bluuebunny/crossref_metadata_2025 huggingface dataset:
THU657 Racing Hearts: A Closer Look At The Connection Between Hyperthyroidism And Coronary Vasospasm
Authors: Elahi Amna , Isidro Mateo Roselyn Cristelle
Published: October 2023

Disclosure: A. Elahi: None. R.I. Mateo: None.

The cardiovascular system is a major target of thyroid hormone action in which subtle changes in thyroid function can lead to cardiac complications such as coronary vasospasm. There are many proposed mechanisms in how this occurs, but further studies are needed to understand the specific pathophysiology. This case illustrates the clinical relevance of encountering a hyperthyroid patient complaining of chest pain and how to address it in real work practice. A 62 year old African American male with history of Graves hyperthyroidism, type 2 diabetes, hypertension, peripheral artery disease, and stroke with residual aphasia presented with acute onset chest pain, shortness of breath, and palpitations. He was noncompliant with his methimazole (MMI) and subsequent labs were significant for free T4 of 2.5 ng/dL, undetectable TSH, and free T3 of 11.53 pg/mL. His high sensitivity troponins were elevated at 29,569 ng/dL. EKG showed sinus tachycardia with T-wave inversions in leads II, III, and AVF with a bedside echo showing inferior lateral wall motion abnormality. He was started on MMI 20mg daily and admitted to the intensive care unit for non-ST elevation myocardial infarction management. Left heart catheterization (LHC) was done after 1 dose of MMI with findings suggestive of vasospasm; specifically, decreased blood flow of the right coronary artery which improved when the catheter was withdrawn and significant dampening of the arterial wave form of the left main coronary artery. Given the unclear differentiation between true coronary artery disease and vasospasm he needed a repeat LHC once his hyperthyroidism was more controlled. His free T3 levels were monitored every 1-2 days with administration of escalating doses of MMI up to 40mg daily. By day 7 of admission, his free T3 level was 4.54 pg/mL, free T4 was 2 ng/dL and repeat LHC was performed showing open vessel lumens with multiple occlusions requiring 2 stents in the right coronary artery and 1 stent in the left circumflex artery. Given that thyroid hormone receptors are present in the myocardium and vascular tissue, alterations in thyroid hormone concentration can affect cardiovascular function. The documentation of coronary spasm, however, is rare and to date, there are only a few limited cases describing the underlying pathophysiology. This case illustrates via cardiac catheterization images and corresponding labs, the positive correlation of coronary vasospasm with thyroid hormone levels in hyperthyroidism.

Presentation: Thursday, June 15, 2023
THU658 My Giant Calves Gave Up My Diagnosis: An Extreme Manifestation Of A Very Rare Syndrome With A Severe Elevation Of Tsh Levels
Authors: Castro Feliu Edgar Emanuel , De Freitas Angelica Ludena , Torres Rodríguez Alexis , Irizarry Gabriel
Published: October 2023

Disclosure: E.E. Castro Feliu: None. A. Ludena De Freitas: None. A. Torres Rodríguez: None. G. Irizarry: None.

Hoffmann’s Syndrome is a rare type of hypothyroidism myopathy in adults that classically presents with muscle cramps, weakness, muscle stiffness, hyporeflexia, delay deep tendon reflexes and pseudohypertrophy. This is the case of a 55-year-old male with history of poorly controlled hypothyroidism and medication non-compliance who was admitted to our institution for non-purulent cellulitis. Vital signs were within normal limits and Body Mass Index was 41.1. Upon physical examination flat affect, periorbital edema, moon facies features and macroglossia were distinguished. Skin had a doughy texture with areas of ichthyosis at upper and lower extremities. Goiter was absent. The most remarkable finding was bilateral calf hypertrophy, with measurements of 56 cm and 55.5 cm in diameter of right and left calves respectively. There was no tenderness to calf palpation and Homan’s sign was absent. Laboratories revealed dyslipidemia with a cholesterol of 308 mg/dL, triglycerides of 782 mg/dL, HDL of 26 mg/dL and LDL of 216 mg/dL with elevated inflammatory markers including sedimentation rate of 77 mm/hr and C-reactive protein of 6.45 mg/dL. Hypothyroidism was suspected therefore thyroid studies were ordered, which was compatible with severe hypothyroidism demonstrated by a record level TSH of 523 lU/ml. Other reported levels were Free T3 0.94pg/ml, total T3 0.5 ng/ml, free thyroxine <0.07 ng/dL, thyroid peroxidase <4, and thyroglobulin AB 19 IU/ml. Hoffmann’s Panel was confirmatory for this diagnosis reporting elevated levels of CPK 1509 U/L, LDH serum of 383 U/L and aldolase of 9.2 u/L. Ultrasound of the neck was non-contributory. Patient received antibiotic therapy for his skin infection and was also treated with IV Levothyroxine, which was prescribed orally upon discharge. Myopathy may be present in patients with longstanding untreated hypothyroidism in which pseudohypertrophy may occur, sometimes involving calf muscles (gastrocnemius). Hoffmann’s Syndrome is associated with changes in muscle fiber type from fast twitch type II to slow twitch type I and alteration of oxidative muscle enzyme activity with deceased calcium ATPase activity of fast twitch type II fibers leading to delayed relaxation. Biopsy of the affected muscle may reveal fiber necrosis, atrophy, hypertrophy with increased number of nuclei and increased connective tissue. Most cases of Hoffmann’s Syndrome improve after treatment with Levothyroxine, therefore, implementing this management on time can be curative. This case highlights the importance of considering this diagnosis when muscle dystrophies are studied and myopathic disorders are suspected, even in the absence of overt manifestations of hypothyroidism.

Presentation: Thursday, June 15, 2023
THU666 Should We Think About Thyroid Disease In A Patient With Thymoma Related Myasthenia Gravis?
Authors: Wintermyer Gelareh , Villanueva Erika
Published: October 2023

Disclosure: G. Wintermyer: None. E. Villanueva: None.

Oftentimes, Graves and Myasthenia Gravis present with very similar symptoms. This can complicate diagnoses of either. At the same time, Graves can cause thymic hyperplasia, and there is a link between Myasthenia Gravis and thymoma. In the following, we discuss a case that presented all three: 59-year-old female with PMHx of hyperlipidemia, GERD, hoarseness, and anxiety developed a sudden diplopia, unintentional weight loss, tremor, palpitation, and ptosis for approximately one week. She had an eye exam and was recommended to have an MRI/MRA of brain and new blood work including CBC, CMP, TSH, Free T4, T3, Acetylcholine receptor antibody, and ANA. TSH came back suppressed and undetectable, Free T4 6.4ug/dL and T3 40 ug/dL. ANA and Acetylcholine receptor antibody were both high. Later, Anti-TPO and TSI measured 235 IU/mL and 34.5 IU/L respectively. Also, due to high concern for stroke given her symptoms, patient had ED visit. While having stroke workup in ED, her CTA of the neck revealed incidental finding of mediastinal mass that was concerning for possible thymoma. Stroke was ruled out. Patient was referred to our endocrinology clinic for her thyrotoxicosis. She was started on Methimazole 30 mg daily and Propranolol 60 mg daily. In the meantime, patient started to see neurologist for her Myasthenia Gravis. The neurologist started her on Prednisone 5 mg daily and Pyridostigmine60 mg daily. She was also referred to thoracic surgery for mediastinal mass resection. She received lugol 7 days prior to surgery to prevent intraoperative thyroid storm. Patient successfully had the surgery, and the mass was removed. The result was thymic hyperplasia. She was clinically well after surgery, though her ocular symptoms worsened by tapering steroids. Patient also had trial of plasma exchange which helped with her ocular symptoms. Her hyperthyroidism symptoms and thyroid function improved. She gradually was able to take a lower dose of methimazole. Patient currently is on Methimazole 5 mg without any complications. Clinicians are advised to always rule out any possibility of thyroid disease in patients that are suspicious for Myasthenia Gravis especially if Myasthenia Gravis is secondary to thymoma. Neglecting thyroid diseases in this group can cause serious consequences including intraoperative thyroid storm. Also, by early diagnosis of both Myasthenia Gravis and hyperthyroidism, there will be a better and faster resolution in patients’ symptoms.

Presentation: Thursday, June 15, 2023
THU676 Real-time Assessment Of The Beneficial Role Of Computer-Aided Diagnosis In The Diagnosis Of Thyroid Nodules On Ultrasound
Authors: Kim Youngsook , Shin Sungjae , Lee Eunjung , Kim Daham , Young Kwak Jin
Published: October 2023

Disclosure: Y. Kim: None. S. Shin: None. E. Lee: None. D. Kim: None. J. Kwak: None.

Objective: Computer-aided Diagnosis (CAD) has been applied in various medical fields. SERA (SEveRance Artificial intelligence program) is a deep convolutional neural network algorithm. We conducted this study to evaluate whether CAD-SERA helps diagnose the malignancy when the ultrasound was used by physicians with low levels of experience and to compare with the experienced radiologist. Methods: In real-time, an inexperienced physician and a radiologist simultaneously assessed the same thyroid nodules to determine malignancy and performed CAD. The diagnosis was changed if it was necessary to correct it by referring to the CAD results, and this was compared with the surgical pathology or biopsy pathology. Results: We evaluated 191 thyroid nodules in 179 patients. Area Under the Receiver Operating Characteristics (AUROC) was analyzed with the diagnoses with/without CAD assistance and pathology results. The AUROC of the inexperienced physician was 0.716, and when assisted by CAD that increased to 0.740 (Accuracy 73.82 -> 76.44%). In the case of the radiologist, AUROC without CAD assist was 0.868 and 0.880 with the assist of CAD (Accuracy 84.29 -> 85.86%). Conclusion: CAD improves diagnostic performance in the diagnosis of thyroid nodules in various experienced physicians in ultrasound. In particular, the extent of this is greater in physicians with less experience in ultrasound.

Presentation: Thursday, June 15, 2023
THU681 Change In The Clinicopathological Characteristics And Outcomes Of Pediatric Thyroid Carcinoma In Korea: Focusing On Data From A Tertiary Hospital In Korea
Authors: Hyun Yoo Ji , Eun Leem Da , Jin Ryu Hyun , Park Hyunju , Han Kim Jung , Lyun Oh Young , Hyuk Kim Tae , Wook Kim Sun , Hoon Chung Jae
Published: October 2023

Disclosure: J. Yoo: None. D. Leem: None. H. Ryu: None. H. Park: None. J. Kim: None. Y. Oh: None. T. Kim: None. S. Kim: None. J.H. Chung: None.

Introduction: The incidence of thyroid carcinoma in adults in Korea increased until 2012, but has declined rapidly since then. However, the incidence of pediatric thyroid carcinoma increased until 2013, decreased slightly, and then increased again. Changes in the clinicopathological characteristics of pediatric thyroid carcinoma over time have not yet been elucidated. In this study, we aimed to evaluate the changes in the clinicopathological characteristics and outcomes of pediatric thyroid carcinoma from 1995 to 2022. Subjects and Methods: A total of 170 patients under the age of 19 years who were diagnosed with differentiated thyroid carcinoma at tertiary hospital in Seoul, Korea were enrolled. The patients were divided into four groups based on the year of initial surgery: 1995 – 2005 (n = 33), 2006 – 2010 (n = 46), 2011 – 2015 (n = 57), and 2016 – 2022 (n = 34). Results: The age at diagnosis, gender, primary tumor size, T stage, N stage, and M stage did not significantly differ among the four groups. Also, there was no significant difference over time in the route of detection (symptomatic vs. asymptomatic; P for trend = 0.519). The incidence of diffuse sclerosing variant of papillary thyroid carcinoma tended to increase over time (P=0.06). Surgical extent (P for trend = 0.001) and cumulative radioactive iodine (RAI) dose (P for trend < 0.001) significantly decreased over time. Nevertheless, the disease-free survival among the four groups did not change during the median follow-up 115.5 (62.3 – 155.3) months (log-rank P = 0.451). Conclusions: Although the overall incidence of pediatric thyroid carcinoma is gradually increasing in Korea, surgical extent and cumulative RAI dose significantly decreased and the clinicopathological characteristics and the disease-free survival did not change over time.

Presentation: Thursday, June 15, 2023
OR03-06 Transmembrane Water Channels Within The Tsh Receptor
Authors: Latif Rauf , Davies Terry F , Mezei Mihaly
Published: October 2023

Disclosure: R. Latif: None. T.F. Davies: Advisory Board Member; Self; Board of Kronus Inc (Starr, ID, USA);. M. Mezei: None.

Using our recently reported hydrated model of the TSH receptor transmembrane (TM) region (Endocrinology 2021,162:7;1-12), we have now identified a network of putative TM water channels within this structure. By analyzing the molecular simulation trajectory for water molecules crossing the plasma membrane embedded TSHR we found evidence of putative water channels suggestive of active transport. To ascertain the biological activity of such TSHR channels we examined the movement of water down osmotic gradients using calcein aceto-oxymethyl ester (Calcein-AM) fluorescence in rat thyrocyte cells (FRTL5). Calcein-AM is a membrane permeant fluorescent dye that is quenched in a concentration-dependent manner and is, therefore, an effective probe of cell volume changes that would result from water movement across the cell membrane. Since thyroid cells are known to contain aquaporin (AQP) channels, principally AQP4, we first blocked these channels (using 3μM of TGN020) prior to examining the effects of TSHR activation using TSH (10-103 µU/ml), stimulating TSHR monoclonal antibodies (mAbs MS1 and M22 at 10μg/ml and 1μg/ml respectively) and TSHR-specific small molecule allosteric agonists (MS437 and MS438 at 10µM) and measured the changes in fluorescence quenching. D-Mannitol at 400mM was used as the hypertonic medium to induce cell shrinkage measured by continuous fluorescence measurements with read intervals of 50msec. Analyzing the normalized fluorescence of cells treated with TSH in a dose-dependent manner we observed ∼25% quenching with 103 µU/ml of TSH. On blocking the binding of TSH using a TSHR blocking mAb K1-70 (1μg/ml), we found marked de-quenching. Furthermore, using equimolar concentrations of stimulating TSHR antibodies the quenching was even more significantly enhanced to 54-60%. These data suggested that ligands that activate the TSHR by binding to the TSHR ectodomain could influence the TM water transport. However, using the allosteric activators, which act at the TM, we also showed similar changes indicating this was not ectodomain dependent. These data confirm the presence of the modeled putative TSHR water channels indicating that TSH and TSHR autoantibodies have an important role in regulating TM water passage.

Presentation: Thursday, June 15, 2023
FRI483 Changes In Thyroid Function Test With Tirzepatide Use In Patients With Hypothyroidism
Authors: Kaylee Yu Gayoung , Nakhle Samer , John Vernetti Nicholas , Chao Alex
Published: October 2023

Disclosure: G.K. Yu: None. S. Nakhle, M.D.: None. N.J. Vernetti: None. A. Chao, DO: None.

Background: Incretin hormone Glucacon-like peptide-1 receptor agonist (GLP-1RA) has been established to treat type 2 diabetes or obesity. A novel dual-receptor agonist to GIPR/GLP-1R, tirzepatide has been approved for type 2 diabetes mellitus treatment and has shown greater weight loss compared to GLP1-RA. Also, since GLP-1 and GIP have effects on multiple organs/tissue including the gut, tirzepatide may have additional effects on levothyroxine absorption. Method: We retrospectively reviewed the charts of patients with hypothyroidism and newly given prescriptions of tirzepatide (Mounjaro) at our outpatient clinic from July 1, 2022, to Nov 30, 2022. Baseline thyroid function test results and follow-up test results were reviewed. Result: A total of seventy patients’ data were identified and reviewed. Patients with insufficient data, early termination of the therapy, and patients whose levothyroxine doses were adjusted at the same time of tirzepatide initiation were excluded. A total of 17 patients on stable dose of levothyroxine replacement who had lab prior to starting tirzepetide and repeated lab within 4 to 8 weeks after that were found and included in the study. TSH of 5/17 patients (29%) was suppressed below the normal range at 6 weeks. TSH of 11/17 patients (65%) decreased compared to baseline. The mean baseline TSH was 2.288. Repeat test was done in 4-8 weeks, (mean 53.28 days, median 47 days), and mean TSH was 1.569. Conclusion: We were able to review only seventeen patients’ thyroid function tests, but there was TSH reduction in 65 % of patients, and 5(29%) out of 17 patients had suppressed TSH in 6-8 weeks (mean 53.28 days, median 47 days). Our results suggest monitoring TSH early after starting tirzepatide might be necessary to avoid iatrogenic hyperthyroidism. We suspect factors other than weight loss play a role in the thyroid hormone level because of early changes in TSH prior to achieving significant weight loss.

Presentation: Friday, June 16, 2023
FRI485 High Interlaboratory Variability In Free Thyroxine Measurement Indicates Need For Method Standardization
Authors: Ribera Ashley , Danilenko Uliana , Sugahara Otoe , Collins Lynn , Buchannan Tatiana , Vazquez Norma , Pokuah Fidelia , Wirtz Douglas , Zhang Li , Lyle Alicia N , Vesper Hubert W
Published: October 2023

Disclosure: A. Ribera: None. U. Danilenko: None. O. Sugahara: None. L. Collins: None. T. Buchannan: None. N. Vazquez: None. F. Pokuah: None. D. Wirtz: None. L. Zhang: None. A.N. Lyle: None. H.W. Vesper: None.

Thyroid function tests are critical to diagnose diseases of the thyroid. Concerns about the accuracy and reliability of thyroid function tests, especially free thyroxine (FT4), have been stated by the clinical laboratory community for many years. In response to these concerns, the CDC Clinical Standardization Program (CSP) has created a standardization program for FT4 based on the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference system and is partnering with IFCC to standardize FT4 and harmonize TSH testing globally. As part of this program, CDC developed an accurate and sensitive reference measurement procedure (RMP) to assign reference values to individual donor sera. Assay manufacturers and research and clinical laboratories can use these sera to assess the analytical performance of their measurements, and monitor analytical performance over time. To obtain initial information about the analytical performance of FT4 and TSH measurements, an interlaboratory study among commercial assays and laboratory developed test was conducted. A panel of 40 blinded, fresh-frozen single donor patient serum samples with FT4 concentration ranging between 11-32 pmol/L concentrations was measured by participants and compared to the results obtained by CDC RMP for FT4. In addition, commercial assay manufacturers were asked to measure thyroid-stimulating hormone (TSH). Results from sixteen commercial assays and four laboratory developed test (LDT) participated. Preliminary results indicate a negative mean bias for all commercial FT4 assays ranging from -34.46% to -5.08%. Some of the assays agreed more closely to the RMP than others (four assays had mean bias over -25%). An equilibrium dialysis mass spectrometry-based assays had mean biases ranging from -8.86% to - 1.72% agreeing well with RMP. The data suggest that the observed bias can be effectively minimized through recalibration to the RMPs operated by the CDC CSP and the IFCC reference laboratory network. The mean TSH concentrations ranged from 0.34 to 21.56 uIU/mL with mean %CV of 11.42% (95%CI 8.07%-14.76%) suggesting good agreement between various platforms. Findings from this study will be used to customize CDC’s protocols and procedures for standardizing FT4 measurements.

Presentation: Friday, June 16, 2023
FRI519 Misleading Free T4 Due To Assay Interference
Authors: Man Pradhan Rubin , Kaur Rai Harpreet , Rai Barsa , Batra Manav
Published: October 2023

Disclosure: R.M. Pradhan: None. H.K. Rai: None. B. Rai: None. M. Batra: None.

Background: Despite Equilibrium Dialysis being the gold standard for measurement of Free t4 (FT4), competitive Immunoassays are the go-to test for clinicians due to its cost and fast turnover. Measuring FT4 which accounts for 0.02% of total T4 is a challenge, but several factors interfering with the assay, sometimes makes it even more difficult. Case Report: 55 years old Male with PMH of CKD III, HTN, HLD, RCC s/p left partial nephrectomy in 2015, and IgG kappa monoclonal gammopathy following with endocrinology for hypothyroidism secondary to Hashimoto’s disease. Patient was doing well on Levothyroxine 125 mcg po daily. He denied any hypothyroidism/ hyperthyroidism symptoms. Patient was not on any heparin and amiodarone. TFT was done for routine follow up. Initial TFT was done via one step automated immunoassay on the Siemens Centaur platform (Center 1): TSH was 1.34 mlU/L (N 0.4-4.5 mlU/L) and Free T4 was 4.9 ng/dL (N 0.8-1.8 ng/dL). As the free T4 was inconsistent to the clinical picture and both the TSH and free T4 were incongruent to each other, it was difficult to interpret. After discussing with the patient, the labs were repeated with total T3 and total T4 as well. Repeat labs in 10 days with same assay (Center 1) showed TSH: 2.34 mlU/L, Free T4: 5.3 ng/dL (elevated), Total T4: 6.3 mcg/ dl (N 4.9-10.5 mcg/ dL) and Total T3: 124 ng/dL (N 76-181 ng/dL). On chart review, patient had similar finding about 2 years ago when the test was done at Center 1 which showed raised free T4 with normal TSH and repeat labs in a different center (Center 2) were normal. Given the h/o monoclonal gammopathy and varied test results in different center, TFTs were repeated in a second diagnostic center. Center 2 used an Abbott’s two chemiluminescent immunoassay (CLIA) which showed that the free T4: 1.01ng/dL (N 0.8-1.8 ng/dL), TSH: 1.39 mcUnit/mL (N 0.4-5 mcUnit/mL), Total T4: 7mcg/dL (N 4.9-11.7 mcg/dL) and Total T3: 85 ng/dL (N 75-165 ng/dL). Patient was recommended to continue with the same dose of levothyroxine and follow up routinely. HAMA and other thyroid autoantibodies were not measured. Conclusion: Various medications and medical conditions that interfere with the binding proteins are sometimes easy to discern by history, but the difference is assays need clinical suspicion from the physicians to avoid further unnecessary labs and radiological investigations. Thyroid hormone autoantibodies/other interfering molecules are likely culprit for our patient’s abnormally high free T4 in the one-step automated immunoassay as the wash out in the two-step CLIA likely resulted in normal values on a clinically euthyroid patient.

Presentation: Friday, June 16, 2023
FRI522 Impact Of TIRADS Score On Thyroid Nodule Biopsy
Authors: Blessing Adeniran Uchechi , Olabumuyi Adeniyi , Adeniran Omolara , Bahtiyar Gul , Rodriguez Giovanna
Published: October 2023

Disclosure: U.B. Adeniran: None. A. Olabumuyi: None. O. Adeniran: None. G. Bahtiyar: None. G. Rodriguez: None.

Introduction: Thyroid nodules are prevalent, however many thyroid nodules biopsied are benign. In 2017, the Thyroid Imaging Reporting and Data systems Committee of the American college of Radiology (TI-RADS) presented the use of TI-RADS score to risk stratify nodules to TR1 to TR5 with recommendations on biopsy vs follow up. The aim of our study was to ascertain any changes in thyroid biopsy rate before and after the use of ACR TI-RADS in thyroid ultrasound scans in a community hospital in Brooklyn, NY. Methods: We conducted a retrospective single center observational cohort study on patients referred for thyroid nodule assessment between March 2019 - March 2020 & March 2021 - March 2022. Inclusion criteria- all patients with thyroid ultrasound scans without TI-RADS scoring from March 2019- March 2020, all patients with TI-RADS scoring from March 2021-March 2022. Duplicate referrals, patients lost to follow up, incomplete records were excluded. Primary endpoint was to ascertain any differences in thyroid biopsy recommendation rate before and after the use of TI-RADS score in ultrasounds. Chi square test was used to determine the association between TI-RADS use in ultrasound scans and thyroid biopsy recommendation rate. Thyroid nodules were categorized based on the Bethesda System for Reporting Thyroid Cytopathology (BSRTC). Results: A total of 91 patients met the inclusion/exclusion criteria, 13 men and 78 women (M:F- 1:6). Thyroid nodules of 53 patients on ultrasound were reported using TI-RADS score and 38 patients without using the TI-RADS score. TI-RADS group and non TI-RADS group were similar in age, gender, race, and ethnicity. The use of the TI-RADS reporting system was associated with a statistically significant reduction in recommendation for biopsy. Only 26.4% of the patients who had TI-RADS were recommended for biopsy compared to 47.4% of the patients who did not have TI-RADS (P-Value 0.039).A total of 32 patients were recommended for biopsy, however biopsy was done in 26 patients. Majority of the nodules biopsied were benign (BSRTC II), 10 of 14 patients (71.5%) were benign (BSRTC II) in Non TI-RADS group, and 8 of 12 (66.7%) were benign (BSRTC II) in TI-RADS group. Conclusion: TI-RADS score significantly reduced the biopsy recommendations. Its implementation thus results in saving the Healthcare commission a significant cost of unnecessary biopsy in the region of $1,999 per biopsy. With the implementation of TIRADS, the proportion of malignant biopsies was expected to rise. However, there was no significant difference in this group. This may be because the total number of biopsies analyzed was small. It could also be that some of the nodules the TIRADS score did not recommend for biopsy may have been malignant. Further studying of a larger cohort is thus warranted.

Presentation: Friday, June 16, 2023
FRI526 Geographic Trends In Thyroid Hormone Prescribing In The US: 2010 - 2020
Authors: Ettleson Matthew D , Laiteerapong Neda , Wan Wen , Bianco Antonio C
Published: October 2023

Disclosure: M.D. Ettleson: None. N. Laiteerapong: None. W. Wan: None. A.C. Bianco: Consulting Fee; Self; Abbvie, Acella, Synthonics, Thyron, Madrigal.

Introduction: Levothyroxine (LT4) is the first line treatment of hypothyroidism. However, some clinical guidelines suggest a trial of adding triiodothyronine (T3) therapy if LT4 monotherapy does not adequately resolve symptoms despite a normal thyrotropin (TSH) level. It is unknown how patterns of thyroid hormone (TH) prescribing (LT4 vs T3-containing therapy) differ across the US. Methods: We conducted a cross-sectional study of TH prescription data from a large, US-based claims database from January 1, 2010 to December 31, 2020. TH type (LT4, liothyronine [LT3], or desiccated thyroid extract [DTE]), geographic, and clinical data were collected. Only patients with a new TH prescription and a diagnosis of hypothyroidism were included. The study population was subdivided into 4 TH treatment classes: 1) LT4 monotherapy, 2) LT3 therapy with or without LT4, 3) DTE therapy with or without LT4, and 4) other. Statewide physician density and urban-rural classification were the primary geographic covariates analyzed. Other covariates included in the analytical models were age, sex, comorbidities, and co-prescribed medications. Results: A total of 524,818 adult patients accounted for 537,594 new TH prescriptions over the 11 year study period. Of the total population, 89.0% received LT4 monotherapy, 8.8% received DTE therapy, and 2.0% received LT3 therapy. The proportion of patients receiving DTE increased from 5.4% to 10.2% during the study period. DTE and LT3 prescriptions were not uniformly distributed throughout the US, with higher rates in the West and South regions. Residence in a state with higher endocrinologist density (3.0/100k population) was associated with a decreased likelihood of receiving LT3 or DTE therapy (adjusted OR 0.33, 95% CI [0.20 – 0.55], p <0.001; adjusted OR 0.18, 95% CI [0.08 – 0.41], p <0.001, respectively). Residence in large central metro zones was associated with an increased likelihood of receiving LT3 or DTE therapy (adjusted OR 1.32, 95% CI [1.22 – 1.42]; p <0.001; adjusted OR 1.05, 95% CI [1.01 – 1.10], p = 0.008, respectively). Conclusions: There do appear to be geographic disparities in the patterns of TH prescribing in the US. Differences in access to endocrine care may contribute to these disparities. Also, patients in more urban zones were more likely to receive LT3 or DTE therapies. Further investigation is necessary to understand the patient and physician-level factors underlying the geographic disparities identified.

Presentation: Friday, June 16, 2023
FRI527 Timing Of Thyroxine Dose During Ramadan: A Randomized Controlled Trial
Authors: Mohammad Alamoudi Reem , Majed Nawar Samah , Saleh Alharbi Hibah , Al Qarni Ali Ahmed , Alzahrani Abdullah , Khaled Almulla Abdulrhman , Tawfeeq Busaad Walaa , Alahmari Nasser F , Daghash Alshamrani Nouf , Alkhalifa Lujain , Mohd Saleh Yousef , Ramadan Majed , Borai Anwar
Published: October 2023

Disclosure: R.M. Alamoudi: None. S.M. Nawar: None. H.S. Alharbi: None. A.A. Al Qarni: None. A. Alzahrani: None. A.K. Almulla: None. W.T. Busaad: None. N.F. Alahmari: None. N.D. Alshamrani: None. L. Alkhalifa: None. Y.M. Saleh: None. M. Ramadan: None. A. Borai: None.

Background: The effect of Ramadan fasting on the thyroid profile, and the best time for L-thyroxine (LT4) intake in relation to fasting during Ramadan remains undetermined. Objectives: To compare two different time points of taking LT4 therapy during fasting the month of Ramadan in regards to thyroid profile and patient satisfaction. Methods: A multicenter open-label randomized controlled trial. Patients with primary hypothyroidism were recruited from three centers in three cities in Saudi Arabia (Jeddah, Riyadh, and Alhasa). Patients with thyroid cancer were excluded. TSH and FreeT4 (FT4) were measured two weeks before Ramadan, and four to six weeks after Ramadan. Results: 303 patients with primary hypothyroidism were randomized; 156 to take the LT4 dose at sunset with sips of water at the time of breaking fast and wait 30-60 minutes to eat the main Iftar meal (pre-Iftar), and 147 to take the LT4 dose just before the start of fasting (pre-dawn) regardless of their last meal intake. There were no significant differences between the two groups in demographics or comorbidities. The mean age was 49 ±12 years, 87% were female, and the average duration of hypothyroidism was 9.7 ±8.25 years. The mean weekly LT4 dose in the pre-Iftar vs. pre-dawn group was 753.3 ±349.4 vs. 733.2 ±265.6 mcg, p=0.001, and the Pre-Ramadan thyroid profile was: TSH 2.56 ±2.16 vs. 2.46 ±1.72 mIU/L, p=0.3, FT4 13.45 ±2.1 vs 13.08 ±2.4 pmol/L, p=0.16. Post-Ramadan thyroid profile values were: TSH 3.64 ± 4.1 vs. 4.07 ±4.17 mIU/L, p=0.78, FT4 12.96 ±0.1 vs. 12.64 ±0.22 pmol/L, p=0.003. The estimated difference within the group means post-Ramadan was - 0.41 ±0.51 mIU/L, p=0.43 for TSH, and 0.32 ±0.28 pmol/L, p=0.24 for FT4. Generalized linear model repeated measures analysis of variance showed no significant difference over time in TSH or FT4 within or between groups (p = 0.47 vs. 0.81). Patient compliance and satisfaction with the regimens were similar between groups. Conclusion: There is no significant change nor difference in thyroid profile between the two regimens related to the change in LT4 intake during the fasting months of Ramadan. Both regimens can be utilized depending on patient preferences. ClinicalTrials.gov: NCT05421468. Saudi FDA: SCTR # 22041002

Presentation: Friday, June 16, 2023
FRI542 Long-term Metabolic Outcomes In Graves’ Disease: Is There A Difference Between Oral Anti-thyroid Medications And Radioactive Iodine Treatment?
Authors: Shemesh Elad , Kolitz Tamara , Nathan Alexandra , Michele Tordjman Karen , Greenman Yona , Izkhakov Elena
Published: October 2023

Disclosure: E. Shemesh: None. T. Kolitz: None. A. Nathan: None. K.M. Tordjman: None. Y. Greenman: None. E. Izkhakov: None.

Introduction: The treatment of hyperthyroidism in patients with Graves’ disease (GD) is associated with various metabolic comorbidities, including weight gain and an increased risk of cardiovascular and cerebrovascular diseases. Few studies have assessed the potential differences in metabolic outcomes between radioactive iodine (RAI) and oral anti-thyroid drug (ATD) therapies. Aim: We sought to investigate the long-term (>10 years) metabolic effects of RAI versus ATD therapy in GD. We also compared the occurrence rates following long-term use to those with short-term (<5 years) use in order to explore a potential "legacy effect". Hypothesis: RAI and oral ATD treatment will differ in their associated risk of metabolic sequelae, including the occurrence of hypertension, dyslipidemia, obesity, and diabetes. Methods: Patients attending the Institute of Endocrinology at the Tel Aviv Sourasky Medical Center filled in a questionnaire on post-RAI or post-ATD treatment for GD. Results: In total, 143 participants had been followed-up for 5 years, and 87 of them (age range 31-88 years, 65 females [74.7%]) had completed >10 years of follow-up (mean follow-up period 14±1 years). During the initial 5-year follow-up period, RAI treatment was associated with a significantly increased rate of obesity and dyslipidemia in the short-term, but no comparable differences persisted into the >10-year follow-up period. However, mean fasting glucose concentrations were higher among RAI recipients compared to ATD recipients (106 and 91 mg/dL, respectively, p=0.037) even after 10 years, and the mean triglyceride concentration was also higher in the former (127 and 88 mg/dL, respectively, p=0.02). There were no significant group differences in the rates of diabetes mellitus or dyslipidemia in the >10-year follow-up period. Conclusions: RAI therapy is associated with long-term higher glucose and triglyceride levels compered to ATD therapy in patients with GD. Clinical metabolic diagnosis are comparable. The significant group differences in the occurrence of metabolic morbidities that had been observed after the first 5 years of follow-up persisted to a greater or lesser extent into the extended >10-year follow-up period, as evidenced by fasting glucose and triglycerides concentrations

Presentation: Friday, June 16, 2023
FRI194 Pheochromocytoma Presenting As Catecholamine-Induced Cardiomyopathy: A Case Report
Authors: Vafea Maria Tsikala , Lee Donna
Published: October 2023

Disclosure: M. Tsikala Vafea: None. D. Lee: None.

Introduction: Pheochromocytoma (PCC) is a rare catecholamine-secreting neuroendocrine tumor presenting with the classic triad of episodic headache, sweating and tachycardia. Catecholamine-induced cardiomyopathy (CICMP) can occur as a complication of PCC in 7-11% of patients. It presents more commonly as dilated cardiomyopathy and inverted Takotsubo cardiomyopathy but also as hypertrophic or unspecified cardiomyopathy. Following appropriate pharmacologic treatment and resection of PCC, these cardiac complications usually resolve. Case report: 36 year old man with history of hypertension presented to the hospital with worsening orthopnea and cough. Following antibiotic treatment failure for suspected pneumonia, he was re-admitted with hemoptysis, tachycardia, hypoxia, and hypertensive emergency. Troponin and brain natriuretic peptide were found to be elevated. CT chest and abdomen showed pulmonary nodules and a large left adrenal mass measuring 9.6x9.3x9.4 cm, concerning for metastatic PCC. He was subsequently started on doxazosin. Transthoracic echo showed bi-atrial enlargement, diffuse severe left ventricle hypokinesis, reduced ejection fraction 25% and diastolic dysfunction. Stress cardiac MRI showed non-ischemic cardiomyopathy, corroborating the diagnosis of CICMP. After achieving adequate alpha-adrenergic blockade, he was started on goal-direct medical therapy consisting of valsartan, metoprolol and empagliflozin. His pulmonary nodular opacities improved on repeat imaging, congruent with pulmonary edema rather than metastases. Plasma and 24-hour urine metanephrines (2,964 pg/mL and 23,310 mcg/24 hr, respectively) and normetanephrines (9,266 pg/mL and 33,927 mcg/24 hr, respectively), as well as dopamine (493 pg/mL), epinephrine (3,205 pg/mL) and norepinephrine (above reportable range of 4,800 pg/mL) eventually came back significantly elevated, confirming his diagnosis of PCC. A month after presentation, he underwent left adrenalectomy, which revealed an 11 cm composite PCC ganglioneuroma. One-month postoperatively, urine metanephrines and normetanephrines were normal but his ejection fraction remained unchanged. Discussion: CICMP should be considered in patients presenting with acute heart failure and an incidental adrenal mass to avoid delays in treatment. Acute pulmonary edema may resemble pulmonary nodules on CT, so interpretation of these findings should correlate with the clinical presentation. Timely initiation of alpha-adrenergic blockade upon suspicion of PCC is crucial as it can significantly improve hemodynamics, and biochemical markers take time to result. 96% of CICMP cases improve after resection of PCC within a variable time frame ranging from one week to several months. Our patient’s CICMP had not improved one month after his adrenalectomy, but it remains to be seen whether he eventually recovers his cardiac function.

Presentation: Friday, June 16, 2023
FRI552 Orbitopathy As The Sole Manifestation Of Hashimoto’s Thyroiditis In A Euthyroid Patient: A Case Report
Authors: Labib Christine , Saeed Zainab , Trabulsi Maja , Ramharrack Frank
Published: October 2023

Disclosure: C. Labib: None. Z. Saeed: None. M. Trabulsi: None. F. Ramharrack: None.

INTRODUCTION: Thyroid associated ophthalmopathy (TAO) is caused by an autoimmune process involving the orbital tissue, however, its etiopathogenesis is still largely unclear. It is common in hyperthyroid patients with Graves’ disease and has also been reported in euthyroid and hypothyroid Graves’ patients with positive thyroid receptor antibodies (TRAb). However, only 5% of patient with Hashimoto’s thyroiditis (HT) develop orbitopathy. Here we report an unusual case of a male patient, clinically and biochemically euthyroid, who had severe bilateral exophthalmos due to underlying Hashimoto’s thyroiditis. CASE PRESENTATION: A 68-year-old male patient was evaluated for worsening bilateral eye protrusion associated with redness and grittiness for many years. The patient was otherwise asymptomatic; denied fatigue, any change in weight, constipation, joint/muscle pain or any other symptoms. On physical examination he was noted to have bilateral moderate periorbital edema, conjunctival injection along with mildly enlarged thyroid. Initial labs showed normal TSH 4.10 mIU/L (0.4-5.0mIU/L) and free T4 0.8 ng/dL (0.8-1.8 ng/dL). Further labs were notable for normal antithyrotropin antibody (TRAb) 1.09 IU/l and normal TSI less than 89%. Anti-thyroid peroxidase antibody (anti-TPO) level was as high as 12 IU/mL (less than 9 IU/mL). Thyroid US showed multinodular goiter with bilateral nodules. A Subsequent FNA was benign. The degree of exophthalmos on the Hertel ophthalmometer was 30 mm bilaterally. Orbital magnetic resonance imaging (MRI) showed proptosis of the left and right globes as well as prominence of intraorbital fat. Extraocular musculature was symmetric bilaterally and only minimally prominent but diffuse. Treatment with teprotumumab infusion was started with improvement in the patient’s symptoms. CASE DISCUSSION: Usually mild eye symptoms are seen in Hashimoto’s thyroiditis such as dryness, blurred vision, upper eyelid retraction and loss of lateral third of eyebrows. In rare cases it can cause orbitopathy similar to that seen in Graves’ disease. Like Graves’ orbitopathy, in addition to reversing the underlying thyroid abnormalities, moderate-to-severe orbitopathy is treated with corticosteroids or teprotumumab. This case sheds the light on exophthalmos being an atypical presentation of Hashimoto’s thyroiditis in a clinically and biochemically euthyroid patient. Physicians should be cognizant of this rare manifestation for prompt recognition and early treatment which can prevent corneal involvement and blindness due to optic nerve compression.

Presentation: Friday, June 16, 2023
FRI198 Acute Pancreatitis And Diabetic Ketoacidosis As A Presentation Of Subclinical Cushing Syndrome
Authors: Alkhidady Wijdan Hasan , Almefgaie Noura B , Ekhzaimy Aysha
Published: October 2023

Disclosure: W.H. Alkhidady: None. N. Almefgaie: None. A. Ekhzaimy: None.

Case Report: A 43-year-old Saudi woman, presented to the emergency department with two days history of right upper quadrant pain, radiating to the back. Associated with nausea and vomiting with no history of diarrhea, constipation, or constitutional symptoms. She has a 4-year history of hypertension on 5 mg amlodipine with no history of endocrine or malignant tumors. On Examination she was alert, severely dehydrated with temperature of 37 °C, pulse of 124 per minute, blood pressure of 147/61 mmHg. The abdomen was tender in the right upper quadrant area. A laboratory examination showed lipemic sample with high triglycerides level 11mmol/L (0.4-1.48), high amylase 763nu/l (25-115), lipase 5773 u/l (73-393), low potassium level 2.6 mmol/l (3.50-5.10) and low calcium level 1.25 mmol/l (2.10-2.55). The urine analysis showed 4+ glucosuria and ketonuria. Her venous blood gas showed pH of 7.18 and bicarbonate of 10 mmol/L, random blood glucose was 16 mmol/L and anion gap could not be calculated at that time. A diagnosis of DKA secondary to acute pancreatitis secondary to high triglycerides level was made and management was started along with plasmapheresis. A CT pancreatitis protocol was done which showing a 4.2 x 3.5 cm well-circumscribed left adrenal lesion. An MRCP showed 4.3 cm well defined collision tumor in left adrenal gland, its peripheral part is suggestive of adenoma. further work up showed negative 24-hours urine metanephrins, normal Aldosterone Renin ratio, High 24-hour urine cortisol level 644 nmol/l, low ACTH 0.6 pmol/l and morning cortisol level post 1 mg DST was not suppressed on two different occasions. Since the patient had no phenotypical presentation of Cushing’s a diagnosis of SCS was made. She underwent left robotic assisted adrenalectomy, with pathological diagnosis of adrenocortical adenoma. 2 days later, AM cortisol level reduced to 230 nmol/L. while blood pressure and serum potassium remained normal with no signs of adrenal insufficiency. Her Diabetes mellitus and Hypertriglyceridemia resolved after left adrenalectomy. Conclusion: This case report demonstrates the uncommon association of subclinical Cushing syndrome and acute pancreatitis as a first presentation therefore it highlights the significant role of endocrine evaluation of any young patient with unexplained acute metabolic presentations.

Presentation: Friday, June 16, 2023
SAT476 A Case of Thyroid Hemiagenesis
Authors: Kachhadia Palak , Khan Shaza , Ukponmwan Esosa U , Aldasouqi Saleh , Limon Ahmad Abu
Published: October 2023

Disclosure: P. Kachhadia: None. S. Khan: None. S. Aldasouqi: None. A. Abu Limon: None.

Introduction: Thyroid hemiagenesis is congenitally rare, in which one side of the thyroid does not develop. Hemiagenesis is more common with an absent left thyroid lobe, at a 4:1 ratio. Though prevalence is sited at 0.05%, actual incidence of hemiagenesis amongst the population is unknown as most patients are euthyroid and asymptomatic. We present a case of a patient who was referred to our clinic for unilateral thyroid enlargement on physical exam. Thyroid Ultrasound (US) was done which showed an absent left thyroid lobe along with enlarged right thyroid lobe and hypervascularity. There was also an incidental thyroid nodule noted on US. Case Presentation: Patient is a 38 year old female who presented to the clinic 4 years prior for enlarged thyroid nodule noted on ultrasound. With symptoms of dysphagia and a visibly enlarged gland, an US with labs was prompted by her primary physician. US showed absent left thyroid lobe and right lobe enlargement with hypervascularity and incidental subcentimeter nodule. Clinically and biochemically, the patient was euthyroid. Singular right lobe was verified on clinic real time ultrasound and on NM uptake scan. The 24 hour uptake was at 30.5%, with the upper limit of normal being 30%. With increased uptake and hypervascularity, thyroid stimulating immunoglobulin and thyrotropin receptor antibodies were checked and were not detected. It was thought that the right thyroid gland enlargement and hypervascularity were compensatory due to the left hemiagenesis. The thyroid nodule was monitored, and within 3 years of original imaging, it enlarged to 0.98 x 0.59 x 0.39 cm, with TI-RADS 5 assessment per ACR criteria. Patient chose to undergo thyroid biopsy which showed Bethesda III, Follicular Lesion of Undetermined Significance (FLUS). Microscopy showed follicular cells arranged in microfollicles and crowded groups with round, enlarged, irregular nuclei and overlapping nucleoli. Intranuclear chromatin clearing and intranuclear grooves are present. Background is hemorrhagic with minimal colloid. Molecular Thyroseq testing was at 5-10% chance of malignancy or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Genetic markers were only positive for copy number alterations. Discussion: Thyroid Hemiagenesis, though rare, has been associated with other thyroid pathologies such as hypothyroidism, hyperthyroidism and thyroid malignancies. Genetic studies have not found a common background within cases reported. As these patients are more likely to incur additional thyroid pathologies, questions still remain as to the clinical management and outcome of such patients. Due to concerning cytological features for PTC, the patient was offered right thyroidectomy and will be looking to make a decision in the near future.

Presentation Date: Saturday, June 17, 2023