MACE and Hyperthyroidism Treated With Medication, Radioactive Iodine, or Thyroidectomy.

Importance: Excessive thyroid hormones from hyperthyroidism increase cardiovascular risks. Among 3 available treatments for hyperthyroidism, comparisons of long-term outcomes associated with antithyroid drugs (ATDs), radioactive iodine (RAI), and surgery to treat newly diagnosed hyperthyroidism are lacking. Objective: To compare risks of major adverse cardiovascular events (MACE) and all-cause mortality among patients with hyperthyroidism treated with ATDs, RAI, or surgery. Design, Setting, and Participants: This nationwide cohort study used the Taiwan National Health Insurance Research Database. Patients aged 20 years or older with newly diagnosed hyperthyroidism between 2011 and 2020 were enrolled. Treatment groups were determined within 18 months from diagnosis, with follow-up until the development of MACE, death, or the end date of the database, whichever came first. Data were analyzed from October 2022 through December 2023. Exposures: The ATD group received ATDs only. RAI and surgery groups could receive ATDs before treatment. Anyone who underwent thyroid surgery without RAI was classified into the surgery group and vice versa. Main Outcomes and Measures: The primary outcomes included MACE (a composite outcome of acute myocardial infarction, stroke, heart failure, and cardiovascular mortality) and all-cause mortality. Results: Among 114 062 patients with newly diagnosed hyperthyroidism (mean [SD] age, 44.1 [13.6] years; 83 505 female [73.2%]), 107 052 patients (93.9%) received ATDs alone, 1238 patients (1.1%) received RAI, and 5772 patients (5.1%) underwent surgery during a mean (SD) follow-up of 4.4 (2.5) years. Patients undergoing surgery had a significantly lower risk of MACE (hazard ratio [HR] = 0.76; 95% CI, 0.59-0.98; P = .04), all-cause mortality (HR = 0.53; 95% CI, 0.41-0.68; P < .001), heart failure (HR = 0.33; 95% CI, 0.18-0.59; P < .001), and cardiovascular mortality (HR = 0.45; 95% CI, 0.26-0.79; P = .005) compared with patients receiving ATDs. Compared with ATDs, RAI was associated with lower MACE risk (HR = 0.45; 95% CI, 0.22-0.93; P = .03). Risks for acute myocardial infarction and stroke did not significantly differ between treatment groups. Conclusions and Relevance: In this study, surgery was associated with lower long-term risks of MACE and all-cause mortality, while RAI was associated with a lower MACE risk compared with ATDs.

Limited English Proficiency and Graves' Disease at an Urban Safety Net Hospital.

INTRODUCTION: Decision-making regarding definitive therapy for Graves' disease requires effective patient-provider communication. We investigated whether patients with limited English proficiency have differences in thyroidectomy outcomes or perioperative management when compared to English proficient (EP) patients at a safety net hospital with high-volume endocrine surgery practice. METHODS: Retrospective study of patients who underwent thyroidectomy (2012-2021) for Graves' disease within a tertiary referral system. Demographics, preoperative factors, and postoperative outcomes were abstracted via chart review and compared between EP and limited English proficient (LEP) patients in univariate analyses. Odds of postoperative complications were assessed via multivariable logistic regression. Time metrics such as time from endocrinology consultation to surgery were compared via Kaplan-Meier analysis and adjusted Cox proportional regression models. RESULTS: Of 236 patients, 85 (36%) had LEP. Low and equivalent complication rates occurred across language groups (<1% permanent). LEP patients had similar odds of thyroidectomy-specific complications (odds ratio = 1.2; 95% confidence interval 0.6-2.4). Adjusted Cox proportional hazards ratios showed that LEP patients experienced significantly shorter time from endocrinology consultation to surgery compared to EP patients [hazard ratio = 0.7; 95% confidence interval 0.5-0.9]. CONCLUSIONS: Thyroidectomy-specific complication rate for patients with Graves' disease was low, and we detected no independent association between complications and English language proficiency. Non-English primary language was independently associated with reduced time from endocrinology consultation to surgery. This finding must be interpreted with nuance and is likely multifactorial. It may reflect a well-organized, efficient system for under-resourced patients, or it may derive from communication barriers that limit robust shared decision-making, thus accelerating time to surgery.

Foreign-Body Reaction Resulting in Thyroiditis-A Complication of Fine-Needle Aspiration Biopsy of the Thyroid.

Fine-needle aspiration biopsy (FNAB) is a cost-effective and safe office procedure performed to evaluate thyroid nodules. We report a case of a 33-year-old woman who presented with pain and swelling of the thyroid after undergoing an FNAB for a right thyroid nodule at an outside hospital. The patient received a course of antibiotics without complete resolution of her symptoms and ultimately, underwent a right thyroid lobectomy. Pathology of the excised thyroid tissue showed chronic lymphohistiocytic inflammation with giant cell reaction and hemorrhage consistent with a foreign-body reaction. The patient's symptoms completely resolved after the surgery. Though uncertain what foreign body was introduced into the thyroid tissue during the FNAB, we surmise that an accidental introduction of ultrasound gel may have caused this rare and unexpected complication of a procedure with usually few and manageable complications.

Hyperthyroidism: A Review.

Importance: Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality. Observations: The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L. Conclusions and Relevance: Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Optical coherence tomography angiography in diabetic retinopathy.

There remain many unanswered questions on how to assess and treat the pathology and complications that arise from diabetic retinopathy (DR). Optical coherence tomography angiography (OCTA) is a novel and non-invasive three-dimensional imaging method that can visualize capillaries in all retinal layers. Numerous studies have confirmed that OCTA can identify early evidence of microvascular changes and provide quantitative assessment of the extent of diseases such as DR and its complications. A number of informative OCTA metrics could be used to assess DR in clinical trials, including measurements of the foveal avascular zone (FAZ; area, acircularity, 3D para-FAZ vessel density), vessel density, extrafoveal avascular zones, and neovascularization. Assessing patients with DR using a full-retinal slab OCTA image can limit segmentation errors and confounding factors such as those related to center-involved diabetic macular edema. Given emerging data suggesting the importance of the peripheral retinal vasculature in assessing and predicting DR progression, wide-field OCTA imaging should also be used. Finally, the use of automated methods and algorithms for OCTA image analysis, such as those that can distinguish between areas of true and false signals, reconstruct images, and produce quantitative metrics, such as FAZ area, will greatly improve the efficiency and standardization of results between studies. Most importantly, clinical trial protocols should account for the relatively high frequency of poor-quality data related to sub-optimal imaging conditions in DR and should incorporate time for assessing OCTA image quality and re-imaging patients where necessary.

Changes in Urinary Iodine Levels Following Bariatric Surgery.

OBJECTIVE: Obesity has become an epidemic in the United States. Although bariatric surgery can effectively achieve weight loss by altering the gastrointestinal tract, it commonly results in micronutrient deficiency, requiring supplementation. Iodine is an essential micronutrient for the synthesis of thyroid hormones. We aimed to investigate changes in urinary iodine concentrations (UIC) in patients following bariatric surgery. METHODS: 85 adults who underwent either laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass surgery were enrolled. At baseline and 3 months after surgery, we evaluated spot UIC and serum thyroid stimulating hormone (TSH), vitamin D, vitamin B12, ferritin, and folate levels. Participants provided a 24-hour diet recall for iodine-rich foods and information about multivitamin use at each time point. RESULTS: There was a significant increase in median UIC (201 [120.0 - 288.5] vs 334.5 [236.3 - 740.3] µg/L; P < .001), a significant decrease in mean body mass index (44.0 ± 6.2 vs 35.8 ± 5.9; P < .001) and a significant decrease in TSH levels (1.5 [1.2 - 2.0] vs 1.1 [0.7 - 1.6] uIU/mL; P < .001) at 3 months postoperatively compared to baseline. Body mass index, UIC, and TSH levels before and after surgery did not differ based on the type of weight loss surgery. CONCLUSION: In an iodine-sufficient area, bariatric surgery does not cause iodine deficiency nor clinically significant changes in thyroid function. Different surgical procedures with different anatomical alterations in the gastrointestinal tract do not significantly affect iodine status.

Changing Iodine Status and the Incidence of Thyroid Disease in Mainland China: A Prospective 20-Year Follow-Up Study.

Background: We aimed to assess the long-term effects of the transition in iodine status on the incidence of thyroid disorders over 20 years of follow-up. Methods: The original prospective cohort study, started in 1999 (n = 3761), classified three regions in north China based on iodine status (insufficient iodine, more than adequate iodine, and excessive iodine, respectively) for 5 years. Subsequently, participants were followed for up to another 15 years to assess the long-term effects of shifts to adequate iodine on the incidence of thyroid disorders. Panshan transitioned from insufficient to adequate iodine, and Huanghua transitioned from excessive to more than adequate iodine. Both regions were compared with Zhangwu, in which iodine status changed from more than adequate to adequate iodine (from 214 to 167.2 µg/L). A cluster sampling method was used to select participants in the three regions. Participants completed questionnaires and underwent thyroid ultrasonography. Urinary iodine concentrations (UICs), serum thyroid hormone concentration, and thyroid antibodies were measured. Results: When the iodine status changed from insufficient to adequate (with the median UIC increasing from 88 to 141.9 µg/L), the incidence density of subclinical hyperthyroidism, positive thyroperoxidase antibody, positive thyroglobulin antibody (TgAb), and goiter decreased significantly (p < 0.05 for all). Additionally, the cumulative incidence of subclinical hypothyroidism was significantly lower compared with the region where the iodine status changed from being more than adequate to adequate (1.9% vs. 6.0%, p < 0.001). When the iodine status changed from excessive to more than adequate (median UIC from 634 to 266.7 µg/L), a significant decrease in the incidence density of subclinical hyperthyroidism, positive thyroid antibodies, positive TgAb, and goiter (p < 0.05 for all) were also found. However, an increase in thyroid nodule incidence density (17.26 vs. 28.25 per 1000 person-years, p < 0.001) was seen. Conclusions: The incidence of thyroid disorders (except for thyroid nodules) stabilized or decreased among adults in the three communities from year 5 to year 15 of follow-up. Appropriate iodine fortification is safe and effective over the long term. Restoring urinary iodine to appropriate levels reduces population risk for thyroid disorders.

Characterization of the Structural and Functional Alteration in Eyes with Diabetic Macular Ischemia.

OBJECTIVE: To investigate the relative effect of disorganization of the retinal inner layers (DRIL) and ellipsoid zone (EZ) loss on visual function in diabetic macular ischemia (DMI). DESIGN: Prospective cross-sectional observational study. PARTICIPANTS: Patients with stable treated proliferative diabetic retinopathy (PDR) without center-involved diabetic macular edema were recruited at the Moorfields Eye Hospital from December 2019 to November 2021. The main inclusion criteria were best-corrected visual acuity (BCVA) of ≥ 40 ETDRS letters (Snellen equivalent 20/160) with OCT angiography (OCTA) evidence of DMI in ≥ 1 eye. METHODS: Each eligible eye of the recruited patients was assessed for BCVA, OCT, and OCTA metrics. The prespecified OCT parameters were DRIL and subfoveal EZ loss. Generalized estimating equations were used. MAIN OUTCOMES MEASURES: The frequency of DRIL and EZ loss, their relative contributions to vision loss, and their associations with microvascular alterations were evaluated. RESULTS: A total of 125 eyes of 86 patients with PDR were enrolled; 104 (83%) eyes had a BCVA of ≥ 70 letters. Disorganization of the retinal inner layers was more prevalent than EZ loss (46% [58 eyes] vs. 19% [24 eyes]). On average, the presence of DRIL had a more pronounced impact on vision, retinal thickness, and microvascular parameters than EZ loss. After multivariable adjustment, the odds of coexisting DRIL increased by 12% with every letter decrease in BCVA; however, there was no statistically significant association of subfoveal EZ loss with BCVA. In eyes with DRIL in the absence of EZ loss, the BCVA declined significantly by 6.67 letters compared with eyes with no DRIL nor EZ loss (95% confidence interval [CI], -9.92 to -3.41; P < 0.001). However, if DRIL and EZ loss coexisted, the resultant BCVA was 13.22 letters less than eyes without these structural abnormalities (95% CI, -18.85 to -7.59; P < 0.001). CONCLUSIONS: In patients with DMI with a Snellen visual acuity of 20/160 or better, eyes with DRIL were associated with more visual function loss and retinal blood circulation alterations than those with subfoveal EZ loss only.

Association between maternal thyroid function and risk of gestational hypertension and pre-eclampsia: a systematic review and individual-participant data meta-analysis.

BACKGROUND: Adequate maternal thyroid function is important for an uncomplicated pregnancy. Although multiple observational studies have evaluated the association between thyroid dysfunction and hypertensive disorders of pregnancy, the methods and definitions of abnormalities in thyroid function tests were heterogeneous, and the results were conflicting. We aimed to examine the association between abnormalities in thyroid function tests and risk of gestational hypertension and pre-eclampsia. METHODS: In this systematic review and meta-analysis of individual-participant data, we searched MEDLINE (Ovid), Embase, Scopus, and the Cochrane Database of Systematic Reviews from date of inception to Dec 27, 2019, for prospective cohort studies with data on maternal concentrations of thyroid-stimulating hormone (TSH), free thyroxine (FT4), thyroid peroxidase (TPO) antibodies, individually or in combination, as well as on gestational hypertension, pre-eclampsia, or both. We issued open invitations to study authors to participate in the Consortium on Thyroid and Pregnancy and to share the individual-participant data. We excluded participants who had pre-existing thyroid disease or multifetal pregnancy, or were taking medications that affect thyroid function. The primary outcomes were documented gestational hypertension and pre-eclampsia. Individual-participant data were analysed using logistic mixed-effects regression models adjusting for maternal age, BMI, smoking, parity, ethnicity, and gestational age at blood sampling. The study protocol was registered with PROSPERO, CRD42019128585. FINDINGS: We identified 1539 published studies, of which 33 cohorts met the inclusion criteria and 19 cohorts were included after the authors agreed to participate. Our study population comprised 46 528 pregnant women, of whom 39 826 (85·6%) women had sufficient data (TSH and FT4 concentrations and TPO antibody status) to be classified according to their thyroid function status. Of these women, 1275 (3·2%) had subclinical hypothyroidism, 933 (2·3%) had isolated hypothyroxinaemia, 619 (1·6%) had subclinical hyperthyroidism, and 337 (0·8%) had overt hyperthyroidism. Compared with euthyroidism, subclinical hypothyroidism was associated with a higher risk of pre-eclampsia (2·1% vs 3·6%; OR 1·53 [95% CI 1·09-2·15]). Subclinical hyperthyroidism, isolated hypothyroxinaemia, or TPO antibody positivity were not associated with gestational hypertension or pre-eclampsia. In continuous analyses, both a higher and a lower TSH concentration were associated with a higher risk of pre-eclampsia (p=0·0001). FT4 concentrations were not associated with the outcomes measured. INTERPRETATION: Compared with euthyroidism, subclinical hypothyroidism during pregnancy was associated with a higher risk of pre-eclampsia. There was a U-shaped association of TSH with pre-eclampsia. These results quantify the risks of gestational hypertension or pre-eclampsia in women with thyroid function test abnormalities, adding to the total body of evidence on the risk of adverse maternal and fetal outcomes of thyroid dysfunction during pregnancy. These findings have potential implications for defining the optimal treatment target in women treated with levothyroxine during pregnancy, which needs to be assessed in future interventional studies. FUNDING: Arkansas Biosciences Institute and Netherlands Organization for Scientific Research.

Assessment and treatment of thyroid disorders in pregnancy and the postpartum period.

Thyroid disorders are prevalent in pregnant women. Furthermore, thyroid hormone has a critical role in fetal development and thyroid dysfunction can adversely affect obstetric outcomes. Thus, the appropriate management of hyperthyroidism, most commonly caused by Graves disease, and hypothyroidism, which in iodine sufficient regions is most commonly caused by Hashimoto thyroiditis, in pregnancy is important for the health of both pregnant women and their offspring. Gestational transient thyrotoxicosis can also occur during pregnancy and should be differentiated from Graves disease. Effects of thyroid autoimmunity and subclinical hypothyroidism in pregnancy remain controversial. Iodine deficiency is the leading cause of hypothyroidism worldwide. Despite global efforts to eradicate iodine deficiency disorders, pregnant women remain at risk of iodine deficiency due to increased iodine requirements during gestation. The incidence of thyroid cancer is increasing worldwide, including in young adults. As such, the diagnosis of thyroid nodules or thyroid cancer during pregnancy is becoming more frequent. The evaluation and management of thyroid nodules and thyroid cancer in pregnancy pose a particular challenge. Postpartum thyroiditis can occur up to 1 year after delivery and must be differentiated from other forms of thyroid dysfunction, as treatment differs. This Review provides current evidence and recommendations for the evaluation and management of thyroid disorders in pregnancy and in the postpartum period.

Validating Techniques for Measurement of Cutaneous Neurofibromas: Recommendations for Clinical Trials.

OBJECTIVE: To assess the reliability and variability of digital calipers, 3D photography, and high-frequency ultrasound (HFUS) for measurement of cutaneous neurofibromas (cNF) in patients with neurofibromatosis type 1 (NF1). BACKGROUND: cNF affect virtually all patients with NF1 and are a major source of morbidity. Reliable techniques for measuring cNF are needed to develop therapies for these tumors. METHODS: Adults with NF1 were recruited. For each participant, 6 cNF were assessed independently by 3 different examiners at 5 different time points using digital calipers, 3D photography, and HFUS. The intraclass correlation coefficient (ICC) was used to assess intrarater and interrater reliability of linear and volumetric measurements for each technique, with ICC values >0.90 defined as excellent reliability. The coefficient of variation (CV) was used to estimate the minimal detectable difference (MDD) for each technique. RESULTS: Fifty-seven cNF across 10 participants were evaluated. The ICC for image acquisition and measurement was >0.97 within and across examiners for HFUS and 3D photography. ICC for digital calipers was 0.62-0.88. CV varied by measurement tool, linear vs volumetric measurement, and tumor size. CONCLUSIONS: HFUS and 3D photography demonstrate excellent reliability whereas digital calipers have good to excellent reliability in measuring cNF. The MDD for each technique was used to create tables of proposed thresholds for investigators to use as guides for clinical trials focused on cNF size. These criteria should be updated as the performance of these end points is evaluated.

Looking Ahead: Visual and Anatomical Endpoints in Future Trials of Diabetic Macular Ischemia.

Diabetic macular ischemia (DMI) is a common complication of diabetic retinopathy that can lead to progressive and irreversible visual loss. Despite substantial clinical burden, there are no treatments for DMI, no validated clinical trial endpoints, and few clinical trials focusing on DMI. Therefore, generating consensus on validated endpoints that can be used in DMI for the development of effective interventions is vital. In this review, we discuss potential endpoints appropriate for use in clinical trials of DMI, and consider the data required to establish acceptable and meaningful endpoints. A combination of anatomical, functional, and patient-reported outcome measures will provide the most complete picture of changes that occur during the progression of DMI. Potential endpoint measures include change in size of the foveal avascular zone measured by optical coherence tomography angiography and change over time in best-corrected visual acuity. However, these endpoints must be supported by further research. We also recommend studies to investigate the natural history and progression of DMI. In addition to improving understanding of how patient demographics and comorbidities such as diabetic macular edema affect clinical trial endpoints, these studies would help to build the consensus definition of DMI that is currently missing from clinical practice and research.

Salivary and lacrimal dysfunction after radioactive iodine for differentiated thyroid cancer: American Head and Neck Society Endocrine Surgery Section and Salivary Gland Section joint multidisciplinary clinical consensus statement of otolaryngology, ophthalmology, nuclear medicine and endocrinology.

BACKGROUND: Postoperative radioactive iodine (RAI) administration is widely utilized in patients with differentiated thyroid cancer. While beneficial in select patients, it is critical to recognize the potential negative sequelae of this treatment. The prevention, diagnosis, and management of the salivary and lacrimal complications of RAI exposure are addressed in this consensus statement. METHODS: A multidisciplinary panel of experts was convened under the auspices of the American Head and Neck Society Endocrine Surgery and Salivary Gland Sections. Following a comprehensive literature review to assess the current best evidence, this group developed six relevant consensus recommendations. RESULTS: Consensus recommendations on RAI were made in the areas of patient assessment, optimal utilization, complication prevention, and complication management. CONCLUSION: Salivary and lacrimal complications secondary to RAI exposure are common and need to be weighed when considering its use. The recommendations included in this statement provide direction for approaches to minimize and manage these complications.

Aflibercept Reduces Retinal Hemorrhages and Intravitreal Microvascular Abnormalities But Not Venous Beading: Secondary Analysis of the CLARITY Study.

PURPOSE: Approximately 50% of patients receiving anti-vascular endothelial growth factor (VEGF) therapy show significant improvement in diabetic retinopathy severity score (DRSS), in particular at DRSS level 47 to 53 (moderately severe to severe nonproliferative diabetic retinopathy). Level 47 to 53 consists of 3 main features: deep hemorrhages (DH), venous beading (VB), and intraretinal microvascular abnormalities (IRMAs). It is unclear whether these features respond to anti-VEGF therapies differently. DESIGN: Post hoc analysis of Intravitreal Aflibercept versus Panretinal Photocoagulation in Patients with Proliferative Diabetic Retinopathy (CLARITY) study. PARTICIPANTS: Treatment-naïve participants randomized to intravitreal aflibercept. METHODS: We reanalyzed the fundus images at baseline, week 12, and week 52 to assess the changes of the 3 main features in DRSS level 47 to 53 in those patients who were treatment naïve and had received aflibercept. MAIN OUTCOME MEASURES: Changes in DH, VB, and IRMA after aflibercept therapy at weeks 12 and 52. RESULTS: Fifty-five treatment-naïve eyes at baseline that received aflibercept were included in the study. Severe DH and severe IRMA improved in approximately 75% of eyes at week 12 and mostly remained improved at week 52; VB remained unchanged in all eyes at week 12. From 12 weeks, 32 eyes that had received injections showed improved or stable DH compared with 7 eyes that did not receive injections, and DH deteriorated in 6 eyes with no further injections compared with 4 eyes that had received more injections (P = 0.0072). Similarly, 15 eyes that continued to receive injections from week 12 showed improved or stable IRMA compared with 4 who did not receive injections (P = 0.006). Worsening of IRMA was seen in 5 eyes with no further injections compared with 4 eyes that continued to receive injections. The improvements in DH and IRMA are more likely to be maintained if less than 16 weeks have elapsed since the last anti-VEGF injection. CONCLUSIONS: Aflibercept seems to improve DH and IRMA after just 3 injections. As soon as the frequency of injections were reduced, DH and IRMA can deteriorate again. It is unclear whether these results can be translated to patients without PDR.

Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis.

BACKGROUND: Adequate transplacental passage of maternal thyroid hormone is important for normal fetal growth and development. Maternal overt hypothyroidism and hyperthyroidism are associated with low birthweight, but important knowledge gaps remain regarding the effect of subclinical thyroid function test abnormalities on birthweight-both in general and during the late second and third trimester of pregnancy. The aim of this study was to examine associations of maternal thyroid function with birthweight. METHODS: In this systematic review and individual-participant data meta-analysis, we searched MEDLINE (Ovid), Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar from inception to Oct 15, 2019, for prospective cohort studies with data on maternal thyroid function during pregnancy and birthweight, and we issued open invitations to identify study authors to join the Consortium on Thyroid and Pregnancy. We excluded participants with multiple pregnancies, in-vitro fertilisation, pre-existing thyroid disease or thyroid medication usage, miscarriages, and stillbirths. The main outcomes assessed were small for gestational age (SGA) neonates, large for gestational age neonates, and newborn birthweight. We analysed individual-participant data using mixed-effects regression models adjusting for maternal age, BMI, ethnicity, smoking, parity, gestational age at blood sampling, fetal sex, and gestational age at birth. The study protocol was pre-registered at the International Prospective Register of Systematic Reviews, CRD42016043496. FINDINGS: We identified 2526 published reports, from which 36 cohorts met the inclusion criteria. The study authors for 15 of these cohorts agreed to participate, and five more unpublished datasets were added, giving a study population of 48 145 mother-child pairs after exclusions, of whom 1275 (3·1%) had subclinical hypothyroidism (increased thyroid stimulating hormone [TSH] with normal free thyroxine [FT4]) and 929 (2·2%) had isolated hypothyroxinaemia (decreased FT4 with normal TSH). Maternal subclinical hypothyroidism was associated with a higher risk of SGA than was euthyroidism (11·8% vs 10·0%; adjusted risk difference 2·43%, 95% CI 0·43 to 4·81; odds ratio [OR] 1·24, 1·04 to 1·48; p=0·015) and lower mean birthweight (mean difference -38 g, -61 to -15; p=0·0015), with a higher effect estimate for measurement in the third trimester than in the first or second. Isolated hypothyroxinaemia was associated with a lower risk of SGA than was euthyroidism (7·3% vs 10·0%, adjusted risk difference -2·91, -4·49 to -0·88; OR 0·70, 0·55 to 0·91; p=0·0073) and higher mean birthweight (mean difference 45 g, 18 to 73; p=0·0012). Each 1 SD increase in maternal TSH concentration was associated with a 6 g lower birthweight (-10 to -2; p=0·0030), with higher effect estimates in women who were thyroid peroxidase antibody positive than for women who were negative (pinteraction=0·10). Each 1 SD increase in FT4 concentration was associated with a 21 g lower birthweight (-25 to -17; p<0·0001), with a higher effect estimate for measurement in the third trimester than the first or second. INTERPRETATION: Maternal subclinical hypothyroidism in pregnancy is associated with a higher risk of SGA and lower birthweight, whereas isolated hypothyroxinaemia is associated with lower risk of SGA and higher birthweight. There was an inverse, dose-response association of maternal TSH and FT4 (even within the normal range) with birthweight. These results advance our understanding of the complex relationships between maternal thyroid function and fetal outcomes, and they should prompt careful consideration of potential risks and benefits of levothyroxine therapy during pregnancy. FUNDING: Netherlands Organization for Scientific Research (grant 401.16.020).

The use of vitamin D in preventing post-thyroidectomy hypocalcemia: An endocrinologist survey study.

OBJECTIVE: To evaluate the use of preoperative vitamin D levels and postoperative vitamin D supplementation among endocrinologists for the prevention of post-thyroidectomy hypocalcaemia. METHODS: Endocrinologist members of the American Thyroid Association (ATA) were contacted via email to complete a 21-question survey, which included both questions about demographic information, and preventing and managing postoperative hypocalcaemia after thyroidectomy. Univariate and multivariate analysis was performed to determine the respondents' use of preoperative vitamin D levels, dose and duration of preoperative vitamin D repletion, decision to delay surgery for low vitamin D levels in the case of a benign or malignant disease, and routine prescription of postoperative calcium or vitamin D supplementation. RESULTS: 225 endocrinologists who were ATA members responded to the questionnaire. When compared to endocrinologists practicing in other countries, those that practice in the United States were 2.5 times more likely to check preoperative vitamin D levels (95% CI[1.404, 4.535], P = .002), significantly more likely to replete vitamin D deficient patients with high-dose vitamin D (ie ≥50K IU/week), 4.458 times more likely to prescribe prophylactic supplemental calcium (95% CI[2.446, 8.126]; P < .0001) and 3.48 more likely to prescribe supplemental vitamin D (95% CI [1.906, 6.355]; P < .0001). Endocrinologists who have been in practice for >10 years were also 1.915 times more likely to prescribe supplemental vitamin D (95% CI (1.080, 3.395); P = .0263). Physicians that treat >50 thyroidectomy cases/year were 2.083 more likely to recommend a vitamin D repletion duration of >1 month than those that treat ≤50 cases/year ([1.036, 4.190], P = .0395). Lastly, if the patient has low preoperative vitamin D levels, 47.05% of respondents chose to delay surgery in a benign disease, while only 11.61% of respondents would do so in a case of malignant disease. CONCLUSIONS: Approximately one-half of surveyed endocrinologists reported using preoperative vitamin D levels to assess a patient's risk for post-thyroidectomy hypocalcaemia. Endocrinologists practicing in the United States, compared to those practicing in other countries, were more likely to both test for preoperative vitamin D levels and to recommend prophylactic post-thyroidectomy calcium and vitamin D supplementation.

Vitamin D Status as a Predictor of Postoperative Hypocalcemia after Thyroidectomy.

OBJECTIVE: To determine whether perioperative vitamin D levels are predictive of postoperative hypocalcemia in patients receiving thyroidectomy. STUDY DESIGN: Single center retrospective study. SUBJECTS AND METHODS: This study included all patients receiving total or completion thyroidectomy between January 2007 and March 2017 at a single tertiary care hospital. 25-Hydroxyvitamin D (25[OH]D) levels were measured within 42 days prior to surgery or 1 day postoperatively. Hypocalcemia was defined as an adjusted serum calcium <8.0 mg/dL (based on albumin levels) or symptomatic hypocalcemia. Univariate analysis was performed with a 2-sample t test and chi-square test, while multivariate analysis was performed with logistic regression analysis to determine whether perioperative 25(OH)D level is a predictor of postoperative hypocalcemia. RESULTS: A total of 517 subjects were included in the study, 15.7% (n = 81) of whom experienced postoperative hypocalcemia with a mean ± SD serum calcium level of 7.6 ± 0.5 mg/dL as compared with 8.9 ± 0.5 mg/dL in the normocalcemic population (P < .01). The mean 25(OH)D level for patients with hypocalcemia was 24.4 ± 12.0 ng/mL as compared with 27.5 ± 12.2 ng/mL in patients with normocalcemia (P = .038). Subjects who were hypocalcemic experienced a significantly longer hospital stay (2.9 ± 2.5 vs 1.4 ± 1.1 days, P < .01). After adjusting for preoperative calcium, age, and performance of a neck dissection, subjects with a 25(OH)D level <30 ng/mL were significantly associated with postoperative hypocalcemia (odds ratio, 1.9; P = .041; 95% CI, 1.0-3.3). CONCLUSION: Using a single-center retrospective study design, we demonstrated that 25(OH)D level is a significant predictor of postoperative hypocalcemia after thyroidectomy.

Excessive iodine intake is associated with formation of thyroid nodules in pregnant Chinese women.

In recent decades, the prevalence of thyroid nodules (TNs) has steadily increased in pregnant women. Therefore, this study aimed to investigate associations between TNs and iodine intake in pregnant women. From March 2016 to May 2017, serum and spot urine samples, as well as demographic data and medical history, were collected from 2353 pregnant women. Urine iodine concentration (UIC) and creatinine (Cr) level were determined in spot urine samples; serum thyroid hormones and thyroid autoantibodies were also determined. We examined the hypothesis that excess iodine intake influences incidence of TNs. Herein, TNs were diagnosed by ultrasonography, whereas demographic data and medical history were collected by questionnaire. Multivariate logistic regression models were used to calculate the odds ratios and their corresponding confidence intervals for TN risk factors. Generalized linear mixed model was used to assess the random effects of the regions. The UIC and UIC to creatinine ratio (I/Cr ratio) were significantly higher in pregnant women with TNs (168 and 190 µg/L, respectively, for UIC [P < .01]; 139 and 155 µg/g, respectively, for I/Cr ratio [P < .01]). Thyroglobulin, age, pre-pregnancy body mass index, and iodine-excessive region were associated with TNs (odds ratio = 1.01, 1.06, 1.04, and 2.38, respectively). Whereas I/Cr ratio was not a significant risk factor for TNs in pregnant women when adjusted for potential confounders, iodine excess (I/Cr ratio >500 µg/g) was a risk factor in pregnant women in their second trimester. People living in areas with excessive iodine in drinking water should decrease their iodine intake, and a safe water source should be provided to ensure that the I/Cr ratio of pregnant women can be maintained at an optimal level.

Effect of perchlorate and thiocyanate exposure on thyroid function of pregnant women from South-West England: a cohort study.

BACKGROUND: Iodine is important for thyroid hormone synthesis, and iodine deficiency in pregnancy may impair fetal neurological development. As perchlorate and thiocyanate inhibit sodium-iodide symporter reducing the transport of iodine from circulation into the thyroid follicular cells, environmental exposure to these substances in pregnancy may impair maternal thyroid hormone synthesis. We aimed to explore the impact of perchlorate and thiocyanate exposure on thyroid status in a cohort of pregnant mothers from South West England. METHODS: Urine samples were obtained from 308 women participating in a study of breech presentation in late pregnancy. They had no known thyroid disease and a singleton pregnancy at 36-38 weeks gestation. Samples were analysed for urinary concentrations of iodine (UIC), perchlorate (UPC) and thiocyanate (UTC). Blood samples were taken for free T4 (FT4), thyrotropin (TSH) and thyroid peroxidase antibodies (TPO-Ab). Baseline data included age, parity, smoking status, ethnicity and BMI at booking. Following delivery, data on offspring's sex, gestational age at birth and birthweight were collected. RESULTS: Participants had a mean (SD) age 31 (5) years, median (IQR) BMI 24.4 (22.0, 28.3) kg/m2, 42% were primiparous, 10% were smokers, and 96% were Caucasian. Median UIC was 88 µg/l, and 174/308 (57%) women had UIC < 100 µg/l. Log transformed UPC negatively correlated with FT4, but not with TSH, in the whole cohort (r = - 0.12, p = 0.03) and in the subgroup of women with UIC < 100 µg/l (r = - 0.15, p = 0.04). Regression analysis with the potential confounders (TPO-Ab status, UIC and UTC) identified UPC to be negatively associated with FT4 (p = 0.01). There was no correlation between UTC and FT4 or TSH. Maternal UPC or UTC was not associated with offspring birthweight. CONCLUSION: Environmental perchlorate exposure is negatively associated with circulating FT4 levels in third trimester pregnant women. This may have an adverse impact on neurocognitive development of the fetus.