Low TSH Research Articles

Thyroid Dysfunction Following Thermal Ablation of Large Solid and Solid-Predominant Thyroid Nodules.

Thermal ablation (TA) is an alternative to lobectomy for thyroid nodules (TNs). While it is believed that thyroid function remains stable after TA for cystic TNs, the impact of TA on solid TNs, especially the large ones, is less explored. This study investigates changes in thyroid hormones after TA in patients with solid-predominant TNs and identifies potential risk factors for thyroid dysfunction after TA. Euthyroid patients with solid-predominant TNs (≥80% solid) were enrolled. The volume, diameter, and cytopathology of TNs were assessed before TA. TA was performed using either microwave or radiofrequency ablation. Thyroid hormone levels were measured at 1 week and 1, 3, 6, and 12 months after TA. 77 euthyroid patients with TNs were included. The euthyroid rate dropped to 70.1% at 1 week after TA but improved to over 90% by 1 month and returned to 100% by 12 months. At 1 week after TA, subclinical hyperthyroidism and hyperthyroidism were observed, with elevated T4, fT3, fT4, and TGAb levels, along with decreased TSH levels. The diameter and total volume of TNs were positively correlated with thyroid dysfunction, while TSH-baseline was negatively correlated with thyroid dysfunction 1 week after TA. A larger diameter and lower baseline TSH were identified as independent risk factors for thyroid dysfunction. TA may cause short-term thyroid dysfunction, especially in patients with large TNs. Monitoring of thyroid hormone levels is recommended from 1 week to 3 months after TA to manage potential thyroid dysfunction effectively.

Exposome-Wide Association Study of Thyroid Function Using U.S. National Health and Nutrition Examination Survey Data.

Previous epidemiologic studies examining thyroid function and chemical exposures have typically focused on a single or a limited number of chemical classes, often neglecting the effects of chemical mixtures. This study addressed this gap by exploring the associations between exposure to hundreds of chemicals and thyroid function using an exposome-wide association study (ExWAS) approach and National Health and Nutrition Examination Survey (NHANES) data. We analyzed data from three NHANES cycles (2007-2008, 2009-2010, 2011-2012), which include measures of thyroid function (free and total triiodothyronine [T3], free and total thyroxine [T4], thyroid-stimulating hormone [TSH]) and chemical biomarker concentrations from 9,082 participants. For adolescents (aged 12-19 years) and adults (aged ≥20 years), we employed multiple regression by accounting for survey weights to identify biomarkers associated with thyroid function test levels and used Bayesian group weighted quantile sum (BGWQS) regression to assess the effects of chemical mixtures on these measurements. After adjusting for multiple comparisons, we found in single exposure scenarios that 44 and 67 biomarkers were associated with at least one thyroid function measure in adolescents and adults, respectively (adjusted p-value <0.05). In scenarios involving mixed chemical exposures, groups such as pesticides, sodium/iodide symporter (NIS) inhibitors, and metals were associated with alterations in thyroid hormones or TSH across both age groups. Volatile organic compounds were specifically linked to lower T4 levels in adolescents, whereas phenols and parabens were associated with lower TSH levels exclusively in adults. Although limited by the cross-sectional data, this study identifies chemical biomarkers linked to thyroid thyroid function.

A higher incidence of cardiovascular complications in hyperthyroid patients with Graves’ disease in comparison to hyperthyroid patients with subacute thyroiditis

Background: Hyperthyroidism, as well as systemic inflammation, are associated with a higher incidence and complications of cardiovascular disease. Both in Graves’ disease and subacute thyroiditis, patients are hyperthyroid. However, in Graves’ disease, there is an autoimmune process in the thyroid, and in subacute thyroiditis, hyperthyroidism is accompanied by systemic inflammation. It is not known if the rate of cardiovascular complications is higher in the course of Graves’ disease or subacute thyroiditis.. Methods: We performed a retrospective study of all hyperthyroid patients newly diagnosed with Graves’ disease or subacute thyroiditis between January 1st 2018 and December 31st 2021 at the Department of Nuclear Medicine, University Medical Centre Ljubljana. Cardiovascular complications in the period 3 months before or after diagnosis were registered. Values are expressed as mean (SD).. Results: The sample analysis included 1028 patients (247 with subacute thyroiditis, 781 with Graves’ disease). The two groups did not significantly differ by sex, age, and body mass index. A cardiovascular complication was registered in 78 patients; the incidence was significantly higher in Graves’ disease than in subacute thyroiditis (74 vs. 4, p&lt;0.001). Compared to patients with subacute thyroiditis, patients with Graves’ disease had significantly lower TSH: 0.010 (0.006) vs. 0.024 (0.044) mIU/L (p&lt;0.001), higher free T4: 44.1 (26.6) vs. 37.0 (14.7) pmol/L (p&lt;0.001), higher incidence of diabetes: 4.3 vs. 0.4% (p=0.001), arterial hypertension: 12.2 vs. 5.7% (p=0.004) and smoking: 26.7 vs. 8.7% (p&lt;0.001). In a logistic regression model, a significantly higher likelihood for cardiovascular complications was found in Graves’ disease vs. subacute thyroiditis (odds ratio 5.82, p=0.001), in patients with arterial hypertension (odds ratio 2.83, p=0.002), and in those with higher body mass index (odds ratio 0.92, p=0.043).. Conclusion: We report a higher incidence of cardiovascular complications in hyperthyroid patients with Graves’ disease in comparison to hyperthyroid patients with subacute thyroiditis. Patients with Graves’ disease were more severely hyperthyroid and had more adverse cardiovascular risk factors.

Euthyroid sick syndrome predicts the risk of ischemic stroke-associated pneumonia in the acute stage of ischemic stroke: a nested case-control study.

Ischemic stroke-associated pneumonia (iSAP) affects about 10% of acute ischemic stroke patients during hospitalization. Current prediction scales for iSAP are insufficient. Identifying early biomarkers for stroke-associated pneumonia is crucial for improving patient outcomes. This study aimed to investigate the predictive value of euthyroid sick syndrome (ESS) for iSAP in acute-stage of ischemic stroke patients. We studied 1767 acute ischemic stroke patients within one week of symptom onset, categorizing them into an infection group (iSAP, n=376) and control group (control, n=1391). COX regression analysis was used to identify the potential risk and protected factors. Kaplan-Meier time-event curves and Log-Rank tests were performed to differentiate infection time in patients with ESS or normal T3 group. The iSAP group had higher rates of risk factors like older age, atrial fibrillation, COPD, and ESS, along with elevated levels of WBC, CRP,and FT4 levels (all P < 0.001). Conversely, iSAP patients had lower GCS scores, eGFR, TSH, T3, FT3 (all P < 0.001) and T4 levels (P = 0.005) upon admission. No significant differences were observed in sex, smoking history, hypertension, diabetes, or LDL-C levels (P > 0.05). COX regression analysis identified age, KWST scores, leukocyte count, CRP, and ESS (all P < 0.001) as significantly correlated with iSAP. ROC analysis revealed ESS as a predictor with sensitivity of 35.64% and specificity of 87.92% for SAP prediction, like atrial fibrillation and higher than COPD and eGFR. ESS at admission predicts a higher risk of stroke-associated pneumonia in acute-stage of ischemic stroke.

Methimazole for Prevention of Iodinated Contrast Media Induced Exacerbation of Thyrotoxicosis in Susceptible Patients

Iodinated contrast media (ICMs) are widely used in a variety of examinations and procedures. The aim of the current study was to investigate the efficacy of methimazole (MMI) in prevention of thyrotoxicosis after ICM exposure. A retrospective cohort study included patients aged ≥18 years admitted to a tertiary medical center who underwent ICM examination or procedure and received MMI prior to iodine exposure. A total of 179 patients with 202 hospitalizations were included. The mean age was 72.3 ± 13.5 years (female, 64%). Nearly all patients (99%) had a history of thyroid disease, and 91% were treated with MMI prior to admission. Seventy-five patients had low thyroid-stimulating hormone (TSH) levels prior to ICM exposure. In this high-risk group, MMI led to normalization of TSH after discharge in 19%, and 64% remained with low TSH levels after discharge but with a small median difference in free thyroxine levels of-0.5 (interquartile range [IQR],-5.9 to 5.2) pmol/L. In the 8 patients with dose increase during hospitalization, treatment with MMI was beneficial with a median free thyroxine decrease of-6.2 (IQR,-9.2 to-1) pmol/L and TSH increase of 0.2 (IQR, 0.02-0.7) mIU/L. In 110 patients with normal TSH levels before admission, with MMI treatment, most (71%) remained euthyroid after discharge, 13% had low TSH levels, and 9% had high TSH levels. In the 15 patients with high TSH levels prior to admission, the TSH levels of only 2 patients normalized, 47% remained with high TSH levels, and 27% had low TSH levels after discharge. In patients with pre-existing thyrotoxicosis treated with antithyroid drugs, MMI therapy before ICM exposure prevented exacerbations. In patients with low TSH levels before admission, increasing the dose of MMI before exposure led to improvement in thyroid functions after discharge.

Predictors for thyroid dysfunction after discontinuation of levothyroxine in children and adolescents with Hashimoto thyroiditis.

Few data on the clinical course after levothyroxine (L-T4) discontinuation in pediatric patients with Hashimoto thyroiditis (HT) are available. We investigated outcomes and predictors for successful withdrawal from L-T4 among children with HT. Among 168 patients diagnosed with HT between January 2000 and March 2021 at Seoul National University Children's Hospital and in whom L-T4 therapy was initiated during childhood, we attempted to discontinue this therapy in 47, 3 boys and 44 girls. L-T4 was restarted when patients developed overt or subclinical hypothyroidism (thyroid-stimulating hormone [TSH] levels≥10 mIU/L) after L-T4 discontinuation. Median age at discontinuation was 15.4 years (12.7-18.4 years) with a median duration of L-T4 therapy of 47 months (20.3-80.3 months). During the median 30 months of follow-up (10.6-61.0 months) after L-T4 discontinuation, 33 (70.2%) developed thyroid dysfunction. Among these patients, 17 were eventually restarted on L-T4. TSH levels over 50 mIU/L at L-T4 initiation (hazard ratio, HR 3.5, P=0.002), age under 12 years at L-T4 discontinuation (HR 11.1, P=0.0001), and TSH levels higher than the upper 50% of normal (above 2.25 mIU/L in the present study) at L-T4 discontinuation (HR 2.7, P=0.014) were significantly predictive for overt hypothyroidism or subclinical hypothyroidism after L-T4 discontinuation. In addition, age under 12 years at L-T4 discontinuation was only predictive factor for restarting L-T4 medication (HR 4.3, P=0.012). L-T4 discontinuation in pediatric patients with HT resulted in thyroid dysfunction in 70.2% of cases; 36.2% of patients who attempted discontinuation required resumption of L-T4. Older age and lower TSH levels at L-T4 discontinuation were advantageous for successful withdrawal.

Stimulating thyrotropin receptor antibodies in early pregnancy.

Thyrotropin-receptor antibodies (TRAb) are used to diagnose Graves' hyperthyroidism in pregnant women. Bioassays provide a measure of thyrotropin-receptor stimulatory antibodies (TSI) specifically. The objective was to measure TSI in pregnant women for establishment of a pregnancy-specific cut-off and comparison with immunoassay measurements of TRAb. The retrospective Danish study was performed within the North Denmark Region Pregnancy Cohort (2011-2015) that includes stored biobank samples from early pregnancy (median week 10) with immunoassay measurements of thyroid function parameters and TRAb. TSI were measured in the same samples using the Turbo TSI bioassay (Quidel/Ortho-Clinical Diagnostics) with a recommended cut-off of 0.0241 IU/L in non-pregnant adults. A pregnancy-specific TSI cut-off (95-percentile) was established using Regression on Order Statistics. The established TSI cut-off was 0.0418 IU/L (95 % CI: 0.0417-0.0419). Among women with early pregnancy hyperthyroidism (n=438), 43 women (9.8 %) were TSI positive using the established cut-off, and these women had lower TSH (median 0.008 mIU/L) compared to women with TSI levels below 0.0241 (median TSH 0.040 mIU/L) or in the range from 0.0241 to 0.0418 (median TSH 0.033 mIU/L). Among the 438 women with early pregnancy hyperthyroidism, 22 women were positive for TSI and TRAb, 388 were negative for both, and 28 women were positive for either TSI or TRAb. This is the first study on TSI measurements in a large cohort of early pregnant women. A pregnancy-specific cut-off for TSI was established and agreement in the classification with immunoassay measurements of TRAb was seen in 94 % of cases.

Occupational Exposure to Unburnt Tobacco Dust and Thyroid Function: A Case-Control Study

Beedi rolling is one of the most common home-based occupations used to meet daily expenses. The process of making beedis is mainly done by women, especially in rural areas. Due to a lack of awareness regarding safety measures, beedi-rolling women are exposed to toxic components present in unburnt tobacco dust. This exposure leads to many health complications among women beedi-rollers. In this study, we investigated how unburnt tobacco dust disrupts thyroid gland homeostasis by altering levels of thyroid hormone and TSH. We included 421 beedi rolling women (BR) and 426 control subjects (NBR) who were not exposed occupationally to any chemical agents. Levels of thyroid hormones (T3, T4) were analysed using competitive ELISA, and TSH levels were analysed using sandwich ELISA. Serum nicotine metabolites were analysed using LC-MS. We observed a statistically significant increase in the levels of T3, T4, anabasine, nornicotine, and cotinine in BR compared to the NBR group. Additionally, significantly lower TSH levels were observed in the BR group. However, the Correlation between nicotine metabolites, and hormones did not show a significant difference in the BR group. We conclude that prolonged exposure to unburnt tobacco dust must have disrupted thyroid function by altering the thyroid hormone, and TSH levels.

Characterizing cognitive phenotypes and clinical correlates in type 2 diabetes using fuzzy clustering and decision tree analysis

Cognitive impairment is frequently seen in patients with type 2 diabetes (T2DM), ranging from mild impairment to dementia. However, our knowledge of the specific profiles and risk factors for these different levels of impairment is limited. In this study involving 152 patients with T2DM, cognitive function was assessed using the Montreal Cognitive Assessment test. The Fuzzy C-means clustering algorithm was utilized to group individuals with similar cognitive characteristics. The study evaluated how well clinical parameters could classify characteristics of clusters using the Classification and Regression Trees algorithm. ROC analysis was then used to assess the classification success. Three distinct cognitive clusters were identified. Cluster 1 had the poorest cognitive performance and was characterized by more women, lower education levels, and lower levels of iron, hemoglobin, and creatine. Cluster 3, the amnestic cluster, was distinguished by low TSH levels. The decision tree model highlighted several parameters, including education level, hemoglobin, duration of diabetes mellitus (DM), iron, TSH, gender, family history of diabetes, and microalbumin/creatinine ratio, as significantly affecting the distinction of cognitive clusters. Diabetes-associated cognitive impairment stems from multifaceted pathophysiological mechanisms influenced by complex risk factors, resulting in diverse types of cognitive deficits.

Subclinical Hyperthyroidism and Cardiovascular Disease.

Background: In this narrative review, we assess published data on subclinical hyperthyroidism (SCHyper) and its association with cardiovascular disease (CVD) in the general population. Summary: We present data on the risk of SCHyper in relation to CVD outcomes, including atrial fibrillation (AF), heart failure, stroke, coronary heart disease (CHD), major adverse cardiac events (MACE), CVD mortality, and all-cause mortality. Evidence indicates that SCHyper is associated with an elevated risk of AF, heart failure, MACE, CVD mortality, and all-cause mortality. SCHyper appears to have little association with stroke risk and has shown conflicting results regarding CHD risk. Regarding the degree of serum TSH suppression, evidence shows a higher risk of CVD in SCHyper individuals with suppressed TSH (<0.1 mIU/L) compared with those with low TSH (0.1-0.4 mIU/L). Despite evidence that older individuals are inherently at a higher risk for CVD, no studies have yet demonstrated an age-related increase in the relative risk of CVD in SCHyper. Conclusion: The studies indicate that SCHyper is associated with an increased risk of AF, heart failure, MACE, CVD mortality, and all-cause mortality. Considering the importance of the degree of serum TSH suppression and age as risk factors for CVD, treatment decisions should be individualized based on their specific risk factors.

6693 Hypopituitarism in Pregnancy

Abstract Disclosure: N.A. Mcheik: None. H. Howarth: None. Background: Hypopituitarism in pregnancy requires careful management to ensure both maternal and fetal well-being. Disruptions of the pituitary gland in pregnancy can be due to adenomas, pituitary infarction, autoimmune disease, trauma, etc. Complications of hypopituitarism in pregnancy stem from inadequate production of thyroid stimulating hormone, growth hormone, gonadotropins and cortisol. Hormone replacement therapy will be necessary in such cases. For instance, patients in late pregnancy may require an increased dose of hydrocortisone due to the rise of corticosteroid-binding globulin. Patients may need increased doses of glucocorticoid therapy during labor given the major surgical stress. Antenatal care should include close follow up with endocrinologists and obstetricians and regular assessment of maternal hormone levels and fetal growth. Case: We present a case of a 37-year-old female G3P0020 at 24 weeks who presented with complaint of constant headache for 6 days. Associated with photophobia, intermittent blurry vision, nausea, and vomiting. She was admitted and given 1 g Magnesium bolus as well as Robaxin and Tylenol for headache without relief. Given persistence of symptoms and non-focal neurologic exam, MRI brain was completed that showed an enlarged pituitary gland with blood products. MRI pituitary showed an approximately 1.3 x 1.2 x 1.8 cm hemorrhagic lesion on the right side of pituitary gland with fluid level, most in keeping with hemorrhagic pituitary apoplexy. Thyroid function studies were consistent with central hypothyroidism with a low TSH 0.05, low Ft4 0.5, and normal Ft3 2.4. Luteinizing hormone was 0.1 mIU/mL (&amp;lt;1.5 normal in pregnancy), follicle stimulating hormone was &amp;lt;0.5 mIU/mL (&amp;lt;0.1 normal in pregnancy), estradiol &amp;gt;5000 pg/mL (1278-7192 normal in pregnancy), and prolactin 254 ng/mL (80-400 normal in pregnancy). IGF-1 was normal at 148 ng/ml. Morning cortisol was low at 1.8 ug/dL and ACTH was 9 pg/mL (low normal). Cortrosyn stimulation test at 60 minutes was normal at 17.7 ug/dL, however, given clinical improvement on steroids, the clinical picture is consistent with central hypoadrenalism. For treatment, she was started on IV hydrocortisone 50 mg every 8 hours and oral levothyroxine 100 mcg daily. The patient was discharged home on oral hydrocortisone 20 mg daily in the morning and 10 mg daily in the afternoon with close follow up. Conclusion: Ultimately, the management of hypopituitarism in pregnancy requires a personalized approach to hormone replacement and obstetric care and this is done through multidisciplinary care involving endocrinologists and obstetricians to optimize outcomes for both the mother and the baby. Presentation: 6/1/2024

8791 A Case of Hyperfunctioning Thyroid Nodules Evaluated for Thyroid Metastasis in the Setting of Oropharyngeal Squamous Cell Carcinoma

Abstract Disclosure: M. Alashoor: None. J. Gogineni: None. A. Bakar: None. Introduction: Identifying and evaluating hyperfunctioning thyroid nodules in the setting of metastatic head and neck cancers represents a diagnostic challenge that may result in inaccurate identification of perithyroidal lymph node metastasis as malignant or metastatic thyroid nodules with standard workup. Case presentation: A 72-year-old male with a history of stage IV metastatic oropharyngeal squamous cell carcinoma, metastasized to the lymph nodes, lungs, mediastinum, and bilateral iliac bones. He was diagnosed two years ago and received chemotherapy, maintenance immunotherapy with pembrolizumab, and targeted palliative radiation therapy, with good clinical response. Restaging PET-CT two years later revealed local progression. During his workup, he was noted to have persistently abnormal thyroid function test with low TSH (0.03​​µIU/mL, n 0.3-5.33), normal free T4 (0.97ng/dL, n 0.60 - 1.40), mildly elevated free T3 (3.91pg/mL, n 2.5-3.9), negative thyrotropin receptor antibodies levels, negative TSI, negative TPO antibody, noted evidence of subclinical hyperthyroidism consistent over the past year. Radioactive iodine uptake demonstrated multinodular gland, mildly elevated 24-hour uptake of 28% consistent with hyperthyroidism, with decreased activity in the left lobe. Thyroid ultrasound revealed multiple probable malignant thyroid nodules, a 1.8 cm TI-RADS 5 lesion of the deep margin of the lower pole of the right lobe, and a 1.6 cm TI-RADS 5 lesion of the upper pole on the right lobe. He was treated with methimazole 5 mg. Further workup with fine needle aspiration demonstrated the right upper lobe nodule sample was positive for squamous cell carcinoma, findings suspicious for metastasis. He subsequently proceeded with radical tonsillectomy, right neck dissection, and right hemithyroidectomy. Surgical pathology results noted, right neck metastatic HPV-associated squamous cell carcinoma involving the lymph nodes with extranodal extension, right oropharyngeal HPV-mediated squamous cell carcinoma. The thyroid gland biopsy was significant for incidental papillary microcarcinoma 2mm, thyroid follicular nodular disease, without evidence of squamous cell carcinoma or metastatic infiltration. Post-hemithyroidectomy, his thyroid function normalized, and methimazole was discontinued. Conclusion: Thyroid metastasis from head and neck cancers represent a rare entity. In patients with a history of malignancy, evaluation of new thyroid masses remains crucial. While FNA is a sensitive method for detecting thyroid metastases, inaccuracies may occur, impacting the identification of thyroid nodules in the presence of local metastatic lymphadenopathy. Identifying squamous cell carcinoma in the thyroid can significantly influence the treatment plan of patients with metastatic carcinomas, therefore careful consideration must be undertaken on evaluation. Presentation: 6/1/2024

7078 Diagnostic Obstacles in Thyroid-Stimulating Hormone-Secreting Pituitary Adenoma (TSH-oma): A Case Report

Abstract Disclosure: V.A. Mendpara: None. P.P. Rao: None. M.D. Lundholm: None. Background: Thyroid-stimulating hormone-secreting pituitary adenoma (TSH-oma) is a rare cause of hyperthyroidism, forming 0.5-3% of all functioning pituitary tumors and &amp;lt;1% of hyperthyroid cases. Here, TSH secretion is autonomous and unresponsive to the normal negative feedback of thyroid hormones, leading to inappropriate TSH, T4 and T3 elevation. In the absence of clinical symptoms it can be difficult to distinguish between thyroid hormone resistance (THR) and lab errors. Clinical Case: A 44-year-old Swahili-speaking female with a history of type 2 diabetes was admitted for hypoglycemia requiring insulin adjustment. In her workup, thyroid function tests were obtained, revealing normal or low TSH (0.28 mIU/L) and high free T4 levels (2.7 ng/dL). At outpatient follow-up, repeat labs showed elevated TSH, T3 and FT4 (5.22 mIU/L, 377 ng/dL and 4.7 ng/dL, respectively). She reported weight loss, occasional palpitations, and chronic insomnia but denied other symptoms. Graves' antibodies (TSI, TSHR Ab) were negative. On exam, she had a 30-40 gm, smooth, non-tender thyroid without adenopathy, and a BMI of 23 kg/m2. The initial differential diagnosis included TFT lab error, THR or TSH-oma. A FT4 by equilibrium dialysis was high at 7.8 ng/dL (1.1-2.4 ng/dL). N-telopeptide (NTX) and sex hormone-binding globulin (SHBG) were elevated, consistent with a true hyperthyroid state. Genetic testing for THR posed time and cost barriers. Elevated alpha-subunit levels (87 ng/mL, normal ≤1.8 ng/mL) with normal levels of other pituitary hormones prompted a pituitary MRI, unveiling a 4.7 cm suprasellar bilobed pituitary mass abutting the optic chiasm and invading the cavernous and sphenoidal sinuses. She denied peripheral vision loss or headaches. Hyperthyroidism was managed with methimazole until surgical intervention for the TSH-oma. A transsphenoidal resection was performed with histopathological confirmation of a TSH-staining pituitary adenoma. She was started on levothyroxine for central hypothyroidism thereafter. Discussion: It is challenging to find the cause of abnormal TFTs when patients are asymptomatic and the differential includes THR, lab errors or TSH-oma. Inaccurate diagnosis can lead to delays in care or unnecessary thyroid ablation or pituitary surgery. Conversely, early identification and appropriate treatment of TSH-omas can prevent neurological and endocrinological complications, such as optic chiasm compression, visual disturbances, headache and hypopituitarism. Despite a lack of convincing symptoms of hyperthyroidism, we used confirmatory labs (NTX, SHBG) to rule in biochemical hyperthyroidism along with alpha-subunit testing and pituitary MRI to solidify the TSH-oma diagnosis, leading to surgical intervention. This case highlights the vital steps in the diagnosis of a TSH-oma, emphasizing the need for logical evaluation and differentiation of this rare condition. Presentation: 6/1/2024

7860 Predictors of Remission in Patients with Graves' Disease Treated with Antithyroid Drugs at the University of Santo Tomas Hospital - A Retrospective Cohort Study

Abstract Disclosure: F.E. Sorsona: None. E.C. Cunanan: None. This is a local study with the objective to determine the predictors of remission in Graves’ disease patients who completed 12 to 18 months of antithyroid drug therapy in University of Santo Tomas Hospital (Manila, Philippines) from 2017 to 2022. The study employed a retrospective cohort design. Patients included were all Graves’ disease patients seen at University of Santo Tomas Hospital who were treated with antithyroid drug methimazole. Data were collected via a retrospective review of medical charts. From the 203 Graves’ disease patients, a total of 59 patients met the inclusion criteria and were included in the study. Following completion of antithyroid drug therapy, patients were divided into remission and non-remission groups. Predictive factors analyzed were age, gender, smoking history, presence of orbitopathy and goiter, duration of ATD therapy, and thyroid function tests (TSH, free T3 and free T4) at time of initiation and completion of ATD. Forty-nine patients (83%) were females, and ten patients (17%) were males. The median age at the time of ATD initiation was 35 years old. The median duration of ATD therapy was 24.2 months. Following completion of ATD, 34 patients had remission with incidence of 57.63% (95% CI: 44.07-70.39%). Age, gender, smoking history, presence of goiter and orbitopathy, duration of ATD therapy, thyroid function tests at initiation, and FT3, FT4 and FT3/FT4 ratio at time of completion showed no significant differences between the two groups. After univariate and multivariate analyses, only one factor was significantly associated with 1-year remission which was the TSH at the time of ATD completion, with a median of 1.54 mIU/L, range: 0.001-7.94 mIU/L. Median TSH was significantly higher among patients who had remission than those with non-remission. Compared to patients with normal TSH at the time of ATD completion, the odds of remission was 14 times lower among patients with low TSH, and 7 times lower among patients with high TSH. A normal TSH at the time of ATD completion was associated with 1-year remission from Graves’ disease. Presentation: 6/2/2024

9370 Thinking Outside the Box: A Rare Case of Using Plasmapheresis Treatment of Amiodarone-Induced Thyrotoxicosis in Preparation For CABG

Abstract Disclosure: K. Shaik: None. A. Kartoumah: None. J. Alsheikh: None. A. Nayeem: None. M.H. Horani: None. Introduction: Amiodarone, a standard treatment for arrhythmias, poses a risk of disrupting thyroid function and causing amiodarone-induced thyrotoxicosis (AIT). In critical cases where AIT is refractory to first-line treatment, plasmapheresis can be a vital option to rapidly lower thyroid hormone levels, which is essential for pre-surgical stabilization. This case report describes plasmapheresis in managing AIT in a patient undergoing coronary artery bypass grafting, highlighting its role in preventing potential thyrotoxic crises. Case Presentation: A 75-year-old male with a past medical history of diabetes mellitus, coronary artery disease, arrhythmias treated with amiodarone, and a ninety-pack-year history of tobacco presented to the ED with complaints of chest pressure and dyspnea. Initial troponin levels were normal at 24 ng/mL but trended upward toward 66 ng/mL. In the ED, he was not tachycardic and denied recurrent pain, fever, or chills. A CT angiogram of his chest showed no pulmonary embolus. The patient was found to have low TSH (0.005), and his T3 and T4 were both elevated (3.89/1.96, respectively), confirming thyrotoxicosis; however, he was negative for Graves’ disease. While in the hospital, his amiodarone was discontinued, and he was started on prednisone 10 mg for 14 days and methimazole 5 mg for 14 days. He was ultimately discharged on the same prednisone and methimazole regimen and told to follow up with outpatient endocrinology. However, the patient reappeared a week later with dyspnea on exertion; blood work performed after admission revealed a higher free T4 at 2.87. The patient was admitted, and angiography showed three-vessel disease; however, a coronary artery bypass graft (CABG) procedure was delayed over the concern of a potential thyroid storm. Thus, CABG was planned for when free T4 was less than 2, and the patient underwent two rounds of plasmapheresis, which initially decreased free T4 to 1.7 and finally to 1.4. Ultimately, a CABG was performed and well tolerated. Discussion: Amiodarone-induced thyrotoxicosis (AIT) poses a challenge in patient management, especially in patients requiring urgent surgeries. Plasmapheresis is shown to be a valuable option for rapidly lowering thyroid hormone levels and stabilizing the patient in the pre-operative stages. This case demonstrates the effectiveness of plasmapheresis in reducing free thyroxine levels, facilitating a safe and successful CABG. Due to its ability to quickly remove circulating thyroid hormones, plasmapheresis has excellent potential in managing refractory AIT. It is crucial to carefully time plasmapheresis relative to surgery and monitor for complications throughout. Further research is required to optimize proper plasmapheresis protocols in AIT. Conclusion: This case study highlights plasmapheresis as a promising adjunctive therapy in managing AIT and preventing potential thyrotoxic crises. Presentation: 6/1/2024

6693 Hypopituitarism in Pregnancy

Abstract Disclosure: N.A. Mcheik: None. H. Howarth: None. Background: Hypopituitarism in pregnancy requires careful management to ensure both maternal and fetal well-being. Disruptions of the pituitary gland in pregnancy can be due to adenomas, pituitary infarction, autoimmune disease, trauma, etc. Complications of hypopituitarism in pregnancy stem from inadequate production of thyroid stimulating hormone, growth hormone, gonadotropins and cortisol. Hormone replacement therapy will be necessary in such cases. For instance, patients in late pregnancy may require an increased dose of hydrocortisone due to the rise of corticosteroid-binding globulin. Patients may need increased doses of glucocorticoid therapy during labor given the major surgical stress. Antenatal care should include close follow up with endocrinologists and obstetricians and regular assessment of maternal hormone levels and fetal growth. Case: We present a case of a 37-year-old female G3P0020 at 24 weeks who presented with complaint of constant headache for 6 days. Associated with photophobia, intermittent blurry vision, nausea, and vomiting. She was admitted and given 1 g Magnesium bolus as well as Robaxin and Tylenol for headache without relief. Given persistence of symptoms and non-focal neurologic exam, MRI brain was completed that showed an enlarged pituitary gland with blood products. MRI pituitary showed an approximately 1.3 x 1.2 x 1.8 cm hemorrhagic lesion on the right side of pituitary gland with fluid level, most in keeping with hemorrhagic pituitary apoplexy. Thyroid function studies were consistent with central hypothyroidism with a low TSH 0.05, low Ft4 0.5, and normal Ft3 2.4. Luteinizing hormone was 0.1 mIU/mL (&amp;lt;1.5 normal in pregnancy), follicle stimulating hormone was &amp;lt;0.5 mIU/mL (&amp;lt;0.1 normal in pregnancy), estradiol &amp;gt;5000 pg/mL (1278-7192 normal in pregnancy), and prolactin 254 ng/mL (80-400 normal in pregnancy). IGF-1 was normal at 148 ng/ml. Morning cortisol was low at 1.8 ug/dL and ACTH was 9 pg/mL (low normal). Cortrosyn stimulation test at 60 minutes was normal at 17.7 ug/dL, however, given clinical improvement on steroids, the clinical picture is consistent with central hypoadrenalism. For treatment, she was started on IV hydrocortisone 50 mg every 8 hours and oral levothyroxine 100 mcg daily. The patient was discharged home on oral hydrocortisone 20 mg daily in the morning and 10 mg daily in the afternoon with close follow up. Conclusion: Ultimately, the management of hypopituitarism in pregnancy requires a personalized approach to hormone replacement and obstetric care and this is done through multidisciplinary care involving endocrinologists and obstetricians to optimize outcomes for both the mother and the baby. Presentation: 6/1/2024

8230 Adrenal Crisis, Unrevealing the Impact of Immigration on Central Adrenal Insufficiency

Abstract Disclosure: D.H. Sacoto: None. K. Madani: None. D. Patel: None. A. De Rosairo: None. G. Rai: None. R. Belokovskaya: None. A.A. Franco-Akel: None. Introduction: Even though patients with secondary adrenal insufficiency (AI) may go through life without an episode of adrenal crisis, there is a 50% chance of developing it. Around 90% have a known precipitating, with infections and surgery being frequent causes. However, emotional stress is unrecognized. With the recent increase in worldwide immigration, it is important to recognize these as potential triggers in those with AI. Here, we present a case of adrenal crisis triggered by immigration. Case presentation: A 41-year-old female diagnosed eighteen years ago with Sheehan syndrome, with unknown replacement therapy status, is brought to ED for altered mental status. One week before, she crossed the Mexican-US border as an illegal immigrant and was hospitalized in Arizona after developing mutism and mood lability. She was initiated and discharged on hormone replacement therapy. She arrived in New York confused with flat affect and impaired recent memory. She was hypotensive (BP: 92/64 mmHg), hyponatremic (Na: 133 mEq/L), and anemic (Hb: 10.6 g/dL). She had an inappropriate normal ACTH of 25 pg/mL (7.2-63.3 pg/mL). MRI findings confirmed empty sella, suggestive of central AI. Additional studies revealed central hypothyroidism (low normal TSH (1.36 uIU/mL), low-normal Free T4 (1.4 ng/dL), gonadotroph dysfunction with low FSH (2.7 IU/L), and low estrogen levels (20 pg/mL) for her age, and low normal prolactin (4.6 ng/mL). After initiating a stress dose of IV hydrocortisone and IV levothyroxine, her affect, memory, mental status, and vital signs (BP: 128/80 mmHg) improved. She was educated regarding the need for maintenance doses as an outpatient. At the one-month follow-up, she continued with a positive response. Discussion: Patients with chronic AI are unable to produce sufficient cortisol and are at risk of acute adrenal crisis when under stress. Stressful situations, including accidents, job interviews, or death in the family, have been described. However, with almost doubling the number of people entering the US without prior authorization between 2022 and 2023, immigration, which poses physical and emotional stress, certainty will become a matter of importance for those with AI. Guidelines to manage cortisol replacement in times of fever, infections, trauma, surgery, or severe pain are available. However, it is more difficult to define how emotional and psychological challenges affect the stress response, mainly because each challenge is unique. Therefore, it is important to advocate for policies to provide medical alert bracelets to immigrants with known AI in addition to providing education about emergency injection kits in cases of impending crisis. Presentation: 6/3/2024

9183 Pituitary Metastasis Of Lung Adenocarcinoma Presenting As Anterior Pituitary Dysfunction

Abstract Disclosure: O. faour: None. M. Kinaan: None. S.K. Suryanarayanan: None. Introduction: The pituitary should not be overlooked as a site for metastasis and can be the first presentation of neoplastic disease in some patients. Most common presenting symptoms: headache, ophthalmoplegia, visual field defect and Arginine Vasopressin Deficiency (AVP-D). We present a case of pituitary metastasis of lung adenocarcinoma presenting as anterior Pituitary dysfunction that also showed partial AVP-D unmasked after starting steroids. Case Description: A 63-year-old male with history of tobacco use, COPD, and hypertension presented with syncope. He reported a 30lbs weight loss within prior 2 months, low energy, increased thirst, and polyuria. Physical exam was significant for cachexia, normal visual field on confrontation, and vital signs of BP 100/61, HR 83, and Weighing 180 lbs. Since he had syncope, Cortisol checked was undetectable and Free T4 was low, He was started on hydrocortisone and levothyroxine. CTA chest revealed a right hilar mass measuring 2.7 x 3 cm. Endobronchial biopsy was consistent with lung adenocarcinoma. MRI of pituitary gland revealed solid hypointense lesion with glandular thickening and diffuse heterogeneity involving most of the pituitary gland measuring up to 16 mm. No cavernous sinus invasion. Pituitary infundibulum showed diffuse thickening and enhancement of the pituitary stalk throughout with Intact posterior pituitary bright spot. Labs showed low LH, cortisol, ACTH, GH, TSH, and ADH. Initially, the patient was able to maintain a euvolemic status through increased water intake; however, he was later found to have partial central AVP-D when steroids were introduced. He responded to the use of Desmopressin, developed hyponatremia after 3 doses. He was started on a combination of carboplatin/pemetrexed/pembrolizumab but had no response and was transferred to palliative care/hospice and passed away within 7months after diagnosis.Discussion:Pituitary metastasis is rare and most commonly occurs in lung and breast cancers. Unfortunately, they are associated with poor prognosis. MRI findings of loss of posterior pituitary bright spot, thickening of the stalk, and dumbbell shape can be helpful in distinguishing between primary pituitary tumors and metastases. PET-FDG scan has limited value. Pituitary metastasis commonly presents with posterior pituitary dysfunction due to direct blood supply. Unmasking or worsening of AVP-D can happen with steroid replacement in patients requiring initiation or intensification of Desmopressin therapy. Treatment involves combination of surgery, radiation therapy, and systemic treatment for the primary cancer which can improve symptoms only but does not improve mortality. Presentation: 6/1/2024

9303 Evaluation of The Consistency of Thyroid Indicators Tests in Minimally Invasive Peripheral Blood and Venous Blood

Abstract Disclosure: Z. Zhu: None. Y. Huang: None. Z. Cao: None. L. Zhang: None. D. Wang: None. S. Wang: None. J. Zhang: None. Y. Gao: None. Y. Zhang: None. Background The detection of thyroid indicators is of high demand in clinical and epidemiological screenings. Compared with existing venous blood tests, peripheral fingertip blood tests are less invasive and have a lower blood collection volume, which is the basis for point-of-care tests of thyroid indicators. Objective To explore the feasibility of minimally invasive and micro blood collection tests for thyroid disease (TD) patients by evaluating the consistency of thyroid indicators and TD diagnostic efficiency between fingertip blood tests and venous blood tests. Method 63 subjects with or without thyroid dysfunction were consecutively recruited. All subjects underwent serum, plasma and fingertip blood (same day collection) measurements for TSH and TT4 detection via the chemiluminescence method and for TPOAb detection via the electrochemiluminescence immunoassay method. The fingertip blood was centrifuged and diluted after EDTA anticoagulation. Bland–Altman plot, Passing–Bablok regression, and weighted kappa test were used for consistency test; AUC of ROC curve, sensitivity and specificity were used for authenticity evaluation among the three collection and testing methods. Results 43 subjects with euthyroidism and 20 subjects with thyroid dysfunction were included; including 29 (46.03%) females, the average age was 50.98±14.76 years. Bland-Altman plots showed more than 90% of the subjects had TSH and TT4 differences within the 95% limits of agreement between peripheral blood (PB) and venous blood (including serum and plasma). Passing–Bablok regression analyses revealed strong correlations between TSH levels in PB and serum (r=0.888) and plasma (r=0.894) (p&amp;lt;0.05); for TT4, there was a strong correlation between PB and serum (r=0.746), and there was also a moderate correlation between PB and plasma (r=0.664) (p&amp;lt;0.05 for both). Weighted kappa tests were performed for low, normal and high TSH values, indicating strong consistency between PB and serum and between PB and plasma, with coefficients of 0.901 and 0.881, respectively (P&amp;lt;0.001); for TT4, the coefficients between PB and serum, PB and plasma were 0.541 and 0.585 (P&amp;lt;0.001), indicating moderate consistency. Regardless of TPOAb positivity or negativity, the consistency among three blood sample sources was 100%. For euthyroidism (n=43), hyperthyroidism (n=6), subclinical hyperthyroidism (n=9), hypothyroidism (n=1), and subclinical hypothyroidism (n=4), the diagnostic sensitivities of PB were 97.06%, 83.33%, 87.50%, 100%, and 75.00%, respectively; the specificities were 94.74%, 97.87%, 95.74%, 98.11%, and 100.00%, respectively. The AUC of PB ROC curve for determining thyroid dysfunction was 0.944 (95% CI 0.867-1.000). Conclusion PB tests of thyroid indicators has high consistency with venous blood tests, offers sufficient diagnostic efficiency for TD, and is a feasible minimally invasive detection method. Presentation: 6/1/2024

6917 Multiple Red Herrings Complicating the Diagnosis of Cyclic Cushing’s Syndrome

Abstract Disclosure: A. Grover: None. R. McGlotten: None. L.K. Nieman: None. Introduction: Cyclic Cushing’s syndrome (CCS) is a rare disorder characterized by intermittent hypercortisolemia. It may be caused by pituitary tumor (Cushing disease), ectopic ACTH tumor secretion (EAS), or primary adrenal disease. We present a case of CCS with multiple red herrings complicating the diagnosis. Case: A 57-year-old Cushingoid appearing woman presented elsewhere with weight gain, brain fog, weakness, hypertension, worsening diabetes, and OSA. Screening tests showed more than three episodes of hypercortisolism with interval eucortisolism: salivary and 24-urine cortisol (UFC) ranged from 0.06-0.34 µg/dL (reference range, RR, ≤0.09 µg/dL) and 59.7-137.1 µg/24 h (RR 4-50 µg/24 h) respectively. The patient was symptomatic throughout. Differential diagnosis was CCS vs a physiologic non-neoplastic condition. As she had no clear etiology for the latter, further testing was performed. ACTH was indeterminate (23-27 pg/mL, RR &amp;lt;46). Pituitary MRI showed a left 7 mm lesion. Inferior petrosal sinus sampling (IPSS) with Corticotropin Releasing Hormone (CRH) administration showed peripheral baseline ACTH levels of 9.0 and 10.0 pg/mL, suggesting that she had cycled out of a hypercortisolemic phase. The left petrosal baseline values were low (9 pg/mL,16 pg/mL), suggesting poor catheterization, which was confirmed by a low prolactin-normalized ACTH ratio. The petrosal levels were lower than expected (maximum 767 pg/ml), due to suppression of normal corticotropes vs poor tumor response. However, a central:peripheral step-up was consistent with Cushing's disease (CD) or pseudo-CS. She was referred to us for re-evaluation. A low FSH, LH, low normal TSH, and UFC of 160 µg/24h supported a diagnosis of CS. ACTH was 14.6 pg/mL. Pituitary MRI showed a 1.3 cm x 0.8 cm mass extending into the left cavernous sinus. She did not suppress cortisol during a dexamethasone suppression test (DST). After CRH administration ACTH levels doubled. Based on the macroadenoma and CRH response, CD was established; IPSS was not repeated. After transsphenoidal hypophysectomy, pathology revealed ACTH positive adenoma. Post-operative adrenal insufficiency required hydrocortisone replacement. Conclusion: CCS can pose a diagnostic challenge due to unpredictable duration and frequency of hypercortisolism. Intermittently elevated cortisol levels with CS symptoms should raise suspicion for CCS. In our case, low peripheral ACTH levels further suggested this possibility. DST may give spurious results in CCS owing to spontaneous falls or rises in cortisol at the time of testing. Prolonged hypercortisolism is required in all patients to ensure suppression of normal corticotropes, which if not complete, may confound results in patients with EAS. Finally, inadequate catheterization may affect accuracy of lateralization in any patient with CS and is ideally evaluated both by venography and prolactin measurement. Presentation: 6/1/2024