Men were at higher risk for the development of thyroid dysfunction than women (men: OR = 1.42, 95% CI = 1.40-1.44; women: OR = 1.16, 95% CI = 1.11-1.21; p -for-interaction <0.001). Conclusions: In this largest analysis of U.S. adults to date, iodine exposure was associated with only clinically small absolute increased risks of thyroid dysfunction, particularly in men. These findings suggest that screening of thyroid function following iodinated contrast administration should be targeted to high-risk individuals.

Importance: Clinical hyperthyroidism accelerates bone resorption without compensatory bone formation, reducing bone density and increasing the risk of fracture. The association between subclinical hyperthyroidism and fracture risk is less clear., Objective: To investigate the association of endogenous subclinical thyroid dysfunction and fracture risk, independent of clinical confounders., Design, Setting, and Participants: This cohort study included 10 946 participants from the Atherosclerosis Risk in Communities Study, an ongoing prospective cohort study of community-dwelling individuals conducted from 1987-1989 through December 31, 2019, in Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and the suburbs of Minneapolis, Minnesota. Participants were not taking thyroid medications and had no history of fractures., Exposures: Thyrotropin and free thyroxine levels were measured at visit 2 (1990-1992). Subclinical hyperthyroidism was defined as a thyrotropin level lower than 0.56 mIU/L, subclinical hypothyroidism as a thyrotropin level higher than 5.1 mIU/L, and euthyroidism as a thyrotropin level of 0.56 to 5.1 mIU/L, with normal free thyroxine levels from 0.85 to 1.4 ng/dL., Main Outcomes and Measures: Incident fracture was ascertained using hospitalization discharge codes through 2019 and linkage to inpatient and outpatient Medicare claims through 2018., Results: Of 10 946 participants (54.3% women; mean [SD] age, 57 [5.7] years), 93.0% had euthyroidism, 2.6% had subclinical hyperthyroidism, and 4.4% had subclinical hypothyroidism. During a median follow-up of 21 years (IQR, 13.0-27.3 years), there were 3556 incident fractures (167.1 per 10 000 person-years). The adjusted hazard ratios of fracture were 1.34 (95% CI, 1.09-1.65) for those with subclinical hyperthyroidism and 0.90 (95% CI, 0.77-1.05) for those with subclinical hypothyroidism compared with individuals with euthyroidism. Among those with normal free thyroxine levels, thyrotropin levels in the lower-than-normal range were significantly associated with higher fracture-related hospitalization risk; fracture risk was greater among individuals with thyrotropin concentrations below 0.56 mIU/L., Conclusions and Relevance: This community-based cohort study suggests that subclinical hyperthyroidism was an independent risk factor associated with fracture. The increased risk for fracture among individuals with a thyrotropin level lower than 0.56 mIU/L highlights a potential role for more aggressive screening and monitoring of patients with subclinical hyperthyroidism to prevent bone mineral disease.

Introduction. The aim of this study was to evaluate the serum levels of resistin and insulin-like growth factor-1 (IGF-1) and and also the potential relationship between thyroid function and levels of resistin and IGF-1 in hypothyroid and hyperthyroid patients. Methods. Fifteen cases of hypothyroid (HT), 16 of subclinically hypothyroid (SCHT), 15 of hyperthyroid (HrT), 15 of subclinically hyperthyroid (SCHrT), and 17 healthy individuals have been included in the study. Serumresistin levels were measured using enzyme-linked immunosorbent assay and IGF-1 and thyroid stimulating hormone (TSH) levels by chemiluminescence method. Results. Resistin levels in total HT group were significantly higher than in controls (12.66 ± 6.04 and 8.45 ± 2.90 ng/mL, resp.). In SCHrT subgroup resistin levels were significantly higher than those of controls (14.88 ± 7.73 and 8.45 ± 2.90 ng/mL, resp.). IGF-1 levels were significantly lower in total HT than in total HrT and control groups (117.22 ± 52.03, 155.17 ± 51.67, and 184.00 ± 49.73 ng/mL, resp.). Furthermore IGF-1 levels in HT subgroup were significantly lower compared to controls (123.70 ± 44.03 and 184 ± 49.73 ng/mL, resp.). In SCHT subgroup IGF-1 levels were significantly lower than those of control and SCHrT groups (111.11 ± 59.35, 184.00 ± 49.73, and 166.60 ± 47.87 ng/mL, resp.). There were significant correlations between IGF-1 and TSH in HT subgroup and between resistin and TSH in total HrT group. Conclusion. It was concluded that increased resistin levels are directly related to thyroid dysfunction, and GH/IGF-1 axis is influenced in clinically or subclinically hypothyroidism patients. [ABSTRACT FROM AUTHOR]

We evaluated the preoperative serum thyrotropin (TSH) levels in 386 patients operated on for nodular thyroid disease (NTD). TSH levels for cases with final benign disease and differentiated thyroid carcinoma (DTC) were compared. No evidence of cancer was detected in 310 patients (80.3%), whereas malignancy was present in 76 cases (19.7%). Mean TSH concentration was 1.36 ± 1.62 mU/L in benign patients and 2.08±2.1 in cases with malignant lesions (P = 0.0013). The group of malignancy was subdivided in papillary thyroid carcinoma (PTMC) versus thyroid cancer of larger size (TCLS). Mean TSH was 1.71 ± 1.52 in PTMC and 2.42 ± 2.5 in TCLS. Significant differences were found when all groups (benign, PTMC and TCLS) were compared (P < 0.001). However, pairwise comparisons between them showed that differences were only significant between benign and TCLS groups (P < 0.01). In conclusion, TSH levels were higher in patients with a final diagnosis of DTC. Moreover, it appears that there exists an increment in tumor size as a function of increment in the TSH level. [ABSTRACT FROM AUTHOR]

Abstract: Objective: We aimed to measure separately the contributions of heat and humidity to changes in levels of 34 markers of inborn disorders in dried-blood-spot (DBS) samples. Design and methods: We stored paired sets of DBSs at 37°C for predetermined intervals in low-humidity and high-humidity environments. Marker levels of all samples in each complete sample set were measured in a single analytic run. Results: During the 30±5day studies, galactose-1-phosphate uridyltransferase and biotinidase lost almost 65% of initial activities in low-humidity storage; most of the degradation in 27 other markers was attributable to adverse effects of high-humidity storage; seven markers in DBSs stored at high humidity lost more than 90% of initial levels by the end of the study and 4 of the 7 lost more than 50% of initial levels within the first week of storage. Conclusions: Minimizing both humidity and temperature in DBS transportation and storage environments is essential to maintaining sample integrity. [Copyright &y& Elsevier]

Summary Objective The incidence of congenital hypothyroidism (CH) detected by newborn screening in the US has increased significantly since the early 1990s. We defined the characteristics associated with the increased incidence. Patients A cohort of children with CH born during an earlier period of low incidence (1991-94) was compared with a cohort born during a later period when the incidence of CH had doubled (2001-04). Measurements Screening was performed with T4 as the primary marker and thyroid stimulating hormone (TSH) on selected specimens. Follow-up on hypothyroid children determined whether they had permanent or transient hypothyroidism. Cases were classified based on laboratory results: initial TSH ≥100 mU/l was 'severe,' initial TSH <100 mU/l but ≥20 mU/l was 'mild' and initial TSH <20 mU/l with subsequent abnormal TSH was 'delayed'. Results The overall incidence of CH almost doubled between the two time periods, from 1:3010 to 1:1660. Excess cases were found in the mild and delayed categories, with no increase in severe cases. The proportion of transient cases was <5% in severe cases, 40% in mild cases and 70% among delayed cases. There was no difference in the proportion of transient case between the two time periods. Modifications to the T4/TSH testing protocol between the two time periods resulted in substantially increased numbers of specimens in the younger cohort being selected for TSH testing in both initial and repeat specimens. Conclusion The rising incidence of CH in Massachusetts is confined to mild and delayed cases. Our findings suggest that this rise is attributable to enhanced detection rather than an absolute increase in numbers. [ABSTRACT FROM AUTHOR]

Background:The use of age- and ethnicity-specific thyrotropin (TSH) reference limits decreases misclassification of patients with thyroid dysfunction. Developing such limits requires TSH measurements in different subpopulations.Methods:We determined, in the National Health and Nutrition Examination Survey III, the TSH median, 2.5th and 97.5th centiles as a function of age, and anti-thyroid antibodies (ABs) in specific racial/ethnic groups (REGs) designated as non-Hispanic Whites, non-Hispanic Blacks, and Mexican Americans, as classified by the U.S. Office of Management and Budget (OMB) Directive 15. We compared TSH limits of a thyroid disease-free population (n= 15,277) to a reference population (n= 13,344) formed by exclusion of AB+ subjects and TSH >10 mIU/L or <0.1 mIU/L. With quantile regression, we examined the effect of age, REG, gender, body weight, and urinary iodine concentration on TSH reference limits in the AB− population.Results:AB status did not affect the 2.5th centile and median TSH in any REG or the 97.5th centile in Blacks. The average 97.5th centile of the disease-free Whites and Mexican Americans was 1.0 mIU/L higher than the reference population group. The TSH 2.5th, 50th, and 97.5th centiles increased with age and were lower in Blacks than in Whites or Mexican Americans. Women had lower 2.5th and 50th centiles than males. From these data, we developed equations to predict subpopulation-specific TSH reference limits.Conclusions:Our study provides a method to determine TSH limits in individual patients of different ages, gender, and REG criteria whose AB status is uncertain and it will enable clinicians to better classify patients within their subpopulation-specific TSH reference range. [ABSTRACT FROM AUTHOR]

The article focuses on a study which examined the risks of coronary heart disease (CHD) and total mortality among adults with subclinical hypothyroidism. The study included 55,287 adults in the U.S., Europe, Australia, Brazil and Japan, who were followed up from 1972 to 2007. Of the total study participants, 3,450 developed subclinical hypothyroidism, while 51,837 had euthyroidism. Study authors found that increased thyroid-stimulating hormone (TSH) concentration increased the risk of CHD and CHD-related mortality. They concluded that patients with subclinical hypothyroidism have higher risk of CHD.

The reported incidence rate of primary congenital hypothyroidism (CH) has been increasing in the United States over the past 2 decades. We have considered the possibility that the inclusion of cases of transient hypothyroidism has inflated the reported incidence rate of CH. Assessing the effects of cases of transient hypothyroidism on the incidence rate is problematic, because the definitions, diagnostic criteria, and differentiation from transient hyperthyrotropinemia vary widely among state newborn screening programs. Among the 4 etiologies for transient hypothyroidism (maternal thyrotropin receptor-blocking antibodies, exposure to maternal antithyroid medications, iodine deficiency, and iodine excess), there is little evidence of increases in the incidence rate from thyrotropin receptor-blocking antibodies. Exposure to antithyroid drugs could contribute significantly to the incidence rate of transient CH, given the high estimated incidence of active maternal hyperthyroidism. Iodine deficiency or excess in the United States seems unlikely to have contributed significantly to the incidence rate of CH, because the secular trend toward lower iodine intake among women of reproductive age in the 1980s and 1990s seems to have plateaued, and perinatal iodine exposure has presumably declined as a result of recommendations to discontinue using iodine-containing disinfectants. Although the female-to-male sex ratio among newborns with thyroid agenesis or dysgenesis (the most common causes of CH) is typically 2:1, analysis of the sex ratio of newborns diagnosed with presumed CH in the United States suggests that a substantial proportion might have transient hypothyroidism or hyperthyrotropinemia, because the sex ratio has been well below the expected 2:1 ratio. Combined ultrasonography and 1231 scintigraphy of the thyroid gland are effective tools for identifying cases of thyroid agenesis and dysgenesis and can help to differentiate cases of transient hypothyroidism from true CH. Imaging is also a vital component in evaluating children who, at 3 years of age, undergo a trial of discontinuation of levothyroxine treatment to test for persistence of hypothyroidism. Ultimately, thyroid gland imaging, in conjunction with longterm follow-up studies that appropriately assess and report whether there was permanence of hypothyroidism, will be necessary to address the true incidence rate of CH and any contribution to the observed rate by transient cases of hypothyroidism or hyperthyrotropinemia. [ABSTRACT FROM AUTHOR]

Thyroid nodules are common and are frequently benign. The prevalence of thyroid nodules ranges from 3-7% (palpation) to 50% (ultrasonography). Thyroid cancer occurs in 5-10% of nodules. Thyroid ultrasonography (US) is not a screening test but all patients with palpable thyroid nodule should undergo US examination. US-guided free-needle aspiration citology (FNC) is recommendend for nodules with suspicious features at US examination or when clinical risk factors occur. A radioisotope scan is useful if the TSH is low or suppressed to detect (benign) functioning nodules. [ABSTRACT FROM AUTHOR]

Objective: To review the iodine status of women as assessed through National Health and Nutrition Examination Surveys from 1971 to 2002.Design and Setting: National normative estimates of iodine status of the civilian, non-institutionalized population in the United States of America.Subjects: Women of reproductive age and pregnant women.Results: In the United States of America, iodine began to be added to the diet in the 1920s. An excessive iodine intake was documented by the first National Health and Nutrition Examination Survey (NHANES I) in the 1970s which reported a median urinary iodine (UI) concentration of 320 μg l-1. In the NHANES III survey, conducted between 1988 and 1994, the median UI concentration had decreased to 145 μg l-1, while 14.9% of women aged 15-44 years and 6.9% of pregnant women had a UI concentration 50 μg l-1. The concentrations of serum T4 and thyroid-stimulating hormone of women with a low UI concentration did not, however, indicate an iodine deficiency.Conclusions: Further studies of the association between iodine excretion and biochemical and physiological changes should be undertaken to better understand women's needs for iodine and to develop criteria to monitor them in pregnancy. Because of the potential harm caused by iodine deficiency during pregnancy, we support the use of iodine supplements for all pregnancies while these data are being collected. [ABSTRACT FROM PUBLISHER]

Objective:Describe thyrotropin (TSH) and thyroxine (T4) levels in the U.S. population and their association with selected participant characteristics. Design:Secondary analysis of data from the National Health and Nutrition Examination Survey (NHANES) collected from 4392 participants, reflecting 222 million individuals, during 1999–2002. Results:Hypothyroidism prevalence (TSH > 4.5 mIU/L) in the general population was 3.7, and hyperthyroidism prevalence (TSH < 0.1 mIU/L) was 0.5. Among women of reproductive age (12–49 years), hypothyroidism prevalence was 3.1. Individuals aged 80 years and older had five times greater odds for hypothyroidism compared to 12- to 49-year-olds (adjusted odds ratio [OR] 5.0, p 0.0002). ORs were adjusted for sex, race, annual income, pregnancy status, and usage of thyroid-related medications (levothyroxine/thyroid, estrogen, androgen, lithium, and amiodarone). Compared to non-Hispanic whites, non-Hispanic blacks had a lower risk for hypothyroidism (OR 0.46, p 0.04) and a higher risk for hyperthyroidism (OR 3.18, p 0.0005), while Mexican Americans had the same risk as non-Hispanic whites for hypothyroidism, but a higher risk for hyperthyroidism (OR 1.98, p 0.04). Among those taking levothyroxine or desiccated thyroid, the adjusted risk for either hypothyroidism (OR 4.0, p 0.0001) or hyperthyroidism (OR 11.4, p 4 × 10−9) was elevated. Conclusions:Associations with known factors such as age, race, and sex were confirmed using this data set. Understanding the prevalence of abnormal thyroid tests among reproductive-aged women informs decisions about screening in this population. The finding that individuals on thyroid hormone replacement medication often remain hypothyroid or become hyperthyroid underscores the importance of monitoring. [ABSTRACT FROM AUTHOR]

Background: Thyroid hormone plays a crucial role in the growth and function of the central nervous system. The purpose of the study was to examine the relationships between the status of subclinical thyroid conditions and cognition among adolescents in the United States. Methods: Study sample included 1,327 adolescents 13 to 16 years old who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Serum thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and subclinical hypothyroidism, subclinical hyperthyroidism, and euthyroid groups were defined. Cognitive performance was assessed using the subscales of the Wide Range Achievement Test-Revised (WRAT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R). The age-corrected scaled scores for arithmetic, reading, block design, and digit span were derived from the cognitive assessments. Results: Subclinical hypothyroidism was found in 1.7% and subclinical hyperthyroidism was found in 2.3% of the adolescents. Cognitive assessment scores on average tended to be lower in adolescents with subclinical hyperthyroidism and higher in those with subclinical hypothyroidism than the score for the euthyroid group. Adolescents with subclinical hypothyroidism had significantly better scores in block design and reading than the euthyroid subjects even after adjustment for a number of variables including sex, age, and family income level. Conclusion: Subclinical hypothyroidism was associated with better performance in some areas of cognitive functions while subclinical hyperthyroidism could be a potential risk factor. [ABSTRACT FROM AUTHOR]

Context.—It is important that the total long-term precision of laboratory methods meet the medical needs of the patients being served. Objectives.—To determine the long-term within- and between-laboratory variation of cortisol, ferritin, thyroxine, free thyroxine, and thyroid-stimulating hormone measurements using commonly available methods and to determine if these variations are within accepted medical needs. Design.—Two vials of pooled frozen serum were mailed 6 months apart to laboratories participating in 2 separate College of American Pathologists surveys. The data from those laboratories that analyzed an analyte in both surveys were used to determine for each method the total variance and the within- and between-laboratory components. Setting.—The study included the A mailing of the 2003 College of American Pathologists Ligand Survey and the C mailing of the Chemistry Survey. Main Outcome Measures.—For each analyte, total variance was partitioned into within- and between-laboratory components for each analytic method. The within-laboratory variations were then compared with imprecision criteria based on biological variation. Participants.—The laboratories that reported results on the same analyte using the same method in both surveys. Results.—For each analyte, the median of the long-term within-laboratory variances of each peer group was 78% to 95% of its total-survey variance, and the median longterm within-laboratory coefficients of variation varied from 5.1% to 7.6%. The number of methods that met within-laboratory imprecision goals based on biological criteria were 5 of 5 for cortisol; 5 of 7 for ferritin; 0 of 7 for thyroxine and free thyroxine; and 8 of 8 for thyroid-stimulating hormone. Conclusions.—For all analytes tested, the total withinlaboratory component of variance was the major source of variability in this study. In addition, there are several methods, especially for thyroxine and free thyroxine, that may not meet analytic goals in terms of their imprecision. [ABSTRACT FROM AUTHOR]

Examines the association between low levels of thyroid-stimulating hormone (TSH) and fracture in older women in the United States. TSH level and hip fracture; TSH level and vertebral fracture; TSH level and nonspine fracture; History of hyperthyroidism, thyroid hormone use and fracture risk.

Importance: Cardiovascular disease is the leading cause of death in the United States. Synthetic thyroid hormones are among the 3 most commonly prescribed medications, yet studies evaluating the association between the intensity of thyroid hormone treatment and cardiovascular mortality are scarce., Objective: To evaluate the association between thyroid hormone treatment intensity and cardiovascular mortality., Design, Setting, and Participants: This retrospective cohort study used data on 705 307 adults who received thyroid hormone treatment from the Veterans Health Administration Corporate Data Warehouse between January 1, 2004, and December 31, 2017, with a median follow-up of 4 years (IQR, 2-9 years). Two cohorts were studied: 701 929 adults aged 18 years or older who initiated thyroid hormone treatment with at least 2 thyrotropin measurements between treatment initiation and either death or the end of the study period, and, separately, 373 981 patients with at least 2 free thyroxine (FT4) measurements. Data were merged with the National Death Index for mortality ascertainment and cause of death, and analysis was conducted from March 25 to September 2, 2020., Exposures: Time-varying serum thyrotropin and FT4 levels (euthyroidism: thyrotropin level, 0.5-5.5 mIU/L; FT4 level, 0.7-1.9 ng/dL; exogenous hyperthyroidism: thyrotropin level, <0.5 mIU/L; FT4 level, >1.9 ng/dL; exogenous hypothyroidism: thyrotropin level, >5.5 mIU/L; FT4 level, <0.7 ng/dL)., Main Outcomes and Measures: Cardiovascular mortality (ie, death from cardiovascular causes, including myocardial infarction, heart failure, or stroke). Survival analyses were performed using Cox proportional hazards regression models using serum thyrotropin and FT4 levels as time-varying covariates., Results: Of the 705 307 patients in the study, 625 444 (88.7%) were men, and the median age was 67 years (IQR, 57-78 years; range, 18-110 years). Overall, 75 963 patients (10.8%) died of cardiovascular causes. After adjusting for age, sex, traditional cardiovascular risk factors (eg, hypertension, smoking, and previous cardiovascular disease or arrhythmia), patients with exogenous hyperthyroidism (eg, thyrotropin levels, <0.1 mIU/L: adjusted hazard ratio [AHR], 1.39; 95% CI, 1.32-1.47; FT4 levels, >1.9 ng/dL: AHR, 1.29; 95% CI, 1.20-1.40) and patients with exogenous hypothyroidism (eg, thyrotropin levels, >20 mIU/L: AHR, 2.67; 95% CI, 2.55-2.80; FT4 levels, <0.7 ng/dL: AHR, 1.56; 95% CI, 1.50-1.63) had increased risk of cardiovascular mortality compared with individuals with euthyroidism., Conclusions and Relevance: This study suggests that both exogenous hyperthyroidism and exogenous hypothyroidism were associated with increased risk of cardiovascular mortality. These findings emphasize the importance of maintaining euthyroidism to decrease cardiovascular risk and death among patients receiving thyroid hormone treatment.

Recent studies have provided major new insights into the syndromes of inappropriate secretion of thyroid-stimulating hormone (TSH), a heterogeneous group of disorders in which patients show inappropriately elevated levels of serum immunoactive TSH in the presence of elevated free thyroid hormone levels. Certain of these patients appear to have a non-neoplastic disorder associated with variable degrees of pituitary and peripheral resistance to the action of thyroid hormone, whereas others harbor a tumor of pituitary thyrotropic cells. Measurement of free serum alpha subunit has proved valuable in differentiating these disorders, showing normal alpha concentration and alpha-to-TSH ratios in the non-neoplastic and highly elevated values in the neoplastic disorders. All these syndromes appear unrelated to Graves' disease because thyroid-binding and thyroid-stimulating antibodies are usually absent. Some of these patients also have abnormal metabolism of thyroid hormones. Although the pathogenesis of these syndromes remains to be elucidated, increased recognition and study of these patients should provide fundamental insights into the regulation of TSH secretion as well as the action of thyroid hormone. [ABSTRACT FROM AUTHOR]

The author focuses on the use of recombinant human thyroid stimulating hormone (TSH) in metastatic differentiated thyroid cancer treatment. He says that recombinant TSH was developed to exogenously raise serum TSH to avoid hypothyroid morbidity in euthyroid patients undergoing radiotherapy of differentiated thyroid cancer. He adds that recombinant TSH has been approved for therapeutic use by the U.S. Food and Drug Administration and the European Medicines Agency in differentiated thyroid cancer.

The article discusses the significance of autoantibodies in diagnosing thyroid disorders in the U.S. It states that thyrotropin receptor antibodies (TRAb) may help predict hypothyroidism. In relevance, thyroid antibody tests may assess in equivocal situations such as normal radioiodine study in hyperthyroidism or evaluating the cause of hypothyroidism when infiltrative disorders are suspected. It highlights a study which examines the importance of thyroid peroxidase antibody (TPOAb) in determining thyroid-related disorders.

Background: Subclinical hypothyroidism (SCH) is the most common thyroid dysfunction, and its relationship with blood pressure (BP) has been controversial. The aim of the study was to analyze the association between SCH and newly-diagnosed hypertension., Methods: Based on data from the Thyroid disease, Iodine nutrition and Diabetes Epidemiology (TIDE) study, 49,433 euthyroid individuals and 7,719 SCH patients aged ≥18 years were enrolled. Patients with a history of hypertension or thyroid disease were excluded. SCH was determined by manufacturer reference range. Overall hypertension and stage 1 and 2 hypertension were diagnosed according to the guidelines issued by the American College of Cardiology/American Heart Association in 2017., Results: The prevalence of overall hypertension (48.7%), including stage 1 (28.9%) and 2 (19.8%) hypertension, increased significantly in SCH patients compared with euthyroid subjects. With elevated serum thyroid stimulating hormone (TSH) level, the hypertension prevalence also increased significantly from the euthyroid to different SCH subgroups, which was more profound in females or subjects aged <65 years. The age- and sex-specific regression analysis further demonstrated the same trends in the general population and in the 1:1 propensity matched population. Similarly, several BP components (i.e., systolic, diastolic, and mean arterial BP) were positively associated with TSH elevation, and regression analysis also confirmed that all BP components were closely related with SCH in female subjects aged <65 years., Conclusion: The prevalence of hypertension increases for patients with SCH. SCH tends to be associated with hypertension and BP components in females younger than 65 years.

Background: 2015 American Thyroid Association (ATA) guidelines recommended more conservative treatment in low-risk well-differentiated thyroid cancer (WDTC), stating that lobectomy alone may be sufficient. The guidelines further recommend mild thyroid-stimulating hormone (TSH) level suppression (0.5-2 mU/L) for this population. Our goal is to evaluate the natural history of patients undergoing lobectomy to determine the percentage that would require postoperative levothyroxine supplementation under these guidelines., Methods: Retrospective chart review of 168 patients that underwent lobectomy between 2010 and 2019 was performed. Preoperative and postoperative TSH values and the rate of patients prescribed levothyroxine were analyzed., Results: Thirty-five percent of patients were prescribed levothyroxine postoperatively. At 6 weeks postoperatively, 66% had TSH value of >2; this increased to 76% by 6 to 12 months., Conclusion: To adhere to ATA guidelines for WDTC managed with lobectomy alone, the majority of patients (76%) would require postoperative levothyroxine supplementation. Low preoperative TSH was found to be the most significant predictor for postoperative TSH < 2., (© 2020 Wiley Periodicals LLC.)

Objective: Recombinant human thyroid-stimulating hormone (rhTSH) has been approved for diagnostic (1998) and therapeutic (2008) indications in conjunction with radioactive iodine (RAI) administration post-thyroidectomy. Potential benefits of rhTSH, including avoidance of hypothyroidism side effects and shorter, less costly hospital stays, have not been assessed at the population level within the United States. In this study we quantify utilization, outcomes, and associated costs of rhTSH within the nationally representative Surveillance, Epidemiology, and End Results (SEER)-Medicare patient population., Methods: We conducted a retrospective analysis of beneficiaries aged >65 years diagnosed within the SEER-Medicare data with differentiated thyroid cancer. Endpoints examined included ( 1) rhTSH utilization in the 2 years post-thyroidectomy (patients diagnosed 1996-2011 [utilization cohort]) and ( 2) comparison of resource utilization and costs as a function of rhTSH receipt in the 30 days prior to and 1 year following therapeutic RAI administration (patients diagnosed 2008-2011 [resource use cohort]). All costs were adjusted to reflect 2013 dollars., Results: A total of 6,482 patients met inclusion criteria, of which, 1,363 (21.0%) received rhTSH. Receipt varied by region and was higher in the South (18%), Northeast (28%), and West (44%) compared to the Midwest (10%), and lower in census tracts in the bottom quartile of high school education rates (odds ratio 0.68, 95% confidence interval [CI] 0.55-0.83). rhTSH receipt was not associated with patient sex, age, comorbidities, or stage. Post-therapeutic RAI, 1,444 patients were assessed for resource utilization (2008-2011). The average cost of rhTSH was $905 per patient, with $2,483 being spent on average among patients who received rhTSH in association with therapeutic RAI. rhTSH receipt was not significantly associated with total inpatient days or number of outpatient and emergency department visits. Multivariable analyses showed similar overall costs among patients who did versus did not receive rhTSH (cost ratio [CR] 0.96, 95% CI 0.86-1.09), partially due to increased mean outpatient costs ($5,213 vs. $4,190) being offset by lower inpatient costs ($3,493 vs. $6,143). Overall costs were significantly higher in multivariable analyses among patients with distant metastatic disease (CR 1.92, 95% CI 1.58-2.32) and multiple comorbidities (CR 2.15, 95% CI 1.83-2.53)., Conclusion: rhTSH recipients had higher outpatient, lower inpatient, and similar total Medicare payments as those not receiving rhTSH in conjunction with RAI, lending support to the use of rhTSH as a cost-neutral treatment option from the payer perspective., Abbreviations: CI = confidence interval; CMS = Centers for Medicare & Medicaid Services; CR = cost ratio; HCPCS = Healthcare Common Procedure Coding System; IQR = interquartile range; mCi = millicurie; OR = odds ratio; PET = positron emission tomography; RAI = radioactive iodine; rhTSH = recombinant human thyroid-stimulating hormone; RR = risk ratio; SEER = Surveillance, Epidemiology, and End Results.

Objective: Latin American Thyroid Society (LATS) Hypothyroidism Clinical Practice Guidelines recommend case finding of hypothyroid patients in multiple and different situations that agree with other Society guidelines. However, the detection of hypothyroidism in type 2 diabetes mellitus (T2DM) or metabolic syndrome (MetS) patients is not mentioned in particular. In the recent years, several basic and epidemiologic studies have appeared showing that a lower thyroid function and MetS/T2DM are associated. Hence, the aim of this review is to manifest the LATS position on the diagnosis of hypothyroidism in both MetS and T2DM patients., Methods: A search was made in PubMed using the following terms: "hypothyroidism" AND "diabetes" OR "metabolic syndrome." The most relevant studies describing the prevalence and complications due to hypothyroidism in both MetS and T2DM patients were selected., Results: The current document reviews new information from studies that have shown that the prevalence of hypothyroidism is higher in T2DM patients (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.5 to 4.7) and that diabetic complications are more prevalent in subclinical hypothyroidism (ScH). The incidence of T2DM is 1.09-fold higher with each doubling of thyroid-stimulating hormone (TSH) mIU/L (95% CI, 1.06 to 1.12), and the incidence of prediabetes increases 15% (hazard ratio, 1.15; 95% CI, 1.04 to 1.26) in patients with TSH >5 mIU/L. Similarly, MetS is more prevalent in ScH compared to euthyroid individuals (OR, 1.31; 95% CI, 1.08 to 1.60)., Conclusion: Thyroid function is affected in MetS and T2DM, and hypothyroidism is more common in these patients. Diabetic complications are more frequent in ScH patients. Therefore, LATS now recommends aggressive case finding of hypothyroidism in both MetS and T2DM patients., Abbreviations: CI = confidence interval; GLUT4 = glucose transporter 4; HOMA-IR = homeostatic model assessment for insulin resistance; HR = hazard ratio; LATS = Latin American Thyroid Society; MetS = metabolic syndrome; OR = odds ratio; ScH = subclinical hypothyroidism; T2DM = type 2 diabetes mellitus; T3 = triiodothyronine; T4 = thyroxine; TSH = thyroid-stimulating hormone.

The 2017 American Thyroid Association guidelines for the diagnosis and management of thyroid disease during pregnancy and the postpartum were published six years after the previous ones. They provide comprehensive clinical recommendations for the whole spectrum of thyroid diseases, as well as for optimal iodine intake during pregnancy, postpartum, and lactation. The present position statement mainly regards the recommended flow chart for therapeutic decision making in pregnant women being diagnosed with subclinical hypothyroidism. Here, we comment on the major biochemical and clinical situations and the corresponding therapeutic recommendations. In particular, we welcome the critical revision of the thyrotropin (TSH) reference range in pregnancy, and we agree that there is no need to treat thyroid peroxidase antibody-negative women with a serum TSH ranging from 2.5 μIU/mL to the upper limit of the reference range. This recommendation will hopefully reduce the huge proportion of healthy pregnant women in whom, according to the previous guidelines, levothyroxine therapy had to be initiated. On the other hand, we are concerned with the recommendation to only "consider treatment" in thyroid peroxidase antibody-negative pregnant women with a serum TSH ranging from the upper limit of the reference range to 10.0 μIU/mL. This is because thyroid antibodies may be falsely negative during gestation, and serum negative chronic autoimmune thyroiditis is a well-known clinical entity even outside pregnancy. Based on these and other arguments, we recommend treatment with levothyroxine in pregnant women with TSH levels ranging between the upper limit of the reference range and 10.0 μIU/mL independently from their thyroid antibody status.

The author ponders whether to treat subclinical hyperthyroidism or low levels of serum thyroid-stimulating hormone (TSH) in association with normal serum levels. The differential diagnosis is one of the factors to be consider when evaluating a patient with subclinical hyperthyroidism. She mentions the use of radioiodine as a treatment regime by thyroid specialists in the U.S. She supports awaiting results of cost-benefit analyses before radioiodine treatment is routinely offered.

The article reports on the issue of whether thyroid replacement with levothyroxine (LT4) delivers adequate levels of triiodothyronine (T3) in hypothyroid patients through peripheral conversion. Several U.S. researchers found that such replacement to achieve thyrotropin (TSH) levels less than 4.5 resulted in normal T3 levels through peripheral conversion of T4 to T3, which suggests that T3 administration is not needed.

The article reports on the findings of the researchers at the U.S. Centers for Disease Control and Prevention on the association between measurable levels of perchlorate and thyroid function in women with low but normal iodide levels. The study was published online at the "Environmental Health Perspectives" on October 5, 2006. It suggested that some women, specifically those at childbearing stage, might need to raise their consumption of iodine. High levels of perchlorate in the body could block the uptake of iodine in the thyroid, which could interfere with the production of thyroid stimulating hormone.

Reports on the clinical practice guidelines released by the American Association of Clinical Endocrinologists (AACE) and the American College of Endocrinology. Call for the use of new thyroid-stimulating hormone (TSH) tests to detect subclinical thyroid disease; Other highlights of the guidelines.

Abstract: Autoimmune thyrotoxicosis or Graves'' disease (GD) is the most common cause of hyperthyroidism in the United States (full text available online: http://education.amjmed.com/pp1/249). GD occurs more often in women (ratio 5:1) and has a population prevalence of 1-2%. A genetic determinant to the susceptibility to GD is suspected because of familial clustering of the disease, a high sibling recurrence risk, and the familial occurrence of thyroid autoantibodies. GD is a systemic autoimmune thyroid disorder characterized by the infiltration of immune effector cells and thyroid-antigen-specific T cells into the thyroid and thyroid stimulating hormone receptor (TSHR) expressing tissues, i.e. orbit, skin, with the production of autoantibodies to well-defined thyroidal antigens. Stimulatory autoantibodies in GD activate the TSHR leading to thyroid hyperplasia and unregulated thyroid hormone production and secretion. Diagnosis of GD is straightforward in a patient with a diffusely enlarged, heterogeneous, hypervascular (increased Doppler flow on neck ultrasound) thyroid gland, associated orbitopathy, biochemically confirmed thyrotoxicosis, positive TSHR autoantibodies, and often a family history of autoimmune disorders. [Copyright &y& Elsevier]