INTRODUCTION:Stress fractures affect military personnel at higher rates than the general population. They can lead to serious injury and negatively impact military force readiness. Most prior studies have focused on recruits undergoing basic training. Our goal was to characterize stress fractures over the full spectrum of military career stages to identify whether fracture locations varied by career length. MATERIALS AND METHODS:A retrospective chart review was conducted of a 3-year period (January 1, 2017-December 31, 2019) to identify active duty military patients in the National Capital Region diagnosed with a new stress fracture. Patients were stratified by career length: New Recruit (<12 months of service), Early-Career (1-5 years of service), Mid-Career (5-14 years of service), and Late-Career (>14 years of service). The percentage of fractures at each anatomic location was reported and compared by binary career length (New Recruit vs. others) with Chi-square or Fisher's exact tests performed among the full cohort. The total cohort was stratified by sex, and the analysis was repeated separately in males and females. The percentage of patients who presented with multiple fractures was similarly reported and compared by career length, among the full cohort and by sex strata. The study was approved by the Walter Reed National Military Medical Center Institutional Review Board, protocol # WRNMMC-2018-0162. RESULTS:The study population included 446 military members with 537 total fractures. Percentages of femoral neck (11.1% vs. 3.6%, P = .001), femoral shaft (8.1% vs. 1.8%, P = .001) and pelvis fractures (3.8% vs. 0.7%, P = .031) were greater in the New Recruit group compared to the other career-length groups. Percentage of foot fractures was lower (19.2% vs. 34.3%, P < .001) in the New Recruit group vs. the other career-length groups. Percentage of patients presenting with multiple stress fractures (23.7% vs. 10.1%, P < .001) was greater in the New Recruit group vs. the other career-length groups. The significant differences in femoral shaft and foot fractures persisted when males and females were analyzed separately. CONCLUSIONS:Our findings support that the distribution of the anatomic locations of stress fractures differs between military members in the New Recruit period versus later in their careers. Specifically, New Recruits had a higher percentage of femoral neck, femoral shaft, and pelvic fractures. Providers may consider having a lower threshold for imaging new recruits with hip pain as this could identify a stress reaction before it becomes a stress fracture. Potential explanations for the findings include sex, training intensity, and force attrition. Some of the significant findings persisted when males and females were analyzed separately, which supports that there are contributions from other factors than patient's sex. Additional studies are needed to build upon these findings. Limitations included the use of ICD-10 codes and physician reporting to identify stress fractures, the lower numbers of patients once the total study population was stratified by sex, unavailability of bone density data, and unclear generalizability of the findings.

Background In patients with Thyroid Eye Disease (TED), intravenous glucocorticoids, or an 8-infusion protocol of Teprotumumab are viable treatments; however, when first-line therapy is inadequate, a second course beyond the standard 8 infusions of Teprotumumab can be utilized. CASE REPORT A 72-year-old woman with a history of Graves’ disease and TED status post total thyroidectomy in 2021, a short course of oral steroids followed by 8 infusions of Teprotumumab every 3 weeks over 6 months in 2022 had no improvement in her TED symptoms. She returned to medical care 3 years later with symptoms that had been stable since her initial infusion protocol that included ocular itching and burning sensation bilaterally, spontaneous left retrobulbar pain, diplopia with extreme ocular movement, chemosis, proptosis, and conjunctivitis with a clinical activity score (CAS) of 5/10. Given her refractory TED, a 2nd 8-infusion course of Teprotumumab was started leading to a sustained improvement of her symptoms and a reduced CAS of 1/10 and 5mm proptosis reduction in OS, and 2mm proptosis reduction in OD. She also had no severe adverse effects; however, some nail changes, brief muscle cramps, and mild fatigue occurred after being followed up for 13 months after treatment ended. Discussion/Conclusion Our case highlights an alternative therapy for TED refractory to the 8-infusion Teprotumumab protocol which includes a 2nd 8-infusion Teprotumumab course when the standard treatment did not adequately alleviate TED symptoms initially. This case report adds to the growing literature on treatment of refractory TED. Further studies are needed.

Disclosure: H. Diep: None. M.K. Shakir: None. G.A. Cook: None. T.D. Hoang: None. Introduction: Myopathy occurs in 30-80% patients with hypothyroidism and there have been several case studies of myopathy due to rapid correction of hyperthyroidism or Graves’ disease. We present a rare case of persistent, exercise induced myopathy after radioactive iodine therapy (RAI) in a patient with Graves’ disease. Case Report: A 25-year-old man with no family history of autoimmune thyroid disease presented with new-onset Graves’ disease treated with RAI resulting in hypothyroidism. Five months after the RAI therapy and levothyroxine replacement the patient noticed muscle spasms and cramping in his biceps, triceps, and pectoral muscles after upper body exercises that lasted for 60 seconds and were accompanied by pain and fatigue that lasted for 15-30 minutes. The patient reported his symptoms improved after stopping levothyroxine. Patient later started desiccated thyroid extract with initial improvement followed by a recurrence of myopathy symptoms. An EMG initially showed irritable myopathy, which improved on a repeat EMG a year later. Further work up with a myomarker antibody panel, muscle biopsy, and muscular dystrophy panel were unrevealing. He began taking magnesium, calcium, vitamin D, and B12 daily and prioritizing improved hydration, with no noticeable improvement. Patient was prescribed dantrolene 25mg one hour prior to exercise with mild improvement. Discussion: Thyroid hormone deficiency can result in impaired mitochondrial oxidative capacity, resulting in a selective atrophy of type II muscle fibers as they become dependent on glycolysis for energy. Oxidative damage can cause muscle cell injury and potentially rhabdomyolysis. The degree of muscle weakness does not always correlate with the severity of hormone deficiency and myopathy is also observed in hyperthyroid patients, indicating that muscle injury is likely a contributing factor to the myopathy symptoms. The cause of the patient's myopathy, whether due to Graves' disease or RAI-induced remission, is unclear. Dantrolene mildly improved the patient’s symptoms suggesting an underlying pathology with the muscle excitation-contraction coupling interaction and muscle contractility. This case outlines the variable presentation of myopathy in a patient with rapid correction of hyperthyroidism in Graves’ disease and limited treatment options. Presentation: Saturday, July 12, 2025

Background/Objective Atypical presentations of acromegaly are rare. We present long-term follow-up of 2 patients with acromegaly who had nonspecific symptoms with elevated growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels but lacked classical clinical features. Case Report The first case was a 34-year-old woman who presented with arthralgias, cognitive slowing, and headaches. An incidental brain magnetic resonance imaging scan showed a cystic pituitary lesion. Laboratory tests performed 2 years after initial presentation showed elevated IGF-1 and GH levels, after which she underwent transsphenoidal surgery and lanreotide treatment for symptom control. The second case was a 78-year-old woman with a history of bipolar disorder in whom brain magnetic resonance imaging revealed a 1.5-cm incidental pituitary macroadenoma. Subsequent screening showed elevated GH and IGF-1 levels. She also had laboratory values consistent with primary hyperparathyroidism. Multiple endocrine neoplasia type-1 was ruled out by history. Following parathyroid surgery, the patient remained eucalcemic. She was started on long-acting octreotide due to reluctance for transsphenoidal surgery. Long-term follow-up of both patients was uneventful. Discussion We recommend the term subclinical acromegaly to refer to such patients. These cases highlight the importance of screening all patients with pituitary lesions using an IGF-1 level regardless of presence of classical symptoms of acromegaly. Conclusion On long-term follow-up, subclinical acromegaly after treatment has a relatively benign course without development of associated comorbidities, although additional studies involving large number of patients are needed.

Background/Objective: Gallium-68 DOTATATE (68Ga-DOTATATE) positron emission tomography/computed tomography (CT) is a somatostatin receptor (SSTR)-based imaging with high sensitivity that can be used for detection of pheochromocytomas and paragangliomas. We report a pheochromocytoma with negative SSTR2 expression and low uptake on 68Ga-DOTATATE, whose detection was masked by the uptake of normal adrenal tissue. Case Report: A 50-year-old man presented with a right adrenal incidentaloma. He had mildly elevated plasma normetanephrine levels of 194 pg/mL (ref. 0-145 pg/mL). Adrenal CT scan showed a right 1.9-cm lesion with unenhanced attenuation of 38 Hounsfield units. 68Ga-DOTATATE showed a 1.9-cm right adrenal lesion and reported diffuse uptake in the adrenal glands, with maximum standardized uptake value (SUVmax) of 17.23 on the right and SUVmax of 22.78 on the left. After a 2-year interval, plasma normetanephrine level increased to 420 pg/mL (ref. 0-136.8 pg/mL). Adrenal CT scan showed the right adrenal lesion increased in size to 2.6 cm. He underwent right adrenalectomy, and pathology reported a 2.3-cm pheochromocytoma. Subsequent review of the initial 68Ga-DOTATATE identified the pheochromocytoma as a photopenic area in the right adrenal gland with 7.73 SUVmax. Tissue staining was negative for SSTR2 expression. Genetic testing was negative for pheochromocytoma syndromes. Discussion: Although 68Ga-DOTATATE has strong affinity for SSTR2, some pheochromocytomas have low expression of SSTR2. The negative SSTR2 expression, small lesion size, and background uptake of the adrenal gland can affect the detection of pheochromocytoma. Conclusion: 68Ga-DOTATATE may have limitations when evaluating small pheochromocytomas or other neuroendocrine tumors with low SSTR2 expression.

Disclosure: I. Ebrahim: None. D.B. Maxwell: None. N.O. Vietor: None. T.D. Hoang: None. M.K. Shakir: None. In high-risk patients with osteoporosis, anabolic agent such as teriparatide, is generally recommended as a first-line therapy. The most frequent adverse events reported with teriparatide are hypercalcemia, often transient, and other nonspefic symptoms. Hypomagnesemia has been observed as an adverse event during the use of teriparatide although the exact pathogenesis is not known. We are reporting 2 patients, treated with teriparatide-induced hypomagnesemia due to increased renal loss of magnesium (Mg). Case 1: A 68-year-old woman was evaluated for management of severe osteoporosis (T-scores: L- Spine -3.2, Total Hip -3.8, Femoral Neck -3.1). Patient had no other risk factors other than early menopause. Lab values: serum calcium 9.8 mg/dL, phosphorus 3.6 mg/dL, Mg 1.8 mg/dL (ref 1.7 to 2.2 mg/dL), creatinine 0.91 mg/dL, PTH 45 pg/mL. LitholinkTM (Lab Corp) performed as part of screening for an increased risk of nephrolithiasis 24-hrs urine: calcium 178 mg, Mg 118 mg (ref 30 - 120). Patient was treated with teriparatide 20 mcg s.c daily. Six months later, lab values: serum calcium 10.1 mg/dL, Mg 0.98 mg/dL, 24-hrs urine Mg 368 mg/24 hrs, fractional excretion of Mg (FeMg) 3.4% (ref 0.5-3%). The patient was treated with magnesium oxide and Teriparatide was continued. Case 2: A 63-year-old man presented for management of osteoporosis (T-scores: L- Spine -3.1, Total Hip -2.9, Femoral Neck -3.2). He also had a history of lumbar vertebral fracture. Lab values: serum calcium 9.1 mg/dL, Mg 1.8 mg/dL, 25-Vitamin D 32 ng/mL, PTH 39 pg/mL, 24-hour urine calcium 210 mg. Patient was treated with teriparatide 20 mcg s.c daily, and 5 months later, laboratory values showed: serum calcium 10.1 mg/dL, Mg 1.0 mg/dL, 24-hour urine Mg 311 mg, FeMg 3.1%. Patient was treated with magnesium oxide and was continued on calcium citrate and Vit D. Two years later, after discontinuing teriparatide, the 24-hour urine Mg normalized (112 mg) . Serum calcium, creatinine, and PTH remained normal throughout the treatment period in both patients. Previous studies have shown that old age and lower baseline serum Mg were associated with teriparatide-induced hypomagnesemia. Although the underlying mechanisms are not known, deposition of Mg into bones due to increased bone metabolism and renal Mg losses due to transient hypercalcemia and its activation of calcium-sensing receptor (CaSR) on the Henle's loop inhibiting paracellular reabsorption of Mg may play a role. Additionally, teriparatide administration may affect the recently reported transient receptor potential channels in the renal tubules. In our 2 patients renal Mg losses could have played a role although, deposition of Mg into bones due to increased teriparatide induced-bone metabolism may also be involved. Monitoring of serum Mg along with other labs should be considered in these patients treated with teriparatide. Presentation: Saturday, July 12, 2025

Disclosure: P.N. Truong: None. M.K. Shakir: None. T.D. Hoang: None. Background: Graves’ orbitopathy, also known as thyroid eye disease (TED), is an autoimmune inflammatory disorder related to the overexpression of insulin-like growth factor 1 receptor (IGF-1R). Teprotumumab, a human monoclonal antibody targets and inhibits the IGF-1R and has been first-line therapy for patients with moderate to severe TED. We present a descriptive study of IGF-1 and growth hormone (GH) levels during Teprotumumab treatment in patients with TED. Methods: A retrospective review was carried out on 19 patients (>18 years old) with a diagnosis of TED who underwent a total of 8 intravenous infusions over a 24-week period. Our goal was to assess IGF-1 and GH levels before, during, and after Teprotumumab treatment and observe for any trends. Adverse events were also assessed. Not all patients had laboratory studies consistently obtained during all phases of treatment. Results: Prior to Teprotumumab initiation, all 19 patients had normal IGF-1 levels with a range from 75 ng/mL to 242 ng/mL (age and gender matched). All 19 patients had elevated in IGF-1 levels during treatment with a range from 343 ng/mL to 1684 ng/mL. A 53-year-old male’s baseline IGF-1 level of 152 ng/mL increased to a peak of 738 ng/mL and decreased to an IGF-1 level of 137 ng/mL after 7 months of discontinuing Teprotumumab treatment . An 18-year-old female’s baseline IGF-1 level was 242 ng/mL and increased to a peak of 757 ng/mL and trended toward 345 ng/mL after 8 months. A 49-year-old male’s IGF-1 level starting treatment was 646 ng/mL and increased to 885 ng/mL, but his IGF-1 level was 168 ng/mL 3 months after the last infusion. In 2 out of 19 patients with GH levels obtained, a 30-year-old female and a 45-year-old female showed elevated GH levels with peaks of 13.7 ng/mL and 26.7 ng/mL, respectively, and had elevated IGF-1 levels of 682 ng/mL and 568 ng/mL, respectively. Significant drug related adverse events include hyperglycemia and increase in hemoglobin A1c level. Discussion: In our study, serum IGF-1 levels increased in all patients, and IGF-1 levels were normalized only after 7-8 months approximately after the last infusion of Teprotumumab. In the two patients that had elevated GH levels, it was observed that IGF-1 levels also rose in relation toward peak level. Future studies may be able to investigate this feedback regulation pathway between IGF-1 and GH. In conclusion, Teprotumumab administration can cause elevated IGF-1 and GH levels and this may persist for several months. Presentation: Saturday, July 12, 2025

Background/Objective: Thiamine deficiency, which may occur following bariatric surgery, can lead to the development of Wernicke's encephalopathy (WE). This case report describes a patient developing WE postbariatric surgery, due to the use of over-the-counter transcutaneous multivitamin patch rather than recommended vitamin tablets. Case Report: A 61-year-old female presented with 45 pounds of weight gain over the past year with a body mass index of 39.58 kg/m2. She underwent lifestyle modification and treatment with dulaglutide with limited success. After evaluation and counseling, the patient underwent Roux-en-Y gastric bypass surgery and was prescribed thiamine, cholecalciferol, vitamin B12, and multivitamin tablets postoperatively. Eight months later, she presented to the emergency room with confusion, bilateral lower extremity weakness, paresthesia, and ataxia. Neurological examination revealed disorientation, nystagmus, and bilateral lateral rectus palsies. She reported using transcutaneous multivitamin patches instead of the recommended oral supplementation. The clinical features, low serum thiamine level of 1.28 mg/dL (reference 2.5-7.5 mg/dL), and resolution of symptoms following supplementation confirmed the diagnosis of WE. Discussion: Obesity often predisposes individuals to multiple nutritional deficiencies. It is critical that these patients take adequate vitamin supplementation before and after bariatric surgery. Thiamine deficiency can present as WE due to inappropriate supplementation such as use of a transcutaneous patch as seen in our patient. Conclusion: Adequate nutritional counseling and supplementation before and after bariatric surgery is required to prevent complications. Transcutaneous patch as a mode of multivitamin supplementation is questionable in its current state and should be avoided. Published by Elsevier Inc. on behalf of the AACE. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

OBJECTIVE:To determine the association between a transition from levothyroxine (LT4) to combination therapy and change in the Thyroid Symptom Questionnaire (TSQ-36). METHODS:We performed a post hoc subgroup analysis of 2 previous randomized, double-blind, crossover studies (total n = 143) to evaluate patient symptoms on treatment with LT4, desiccated thyroid extract (DTE), and levothyroxine + liothyronine (LT4+LT3). The TSQ-36 was completed at the end of each treatment period in the context of normal thyroid stimulating hormone levels. Patients were stratified based on their TSQ-36 score on LT4: Low Symptoms (TSQ-36: 0-12), Moderate Symptoms (TSQ-36: 13-24), and High Symptoms (TSQ-36: 25-36). Mean TSQ-36 scores were compared on LT4, LT4+LT3, and DTE. Treatment-blinded preference of therapy was also stratified by TSQ-36 score on LT4. RESULTS:In cohort 1, the Moderate-High Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (P = .01). In cohort 2, the High Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (P < .01) and on LT4+LT3 vs LT4 (P < .001). The Moderate Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (P = .02). The Low Symptoms group had significantly lower TSQ-36 scores on LT4 vs DTE (P = .03) and LT4+LT3 (P = .02). Patients who preferred combination therapy had significantly higher TSQ-36 scores than patients who preferred LT4. Persistent symptoms may be due to a relative deficiency in triiodothyronine, which could be remedied by combination therapy. CONCLUSION:The TSQ-36 can potentially be used to quantify patient symptoms and guide thyroid hormone therapy. Patients on LT4, with moderate-to-severe symptoms despite normalization of thyroid stimulating hormone, could consider a trial of combination therapy. Patients with low symptoms on LT4 should generally avoid combination therapy.

It is important to recognize artifacts of dual-energy X-ray absorptiometry because they may alter bone mineral density measurements. To prevent erroneous decisions and misdiagnosis regarding treatment and follow-up, bone mineral density measurement adjustments are needed. We present three cases in which artifacts altered the measurements of bone mineral density in the lumbar field of a dual-energy X-ray absorptiometry scan. The first case was oral contrast in the transverse colon in a 55-year-old white Hispanic American woman; the second case was kyphoplasty in lumbar spine in a 73-year-old white Hispanic American woman; and the third case was spinal fusion with vertebroplasty in a 70-year-old white European American man. Clinicians who interpret dual-energy X-ray absorptiometry imaging should routinely reexamine the scans and be attentive toward potential artifact involvement and other alternative origins of unreliable data.

Disclosure: M.K. Shakir: None. H. Babu: None. N.O. Vietor: None. A.J. Spiro: None. T.D. Hoang: None. Background: Clomiphene Citrate (CC), a selective estrogen receptor modulator, is widely used for treating male hypogonadism. Although serum testosterone (T) levels show a diurnal variation, it is not clear whether patients receiving CC demonstrate such diurnal variation. The diurnal variation of serum T was analyzed in 3 CC-treated patients with secondary hypogonadism. Methods: The serum T was drawn at 7AM while fasting, 11AM before lunch, and 4PM before dinner. T levels were assayed by LC/MS LabCorp TM. Case 1. A 48-year-old man presented with symptoms of hypogonadism. Lab Results: Serum T 148 ng/dL, FSH 4.8 mlU/mL, LH 9.2 mIUL, prolactin 9.6 ng/mL and IGF-1 168 ng/mL. Pituitary MRI revealed a 4 mm pituitary tumor (non-functioning). After counseling, patient was placed on CC 25 mg every other day. Patient noted improvement in hypogonadism symptoms and pituitary MRI remained stable. T levels performed 12 months later showed the following values: T: 7 AM 438 ng/dL; 11AM 399 ng/dL; and 4 PM 378 ng/dL. Case 2. A 38-year-old man presented with symptoms of hypogonadism. Laboratory values: Serum T 154 ng/dL, FSH 4.9 mIU/mL. LH 5.8 mIU/mL, prolactin 9.8 ng/mL, IGF-1 198 ng/mL. Pituitary MRI was normal. He was treated with CC 25 mg every other day. Six months later, T level showed the following values: T 7 AM 326 ng/dL; 11 AM 411 ng/dL; and 4 PM 458 ng/dL. He also had significant improvement in symptoms. Case 3. A 52-year-old man was seen for evaluation of erectile dysfunction and secondary hypogonadism. Laboratory values: Serum T 138 ng/dL, FSH 3.0 mIU/mL, LH 7.1 mIU/mL, prolactin 11.8 ng/mL, IGF-1 138 ng/mL. Pituitary MRI was normal. Patient was treated with CC 50 mg every other day and 9 months later T values were: T 7 AM 478 ng/dL; 11AM 412 ng/dL and 4 pm 398 ng/dL. He noted significant improvement in hypogonadal symptoms. Conclusion: In this case series the serum T levels did not show any diurnal variation. The exact significance of a steady state serum T levels during daytime is not clear. Further studies involving a large number of patients are needed. Presentation: Saturday, July 12, 2025

Disclosure: T.D. Hoang: None. A.A. Patel: None. A.J. Spiro: None. N.L. Watson: None. M.K. Shakir: None. Levothyroxine monotherapy (LT4) is the standard of care for treating patients with hypothyroidism; however, a subset of patients have bothersome symptoms despite normal thyroid stimulating hormone (TSH) values. Some patients may benefit from combination thyroid hormone replacement therapy, like desiccated thyroid extract (DTE) or levothyroxine with liothyronine (LT4+LT3). Objective: To determine whether the 36-Point Thyroid Symptom Questionnaire (TSQ-36) can guide which patients should trial combination replacement therapy. Methods: We performed a post-hoc subgroup analysis of two previous randomized, double-blind, cross-over studies (total n=143) to evaluate patient symptoms on treatment with LT4, DTE, and LT4+LT3. The TSQ-36 was completed at the end of each treatment period. Patients were stratified based on their TSQ-36 score on LT4: Low Symptoms (TSQ-36: 0-12), Moderate Symptoms (TSQ-36: 13-24), High Symptoms (TSQ-36: 25-36). Mean TSQ-36 scores were compared on LT4, LT4+LT3, and DTE. Treatment-blinded preference of therapy was also stratified by TSQ-36 score on LT4.Results:In Cohort 1, the Moderate-High Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (p=0.01).In Cohort 2, the High Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (p<0.01) and on LT4+LT3 vs LT4 (p<0.001). The Moderate Symptoms group had significantly lower TSQ-36 scores on DTE vs LT4 (p=0.02). The Low Symptoms group had significantly lower TSQ-36 scores on LT4 vs DTE (p=0.03) and LT4+LT3 (p=0.02).Patients who preferred combination therapy had significantly higher TSQ-36 scores than patients who preferred LT4. Conclusion: The TSQ-36 can be used to quantify patient symptoms and guide thyroid hormone replacement therapy. Patients on LT4, with moderate-to-severe symptoms despite normalization of TSH, should consider a trial of combination therapy. Patients with low symptoms on LT4 should generally avoid combination therapy. Presentation: Sunday, July 13, 2025

Disclosure: G.S. Schmidt: None. S.C. De La Torre: None. T.S. Knee: None. M.K. Shakir: None. T.D. Hoang: None. Background: Insulin-like growth factor-1 receptor (IGF-1R) signaling plays a role in thyroid eye disease (TED) pathogenesis. Teprotumumab is a monoclonal antibody against IGF-1R approved for treatment of TED. Elevated serum IGF-1 levels are noted in patients treated with teprotumumab but the degree and duration of this elevation is not well characterized. We report the case of a 50-year-old man with Graves’ disease complicated by moderate TED who received treatment with teprotumumab and demonstrated elevated serum IGF-1 levels more than 6 months after the completion of therapy. Clinical Case: A 50-year-old man with no significant past medical history presented to the emergency department with heat intolerance, exertional dyspnea, tachycardia, hyperhidrosis, brain fog, and difficulty in concentrating. Laboratory evaluation demonstrated a suppressed TSH, elevated free T4, and positive thyrotropin receptor antibodies consistent with Graves’ disease. At the time of diagnosis patient had proptosis with a clinical activity score (CAS) of 3. CT scan of the orbits noted moderate bilateral proptosis with mild bilateral enlargement of the extraocular muscles consistent with TED. Patient started treatment with methimazole but one year after initial diagnosis he reported subjective worsening in eye symptoms including worsening lid retraction, exposure keratopathy, and lid edema with CAS increased to 4. Patient elected for therapy with teprotumumab. During treatment, routine labs showed elevated serum IGF-1 levels that remained elevated throughout treatment. Three months after treatment he had an oral glucose tolerance test (OGTT) with appropriate suppression of growth hormone (GH) levels. Patient’s serum IGF-1 level eventually normalized more than 6 months after completion of treatment. Conclusion: Inhibition of IGF-1R reduces feedback inhibition of GH secretion. This results in elevated GH which in turn results in increased production of insulin-like growth factors by the liver and other tissues. This has been implicated in some of the adverse effects with teprotumumab including hyperglycemia and ototoxicity but specific relationships remain unclear. This case demonstrates serum IGF-1 levels can remain elevated for greater than 6 months after completion of treatment with teprotumumab for TED. The clinical significance of persistently elevated serum IGF-1 levels is unclear and requires further characterization. Presentation: Saturday, July 12, 2025

Background/Objective:In general, with type 2 amiodarone-induced thyrotoxicosis (type 2 AIT), initial treatment with glucocorticoids (oral prednisone, 30 to 40 mg/d) is recommended. However, for patients with type 2 AIT who have active hepatitis B (HBV) or osteoporosis, high-dose prednisone is relatively contraindicated. We report 2 cases of type 2 AIT that were managed with a combination of moderately low-dose prednisone and bile acid binding resin. Case Report:The first patient, a 68-year-old man with atrial fibrillation and active chronic HBV, developed thyrotoxicosis after 6 months of amiodarone therapy. The second patient, a 59-year-old woman with osteoporosis, developed hyperthyroidism after 6 months of amiodarone use. In both cases, thyroid function studies suggested type 2 AIT. Color doppler ultrasonography and nuclear studies also supported a diagnosis of type 2 AIT. The patients were treated with a combination of moderately low-dose prednisone (25 mg/d and 20 mg/d, respectively) and bile acid binding resins (colestipol 3 g/d and cholestyramine 12 g/d, respectively). Over 3 months, thyroid hormone levels normalized without complications. Discussion:Glucocorticoid use in HBV can increase viral reactivation risk, while in osteoporosis it accelerates bone loss. Bile acid resins disrupt the enterohepatic circulation of both thyroid hormones and amiodarone, promoting their rapid elimination. This combination treatment effectively managed thyrotoxicosis while minimizing steroid exposure. Conclusion:In patients with type 2 AIT and relative contraindication to high-dose steroids, a combination of moderately low-dose prednisone and bile acid binding resins offers a safe and effective treatment alternative.

Disclosure: A.J. Spiro: None. N.O. Vietor: None. T.D. Hoang: None. M.K. Shakir: None. The risk of amiodarone-induced thyrotoxicosis (AIT) increases with higher cumulative doses of amiodarone. For most patients with type 2 AIT, initial treatment with glucocorticoids (oral prednisone, 30 to 40 mg/day) rather than other therapies is suggested. However, in patients with type 2 AIT and active hepatitis B infection, treatment with high-dose prednisone is relatively contraindicated. We report a patient with type 2 AIT, treated with a combination of relatively low dose prednisone and colestipol, a bile acid binding resin.A 68-year-old man presented for evaluation of recent onset thyrotoxicosis. He was seen by cardiology for non-ischemic cardiomyopathy, systolic heart failure, and atrial fibrillation. Baseline thyroid function tests were normal. He was treated with amiodarone 6 months ago, but with onset of thyrotoxicosis, he was switched to dronedarone. He also had active hepatitis B. He was physically active with no exertional symptoms. His vital signs were normal and had no evidence of thyroid eye disease. Thyroid examination was normal with a 20-gram gland without nodules or tenderness. Lab tests showed TSH 0.001 uIU/mL(0.450 − 4.500) , free T4 2.02 ng/dL(0.82 − 1.77) , total T3 211 ng/dL(71 − 180), TSI <0.1 IU/L(0.00 - 0.55), reverse T3 37.5 ng/dL(9.2 - 24.1), serum iodine 559 ug/L(40.0 - 92.0), HBV 34,880 IU/mL(>20,000 significant), ALT 82 IU/L(0 − 44), AST 74 IU/L(0 − 40). Thyroid ultrasound with Doppler color showed absent vascular flow (pattern 0). A Tc-99m pertechnetate scintigraphy showed low uptake. Chronic HBV infection was also diagnosed and antiviral treatment with tenofovir was considered, although the treatment could not be initiated because of the need for steroid treatment. He was started on a low dose 25 mg prednisone and colestipol 3 gms daily. Two months later laboratory studies showed TSH 0.03 uIU/mL(0.450 − 4.500), free T4 1.99 ng/dL(0.82 − 1.77) , serum iodine 582 ug/L40.0 - 92.0). Five months later, prednisone was tapered to 7.5 mg daily and labs showed TSH 0.99 uIU/L(0.450 − 4.500), free T4 1.56 ng/dL(0.82 − 1.77) and total T3 130 ng/dL(71 − 180). The liver associated enzymes remained stable. At present, it is planned to taper prednisone and initiate the antiviral treatment.Conclusion: Colestipol, a bile acid binding resin has dual mechanism of action in the management of thyrotoxicosis associated with thyroiditis. Bile-salt sequestrants bind thyroid hormones in the intestine and thereby increase their fecal excretion. Studies have also indicated that colestipol significantly reduces the enterohepatic circulation of amiodarone and lowers the serum levels of amiodarone. Therefore, combination therapy with bile acid binding resins along with low dose prednisone can be utilized in patients with type II AIT. Presentation: Saturday, July 12, 2025

Disclosure: H.M. Babu: None. A.J. Spiro: None. N.O. Vietor: None. T.D. Hoang: None. M.K. Shakir: None. Background: Fracture risk assessment tool (FRAX) has been instrumental in calculating the 10-year probability of hip and major osteoporotic fractures using clinical risk factors and femoral neck bone density (BMD). This score is used to initiate antiresorptive treatment, typically in patients with risks of a major osteoporotic fracture ≥ 20% or hip fracture ≥ 3%. The FDA has cleared Hologic’s Horizon DXA SystemTM to incorporate the FRAX tool into its report. Trabecular Bone Score (TBS) assesses bone microarchitecture which can be used to calculate more accurate TBS adjusted FRAX scores. In our tertiary center, we noticed discrepancies between the FRAX scores reported by the HologicTM machines versus FRAX score calculated using the web-based tool. We also noticed differences in fracture risk prediction between unadjusted FRAX score and TBS adjusted FRAX score. We analyzed 150 DXA reports to find possible causes of these discrepancies. Methods: A retrospective analysis of 150 DXA reports was conducted using data from a previously approved research protocol including patients aged 40-90 years, weighing less than 275 lbs. Patients were classified into 3 categories, based on normal, osteopenic and osteoporotic BMD values. HologicTM only measures FRAX scores for patients that have BMD in the osteopenic range. FRAX scores were calculated by inputting data including patient risk factors from patient questionnaires and the calculated BMD into the FRAX web-based tool. We also collected data for TBS adjusted FRAX score. Results: A difference in FRAX scores was found in 42 out of 90 patients with osteopenia. In 12 patients, the difference was significant enough to alter management. All patients with discrepancy had one or more clinical risk factors present in the questionnaires. It was concluded that the differences in FRAX scores between HologicTM data and scores obtained from the web-based tool were due to the inaccurate entry of risk factors. Additionally, when the web-based tool calculated FRAX scores were compared to the TBS adjusted FRAX scores for osteopenic patients, in 1 patient the difference was significant enough to alter management. Conclusion: These findings highlight the importance of ensuring accurate and complete data entry into DXA machines. Training operators and implementing verification processes could mitigate these discrepancies and improve clinical decision making in osteoporosis management. This is critical as antiresorptive therapies can have potential adverse side effects. Furthermore, having a questionnaire with the same format as the HologicTM system can increase compliance and decrease inaccuracies with the entry of risk factors. We also recommend using the TBS adjusted FRAX scores, if available as it can change decision making for treatment of patients with borderline T-scores and unadjusted FRAX scores. Presentation: Monday, July 14, 2025