Thyroid Dysfunction Risk After Iodinated Contrast Media Administration: A Prospective Longitudinal Cohort Analysis

CONTEXT

Iodinated contrast media (ICM) is a common source of excess iodine in medical settings, given the common use of iodinated radiologic procedures.

OBJECTIVE

To determine the long-term risks of thyroid dysfunction following iodinated contrast administration in a prospective study.

DESIGN, SETTING, PARTICIPANTS

A longitudinal cohort study was conducted of patients in the U.S. Veterans Affairs medical system who received ICM.

MAIN OUTCOME MEASURES

Serum thyroid function, thyroid antibody, and inflammatory markers were measured at baseline. Thyroid function tests were repeated at 1 month, 3 months, and every 6 months thereafter until 36 months. Risk of thyroid dysfunction and longitudinal changes in thyroid hormone levels were assessed using mixed effect models.

RESULTS

There were 122 participants (median age, 70.0 [IQR 62.2-74.0] years; 98.4% male). At baseline, six subjects had subclinical thyroid dysfunction prior to ICM receipt. During median follow-up of 18 months, iodine-induced thyroid dysfunction was observed in 11.5% (14/122); six (4.9%) developed hyperthyroidism (including one with overt hyperthyroidism) and eight (6.6%) subclinical hypothyroidism. At last follow-up, ten of 20 subjects with thyroid dysfunction (14 new-onset cases and six with preexisting thyroid dysfunction) had persistent subclinical hyperthyroidism or hypothyroidism. There were also subtle changes in thyroid hormones observed longitudinally within the reference ranges in the overall cohort.

CONCLUSIONS

There is a rare long-term risk of an excess iodine load on thyroid dysfunction even among individuals from an overall iodine-sufficient region, supporting the need for targeted monitoring following iodinated contrast administration.

Overview of Thyroid and Parathyroid Disease-The Endocrinology Perspective

Thyroid and parathyroid disorders are quite common in the population and range from benign to malignant conditions that may be hormonally active or inactive. Select disorders of the thyroid and parathyroid can be managed medically, although there are a variety of circumstances that may require definitive management with surgery. Surgical intervention may be required for hormonal control, compressive symptoms, or for the removal and/or control of malignancy. The endocrinologist's perspective of the preoperative and postoperative management regarding thyroid and parathyroid surgeries will be discussed.

Iodine-Induced Hypothyroidism and Long-Term Risks of Incident Heart Failure

Background Although most individuals can adapt to a large iodine load and remain euthyroid, hypothyroidism can develop after iodine exposure. Hypothyroidism is associated with adverse cardiovascular consequences, including heart failure. This study was performed to investigate the relationships between iodine-induced hypothyroidism and incident heart failure. Methods and Results This cohort study of the US Veterans Health Administration (1998-2021) included adults aged ≥18 years with a serum thyroid-stimulating hormone (thyrotropin) <60 days of iodine contrast administration, and <1 year of a baseline normal serum thyroid-stimulating hormone. Cox proportional hazards regression ascertained risk of incident heart failure following iodine-induced hypothyroidism, adjusting for age, sex, race and ethnicity, body mass index, and history of coronary heart disease, dyslipidemia, diabetes, and hypertension. Of 45 470 veterans (mean±SD age, 61.1±14.1 years; 88% men), 3361 (7.4%) developed iodine-induced hypothyroidism. Heart failure developed in 5685 (12.5%) individuals over a median follow-up of 3.6 years (interquartile range, 1.9-7.2 years). Adjusted for risk factors, iodine-induced hypothyroidism was associated with increased risk of heart failure, compared with those who remained euthyroid after iodine exposure (adjusted hazard ratio [HR], 1.11 [95% CI, 1.01-1.22]). Women were at greater risk than men (adjusted HR: women, 1.65 [95% CI, 1.13-2.40]; men, 1.08 [95% CI, 0.98-1.19]; P for interaction, 0.02). Conclusions In the largest US study of this topic, hypothyroidism following iodine exposure was associated with an increased risk of incident heart failure, particularly in women. These findings support the need for further research to address the clinical significance of this issue, including the possible sex-specific risks of incident heart failure in more diverse data sets and study populations.

Iodine-Induced Hyperthyroidism and Long-term Risks of Incident Atrial Fibrillation and Flutter

CONTEXT

Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied.

OBJECTIVE

To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/flutter.

METHODS

Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism.

RESULTS

Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04).

CONCLUSION

Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost-benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated.

Per- and Polyfluoroalkyl Substances (PFAS) in Community Water Systems (CWS) and the Risk of Thyroid Cancer: An Ecological Study

Thyroid cancer incidence has been steadily increasing over the past decade in the United States (US). A discussion exists regarding the potential contribution of exposure to endocrine-disrupting chemicals, encompassing certain per- and poly-fluoroalkyl substances (PFASs). This ecological study evaluated the potential correlation between PFAS levels in drinking water and thyroid cancer incidence in the US. Data on age-adjusted thyroid cancer incidence rate (per 100,000 persons) by county were obtained from the Centers for Disease Control and Prevention (CDC) for US counties with available data in 2015-2019. Data on PFAS concentrations in the drinking water of selected community water systems (CWSs) were obtained from the CDC National Environmental Public Health Tracking Network in 2013-2015. The correlation between PFASs in CWSs and thyroid cancer incidence was calculated using Spearman correlation. A statistically significant correlation was found between perfluorooctanoic acid (PFOA) (r = 0.031; p = 0.043), perfluorononanoic acid (PFNA) (r = 0.058; p ≤ 0.001), and thyroid cancer incidence. The results suggest a potential link between certain PFAS exposures and thyroid cancer risk. However, due to the nature of an ecological study, no conclusions can be drawn at the individual level or causality. More research is needed, particularly on an individual level to allow for more detailed exposure assessment.

Patient Preference in Physician Decision-Making for Patients With Low- to Intermediate-Risk Differentiated Thyroid Cancer

This survey study describes the association between patient preference and physician decision-making in thyroid cancer.

Landmark Discoveries in Maternal-Fetal Thyroid Disease Over the Past Century

There have been significant advancements in the understanding of maternal-fetal disease over the past century. This narrative review summarizes the landmark studies that have advanced the understanding of thyroid pathophysiology and thyroid disease during preconception, pregnancy, and postpartum, written to commemorate the 100th year anniversary of the founding of the American Thyroid Association.

Iodinated Contrast Administration and Risks of Thyroid Dysfunction: A Retrospective Cohort Analysis of the U.S. Veterans Health Administration System

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

Iodine contrast exposure and incident COVID-19 infection

Background

Iodine and particularly its oxidated forms have long been recognized for its effective antiseptic properties. Limited in vitro and in vivo data suggest that iodine exposure may rapidly inactivate, reduce transmission, and reduce infectivity of SARS-CoV-2. We hypothesized that iodine exposure may be associated with decreased incident COVID-19 infection.

Methods

A retrospective population-level cohort analysis was performed of the U.S. Veterans Health Administration between 1 March 2020 and 31 December 2020, before the widespread availability of vaccines against SARS-CoV-2. Multivariable logistic regression models estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) of the associations between iodinated contrast exposure and incident COVID-19 infection, adjusting for age, sex, race/ethnicity, place of residence, socioeconomic status, and insurance status.

Results

530,942 COVID-19 tests from 333,841 Veterans (mean ± SD age, 62.7 ± 15.2 years; 90.2% men; 61.9% non-Hispanic Whites) were analyzed, of whom 9% had received iodinated contrast ≤60 days of a COVID-19 test. Iodine exposure was associated with decreased incident COVID-19 test positivity (OR, 0.75 95% CI, 0.71–0.78). In stratified analyses, the associations between iodinated contrast use and decreased COVID-19 infection risk did not differ by age, sex, and race/ethnicity.

Conclusion

Iodine exposure may be protective against incident COVID-19 infection. Weighed against the risks of supraphysiologic iodine intake, dietary, and supplemental iodine nutrition not to exceed its Tolerable Upper Limit may confer an antimicrobial benefit against SARS-CoV-2. A safe but antimicrobial level of iodine supplementation may be considered in susceptible individuals, particularly in geographic regions where effective COVID-19 vaccines are not yet readily available.

Management of Thyroid Eye Disease: A Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this consensus statement.

Management of thyroid eye disease: a Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this Consensus Statement.

An Electronic Medical Record-Based Decision Support Tool for the Diagnosis of Primary Hyperparathyroidism

This cohort study evaluates an electronic medical record–based tool for diagnosis of primary hyperparathyroidism in patients with chronic hypercalcemia.

Serum Thyroglobulin Measurement Following Surgery Without Radioactive Iodine for Differentiated Thyroid Cancer: A Systematic Review

Background: The utility of serum thyroglobulin (Tg) measurement following partial thyroidectomy or total/near-total thyroidectomy without radioactive iodine (RAI) for differentiated thyroid cancer is unclear. This systematic review examines the diagnostic accuracy of serum Tg measurement for persistent, recurrent, and/or metastatic cancer in these situations. Methods: Ovid MEDLINE, Embase, and Cochrane Central were searched in October 2021 for studies on Tg measurement following partial thyroidectomy or total/near-total thyroidectomy without or before RAI. Quality assessment was performed, and evidence was synthesized qualitatively. Results: Thirty-seven studies met inclusion criteria. Four studies (N = 561) evaluated serum Tg measurement following partial thyroidectomy, five studies (N = 751) evaluated Tg measurement following total/near-total thyroidectomy without RAI, and 28 studies (N = 7618) evaluated Tg measurement following total or near-total thyroidectomy before RAI administration. Following partial thyroidectomy, Tg measurement was not accurate for diagnosing recurrence or metastasis, or estimates were imprecise. Following total/near-total thyroidectomy without RAI, evidence was limited due to few studies with very low rates of recurrence or metastasis, but indicated that Tg levels were usually stable and low. For Tg measurements before RAI administration, diagnostic accuracy for metastatic disease or persistence varied, although sensitivity appeared high (but specificity low) at a cutoff of >1 to 2.5 ng/mL. However, applicability to patients who do not undergo RAI is uncertain because patients selected for RAI are likely to represent a higher risk group. The evidence was very low quality for all scenarios. All studies had methodological limitations, and there was variability in the Tg thresholds evaluated, patient populations, outcomes assessed, and other factors. Conclusions: Very limited evidence suggests low utility of Tg measurement for identifying recurrent or metastatic disease following partial thyroidectomy. Following total/near-total thyroidectomy, Tg levels using a cutoff of 1-2.5 ng/mL might identify patients at low risk for persistent or metastatic disease. Additional research is needed to clarify the role of Tg measurement in these settings, determine optimal Tg thresholds, and determine appropriate measurement intervals.

Diagnostic and Treatment Considerations for Thyroid Cancer in Women of Reproductive Age and the Perinatal Period

Thyroid cancer is one of the most common cancers diagnosed in women of reproductive age and during pregnancy. This leads to important questions about thyroid cancer prognosis and treatment, but also fertility and risk for adverse obstetric and/or fetal and neonatal outcomes. The benefits of thyroid cancer treatment should be weighed against its harms, as various options may adversely impact maternal and fetal health. In the current review, the authors focus on perinatal-specific clinical considerations related to the care of patients with thyroid cancer.

Driving Factors to Pursue Endocrinology Training Fellowship: Empirical Survey Data and Future Strategies

OBJECTIVE

There is a current and anticipated labor shortage of endocrinologists in the United States. Over the past decade, the number of applications to endocrinology fellowship programs has plateaued despite increased available positions, and interest in endocrinology has declined relative to other internal medicine subspecialty fields. The examination of driving factors for pursuit of endocrinology as a subspecialty career is needed.

METHODS

A 12-question online survey was developed to identify the primary reasons for current endocrinology fellows/trainees to pursue the field. This survey was sent to 152 U.S. endocrinology fellowship program directors for completion by their fellows between July and August 2021.

RESULTS

A total of 176 of 629 fellows (28.0%) completed the survey. The majority (57.4%) had decided to pursue endocrinology as a career during residency, while 27.3% had decided during medical school. The endocrinology rotation during residency was ranked by 79 fellows (44.9%) as the most influential factor, followed by having positive experiences with a clinical mentor (27.3%). Endocrinology exposure during medical school was sparse, with only 2.8% noting the availability of an endocrinology student interest group, while 59.7% reported inadequate endocrinology exposure during their medical school curriculum.

CONCLUSION

The majority of current endocrinology fellows/trainees report that exposure to the field during medical school was limited, and that their endocrinology elective and mentorship experiences during residency were the most influential factors for pursuing endocrinology as a subspecialty. Improved integration of endocrinology experiences between medical school and residency may enhance career interest in endocrinology.

The Current Status of Preclinical Endocrine Education in U.S. Medical Schools

OBJECTIVE

To characterize the current landscape of pre-clinical medical endocrine education in United States (U.S.) allopathic medical schools.

METHODS

U.S. endocrine curriculum directors were asked to voluntarily complete a 16-question emailed survey surveying the status of endocrine pre-clinical education at their medical school.

RESULTS

There were 69 of 155 (45%) endocrine block director respondents who completed the online survey between July to Sept 2021. A larger incoming class, a longer duration of an endocrine curriculum, and the offering of a separate endocrine curriculum (i.e. apart from the teaching of other organ systems) were each independently associated with an increased number of faculty teaching the course. Schools that used a gland/organ-based curriculum only and those that used a combination of gland/organ with topic based were differed significantly in their use of large lectures, small groups, and several curriculum components including point of care glucose testing, continuous glucose monitoring, and insulin pumps.

CONCLUSION

This survey study reports the current landscape of preclinical endocrine education in the U.S. and describes opportunities to improve interest in pursuing endocrinology as a career.

Active Surveillance Versus Thyroid Surgery for Differentiated Thyroid Cancer: A Systematic Review

Background: Active surveillance has been proposed as an appropriate management strategy for low-risk differentiated thyroid cancer (DTC), due to the typically favorable prognosis of this condition. This systematic review examines the benefits and harms of active surveillance vs. immediate surgery for DTC, to inform the updated American Thyroid Association guidelines. Methods: A search on Ovid MEDLINE, Embase, and Cochrane Central was conducted in July 2021 for studies on active surveillance vs. immediate surgery. Studies of surgery vs. no surgery for DTC were assessed separately to evaluate relevance to active surveillance. Quality assessment was performed, and evidence was synthesized narratively. Results: Seven studies (five cohort studies [N = 5432] and two cross-sectional studies [N = 538]) of active surveillance vs. immediate surgery, and seven uncontrolled treatment series of active surveillance (N = 1219) were included. One cross-sectional study was rated fair quality, and the remainder were rated poor quality. In patients with low risk (primarily papillary), small (primarily ≤1 cm) DTC, active surveillance, and immediate surgery were associated with similar, low risk of all-cause or cancer-specific mortality, distant metastasis, and recurrence after surgery. Uncontrolled treatment series reported no cases of mortality in low-risk DTC managed with active surveillance. Among patients managed with active surveillance, rates of tumor growth were low; rates of subsequent surgery varied and primarily occurred due to patient preference rather than tumor progression. Four cohort studies (N = 88,654) found that surgery associated with improved all-cause or thyroid cancer mortality compared with nonsurgical management, but findings were potentially influenced by patient age and tumor risk category and highly susceptible to confounding by indication; eligibility for, and receipt of, active surveillance; and timing of surgery was unclear. Conclusions: In patients with small low-risk (primarily papillary) DTC, active surveillance and immediate surgery may be associated with similar mortality, risk of recurrence, and other outcomes, but methodological limitations preclude strong conclusions. Studies of no surgery vs. surgery are difficult to interpret due to clinical heterogeneity and potential confounding factors and are unsuitable for assessing the utility of active surveillance. Research is needed to clarify the benefits and harms of active surveillance and determine outcomes in nonpapillary DTC, larger (>1 cm) cancers, and older patients.

Perception of risk and treatment decisions in the management of differentiated thyroid cancer

BACKGROUND AND OBJECTIVES

The recent de-escalation of care for differentiated thyroid cancer (DTC) has broadened the range of initial treatment options. We examined the association between physicians' perception of risk and their management of DTC.

METHODS

Thyroid specialists were surveyed with four clinical vignettes: (1) indeterminate nodule (2) tall cell variant papillary thyroid cancer (PTC), (3) papillary thyroid microcarcinoma (mPTC), and (4) classic PTC. Participants judged the operative risks and likelihood of structural cancer recurrence associated with more versus less aggressive treatments. A logistic mixed effect model was used to predict treatment choice.

RESULTS

Among 183 respondents (13.4% response rate), 44% were surgical and 56% medical thyroid specialists. Risk estimates and treatment recommendation varied markedly in each case. Respondents' estimated risk of 10-year cancer recurrence after lobectomy for a 2.0-cm PTC ranged from 1% to 53% (interquartile range [IQR]: 3%-12%), with 66% recommending lobectomy and 34% total thyroidectomy. Respondents' estimated 5-year risk of metastastic disease during active surveillance of an 0.8-cm mPTC ranged from 0% to 95% (IQR: 4%-15%), with 36% choosing active surveillance. Overall, differences in perceived risk reduction explained 10.3% of the observed variance in decision-making.

CONCLUSIONS

Most of the variation in thyroid cancer treatment aggressiveness is unrelated to perceived risk of cancer recurrence.

Systems-Level Opportunities in the Management of Primary Hyperparathyroidism: An Informatics-based Assessment

CONTEXT

Primary hyperparathyroidism (PHPT), a leading cause of hypercalcemia and secondary osteoporosis, is underdiagnosed.

OBJECTIVE

This work aims to establish a foundation for an electronic medical record-based intervention that would prompt serum parathyroid hormone (PTH) assessment in patients with persistent hypercalcemia and identify care gaps in their management.

METHODS

A retrospective cohort study was conducted in a tertiary academic health system of outpatients with persistent hypercalcemia, who were categorized as having classic or normohormonal PHPT. Main outcome measures included the frequencies of serum PTH measurement in patients with persistent hypercalcemia, and their subsequent workup with bone mineral density (BMD) assessment, and ultimately, medical therapy or parathyroidectomy.

RESULTS

Among 3151 patients with persistent hypercalcemia, 1526 (48%) had PTH measured, of whom 1377 (90%) were confirmed to have classic (49%) or normohormonal (41%) PHPT. PTH was measured in 65% of hypercalcemic patients with osteopenia or osteoporosis (P < .001). At median 2-year follow-up, bone density was assessed in 275 (20%) patients with either variant of PHPT (P = .003). Of women aged 50 years or older with classic PHPT, 95 (19%) underwent BMD assessment. Of patients with classic or normohormonal PHPT, 919 patients (67%) met consensus criteria for surgical intervention, though only 143 (15%) underwent parathyroidectomy.

CONCLUSION

Within a large academic health system, more than half of patients with confirmed hypercalcemia were not assessed for PHPT, including many patients with preexisting bone disease. Care gaps in BMD assessment and medical or surgical therapy represent missed opportunities to avoid skeletal and other complications of PHPT.

Recombinant human thyroid-stimulating hormone versus thyroid hormone withdrawal preparation for radioiodine ablation in differentiated thyroid cancer in children, adolescents and young adults

OBJECTIVE

Recombinant human TSH (rhTSH) is commonly used to prepare patients for postoperative radioiodine (I-131) ablation after surgery for differentiated thyroid cancer (DTC). In adults, rhTSH is associated with equivalent oncologic efficacy in comparison to thyroid hormone withdrawal (THW), but its use has not been well studied in children. We aimed to measure time to disease progression after rhTSH stimulation vs. THW in paediatric patients under the age of 21 with DTC following total thyroidectomy.

DESIGN

Retrospective cohort study (March 2001-July 2018).

PATIENTS

Sixteen children and adolescents (75% female, median age, 17.4 years) who received rhTSH were compared to 29 historical controls (72% female, median age, 18.5 years) prepared with THW, followed for a median of 2.4 years (range, 0.5-14).

MEASUREMENTS

Stimulated serum TSH concentrations prior to I-131 ablation and time to disease progression, as determined by a component outcome variable encompassing both structural and biochemical disease persistence/recurrence.

RESULTS

No differences were observed in tumour characteristics and I-131 dose (median 2.3 [1.8-2.90] mCi/kg rhTSH) between groups. Patients who received rhTSH achieved a similar median stimulated TSH level (163 [127-184] mU/L), compared to those who underwent THW (136 [94.5-197] mU/L; p = .20). Both groups exhibited similar time to progression (p = .13) and disease persistence/recurrence rates (rhTSH 31% vs. THW 59%, p = .14).

CONCLUSION

In this cohort of children and adolescents with DTC, we observed similar time to disease progression among those who received rhTSH or underwent THW prior to postoperative I-131 ablation.

Systemic light-chain amyloidosis incidentally diagnosed after subtotal parathyroidectomy and thyroid lobectomy

A 74-year-old woman with a history of primary hyperparathyroidism, thyroid nodules, atrial fibrillation and pacemaker placement for sick sinus syndrome presented with fatigue, constipation and persistent lower extremity oedema. She underwent subtotal parathyroidectomy and left thyroid lobectomy. Histopathology revealed amyloidosis affecting the thyroidand parathyroids confirmed by Congo Red Staining with Mayo Clinic subtyping of light chain kappa-type amyloidosis. She was found to have combined systolic and diastolic cardiac dysfunction, carpal tunnel neuropathy and pre-diabetes suggestive of systemic amyloidosis with involvement of the heart, nerves and pancreas. Congo red stain was positive for amyloidosis on bone marrow biopsy suggestive of a diagnosis of systemic amyloidosis. She was treated with daratumumab with good clinical response. This case illustrates the necessity of considering systemic amyloidosis in patients with incidentally discovered diffuse amyloid deposits on biopsy of an endocrine organ, as endocrine effects are a rare but likely underdiagnosed consequence of systemic amyloidosis.

Frequency of Thyroid Hormone Replacement After Lobectomy for Differentiated Thyroid Cancer

OBJECTIVE

To determine the frequency of levothyroxine (LT4) supplementation after therapeutic lobectomy for low-risk differentiated thyroid cancer (DTC).

METHODS

This retrospective cohort study enrolled adult patients with low-risk DTC confirmed using surgical pathology who underwent therapeutic lobectomy at a single institution from January 2016 through May 2020. The outcome measures were postoperative serum thyroid-stimulating hormone (TSH) levels and the initiation of LT4. The predictors of a postoperative TSH level of >2 mU/L and initiation of LT4 were evaluated using Cox proportional hazards models.

RESULTS

Postoperative TSH levels were available for 115 patients (91%), of whom 97 (84%) had TSH levels >2 mU/L after thyroid lobectomy. Over a median follow-up of 2.6 years, a postoperative TSH level of >2 mU/L was associated with older age (median 52 vs 37 years; P = .01), higher preoperative TSH level (1.7 vs 0.85 mU/L; P < .001), and primary tumor size of <1 cm (38% vs 11%, P = .03). Multivariate analysis revealed that only preoperative TSH level was an independent predictor of a postoperative TSH level of >2 mU/L (hazard ratio [HR] 1.53, P = .003). Among patients with a postoperative TSH level of >2 mU/L, 66 (68%) were started on LT4 at a median of 74 days (interquartile range 41-126) after lobectomy, with 51 (77%) undergoing at least 1 subsequent dose adjustment to maintain compliance with current guidelines.

CONCLUSION

More than 80% of the patients who underwent therapeutic lobectomy for DTC developed TSH levels that were elevated beyond the recommended range, and most of these patients were prescribed LT4 soon after the surgery.

Effectiveness of Molecular Testing Techniques for Diagnosis of Indeterminate Thyroid Nodules: A Randomized Clinical Trial

Importance

Approximately 20% of thyroid nodules display indeterminate cytology. Molecular testing can refine the risk of malignancy and reduce the need for diagnostic hemithyroidectomy.

Objective

To compare the diagnostic performance between an RNA test (Afirma genomic sequencing classifier) and DNA-RNA test (ThyroSeq v3 multigene genomic classifier).

Design, Setting, and Participants

This parallel randomized clinical trial of monthly block randomization included patients in the UCLA Health system who underwent thyroid biopsy from August 2017 to January 2020 with indeterminate cytology (Bethesda System for Reporting Thyroid Cytopathology category III or IV).

Interventions

Molecular testing with the RNA test or DNA-RNA test.

Main Outcomes and Measures

Diagnostic test performance of the RNA test compared with the DNA-RNA test. The secondary outcome was comparison of test performance with prior versions of the molecular tests.

Results

Of 2368 patients, 397 were eligible for inclusion based on indeterminate cytology, and 346 (median [interquartile range] age, 55 [44-67] years; 266 [76.9%] women) were randomized to 1 of the 2 tests. In the total cohort assessed for eligibility, 3140 thyroid nodules were assessed, and 427 (13.6%) nodules were cytologically indeterminate. The prevalence of malignancy was 20% among indeterminate nodules. The benign call rate was 53% (95% CI, 47%-61%) for the RNA test and 61% (95% CI, 53%-68%) for the DNA-RNA test. The specificities of the RNA test and DNA-RNA test were 80% (95% CI, 72%-86%) and 85% (95% CI, 77%-91%), respectively (P = .33); the positive predictive values (PPV) of the RNA test and DNA-RNA test were 53% (95% CI, 40%-67%) and 63% (95% CI, 48%-77%), respectively (P = .33). The RNA test exhibited a higher PPV compared with the prior test version (Afirma gene expression classifier) (54% [95% CI, 40%-67%] vs 38% [95% CI, 27%-48%]; P = .01). The DNA-RNA test had no statistically significant difference in PPV compared with its prior version (ThyroSeq v2 next-generation sequencing) (63% [95% CI, 48%-77%] vs 58% [95% CI, 43%-73%]; P = .75). Diagnostic thyroidectomy was avoided in 87 (51%) patients tested with the RNA test and 83 (49%) patients tested with the DNA-RNA test. Surveillance ultrasonography was available for 90 nodules, of which 85 (94%) remained stable over a median of 12 months follow-up.

Conclusions and Relevance

Both the RNA test and DNA-RNA test displayed high specificity and allowed 49% of patients with indeterminate nodules to avoid diagnostic surgery. Although previous trials demonstrated that the prior version of the DNA-RNA test was more specific than the prior version of the RNA test, the current molecular test techniques have no statistically significant difference in performance.

Trial Registration

ClinicalTrials.gov Identifier: NCT02681328.

Correlation of ThyroSeq Results with Surgical Histopathology in Cytologically Indeterminate Thyroid Nodules

The ThyroSeq next-generation sequencing test refines the risk of malignancy in cytologically indeterminate thyroid nodules. Specific genetic alterations have distinct cancer probabilities and clinical phenotypes. There is limited data on the association between specific genetic alterations and histopathologic features. The aim of this study was to evaluate specific ThyroSeq alterations in prognosticating high-risk histopathologic characteristics. We performed a retrospective single-institution study of all patients diagnosed with indeterminate thyroid nodules (May 2016-December 2019) who had a mutation identified with ThyroSeq v2 or v3 and underwent surgical resection. Specific genetic alterations were correlated with surgical histopathology. The main outcomes were risk of malignancy and structural recurrence risk based on histopathologic features and the 2015 American Thyroid Association (ATA) risk stratification. Of the 78 nodules, 50 (64%) were thyroid cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) on surgical histopathology. Nodules with high-risk TERT or TP53 combination mutations (TERT/TP53) and those with BRAF-like mutations were associated with a 100% probability of cancer and higher rates of extrathyroidal extension and regional nodal involvement than nodules with RAS-like mutations. Among nodules with RAS-like mutations, there was an even distribution between benign, NIFTP, and malignant results, the latter of which were all ATA low risk for structural disease recurrence. Overall, TERT/TP53 and BRAF-like ThyroSeq mutations are associated with an increased cancer probability and risk of recurrence defined by histopathologic features, while RAS-like mutations are associated with lower cancer probability and indolent disease. Individualized management, including extent of surgery, should be considered based on specific genetic alterations found in cytologically indeterminate thyroid nodules.

Normocalcaemic primary hyperparathyroidism: An update on diagnostic and management challenges

Normocalcaemic primary hyperparathyroidism is a condition that can present with intermittent hypercalcemia or may evolve into hypercalcemic primary hyperparathyroidism. This milder biochemical entity remains incompletely understood because of a lack of long-term health outcomes regarding both medical and surgical approaches to its management. Medical therapies have shown some efficacy. A limited number of studies have found that bisphosphonates increase bone mineral density, and calcimimetics may decrease the risk of nephrolithiasis in patients with normocalcaemic primary hyperparathyroidism. Studies have also described patient outcomes after applying the same surgical criteria used for patients with hypercalcaemic primary hyperparathyroidism to those with the normocalcaemic form of the disease. These studies suggest that parathyroid surgery appears to be effective in normalizing elevated serum parathyroid hormone concentrations and decreasing adverse renal and skeletal outcomes in patients with normocalcaemic hyperparathyroidism. Given the available data and overall lack of consensus regarding the optimal management of these patients, a reasonable approach is to tailor treatment to the individual patient by considering their risk factors for new or accelerated bone loss, kidney stones, diminished quality of life, and cardiovascular disease.

Diagnostic Value of Molecular Testing in Sonographically Suspicious Thyroid Nodules

Objective

Molecular testing can refine the diagnosis for the 20% of thyroid fine-needle aspiration biopsies that have indeterminate cytology. We assessed the diagnostic accuracy of molecular testing based on ultrasound risk classification.

Methods

This retrospective cohort study analyzed all thyroid nodules with indeterminate cytology at an academic US medical center (2012-2016). All indeterminate nodules underwent reflexive molecular testing with the Afirma Gene Expression Classifier (GEC). Radiologists performed blinded reviews to categorize each nodule according to the American Thyroid Association (ATA) ultrasound classification and the American College of Radiology Thyroid Imaging, Reporting and Data System. GEC results and diagnostic performance were compared across ultrasound risk categories.

Results

Of 297 nodules, histopathology confirmed malignancy in 65 (22%). Nodules by ATA classification were 8% high suspicion, 44% intermediate, and 48% low/very low suspicion. A suspicious GEC result was more likely in ATA high-suspicion nodules (81%) than in nodules of all other ATA categories (57%; P = .04). The positive predictive value (PPV) of GEC remained consistent across ultrasound categories (ATA high suspicion, 64% vs all other ATA categories, 48%; P = .39). The ATA high-suspicion category had higher specificity than a suspicious GEC result (93% vs 51%; P < .01). A suspicious GEC result did not increase specificity for the ATA high-suspicion category.

Conclusion

The PPV of molecular testing remained consistent across ultrasound risk categories. However, a suspicious GEC result was very likely in ATA high-suspicion nodules and did not improve specificity in this sonographic category.

Rising Incidence and Incidence-Based Mortality of Thyroid Cancer in California, 2000-2017

CONTEXT

The increased incidence of thyroid cancer globally over the past several decades is principally attributed to small, indolent papillary thyroid cancers. A possible concomitant increase in thyroid cancer-specific mortality remains debated.

OBJECTIVE

The changes in thyroid cancer incidence and incidence-based mortality were assessed using a large population-based cohort over an 18-year period.

DESIGN & PATIENTS

A retrospective analysis of all thyroid cancers reported in the California Cancer Registry was performed (2000-2017). Age-adjusted incidence and incidence-based mortality rates were analyzed using a log-linear model to estimate annual percent change.

RESULTS

We identified 69 684 individuals (76% female, median age 50 years) diagnosed with thyroid cancer. The incidence of thyroid cancer increased across all histological subtypes (papillary, follicular, medullary, and anaplastic) and all tumor sizes. The incidence increased from 6.43 to 11.13 per 100 000 person-years (average increase 4% per year; P < 0.001) over the study period. Thyroid cancer-specific mortality rates increased on average by 1.7% per year (P < 0.001). The increased mortality rates were greater in men (2.7% per year, P < 0.001) and patients with larger tumors (2-4 cm) (3.4% per year, P < 0.05).

CONCLUSIONS

Data from this statewide registry demonstrate that the incidence of thyroid cancer is increasing, and that this phenomenon is not restricted to small papillary thyroid cancers. Rising incidence in thyroid cancers of all sizes with concurrent increase of incidence-based mortality in men and those with larger tumors suggest a true increase in clinically significant disease.

MON-LB87 Recombinant Human TSH vs Thyroid Hormone Withdrawal Preparation for Radioiodine Ablation in Pediatric Differentiated Thyroid Cancer

Introduction: Recombinant human TSH (rhTSH) is commonly used to prepare patients with differentiated thyroid cancer (DTC) for radioiodine (I-131) ablation after total thyroidectomy (TT). In adults, rhTSH is associated with equivalent oncologic efficacy and improved health-related quality of life in comparison to thyroid hormone withdrawal (THW). In this study, we aimed to measure disease-free survival after rhTSH stimulation vs. THW in pediatric patients with DTC. Methods: A prospective database was analyzed for pediatric patients under the age of 21 with DTC who underwent TT and I-131 ablation with rhTSH preparation at a single tertiary institution from 2012 through 2018. These patients were compared against historical controls prepared with THW. Tumor stage, I-131 treatment details, disease-free survival, structural recurrence, biochemical recurrence (defined as serum Tg > 2 at one year), and postoperative serum TSH, thyroglobulin (Tg) and Tg antibody levels were recorded. The log-rank test was used to compare groups, and time to recurrence was estimated by Kaplan-Meier analysis. Results: Seventeen patients who received rhTSH (mean age, 16.6±3.2 [SD] years) were compared to 28 historical controls prepared with THW. No differences were observed in RAI dose (mean 2.3±0.7 mCi/kg), tumor stage, or follow-up time (median [IQR] 2.6 [1.1-3.1] years) between groups. The THW group exhibited a nonsignificantly greater recurrence rate (14 [50%], 7 with biochemical recurrence and 7 with structural recurrence) than the rhTSH group (three [18%], 2 with biochemical recurrence and 1 with structural recurrence, p=0.2). A trend toward improved disease-free survival was identified in those treated with rhTSH compared to THW. Conclusion: In this cohort of pediatric patients with DTC, we observed a trend toward improved disease-free survival among those prepared with rhTSH compared to historical controls prepared with THW. Long-term follow up is needed to better characterize outcomes associated with rhTSH stimulation prior to I-131 ablation in the pediatric population.

MON-123 Underdiagnosis of Primary Hyperparathyroidism in the Outpatient Setting of an Academic Health Care System

Background: Primary hyperparathyroidism (PHPT) is the leading cause of hypercalcemia in the outpatient population and is associated with nephrolithiasis, osteoporosis, and further end-organ effects. When indicated, parathyroidectomy is an effective intervention. The aim of this study was to assess the prevalence of patients with hypercalcemia resulting from undiagnosed PHPT within a large, urban, academic healthcare system.

Methods: The study population comprised all patients within UCLA Health. The electronic medical record was queried between 01/01/2016-12/31/2018 to include patients with at least two elevated serum total calcium concentrations (>10.4 mg/dL) within a six-month period in the outpatient setting. Causes of secondary and tertiary PHPT were excluded. In concordance with the PHPT diagnostic criteria outlined by the Fourth International Workshop, we evaluated the proportion of patients with hypercalcemia who were further assessed with a serum intact parathyroid hormone (iPTH) test. The study identified cases of PHPT as defined by confirmed elevated serum total calcium concentrations and elevated or inappropriately normal iPTH concentrations.

Results: There were 7102 patients with a single elevated serum total calcium result who never received a repeat assessment within the study period. Although there were 5617 patients with confirmed hypercalcemia, only 2773 (51%) had an iPTH level assessed within six months of the repeated calcium measurement. Of those who underwent iPTH testing, 1931 (69%) were biochemically confirmed to have classic (34.2%) or normohormonal (35.4%) PHPT; the remaining 31% had an appropriately suppressed iPTH concentration relative to the hypercalcemia.

Conclusions: In a large, academic, tertiary healthcare center, over half of the ambulatory patients with confirmed hypercalcemia did not receive further work-up to assess for possible PHPT. Efforts to improve diagnosis of PHPT and expand curative treatment have the potential to decrease the prevalence of nephrolithiasis, bone loss, and further end-organ effects associated with the disease.

SAT-447 Thyroid Function, Cardiovascular Disease, and Mortality: A Mediation Analysis

Background: Subclinical hypothyroidism is a common clinical entity among the United States (U.S) adults and has been associated with increased risk of cardiovascular disease (CVD) and mortality in some studies. However, the mediation effect of CVD from elevated serum thyroid stimulating hormone (TSH) to mortality has not yet been well established or sufficiently quantified. In this study, we aimed to elucidate the extent to which subclinical hypothyroidism or high-normal thyroid stimulating hormone [TSH] concentrations (i.e. upper normative-range TSH concentrations) contribute to mortality through its effect on CVD among U.S. adults.

Methods: This study relies on the U.S. representative samples of 9,020 adults enrolled in the National Health and Nutrition Examination Surveys (NHANES) 2001-2002, 2007-2012 and their mortality data through 2015. We employed Cox proportional hazards regression models to investigate associations between the TSH concentration categories (subclinical hypothyroidism or tertiles of serum TSH concentrations within the reference range) and all-cause mortality. Utilizing mediation analysis within the counterfactual framework, we estimated the mediation effect of CVD on the association between TSH and all-cause mortality.

Results: The median duration of follow-up for mortality ascertainment was 7.3 (interquartile range, 5.4–8.3) years, during which 435 deaths from all causes were identified. Subjects with TSH in the subclinical hypothyroidism and the high-normal TSH tertile concentrations were associated with increased all-cause mortality (subclinical hypothyroidism: hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.14–3.19; high-normal TSH: HR, 1.36; 95% CI, 1.07–1.73) compared with the middle-normal TSH tertile concentration. CVD mediated 14.3% and 5.9% of the effects of subclinical hypothyroidism and high-normal TSH on all-cause mortality, respectively, with the CVD mediation effect being most pronounced in women and subjects ≥60 years old. No mediation through CVD was found for low-normal TSH levels and all-cause mortality.

Conclusion: CVD mediated the effects of subclinical hypothyroid and high-normal TSH concentrations on all-cause mortality in the U.S. general population. These findings may have potential implications for treatment, and early and more aggressive CVD screening for such at risk populations. Further studies are needed to examine the clinical impact of targeted therapy towards mid-normal TSH concentration.

MON-120 The Implementation of a Scholarly Activity Curriculum: Impact Assessment

Introduction:

As detailed in the 2018 ACGME Common Program Requirements statement for fellowship institutions, “The physician is a humanistic scientist who cares for patients. This requires the ability to think critically, evaluate the literature, appropriately assimilate new knowledge, and practice lifelong learning.” Endocrinology fellowship programs are tasked with the expectation of creating an environment that fosters scholarly pursuit. It is under the discretion of each program to consider its institutional resources and community needs in order to meet this ACGME requirement.¹

With the goal of enhancing trainee scholarly activity, our fellowship program created a Scholarly Activity Curriculum in 2017. The core curriculum pillars include delineating a yearly timeline of objectives and expectations, facilitating regular individual mentoring, permitting allotment of protected time, and advocating involvement in faculty scholarship and national conferences.

Objective:

To assess the impact of the 2017 Endocrinology Fellowship Scholarly Activity Curriculum with respect to its ability to increase trainee scholarship.

Methods:

The scholarly activities of the fellowship classes of 2017-2020 were extracted from archived Fellow Scholarly Activity Update presentations and exit-interview curricula vitae. The activities were categorized as conference presentations (oral/poster), basic scientific research, clinical scientific research, quality improvement, book chapters, review articles, case reports, and teaching activities. With the 2017 and 2018 classes representing the pre-curriculum study group and the 2019 and 2020 classes representing the post-curriculum study group, the number of activities per study group per scholarly category were tabulated and compared.

Results:

An increase in scholarly activity was noted in five of the delineated categories: conference presentations (80%), clinical scientific research (86%), review articles (100%), case reports (100%), and teaching activities (38%). The remaining three categories of basic scientific research, quality improvement, and book chapters showed no change.

Conclusions:

The implementation of the 2017 Endocrinology Fellowship Scholarly Activity Curriculum was associated with a rise in trainee scholarly activity. Four of eight categories showed an 80% or more increase. Interestingly, the fellows involved in basic scientific research both pre and post-curriculum implementation were limited to those in the Specialty Training and Advanced Research (STAR) Program. Finally, identifying the need to increase involvement in quality improvement research, our program has implemented a 2019 Quality Improvement Curriculum.

¹Common Program Requirements (Fellowship). ACGME. https://www.acgme.org/What-We-Do/Accreditation/Common-Program-Requirements. 2018. Accessed Nov 2019.

Association of Subclinical Hypothyroidism and Cardiovascular Disease With Mortality

IMPORTANCE

Subclinical hypothyroidism is a common clinical entity among US adults associated in some studies with an increase in the risk of cardiovascular disease (CVD) and mortality. However, the extent to which CVD mediates the association between elevated serum thyrotropin (TSH) and mortality has not yet been well established or sufficiently quantified.

OBJECTIVE

To elucidate the extent to which subclinical hypothyroidism, elevated serum TSH and normal serum free thyroxine, or high-normal TSH concentrations (ie, upper normative-range TSH concentrations) are associated with mortality through CVD among US adults.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study relied on representative samples of US adults enrolled in the National Health and Nutrition Examination Survey in 2001 to 2002, 2007 to 2008, 2009 to 2010, and 2011 to 2012 and their mortality data through 2015. Data were analyzed from January to August 2019.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards regression models were used to investigate associations between the TSH concentration category (subclinical hypothyroidism or tertiles of serum TSH concentrations within the reference range; low-normal TSH, 0.34-1.19 mIU/L; middle-normal TSH, 1.20-1.95 mIU/L; and high-normal TSH, 1.96-5.60 mIU/L) and all-cause mortality. Mediation analysis was used within the counterfactual framework to estimate natural direct associations (not through CVD) and indirect associations (through CVD).

RESULTS

Of 9020 participants, 4658 (51.6%) were men; the mean (SD) age was 49.4 (17.8) years. Throughout follow-up (median [interquartile range], 7.3 [5.4-8.3] years), serum thyroid function test results consistent with subclinical hypothyroidism and high-normal TSH concentrations were both associated with increased all-cause mortality (subclinical hypothyroidism: hazard ratio, 1.90; 95% CI, 1.14-3.19; high-normal TSH: hazard ratio, 1.36; 95% CI, 1.07-1.73) compared with the middle-normal TSH group. Cardiovascular disease mediated 14.3% and 5.9% of the associations of subclinical hypothyroidism and high-normal TSH with all-cause mortality, respectively, with the CVD mediation being most pronounced in women (7.5%-13.7% of the association) and participants aged 60 years and older (6.0%-14.8% of the association).

CONCLUSIONS AND RELEVANCE

In this study, CVD mediated the associations of subclinical hypothyroidism and high-normal TSH concentrations with all-cause mortality in the US general population. Further studies are needed to examine the clinical benefit of thyroid hormone replacement therapy targeted to a middle-normal TSH concentration or active CVD screening for people with elevated TSH concentrations.

Levothyroxine for the Treatment of Subclinical Hypothyroidism and Cardiovascular Disease

Subclinical hypothyroidism is a biochemical condition defined by elevated serum thyroid-stimulating hormone levels in the setting of normal levels of the peripheral thyroid hormones, thyroxine and triiodothyronine. Thyroid hormones act on the heart through various mechanisms and subclinical hypothyroidism has been associated with risk factors for cardiovascular disease, such as hypertension and dyslipidemia. In addition, evidence from multiple studies supports an association between subclinical hypothyroidism and cardiovascular disease. However, the use of levothyroxine in subclinical hypothyroidism to reduce cardiovascular disease risk is not clearly beneficial. Treatment with levothyroxine may only provide benefit in certain subgroups, such as patients who are younger or at higher risk of cardiovascular disease. At present, most of the international societal guidelines advise that treatment decisions should be individualized based on patient age, degree of serum thyroid-stimulating hormone (TSH) elevation, symptoms, cardiovascular disease (CVD) risk, and other co-morbidities. Further study in this area is recommended.

The Role of Serum Procalcitonin in Predicting Bacterial Sepsis in Patients With Hypothyroidism

CONTEXT

Serum levels of procalcitonin (PCT), a protein produced by the thyroid C cells under physiologic conditions, are high during sepsis.

OBJECTIVE

To assess the test performance of serum PCT in predicting bacterial sepsis and septic shock in patients with hypothyroidism compared with those who have euthyroidism.

DESIGN AND METHODS

This retrospective study evaluated patients with no history of thyroid dysfunction (euthyroid), primary hypothyroidism [medical hypothyroidism (MH)], and postsurgical hypothyroidism from total thyroidectomy (TT) identified from a prospectively maintained database who had PCT testing from 2005 to 2018. Quick Sequential Organ Failure Assessment score ≥ 2 or positive bacterial cultures identified bacterial sepsis, and a mean arterial pressure less than 65 mm Hg or a vasopressor requirement defined septic shock. Sensitivity and specificity of PCT for evaluation of bacterial sepsis and septic shock were measured.

RESULTS

We identified 217 euthyroid patients, 197 patients with MH, and 84 patients with TT. Bacterial sepsis was found in 98 (45.2%), 92 (46.7%), and 36 (42.9%) of these patients, respectively (P > 0.05). Septic shock was identified in 13 (6.0%), 13 (6.6%), and 5 (6.0%) patients (P > 0.05), respectively. With use of a PCT cutoff of 0.5 µg/L for bacterial sepsis, the sensitivity was 59%, 61%, and 53% (P > 0.05) and specificity was 81%, 77%, and 81% (P > 0.05) for the diagnosis of bacterial sepsis in euthyroid, MH, and TT patients, respectively. With use of a PCT cutoff of 2.0 µg/L for septic shock, the sensitivity was 46%, 62%, and 63% (P > 0.05) and specificity was 86%, 82%, and 91% (P > 0.05) for the diagnosis of septic shock in these patients, respectively.

CONCLUSIONS

Despite the thyroidal origin of PCT, hypothyroidism did not affect the diagnostic performance of serum PCT levels in predicting bacterial sepsis or septic shock.

NO BENEFIT OF DEDICATED THYROID NODULE SCREENING IN PATIENTS WITH ACROMEGALY

Objective: Acromegaly results from the excessive production of growth hormone and insulin-like growth factor-1. While there is up to a 2-fold increased prevalence of thyroid nodules in patients with acromegaly, the incidence of thyroid cancer in this population varies from 1.6 to 10.6% in several European studies. The goal of our study was to determine the prevalence of thyroid nodules and thyroid cancer among patients with acromegaly at a large urban academic medical center in the United States (U.S.). Methods: A retrospective chart review was performed of all patients with acromegaly between 2006-2015 within the University of California, Los Angeles health system. Data were collected regarding patient demographics, thyroid ultrasounds, thyroid nodule fine needle aspiration (FNA) biopsy cytology, and thyroid surgical pathology. Results: In this cohort (n = 221, 49.3% women, mean age 53.8 ± 15.2 [SD] years, 55.2% Caucasian), 102 patients (46.2%) underwent a thyroid ultrasound, from which 71 patients (52.1% women, mean age 52.9 ± 15.2 [SD] years, 56.3% Caucasian) were found to have a thyroid nodule. Seventeen patients underwent a thyroid nodule FNA biopsy and the results revealed 12 benign biopsies, 1 follicular neoplasm, 3 suspicious for malignancy, and 1 papillary thyroid cancer (PTC), from which 6 underwent thyroidectomy; PTC was confirmed by surgical pathology for all cases (8.5% of all nodules observed). Conclusion: In this sample, the prevalence of thyroid cancer in patients with acromegaly and coexisting thyroid nodules is similar to that reported in the general U.S. population with thyroid nodules (7 to 15%). These findings suggest that there is no benefit of dedicated thyroid nodule screening in patients newly diagnosed with acromegaly. Abbreviations: AACE = American Association of Clinical Endocrinologists; ATA = American Thyroid Association; DTC = differentiated thyroid cancer; FNA = fine needle aspiration; GH = growth hormone; IGF-1 = insulin-like growth factor-1; PTC = papillary thyroid cancer; U.S. = United States.

REDUCING INAPPROPRIATE SERUM T3 LABORATORY TEST ORDERING IN PATIENTS WITH TREATED HYPOTHYROIDISM

Objective: Choosing Wisely is a campaign of the American Board of Internal Medicine that aims to promote evidence-based practices to reduce unnecessary ordering of tests or procedures. As part of this campaign, the Endocrine Society advises against ordering a serum total or free triiodothyronine (T3) level when assessing levothyroxine dosing in hypothyroid patients. This study was performed to assess and reduce inappropriate laboratory ordering practices among providers who manage patients with hypothyroidism within a large U.S. academic health system. Methods: A best practice alert (BPA) in the health record was developed and implemented following the collection of baseline data. This alert consisted of a popup window that was triggered when a serum T3 laboratory test was ordered for patients prescribed levothyroxine. The alert required user acknowledgement before the serum T3 laboratory test could be ordered. Results: During the 6-week period prior to launching the BPA, serum T3 tests were ordered a mean of 162.3 ± 15.4 (standard deviation) occurrences per 10,000 patients per week. Over a 15-week period following implementation of the BPA, the frequency of serum T3 orders steadily decreased and resulted in >44% fewer inappropriate tests being ordered. Conclusion: Although national societal guidelines recommend against ordering serum T3 concentrations while monitoring patients with hypothyroidism managed with levothyroxine, these laboratory tests are frequently ordered. Development of a triggered alert in the health record may reduce inappropriate monitoring practices, decrease costs, and improve utilization of limited health-care resources for this common clinical condition. Abbreviations: ATA = American Thyroid Association; BPA = best practice alert; T3 = triiodothyronine; TSH = thyroid-stimulating hormone.

Endocrinology practice patterns of hypothyroidism and osteoporosis management in a U.S. tertiary academic medical center

Background

The major published clinical guidelines for the management of hypothyroidism and osteoporosis are not uniformly consistent and may be a significant contributor to variability of clinical care delivered by endocrinologists, in addition to other factors, such as physician experience, physician and patient perceptions, and patient comorbidities. The purpose of this study was to assess practice patterns of hypothyroidism and osteoporosis within an academic endocrine clinic.

Methods

A retrospective medical record review of the first 200 adult patients (n = 100 with primary hypothyroidism and n = 100 with osteoporosis or osteopenia) seen by an endocrinologist beginning January 2, 2017at a large U.S. urban tertiary academic medical center was performed. Data were collected regarding patient demographics, clinic visit type, patterns of ordering laboratory tests and imaging, and choice of pharmacologic treatment.

Results

Most patients with hypothyroidism (99%) had a serum thyroid stimulating hormone concentration measured. Other thyroid indices measured included serum total thyroxine (10%), serum free thyroxine [T4] (82%), serum free T4 index (6%), serum total triiodothyronine [T3] (9%), and serum free T3 (12%). Forty-eight percent also had serum thyroid antibodies checked. A variety of thyroid hormone supplements were used to treat hypothyroidism, including levothyroxine (83%), levothyroxine and liothyronine combination (8%), and desiccated thyroid extract (6%). In regards to patients with osteoporosis, mean duration of all pharmacologic therapy combined was 73.4 ± 81.9 months. For those with more than one bone density (DXA) scans (64%), the mean time interval between two consecutive DXA scans was variable (mean 32.0 ± 24.7 [SD] months). Sixty eight percent of the patients had bone turnover markers assessed within 7 months of the visit.

Conclusions

This study reports a real-world experience of endocrinology practice patterns at a large U.S. academic healthcare system. For the common diagnoses of hypothyroidism and osteoporosis, there are opportunities for increased standardization of care, particularly regarding the ordering of laboratory testing and radiologic studies. Identifying areas with significant practice variability may improve the quality and health outcomes and reduce the cost of care for patients with these conditions. Increased understanding regarding the reasons behind ordering various studies may help physician and patients further align their goals.