Feldt-Rasmussen, Ulla

Background: International guidelines recommend targeted screening to identify gestational thyroid dysfunction. However, currently used risk factors have questionable discriminative ability. We quantified the risk for thyroid function test abnormalities for a subset of risk factors currently used in international guidelines. Methods: We included prospective cohort studies with data on gestational maternal thyroid function and potential risk factors (maternal age, body mass index [BMI], parity, smoking status, pregnancy through in vitro fertilization, twin pregnancy, gestational age, maternal education, and thyroid peroxidase antibody [TPOAb] or thyroglobulin antibody [TgAb] positivity). Exclusion criteria were pre-existing thyroid disease and use of thyroid interfering medication. We analyzed individual participant data using mixed-effects regression models. Primary outcomes were overt and subclinical hypothyroidism and a treatment indication (defined as overt hypothyroidism, subclinical hypothyroidism with thyrotropin >10 mU/L, or subclinical hypothyroidism with TPOAb positivity). Results: The study population comprised 65,559 participants in 25 cohorts. The screening rate in cohorts using risk factors currently recommended (age >30 years, parity ≥2, BMI ≥40) was 58%, with a detection rate for overt and subclinical hypothyroidism of 59%. The absolute risk for overt or subclinical hypothyroidism varied <2% over the full range of age and BMI and for any parity. Receiver operating characteristic curves, fitted using maternal age, BMI, smoking status, parity, and gestational age at blood sampling as explanatory variables, yielded areas under the curve ranging from 0.58 to 0.63 for the primary outcomes. TPOAbs/TgAbs positivity was associated with overt hypothyroidism (approximate risk for antibody negativity 0.1%, isolated TgAb positivity 2.4%, isolated TPOAb positivity 3.8%, combined antibody positivity 7.0%; p < 0.001), subclinical hypothyroidism (risk for antibody negativity 2.2%, isolated TgAb positivity 8.1%, isolated TPOAb positivity 14.2%, combined antibody positivity 20.0%; p < 0.001) and a treatment indication (risk for antibody negativity 0.2%, isolated TgAb positivity 2.2%, isolated TPOAb positivity 3.0%, and combined antibody positivity 5.1%; p < 0.001). Twin pregnancy was associated with a higher risk of overt hyperthyroidism (5.6% vs. 0.7%; p < 0.001). Conclusions: The risk factors assessed in this study had poor predictive ability for detecting thyroid function test abnormalities, questioning their clinical usability for targeted screening. As expected, TPOAb positivity (used as a benchmark) was a relevant risk factor for (subclinical) hypothyroidism. These results provide insights into different risk factors for gestational thyroid dysfunction.

Abstract Disclosure: S.L. Samson: Consulting Fee; Self; Novartis Pharmaceuticals, Chiasma. M. Bolanowski: Grant Recipient; Self; Amryt, Recordati, Pfizer, Inc., Novartis Pharmaceuticals, Ipsen, IBSA, Teva Pharmaceutical Industries Ltd., Berlin Chemie. Speaker; Self; Amryt, Recordati, Pfizer, Inc., Novartis Pharmaceuticals, Ipsen, IBSA, Teva Pharmaceutical Industries Ltd., Berlin Chemie. S. Zhang: None. Y. Yu: None. P. Witek: Grant Recipient; Self; Novartis Pharmaceuticals, Ipsen, Recordati, Novo Nordisk, Xeris Pharmaceuticals (Strongbridge), Lilly USA, LLC. Speaker; Self; Novartis Pharmaceuticals, Ipsen, Recordati, Novo Nordisk, Xeris Pharmaceuticals (Strongbridge), Lilly USA, LLC. N. Kietsiriroje: None. A. Piacentini: Employee; Self; Recordati. A.M. Pedroncelli: Employee; Self; Recordati. U. Feldt-Rasmussen: Advisory Board Member; Self; Novartis Pharmaceuticals, Recordati, Novo Nordisk, Xeris Pharmaceuticals (Strongbridge). Grant Recipient; Self; Ipsen, Recordati, Novo Nordisk. Speaker; Self; Ipsen, Recordati, Novo Nordisk. Introduction: Pasireotide efficacy and safety in persons with acromegaly or Cushing’s disease (CD) is confirmed in a comprehensive clinical trial program. Pasireotide-induced hyperglycemia events, expected based on the drug’s mechanism of action, are manageable with low rates of treatment discontinuation. To advance knowledge on pasireotide-induced hyperglycemia management, a prospective randomized Phase IV study (B2219, NCT02060383) was conducted. This secondary analysis assessed factors that might predict development of pasireotide-induced hyperglycemia. Methods: In B2219, participants (Pts) with acromegaly or CD who did not need therapy for hyperglycemia or were managed with metformin alone entered the non-randomized observational arm. Pts who developed hyperglycemia not managed with metformin alone were randomized to incretin-based therapy or insulin. This analysis evaluated Pts according to whether therapy for hyperglycemia during pasireotide treatment was needed. Logistic regression analyses evaluated quantitative and qualitative predictive factors associated with pasireotide-induced hyperglycemia. Results: Of 190 Pts with acromegaly and 59 with CD, 88 and 15, respectively, did not need antihyperglycemic medication during pasireotide treatment; Pt characteristics were generally balanced across subgroups at study baseline (BL). Most Pts who did not develop hyperglycemia had a mean age of &lt;40 years (acromegaly 62.5%, CD 86.7%), BL glycated hemoglobin (HbA1c) &lt;6.5% (acromegaly 98.9%, CD 100.0%) and BL fasting plasma glucose (FPG) &lt;100 mg/dL (acromegaly 76.1%, CD 100.0%). Age (odds ratio [OR] 1.0, 95% CI 1.0−1.1), BL HbA1c (OR 3.5, 95% CI 1.3−9.9) and prediabetes or diabetes conditions (OR 3.0, 95% CI 1.2−7.6) were identified as risk factors associated with pasireotide-induced hyperglycemia in Pts with acromegaly. BL FPG (OR 1.2, 95% CI 1.0−1.3) was associated with increased risk of pasireotide-induced hyperglycemia in Pts with CD. Overall, adverse events (AEs) of hyperglycemia and diabetes mellitus (investigator reported) occurred in 21.1% and 14.2% of Pts with acromegaly and 28.8% and 11.9% of Pts with CD, respectively. More Pts who had diabetes or prediabetes conditions at BL had hyperglycemia-related AEs than Pts with normal glucose levels. Hyperglycemia-related AEs were managed with antihyperglycemic medication (acromegaly 26.3%, CD 30.5%); few Pts temporarily interrupted treatment (acromegaly 3.7%, CD 10.2%). Conclusions: These data suggest that age, HbA1c, FPG and having prediabetes or diabetes conditions at BL are associated with increased risk of developing pasireotide-induced hyperglycemia. AEs were manageable with antihyperglycemic medication. Potential risk factors associated with pasireotide-induced hyperglycemia may be used to identify Pts who need vigilant monitoring to ensure optimal outcomes during pasireotide treatment. Presentation: Thursday, June 15, 2023

AbstractObjectiveThyroglobulin measurement is the cornerstone of modern management of differentiated thyroid cancer, with clinical decisions on treatment and follow-up based on the results of such measurements. However, numerous factors need to be considered regarding measurement with and interpretation of thyroglobulin assay results.DesignThe present document provides an integrated update to the 2013 and 2014 separate clinical position papers of our group on these issues.MethodsIssues concerning analytical and clinical aspects of highly-sensitive thyroglobulin measurement will be reviewed and discussed based on an extensive analysis of the available literature.ResultsThyroglobulin measurement remains a highly complex process with many pitfalls and major sources of interference, especially anti-thyroglobulin antibodies, need to be assessed, considered and, when necessary, dealt with appropriately.ConclusionsOur expert consensus group formulated 53 practical, graded recommendations for guidance on highly-sensitive thyroglobulin and TgAb in laboratory and clinical practice, especially valuable where current guidelines do not offer sufficient guidance.

Abstract Context Interpretation of thyroid function tests during pregnancy is limited by the generalizability of reference intervals between cohorts due to inconsistent methodology. Objective (1) To provide an overview of published reference intervals for thyrotropin (TSH) and free thyroxine (FT4) in pregnancy, (2) to assess the consequences of common methodological between-study differences by combining raw data from different cohorts. Methods (1) Ovid MEDLINE, EMBASE, and Web of Science were searched until December 12, 2021. Studies were assessed in duplicate. (2) The individual participant data (IPD) meta-analysis was performed in participating cohorts in the Consortium on Thyroid and Pregnancy. Results (1) Large between-study methodological differences were identified, 11 of 102 included studies were in accordance with current guidelines; (2) 22 cohorts involving 63 198 participants were included in the meta-analysis. Not excluding thyroid peroxidase antibody–positive participants led to a rise in the upper limits of TSH in all cohorts, especially in the first (mean +17.4%; range +1.6 to +30.3%) and second trimester (mean +9.8%; range +0.6 to +32.3%). The use of the 95th percentile led to considerable changes in upper limits, varying from –10.8% to –21.8% for TSH and –1.2% to –13.2% for FT4. All other additional exclusion criteria changed reference interval cut-offs by a maximum of 3.5%. Applying these findings to the 102 studies included in the systematic review, 48 studies could be used in a clinical setting. Conclusion We provide an overview of clinically relevant reference intervals for TSH and FT4 in pregnancy. The results of the meta-analysis indicate that future studies can adopt a simplified study setup without additional exclusion criteria.