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Wu Y, Deng YL, Zhang M, Miao Y, Cui FP, Zeng JY, Liu XY, Li CR, Liu AX, Zhu JQ, Li YJ, Liu C, Zeng Q. Urinary haloacetic acid concentrations and thyroid function among women: Results from the TREE study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172368. [PMID: 38614346 DOI: 10.1016/j.scitotenv.2024.172368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/08/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024]
Abstract
BACKGROUND Disinfection byproducts (DBPs) have been shown to impair thyroid function in experimental models. However, epidemiological evidence is scarce. METHODS This study included 1190 women undergoing assisted reproductive technology (ART) treatment from the Tongji Reproductive and Environmental (TREE) cohort from December 2018 to August 2021. Serum thyrotropin (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were measured as indicators of thyroid function. FT4/FT3 and TSH/FT4 ratios were calculated as markers of thyroid hormone homeostasis. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), the two most abundant HAAs, in urine were detected to assess individual DBP exposures. RESULTS After adjusting for relevant covariates, positive associations were observed between urinary TCAA concentrations and serum TSH and TSH/FT4 levels (e.g., percent change = 5.82 %, 95 % CI: 0.70 %, 11.21 % for TSH), whereas inverse associations were found for serum FT3 and FT4 (e.g., percent change = -1.29 %, 95 % CI: -2.49 %, -0.07 % for FT3). There also was a negative association between urinary DCAA concentration and serum FT4/FT3 (percent change = -2.49 %, 95 % CI: -4.71 %, -0.23 %). These associations were further confirmed in the restricted cubic spline and generalized additive models with linear or U-shaped dose-response relationships. CONCLUSION Urinary HAAs were associated with altered thyroid hormone homeostasis among women undergoing ART treatment.
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Affiliation(s)
- Yang Wu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yan-Ling Deng
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Min Zhang
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yu Miao
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Fei-Peng Cui
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Jia-Yue Zeng
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xiao-Ying Liu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Cheng-Ru Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - A-Xue Liu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Jin-Qin Zhu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yang-Juan Li
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Chong Liu
- Department of Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China..
| | - Qiang Zeng
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China; Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, PR China.
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Kouvari M, Valenzuela-Vallejo L, Axarloglou E, Verrastro O, Papatheodoridis G, Mingrone G, George J, Mantzoros CS. Thyroid function, adipokines and mitokines in metabolic dysfunction-associated steatohepatitis: A multi-centre biopsy-based observational study. Liver Int 2024; 44:848-864. [PMID: 38263703 DOI: 10.1111/liv.15847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/11/2023] [Accepted: 01/07/2024] [Indexed: 01/25/2024]
Abstract
BACKGROUND AND AIMS Thyroid axis is currently under investigation as a therapeutic target in metabolic dysfunction-associated steatotic liver disease (MASLD). Thyroid function was examined herein in the full spectrum of disease. METHODS Subjects were recruited and had liver biopsies in two Gastroenterology-Hepatology Clinics (Greece and Australia) and one Bariatric-Metabolic Surgery Clinic (Italy). The main working sample was n = 677 subjects with MASLD after excluding subjects with abnormal free thyroxine levels. Participants were classified according to thyroid-stimulating hormone (TSH) standard criteria: Subclinical hyperthyroidism (<0.4 uIU/mL); Euthyroidism with relatively low (0.4 to <2.5 uIU/mL); euthyroidism with relatively high (2.5-4.0 uIU/mL); subclinical hypothyroidism (>4 uIU/mL). RESULTS TSH as a continuous variable was positively associated with significant fibrosis (F ≥ 2), metabolic dysfunction-associated steatohepatitis (MASH) and at-risk MASH. Subclinical hypothyroidism was associated with fibrosis F ≥ 2 (odds ratio [OR] = 3.47, 95% confident interval [CI] [1.50, 8.05], p = .02), MASH (OR = 3.44, 95% CI [1.48, 7.98] p = .001) and at-risk MASH (OR = 3.88, 95% CI [1.76, 8.55], p = .001), before and after controlling for adiposity, central obesity, and insulin resistance. When leptin, adiponectin, or growth differentiation factor-15 were examined as moderators, significance was lost. Sex-specific analysis revealed a strong association between TSH and the presence of significant fibrosis among women, eliminated only when adipokines/mitokines were adjusted for. Restricted cubic spline analysis revealed associations between TSH and liver outcomes (p-values < .01) with inflection points for fibrosis F ≥ 2 being 2.49, for MASH being 2.67 and for at-risk MASH being 6.96. CONCLUSIONS These observations provide support for studies on the administration of thyroid hormone in MASLD therapeutics for subclinical hypothyroidism and liver-specific thyroid receptor agonists for subjects across the TSH continuum.
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Affiliation(s)
- Matina Kouvari
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Laura Valenzuela-Vallejo
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Evangelos Axarloglou
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Georgios Papatheodoridis
- Department of Gastroenterology, Medical School of National and Kapodistrian University of Athens, General Hospital of Athens "Laiko", Athens, Greece
| | | | - Jacob George
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Sydney, New South Wales, Australia
| | - Christos S Mantzoros
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medicine, Boston VA Healthcare System, Boston, Massachusetts, USA
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Loh TP, Ehrenkranz J, Halsall D, Hoff K, Spencer CA, Van Uytfanghe K, Köhrle J. Response to Fitzgerald et al. re: "Thyroid Stimulating Hormone and Thyroid Hormones (Triiodothyronine and Thyroxine): An American Thyroid Association-Commissioned Review of Current Clinical and Laboratory Status". Thyroid 2024; 34:276-278. [PMID: 38236706 DOI: 10.1089/thy.2023.0604] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Affiliation(s)
- Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Joel Ehrenkranz
- Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - David Halsall
- Cambridge University Hospitals Trust, Addenbrookes Hospital, Cambridge, United Kingdom
| | - Kelly Hoff
- American Thyroid Association, Headquarters, Alexandria, Virginia, USA
| | - Carole A Spencer
- Department of Medicine, University of Southern California, Los Angeles, California, USA
| | - Katleen Van Uytfanghe
- Ref4U-Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Josef Köhrle
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Experimentelle Endokrinologie, Berlin, Germany
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Alkhalaileh H, Wei R, Lee JKY, Jones J, Li J. Relationship between TSH and free thyroxine in outpatient cancer patient population. Endocrine 2023; 82:319-325. [PMID: 37286745 DOI: 10.1007/s12020-023-03399-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 05/10/2023] [Indexed: 06/09/2023]
Abstract
BACKGROUND The inverse log-linear relationship between Thyroid-stimulating hormone (TSH) and free thyroxine (FT4) is well established and reliably used for evaluation of hypothalamus-pituitary-thyroid (HPT) axis function. However, there are limited data regarding oncologic states in the TSH-FT4 relationship. The purpose of this study was to evaluate thyroid pituitary hypothalamic feedback regulation by the inverse log TSH and FT4 relationship in the cancer patient population at the Ohio State University Comprehensive Cancer Center (OSUCCC-James). METHODS This retrospective study analyzed the correlation between TSH and FT4 results from 18846 outpatient subjects collected in August 2019-November 2021 at the Department of Family Medicine (OSU Wexner Medical Center), Department of Oncology (OSUCCC-James). Patients with diagnoses related to cancers were included in the oncology group. Patients with diagnoses not related to cancers were included in the non-oncology group. Patients of the Department of Endocrinology, Department of Cardiology, Department of Obstetrics & Gynecology and Department of Hematology were excluded from this study. Time of collection for TSH and FT4 was from 7am to 7 pm. Data were analyzed by morning (7am-12pm) and afternoon (12pm-7pm). Spearman correlation and non-linear fit were used for data analysis. Sex differences were analyzed as well in each group. RESULTS Overall, an inverse correlation was observed between TSH and FT4 in both groups (non-oncology and oncology) regardless of sample collection time and sex differences. Further analysis by linear model in log TSH and FT4 showed a significant inverse fit in males compared with females in the group of oncology, both in the afternoon (p < 0.05). Data were further analyzed by ranges of FT4, as lower or higher (pathophysiology) or within (physiology) the reference interval of FT4. There was no statistical significance between the non-oncology and oncology groups, but relatively good correlation in non-oncology group in either physiologic or pathophysiologic FT4 levels and sample collection time. Interestingly, the best correlation between TSH and FT4 was found in the non-oncology group at pathophysiologic FT4 concentrations (abnormally high). In addition, at pathophysiologic FT4 concentrations (abnormally low), the oncology group demonstrated a significant TSH response in the morning than in the afternoon (p < 0.05). CONCLUSIONS Though overall the TSH-FT4 curves showed an inverse relationship, there are variations of TSH-FT4 relationship for collection times when considering FT4 in physiologic or pathophysiologic states. The results advance understanding of TSH response, which is beneficial for the interpretation of thyroid disease. We recommend re-evaluation for interpretation of pituitary hypothalamic axis by TSH results when FT4 is abnormally high in oncology patients or low in non-oncology patients, due to poor predictability and the potential for misdiagnosis. A better understanding of the complex nature of the TSH-FT4 relationship may need further study with better defining subclinical states of cancer patients.
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Affiliation(s)
| | - Ruhan Wei
- Department of Pathology, Duke University School of Medicine, Durham, NC, USA
| | - Jason K Y Lee
- Department of Clinical Laboratory, University Hospital, the Ohio State University, Columbus, OH, USA
| | - JoAnna Jones
- Department of Pathology, the Ohio State University Wexner Medical Center, Columbus, OH, USA.
| | - Jieli Li
- Department of Pathology, the Ohio State University Wexner Medical Center, Columbus, OH, USA.
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5
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Lin Y, Riek AE, Gronowski AM, Farnsworth CW. Limited Utility of Free Triiodothyronine Testing. J Appl Lab Med 2023; 8:847-855. [PMID: 37473430 DOI: 10.1093/jalm/jfad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 03/31/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND Free triiodothyronine (fT3) testing is most useful when thyroid stimulating hormone (TSH) is suppressed, and free thyroxine (fT4) is normal or decreased. These laboratory values in a symptomatic patient are referred to as T3 thyrotoxicosis. Standards for fT3 reflex testing have not been established. Herein, we examined the clinical utility of fT3 with the goal of identifying a TSH cutoff in the context of normal/decreased fT4 that maximizes the utility of measuring fT3. METHODS TSH, fT4, and fT3 results between January 2016 and October 2021 were extracted from the laboratory information system and grouped if resulted on the same day for the same patient. Frequency of biochemical T3 thyrotoxicosis was evaluated at different TSH cutoffs and in outpatient vs inpatient settings. RESULTS Of the 4366 TSH-fT4-fT3 results, 70 (1.6%) were consistent with biochemical T3 thyrotoxicosis. The common reasons were previously diagnosed hyperthyroidism on antithyroid medication (n = 28) or hypothyroidism on thyroid medication (n = 18) and newly diagnosed hyperthyroidism (n = 20, 0.5%). The likelihood of detecting T3 thyrotoxicosis increased with lower TSH cutoff (<0.3 μIU/mL, 10.3% vs <0.0 1μIU/mL, 27.6%). All patients with newly diagnosed hyperthyroidism had TSH <0.01 μIU/mL. Higher frequency of T3 thyrotoxicosis was observed in the outpatient setting (34%) relative to the inpatient setting (14%, P < 0.001) when TSH < 0.01 μIU/mL. CONCLUSIONS T3 thyrotoxicosis is a relatively rare diagnosis and fT3 measurement has limited utility in the vast majority of patients. A fT3 reflex for patients with TSH <0.01 μIU/mL and normal/low fT4 may improve clinical utility and reduce unnecessary testing, especially in the outpatient setting.
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Affiliation(s)
- Yanchun Lin
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Amy E Riek
- Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, MO, United States
| | - Ann M Gronowski
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Christopher W Farnsworth
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
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6
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Odawara S, Shimbo T, Yamauchi T, Kobayashi D. Association of Low-Normal Free T4 Levels With Future Major Depression Development. J Endocr Soc 2023; 7:bvad096. [PMID: 37528949 PMCID: PMC10387582 DOI: 10.1210/jendso/bvad096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Indexed: 08/03/2023] Open
Abstract
Context Hyperthyroidism and overt and subclinical hypothyroidism are associated with major depression; however, the association of major depression across the spectrum of thyroid function within the normal range is unknown. Objective We investigated whether higher or lower levels of free thyroxine (T4) and thyrotropin (TSH) within the normal range are associated with major depression. Methods This was a retrospective cohort study of 66 960 participants with normal thyroid function who visited for health checkups (St. Luke's International Hospital, 2005-2018). The primary outcome was the development of major depression during the follow-up period. Participants were divided into 3 equal groups based on baseline free T4 or TSH values (low-, middle-, or high-normal), and the incidence of major depression was compared using the Cox proportional hazard model after adjusting for potential covariates. Results During the median follow-up of 1883 days, 1363 (2.0%) patients developed major depression. The low-normal free T4 group had a significantly higher risk of major depression (adjusted HR 1.15; 95% CI, 1.01-1.31), but not the high-normal free T4 group or TSH groups. The association between low-normal free T4 and the development of major depression was maintained, rather more obvious, upon exclusion of participants whose thyroid hormone levels became abnormal during follow-up compared with data from all participants (adjusted HR 1.24; 95% CI, 1.07-1.43). Conclusion In this cohort, low-normal free T4 was associated with an increased risk of future major depression, even if subsequent hormone levels were maintained within the normal range. The magnitude of the impact of low-normal free T4 was relatively mild.
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Affiliation(s)
- Sara Odawara
- Correspondence: Sara Odawara, MD, PhD, Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
| | - Takuro Shimbo
- Department of Medicine, Ohta Nishinouchi Hospital, Fukushima 963-8558, Japan
| | - Toshimasa Yamauchi
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Daiki Kobayashi
- Division of General Internal Medicine, Department of Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0332, Japan
- Department of Medicine, Fujita Health University, Aichi 470-1192, Japan
- Department of General Medicine, Juntendo University Faculty of Medicine, Tokyo 113-8421, Japan
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Loh TP, Ehrenkranz J, Halsall D, Spencer CA, Van Uytfanghe K, Köhrle J. Clinical interpretation of thyroid tests: considerations for reference intervals. Thyroid 2023; 33:404-406. [PMID: 36927102 DOI: 10.1089/thy.2023.0096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Affiliation(s)
- Tze Ping Loh
- National University Hospital, Singapore. , Department of Laboratory Medicine, , Singapore, Singapore;
| | - Joel Ehrenkranz
- California Institute of Technology, Department of Chemistry and Chemical Engineering, Pasadena, California, United States;
| | - David Halsall
- Cambridge University Hospitals NHS Foundation Trust, 2153, Clinical BIochemistry, Cambridge, United Kingdom of Great Britain and Northern Ireland, CB2 0QQ;
| | - Carole A Spencer
- University Southern California, Department of Medicine, Los Angeles, California, United States;
| | - Katleen Van Uytfanghe
- Ghent University, 26656, Ref4U (Former Laboratory for Analytical Chemistry) - Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Gent, Belgium;
| | - Josef Köhrle
- Charité, Inst. Exp. Endokrinologie, Schumannstr. 20/21, Berlin, Germany, D-10098;
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Goede SL. Fast Track Treatment of Hypothyroidism with Levothyroxine: Reaching Homeostasis within Four Weeks. Acta Biotheor 2023; 71:10. [PMID: 36881192 DOI: 10.1007/s10441-023-09461-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 02/17/2023] [Indexed: 03/08/2023]
Abstract
With the current clinical method for the treatment of hypothyroidism the target for the optimum individual values for free thyroxine concentrations [FT4] and thyrotropine concentrations [TSH] of the specific patient are unknown. This situation leads to unnecessary long experimental medication administration that can take a period of sometimes one year. In this article a method will be described where hypothyroid patients are characterized with weekly measured FT4 and TSH concentrations during the first three weeks of synthetic thyroxine or levothyroxine (L-T4) treatment to predict their optimum [FT4] and belonging [TSH] endpoint for a euthyroid homeostatic state. The treatment with levothyroxine will start for all patients with a reference dose of 100 µg, which can be adjusted by the treating physician to a more safe and appropriate dose for the individual which is monitored with weekly thyroid function tests to observe the progress. After three weeks all characteristics of the patient can be inferred from the measured data. The final titration target together with the individual thyroxine half life can be calculated. With the known characteristics and the L-T4 titration target the clinician or treating physician has an instrument to reduce the experimental treatment burden for the patient from one year to a maximum of four weeks.
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9
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Derakhshan A, Kortenkamp A, Shu H, Broeren MAC, Lindh CH, Peeters RP, Bornehag CG, Demeneix B, Korevaar TIM. Association of per- and polyfluoroalkyl substances with thyroid homeostasis during pregnancy in the SELMA study. ENVIRONMENT INTERNATIONAL 2022; 167:107420. [PMID: 35870378 DOI: 10.1016/j.envint.2022.107420] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVES To investigate the association of exposure to per- and polyfluoroalkyl substances (PFAS) during early pregnancy with markers of the maternal thyroid system. METHODS Serum concentrations of seven PFAS as well as thyroid stimulating hormone (TSH), free and total thyroxine (FT4 and TT4), free and total triiodothyronine (FT3 and TT3) were measured in pregnant women in early pregnancy in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study. Outcomes were concentrations of TSH and thyroid hormones, FT4/FT3 or TT4/TT3 ratios, TSH/FT4 ratio as a marker of the negative feedback loop, TT4/FT4 or TT3/FT3 ratios as markers of the binding of thyroid hormones to binding proteins. RESULTS The study population comprised 2,008 women with median (95% range) gestational age of 10 (6-14) weeks. There was no association between PFAS and TSH. Higher PFNA, PFDA, PFHpA and PFOA levels were associated with a higher FT4 (largest effect estimate for PFDA: β [95% CI]: 0.27 [0.10 to 0.45], P = 0.002). Higher PFUnDA levels, but no other PFAS, were associated with a lower FT3 (β [95% CI]: -0.05 [-0.09 to -0.01], P = 0.005). Higher PFUnDA levels were associated with lower TT4 (β [95% CI]: -1.58 [-3.07 to -0.09]) and there was an inverted U-shaped association of PFOS with TT4 (P = 0.03). Higher PFDA, PFUnDA, PFHpA levels were associated with a lower TT3. Overall, higher PFAS concentrations were associated with a higher FT4/FT3 ratio and a higher TT4/TT3 ratio. There was no association of PFAS with the TSH/FT4 ratio. Higher concentrations of several PFAS were associated with lower TT4/FT4 and TT3/FT3 ratios. CONCLUSIONS These findings translate results from experimental studies suggesting that exposure to PFAS may interfere with the thyroid system during pregnancy. Further experimental studies should take into account human evidence to better understand the potential underlying mechanisms of thyroid disruption by PFAS exposure.
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Affiliation(s)
- Arash Derakhshan
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands
| | - Andreas Kortenkamp
- Division of Environmental Sciences, College of Health, Medicine and Life Sciences, Brunel University, London, Uxbridge, UK
| | - Huan Shu
- Department of Public Health, Karlstad University, Sweden
| | - Maarten A C Broeren
- Laboratory of Clinical Chemistry and Haematology, Máxima Medical Centre, Veldhoven, De Run, 4600, The Netherlands
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Lund University, Lund, 22363 Lund, Sweden
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands
| | - Carl-Gustaf Bornehag
- Department of Public Health, Karlstad University, Sweden; Icahn School of Medicine at Mount Sinai, New York City, NY, USA
| | - Barbara Demeneix
- Laboratoire d'Evolution des Régulations Endocriniennes, CNRS/Muséum National d'Histoire Naturelle, 57 Rue Cuvier, 75005 Paris, France
| | - Tim I M Korevaar
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, The Netherlands; Department of internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE, Rotterdam, the Netherlands.
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10
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Korem Kohanim Y, Milo T, Raz M, Karin O, Bar A, Mayo A, Mendelson Cohen N, Toledano Y, Alon U. Dynamics of thyroid diseases and thyroid-axis gland masses. Mol Syst Biol 2022; 18:e10919. [PMID: 35938225 PMCID: PMC9358402 DOI: 10.15252/msb.202210919] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 11/23/2022] Open
Abstract
Thyroid disorders are common and often require lifelong hormone replacement. Treating thyroid disorders involves a fascinating and troublesome delay, in which it takes many weeks for serum thyroid‐stimulating hormone (TSH) concentration to normalize after thyroid hormones return to normal. This delay challenges attempts to stabilize thyroid hormones in millions of patients. Despite its importance, the physiological mechanism for the delay is unclear. Here, we present data on hormone delays from Israeli medical records spanning 46 million life‐years and develop a mathematical model for dynamic compensation in the thyroid axis, which explains the delays. The delays are due to a feedback mechanism in which peripheral thyroid hormones and TSH control the growth of the thyroid and pituitary glands; enlarged or atrophied glands take many weeks to recover upon treatment due to the slow turnover of the tissues. The model explains why thyroid disorders such as Hashimoto's thyroiditis and Graves' disease have both subclinical and clinical states and explains the complex inverse relation between TSH and thyroid hormones. The present model may guide approaches to dynamically adjust the treatment of thyroid disorders.
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Affiliation(s)
- Yael Korem Kohanim
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tomer Milo
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Moriya Raz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Omer Karin
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Bar
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Avi Mayo
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Netta Mendelson Cohen
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, Israel
| | - Yoel Toledano
- Division of Maternal Fetal Medicine, Helen Schneider Women's Hospital, Rabin Medical Center, Petah Tikva, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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11
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Derakhshan A, Shu H, Broeren MAC, Lindh CH, Peeters RP, Kortenkamp A, Demeneix B, Bornehag CG, Korevaar TIM. Association of phthalate exposure with thyroid function during pregnancy. ENVIRONMENT INTERNATIONAL 2021; 157:106795. [PMID: 34358912 DOI: 10.1016/j.envint.2021.106795] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/01/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The extent of thyroid disruptive effects of phthalates during pregnancy remains unclear. AIM To investigate the association of maternal urinary phthalates with markers of the thyroid system during early pregnancy. METHODS Urinary concentrations of phthalate metabolites and serum concentrations of thyroid stimulating hormone (TSH), free and total thyroxine (FT4 and TT4) and free and total triiodothyronine (FT3 and TT3) were measured in pregnant women in early pregnancy in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (2007-ongoing), a population-based prospective cohort. RESULTS In the 1,996 included women, higher di-ethyl-hexyl phthalate (DEHP) metabolites were associated with a lower FT4 (β [SE] for the molar sum: -0.13 [0.06], P = 0.03) and a higher TSH/FT4 ratio (0.003 [0.001], P = 0.03). Higher concentrations of di-iso-nonyl phthalate (DINP) metabolites were associated with a lower TT4 (β [SE] for the molar sum: 0.93 [0.44], P = 0.03) as well as with lower TT4/FT4 and TT4/TT3 ratios. Higher metabolites of both dibutyl and butyl-benzyl phthalate (DBP and BBzP) were associated with lower T4/T3 ratio (free and total) and higher FT4/TT4 and FT3/TT3 ratios. A higher diisononyl cyclohexane dicarboxylate (DINCH) metabolite concentration was associated with a higher TT3. CONCLUSIONS These results translate results from experimental studies suggesting that exposure to phthalates may interfere with the thyroid system during pregnancy. This is also true for compounds that have been introduced to replace known disruptive phthalates. Further experimental studies should take into account the human evidence to better investigate the potential underlying mechanisms of thyroid disruption by phthalates.
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Affiliation(s)
- Arash Derakhshan
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands
| | - Huan Shu
- Department of Health Sciences, Karlstad University, 651 88 Karlstad, Sweden
| | - Maarten A C Broeren
- Laboratory of Clinical Chemistry and Haematology, Máxima Medical Centre, Veldhoven, De Run 4600, the Netherlands
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Lund University, Lund, 22363 Lund, Sweden
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands
| | - Andreas Kortenkamp
- Division of Environmental Sciences, College of Health, Medicine and Life Sciences, Brunel University, London, Uxbridge, UK
| | - Barbara Demeneix
- Laboratoire d'Evolution des Régulations Endocriniennes, CNRS/Muséum National d'Histoire Naturelle, 57 Rue Cuvier, 75005 Paris, France
| | - Carl-Gustaf Bornehag
- Department of Health Sciences, Karlstad University, 651 88 Karlstad, Sweden; Icahn School of Medicine at Mount Sinai, New York City, NY 10029-6574, USA
| | - Tim I M Korevaar
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands.
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12
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Khalaf ZA, Jasim HM, Mahdi AA. FOXP3 and IL-10 overexpression: A novel diagnostic biomarker in Iraqi patients having hyperthyroidism treated with radioactive iodine. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Bornikowska K, Gietka-Czernel M, Raczkiewicz D, Glinicki P, Zgliczyński W. Improvements in Quality of Life and Thyroid Parameters in Hypothyroid Patients on Ethanol-Free Formula of Liquid Levothyroxine Therapy in Comparison to Tablet LT4 Form: An Observational Study. J Clin Med 2021; 10:jcm10225233. [PMID: 34830515 PMCID: PMC8624226 DOI: 10.3390/jcm10225233] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 12/17/2022] Open
Abstract
Levothyroxine (LT4) is a standard therapy in hypothyroidism; however, its bioavailability and therapeutic effects might be affected by many factors. Data shows that therapy with liquid LT4 characterized by quicker pharmacokinetics provides better thyroid hormones control than tablet LT4. We addressed the quality of life (QoL) and efficacy of the new ethanol-free formula of liquid LT4 (Tirosint®SOL) treatment in 76 euthyroid patients with primary (PH, n = 46) and central hypothyroidism (CH, n = 30), and compared the results to retrospective data on equivalent doses of tablet L-T4 therapy. After 8 weeks of liquid LT4 therapy, we found a significant improvement in QoL in both PH and CH patients. TSH levels were unaltered in PH patients. Free hormone levels (fT4 and fT3) increased in all the patients, with the exception of fT3 in the CH group. SHBG and low-density lipoprotein (LDL) also improved. Liquid LT4 therapy provided a better thyroid hormone profile and improvement in patients' QoL than the tablet form, which was possibly due to the more favorable pharmacokinetics profile resulting in better absorption, as suggested by the increased free thyroid hormone levels. In summary, this is the first study addressing the QoL in hypothyroid patients, including primary and central hypothyroidism, treated with liquid LT4 formula in everyday practice.
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Affiliation(s)
- Katarzyna Bornikowska
- Department of Endocrinology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland; (M.G.-C.); (P.G.); (W.Z.)
- Correspondence: ; Tel.: +48-600-676-620
| | - Małgorzata Gietka-Czernel
- Department of Endocrinology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland; (M.G.-C.); (P.G.); (W.Z.)
| | - Dorota Raczkiewicz
- Department of Medical Statistics, School of Public Health, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland;
| | - Piotr Glinicki
- Department of Endocrinology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland; (M.G.-C.); (P.G.); (W.Z.)
| | - Wojciech Zgliczyński
- Department of Endocrinology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland; (M.G.-C.); (P.G.); (W.Z.)
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14
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Kuś A, Marouli E, Del Greco M F, Chaker L, Bednarczuk T, Peeters RP, Teumer A, Medici M, Deloukas P. Variation in Normal Range Thyroid Function Affects Serum Cholesterol Levels, Blood Pressure, and Type 2 Diabetes Risk: A Mendelian Randomization Study. Thyroid 2021; 31:721-731. [PMID: 32746749 DOI: 10.1089/thy.2020.0393] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background: Observational studies have demonstrated that variation in normal range thyroid function is associated with major cardiovascular risk factors, including dyslipidemia, hypertension, type 2 diabetes (T2D), and obesity. As observational studies are prone to residual confounding, reverse causality, and selection bias, we used a Mendelian randomization (MR) approach to investigate whether these associations are causal or not. Methods: Two-sample MR analysis using data from the largest available genome-wide association studies on normal range thyrotropin (TSH) and free thyroxine (fT4) levels, serum lipid levels, blood pressure measurements, T2D, and obesity traits (body mass index [BMI] and waist/hip ratio). Results: A one standard deviation (SD) increase in genetically predicted TSH levels was associated with a 0.037 SD increase in total cholesterol levels (p = 3.0 × 10-4). After excluding pleiotropic instruments, we also observed significant associations between TSH levels and low-density lipoprotein levels (β = 0.026 SD, p = 1.9 × 10-3), pulse pressure (β = -0.477 mmHg, p = 7.5 × 10-10), and T2D risk (odds ratio = 0.95, p = 2.5 × 10-3). While we found no evidence of causal associations between TSH or fT4 levels and obesity traits, we found that a one SD increase in genetically predicted BMI was associated with a 0.075 SD decrease in fT4 levels (p = 3.6 × 10-4). Conclusions: Variation in normal range thyroid function affects serum cholesterol levels, blood pressure, and T2D risk.
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Affiliation(s)
- Aleksander Kuś
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Warsaw, Poland
| | - Eirini Marouli
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
- Centre for Genomic Health, Life Sciences, Queen Mary University of London, London, United Kingdom
| | - Fabiola Del Greco M
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lubeck, Bolzano, Italy
| | - Layal Chaker
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Tomasz Bednarczuk
- Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Warsaw, Poland
| | - Robin P Peeters
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Alexander Teumer
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
| | - Marco Medici
- Department of Internal Medicine, Academic Center for Thyroid Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Panos Deloukas
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
- Centre for Genomic Health, Life Sciences, Queen Mary University of London, London, United Kingdom
- Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders (PACER-HD), King Abdulaziz University, Jeddah, Saudi Arabia
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15
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Li E, Yen PM, Dietrich JW, Leow MKS. Profiling retrospective thyroid function data in complete thyroidectomy patients to investigate the HPT axis set point (PREDICT-IT). J Endocrinol Invest 2021; 44:969-977. [PMID: 32808162 DOI: 10.1007/s40618-020-01390-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND The homeostatic euthyroid set point of the hypothalamus-pituitary-thyroid axis of any given individual is unique and oscillates narrowly within substantially broader normal population ranges of circulating free thyroxine (FT4) and thyroid-stimulating hormone (TSH), otherwise termed 'thyroid function test (TFT)'. We developed a mathematical algorithm codenamed Thyroid-SPOT that effectively reconstructs the personalized set point in open-loop situations and evaluated its performance in a retrospective patient sample. METHODS We computed the set points of 101 patients who underwent total thyroidectomy for non-functioning thyroid disease using Thyroid-SPOT on each patient's own serial post-thyroidectomy TFT. Every predicted set point was compared against its respective healthy pre-operative euthyroid TFT per individual and their separation (i.e. predicted-observed TFT) quantified. RESULTS Bland-Altman analysis to measure the agreement between each pair of an individual's predicted and actual set points revealed a mean difference in FT4 and TSH of + 3.03 pmol/L (95% CI 2.64, 3.43) and - 0.03 mIU/L (95% CI - 0.25, 0.19), respectively. These differences are small compared to the width of the reference intervals. Thyroid-SPOT can predict the euthyroid set point remarkably well, especially for TSH with a 10-16-fold spread in magnitude between population normal limits. CONCLUSION Every individual's equilibrium euthyroid set point is unique. Thyroid-SPOT serves as an accurate, precise and reliable targeting system for optimal personalized restoration of euthyroidism. This algorithm can guide clinicians in L-thyroxine dose titrations to resolve persistent dysthyroid symptoms among challenging cases harbouring "normal TFT" within the laboratory ranges but differing significantly from their actual euthyroid set points.
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Affiliation(s)
- E Li
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore.
| | - P M Yen
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - J W Dietrich
- Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
| | - M K-S Leow
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), Singapore, Singapore
- Department of Endocrinology, Division of Medicine, Tan Tock Seng Hospital (TTSH), Singapore, Singapore
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16
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Markantes GK, Dimitropoulos K, Mamali I, Tseti I, Sakellaropoulos G, Markou KB, Michalaki MA. Therapeutic Equivalence of a New Preparation of Liquid Levothyroxine with Tablets in Patients with Overt Primary Hypothyroidism. Eur Thyroid J 2021; 10:59-64. [PMID: 33777820 PMCID: PMC7983587 DOI: 10.1159/000508216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 04/26/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND A new liquid levothyroxine (LT4) dissolved in glycerol and water has recently been developed by a Greek pharmaceutical company (Uni-Pharma, Athens, Greece). OBJECTIVES To evaluate the therapeutic equivalence of this new liquid LT4 preparation versus the already existing tablet formulation of the same manufacturer, in order to obtain approval by the Greek National Organization for Medicines. METHODS This was a prospective, randomized, cross-over phase III study. The study included 50 patients (9 men and 41 non-pregnant women, with a mean age of 42.5 ± 12.5 years), with documented overt primary hypothyroidism. All subjects were well controlled on substitution therapy with various LT4 formulations. None of the patients had known LT4 malabsorption. The patients were randomized into 2 groups (A and B). The individuals of group A initially received T4® tablets for 10 ± 2 weeks and subsequently switched to T4® drops (100 μg/mL solution) at the same dose for another 10 ± 2 weeks. In group B, the reverse procedure was followed. Total T3 (T3), free T4 (fT4), and TSH were measured in all participants at enrollment and at the end of each 10 ± 2-week trial period. RESULTS Out of the 50 recruited patients, 6 were lost to follow-up and 5 were excluded due to non-compliance with the study protocol. In the 39 patients who completed the study, the serum TSH levels after 10 ± 2 weeks of treatment either with T4® tablets or with T4® drops did not differ (1.759 ± 1.104 vs. 2.076 ± 1.334 mIU/L, mean ± SD). CONCLUSIONS In hypothyroid patients, the new liquid LT4 preparation (T4® drops) is therapeutically equivalent to the tablet form (T4® tablets).
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Affiliation(s)
- Georgios K. Markantes
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
| | - Konstantinos Dimitropoulos
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
| | - Irene Mamali
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
| | | | | | - Kostas B. Markou
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
- *Kostas B. Markou, Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Rio-Patras, GR–26500 Patras (Greece),
| | - Marina A. Michalaki
- Division of Endocrinology, Department of Internal Medicine, University of Patras Medical School, Patras, Greece
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17
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Goichot B, Raverot V, Klein M, Vija Racaru L, Abeillon-du Payrat J, Lairez O, Leroy R, Cailleux A, Wolff P, Groussin L, Kaltenbach G, Caron P. Management of thyroid dysfunctions in the elderly. French Endocrine Society consensus 2019 guidelines. Short version. ANNALES D'ENDOCRINOLOGIE 2020; 81:511-515. [PMID: 32446837 DOI: 10.1016/j.ando.2020.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Bernard Goichot
- Service de médecine interne, endocrinologie et nutrition, hôpitaux universitaires de Strasbourg, hôpital de Hautepierre, 1, avenue Molière, 67098 Strasbourg cedex, France.
| | - Véronique Raverot
- Laboratoire d'hormonologie, LBMMS, Groupement hospitalier est, hospices civils de Lyon, 69677 Bron cedex, France.
| | - Marc Klein
- Service EDN, CHU de Nancy, 54500 Vandoeuvre-les-Nancy, France.
| | - Lavinia Vija Racaru
- Service de médecine nucléaire, Institut universitaire de cancérologie de Toulouse oncopole, 31059 Toulouse, France.
| | | | - Olivier Lairez
- Fédération des services de cardiologie, CHU de Rangueil, Toulouse, France; Centre d'imagerie cardiaque, CHU de Toulouse, Toulouse, France.
| | - Remy Leroy
- Cabinet d'endocrinologie et diabétologie, 71, rue de La Louvière, 59000 Lille, France.
| | - Anne Cailleux
- Endocrinologist, clinique Mathilde, 7, boulevard de l'Europe, 76100 Rouen, France.
| | - Pierre Wolff
- Espace santé, 8, rue de Lattre de Tassigny, 69350 La Mulatiere, France.
| | - Lionel Groussin
- Inserm U1016, CNRS UMR8104, service d'endocrinologie, université de Paris, Institut Cochin, hôpital Cochin, AP-HP, 75014 Paris, France.
| | - Georges Kaltenbach
- Pôle de gériatrie, hôpitaux universitaires de Strasbourg, hôpital de la Robertsau, 67000 Strasbourg, France.
| | - Philippe Caron
- Service d'endocrinologie et maladies métaboliques, CHU de Larrey, 31059 Toulouse, France.
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18
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Goichot B, Raverot V, Klein M, Vija Racaru L, Abeillon-Du Payrat J, Lairez O, Leroy R, Cailleux A, Wolff P, Groussin L, Kaltenbach G, Caron P. Management of thyroid dysfunctions in the elderly. French Endocrine Society consensus statement 2019. Long version. ANNALES D'ENDOCRINOLOGIE 2020; 81:89-100. [PMID: 32416938 DOI: 10.1016/j.ando.2020.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Bernard Goichot
- Service de médecine interne, endocrinologie et nutrition, hôpital de Hautepierre, hôpitaux universitaires, 67098 Strasbourg cedex, France.
| | - Véronique Raverot
- Hospices civils de Lyon, groupement hospitalier Est, LBMMS, laboratoire d'hormonologie, 69677 Bron cedex, France.
| | - Marc Klein
- Service EDN, CHU de Nancy, 54500 Vandœuvre-Lès-Nancy, France.
| | - Lavinia Vija Racaru
- Service de médecine nucléaire, institut universitaire de cancérologie de Toulouse Oncopole, 31059 Toulouse, France.
| | | | - Olivier Lairez
- Fédération des services de cardiologie, centre d'imagerie cardiaque, CHU Rangueil, CHU de Toulouse, Toulouse, France.
| | - Rémy Leroy
- Cabinet d'endocrinologie et diabétologie, 71, rue de La Louvière, 59000 Lille, France.
| | - Anne Cailleux
- Clinique Mathilde, 7, boulevard de l'Europe, 76100 Rouen, France.
| | - Pierre Wolff
- Espace santé, 8, rue de Lattre de Tassigny, 69350 La Mulatière, France.
| | - Lionel Groussin
- Université de Paris, Inserm U1016, CNRS UMR8104, institut Cochin, service d'endocrinologie, AP-HP, hôpital Cochin, 75014 Paris, France.
| | - Georges Kaltenbach
- Pôle de gériatrie, hôpital de la Robertsau, hôpitaux universitaires de Strasbourg, 67000 Strasbourg, France.
| | - Philippe Caron
- Service d'endocrinologie et maladies métaboliques, CHU Larrey, 31059 Toulouse, France.
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Atmospheric Pollution and Thyroid Function of Pregnant Women in Athens, Greece: A Pilot Study. Med Sci (Basel) 2020; 8:medsci8020019. [PMID: 32260367 PMCID: PMC7353503 DOI: 10.3390/medsci8020019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/18/2020] [Accepted: 04/01/2020] [Indexed: 11/16/2022] Open
Abstract
Exposure to air pollution and, in particular, to nitrogen dioxide (NO2) or particulate pollutants less than 2.5 μm (PM2.5) or 10 μm (PM10) in diameter has been linked to thyroid (dys)function in pregnant women. We hypothesized that there may be a dose-effect relationship between air pollutants and thyroid function parameters. We retrospectively evaluated thyrotropin (TSH) in 293 women, NO2, PM2.5 and PM10 levels in Athens. All the women were diagnosed with hypothyroidism for the first time during their pregnancy. Exposure to air pollution for each woman was considered according to her place of residence. Statistical analysis of age, pregnancy weight change, and air pollutants versus TSH was performed with ordinary least squares regression (OLS-R) and quantile regression (Q-R). A positive correlation for logTSH and PM2.5(r = +0.13, p = 0.02) was found, using OLS-R. Further analysis with Q-R showed that each incremental unit increase (for the 10th to the 90th response quantile) in PM2.5 increased logTSH(±SE) between +0.029 (0.001) to +0.025 (0.001) mIU/L (p < 0.01). The other parameters and pollutants (PM10 and NO2) had no significant effect on TSH. Our results indeed show a dose-response relationship between PM2.5 and TSH. The mechanisms involved in the pathophysiological effects of atmospheric pollutants, in particular PM2.5, are being investigated.
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Gyuricsko E. The "slightly" abnormal thyroid test: What is the pediatrician to do? Curr Probl Pediatr Adolesc Health Care 2020; 50:100770. [PMID: 32418870 DOI: 10.1016/j.cppeds.2020.100770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Thyroid disorders are common in pediatrics. Tests of thyroid function are widely available and frequently ordered in the pediatric healthcare setting. This is sometimes driven by common signs or symptoms of thyroid disease. All too often, it is driven by patients and their parents requesting thyroid tests for nonspecific symptoms, such as fatigue, obesity or family history of thyroid disease. The decision to order thyroid tests, as well as which test(s) of thyroid function to order, deserves careful thought rather than a reflexive "thyroid panel" for every patient. Thyroid stimulating hormone (TSH) is the single most appropriate test of thyroid function when screening a pediatric or adolescent for thyroid disorders. Adding more tests only increases the likelihood that a minor (and often insignificant) abnormality will be found. These incidental abnormalities can create anxiety for the parent and child, and usually results in additional testing, referral to a pediatric endocrinologist, and further expense. This review will aim to guide the pediatric primary care provider on the choice of appropriate screening test(s) for acquired thyroid dysfunction in children and adolescents, as well as the proper interpretation of the test(s). Emphasis will be placed on the "slightly" abnormal thyroid screening test. Specific thyroid tests to be reviewed include TSH, (free) T4, (free) T3, and thyroid antibodies. Finally, this review will aim to guide decisions on follow-up, additional testing, and reasons for referral to a pediatric endocrinologist. Congenital hypothyroidism, including abnormalities on state newborn screening, will not be discussed.
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Affiliation(s)
- Eric Gyuricsko
- Assistant Professor of Pediatrics, Eastern Virginia Medical School, Division of Pediatric Endocrinology, Children's Hospital of The King's Daughters, Children's Specialty Group, PLLC, Norfolk, VA, United States.
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Derakhshan A, Shu H, Peeters RP, Kortenkamp A, Lindh CH, Demeneix B, Bornehag CG, Korevaar TIM. Association of urinary bisphenols and triclosan with thyroid function during early pregnancy. ENVIRONMENT INTERNATIONAL 2019; 133:105123. [PMID: 31521814 DOI: 10.1016/j.envint.2019.105123] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/20/2019] [Accepted: 08/23/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Bisphenols and triclosan are considered as potential thyroid disruptors. While mild alterations in maternal thyroid function can result in adverse pregnancy and child developmental outcomes, there is still uncertainty whether bisphenols or triclosan can interfere with thyroid function during pregnancy. OBJECTIVES We aimed to investigate the association of urinary bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF) and triclosan with early pregnancy thyroid function. METHODS This study was embedded in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA), a population-based prospective pregnancy cohort. In total, 1996 participants were included in the current study. Maternal urinary concentrations of three bisphenols and triclosan, collected at median (95% range) 10 (6-14) weeks of pregnancy as well as serum concentrations of thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total thyroxine (TT4), and total triiodothyronine (TT3) were measured. RESULTS Higher BPA levels were associated with lower TT4 concentrations (non-monotonic, P = 0.03), a lower FT4/FT3 ratio (β [SE] -0.02 [0.01], P = 0.03) and a lower TT4/TT3 ratio (β [SE] -0.73 [0.27], P = 0.008). Higher BPF levels were associated with a higher FT3 (β [SE] 0.01 [0.007], P = 0.04). There were no associations between other bisphenols or triclosan and absolute TSH, (F)T4 or (F)T3 concentrations. The association of BPA with thyroid function differed with gestational age. The negative association of BPA with FT4/FT3 and TT4/TT3 ratios was only apparent in early but not late gestation (P for interaction: 0.003, 0.008, respectively). CONCLUSION These human data during pregnancy substantiate experimental findings suggesting that BPA could potentially affect thyroid function and deiodinase activities in early gestation.
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Affiliation(s)
- Arash Derakhshan
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands
| | - Huan Shu
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Sweden
| | - Robin P Peeters
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands
| | - Andreas Kortenkamp
- Institute of Environment, Health and Societies, Brunel University, London, Uxbridge, UK
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Lund University, 22363 Lund, Sweden
| | - Barbara Demeneix
- Laboratoire d'Evolution des Régulations Endocriniennes, Muséum National d'Histoire Naturelle, 57 Rue Cuvier, 75005 Paris, France
| | - Carl-Gustaf Bornehag
- Division of Public Health Sciences, Karlstad University, Karlstad, Sweden; Icahn School of Medicine at Mount Sinai, New York City, NY, USA
| | - Tim I M Korevaar
- Academic Center for Thyroid Diseases, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands; Department of Internal Medicine, Erasmus MC, Dr. Molewaterplein 15, 3051 GE Rotterdam, the Netherlands.
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Challenges in Interpreting Thyroid Stimulating Hormone Results in the Diagnosis of Thyroid Dysfunction. J Thyroid Res 2019; 2019:4106816. [PMID: 31662841 PMCID: PMC6778876 DOI: 10.1155/2019/4106816] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/01/2019] [Indexed: 12/16/2022] Open
Abstract
The pituitary hormone, thyrotropin (TSH), is regarded as the primary biomarker for evaluating thyroid function and is useful in guiding treatment with levothyroxine for patients with hypothyroidism. The amplified response of TSH to slight changes in thyroid hormone levels provides a large and easily measured signal in the routine care setting. Laboratories provide reference ranges with upper and lower cutoffs for TSH to define normal thyroid function. The upper limit of the range, used to diagnose subclinical (mild) hypothyroidism, is itself a matter for debate, with authoritative guidelines recommending treatment to within the lower half of the range. Concomitant diseases, medications, supplements, age, gender, ethnicity, iodine status, time of day, time of year, autoantibodies, heterophilic antibodies, smoking, and other factors influence the level of TSH, or the performance of current TSH assays. The long-term prognostic implications of small deviations of TSH from the reference range are unclear. Correction of TSH to within the reference range does not always bring thyroid and other biomarkers into range and will not always resolve the patient's symptoms. Overt hypothyroidism requires intervention with levothyroxine. It remains important that physicians managing a patient with symptoms suggestive of thyroid disease consider all of the patient's relevant disease, lifestyle, and other factors before intervening on the basis of a marginally raised TSH level alone. Finally, these limitations of TSH testing mitigate against screening the population for the undoubtedly substantial prevalence of undiagnosed thyroid disease, until appropriately designed randomised trials have quantified the benefits and harms from this approach.
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Razvi S, Hostalek U. Therapeutic challenges in the application of serum thyroid stimulating hormone testing in the management of patients with hypothyroidism on replacement thyroid hormone therapy: a review. Curr Med Res Opin 2019; 35:1215-1220. [PMID: 30648440 DOI: 10.1080/03007995.2019.1570769] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Normalizing serum thyroid stimulating hormone (TSH) levels by lifelong treatment with levothyroxine (LT4) remains the primary goal of therapy for patients with hypothyroidism. The reference ranges for TSH are derived from populations with (supposedly) normal thyroid function. But, TSH results are affected by a number of factors including alterations in TSH levels with age, concurrent illnesses, circadian rhythm, inter- and intra-assay differences, and some commonly used medications that interfere with thyroid function or the TSH test. Furthermore, some patients are complex to manage and bringing serum TSH to within its reference range does not always resolve their symptoms of hypothyroidism. Furthermore, changes in TSH within the reference range may provoke symptoms in some sensitive patients, and others may have a personal "set point" for thyroid hormone levels that represents normal function for that individual, but which is outside the population reference range. The introduction of updated LT4 formulations, with better dosing accuracy and stability compared with older versions, should, in theory at least, provide better stability and accuracy of dosing over time. However, the new LT4 formulations are associated with manifold increases in the number of self-reported adverse events. Therefore, patients with hypothyroidism as well as the clinicians managing them need to better understand the utility as well as the limitations of the widely used TSH measurement. In addition, both pharmaceutical companies and the prescribing clinician need to take greater care when patients are switched from older to newer formulations.
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Affiliation(s)
- Salman Razvi
- a Institute of Genetic Medicine, University of Newcastle , Newcastle-upon-Tyne , UK
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Soh SB, Aw TC. Laboratory Testing in Thyroid Conditions - Pitfalls and Clinical Utility. Ann Lab Med 2019; 39:3-14. [PMID: 30215224 PMCID: PMC6143469 DOI: 10.3343/alm.2019.39.1.3] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 05/29/2018] [Accepted: 09/02/2018] [Indexed: 12/18/2022] Open
Abstract
Thyroid disorders are common, affecting more than 10% of people in the US, and laboratory tests are integral in the management of these conditions. The repertoire of thyroid tests includes blood tests for thyroid-stimulating hormone (TSH), free thyroxine, free triiodothyronine, thyroglobulin (Tg), thyroglobulin antibodies (Tg-Ab), thyroid peroxidase antibodies (TPO-Ab), TSH receptor antibodies (TRAb), and calcitonin. TSH and free thyroid hormone tests are frequently used to assess the functional status of the thyroid. TPO-Ab and TRAb tests are used to diagnose Hashimoto's thyroiditis and Graves' disease, respectively. Tg and calcitonin are important tumor markers used in the management of differentiated thyroid carcinoma and medullary thyroid carcinoma (MTC), respectively. Procalcitonin may replace calcitonin as a biomarker for MTC. Apart from understanding normal thyroid physiology, it is important to be familiar with the possible pitfalls and caveats in the use of these tests so that they can be interpreted properly and accurately. When results are discordant, clinicians and laboratorians should be mindful of possible assay interferences and/or the effects of concurrent medications. In addition, thyroid function may appear abnormal in the absence of actual thyroid dysfunction during pregnancy and in critical illness. Hence, it is important to consider the clinical context when interpreting results. This review aims to describe the above-mentioned blood tests used in the diagnosis and management of thyroid disorders, as well as the pitfalls in their interpretation. With due knowledge and care, clinicians and laboratorians will be able to fully appreciate the clinical utility of these important laboratory tests.
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Affiliation(s)
- Shui Boon Soh
- Department of Endocrinology, Changi General Hospital, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tar Choon Aw
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Laboratory Medicine, Changi General Hospital, Singapore.
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Abstract
Background: Small variations in the dose of levothyroxine have been associated with marked variations in thyroid function in people with hypothyroidism. Accordingly, regulators have identified levothyroxine as a "narrow therapeutic index" drug subject to more stringent regulations compared with other drugs, in terms of the accuracy and stability of the amount of active drug in each tablet (typically required to be 95-105% of the labelled amount over its full shelf life), and its bioavailability geometric mean ratios (90% confidence intervals between 90-111.1%, including 100%).Review: This review describes a reformulation of a widely used levothyroxine product (Euthyrox.*). The new tablet fulfils all criteria according to the new specification regulations for dosage accuracy over a shelf life of 3 years in all climate zones, and for bioequivalence compared to the conventional formulation used for many years. In addition, a clinical trial demonstrated equivalent exposure between three different tablet strengths of the new formulation, amounting to the same total dose (dose form proportionality). As a consequence, switching from the conventional to the new formulation can be undertaken on a 1:1 dose-for-dose basis, without re-titration or additional thyroid function testing.Conclusion: The new formulation, which is more stable, will assist in the accurate dosage and titration of levothyroxine in the management of hypothyroidism.
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Hoermann R, Midgley JEM, Larisch R, Dietrich JWC. Advances in applied homeostatic modelling of the relationship between thyrotropin and free thyroxine. PLoS One 2017; 12:e0187232. [PMID: 29155897 PMCID: PMC5695809 DOI: 10.1371/journal.pone.0187232] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 10/16/2017] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION The relationship between pituitary TSH and thyroid hormones is central to our understanding of thyroid physiology and thyroid function testing. Here, we generated distribution patterns by using validated tools of thyroid modelling. METHODS We simulated patterns of individual set points under various conditions, based on a homeostatic model of thyroid feedback control. These were compared with observed data points derived from clinical trials. RESULTS A random mix of individual set points was reconstructed by simulative modelling with defined structural parameters. The pattern displayed by the cluster of hypothetical points resembled that observed in a natural control group. Moderate variation of the TSH-FT4 gradient over the functional range introduced further flexibility, implementing a scenario of adaptive set points. Such a scenario may be a realistic possibility for instance in treatment where relationships and equilibria between thyroid parameters are altered by various influences such as LT4 dose and conversion efficiency. CONCLUSIONS We validated a physiologically based homeostatic model that permits simulative reconstruction of individual set points. This produced a pattern resembling the observed data under various conditions. Applied modelling, although still experimental at this stage, shows a potential to aid our physiological understanding of the interplay between TSH and thyroid hormones. It should eventually benefit personalised clinical decision making.
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Affiliation(s)
- Rudolf Hoermann
- Department for Nuclear Medicine, Klinikum Lüdenscheid, Paulmannshöherstr, Lüdenscheid, Germany
| | | | - Rolf Larisch
- Department for Nuclear Medicine, Klinikum Lüdenscheid, Paulmannshöherstr, Lüdenscheid, Germany
| | - Johannes Wolfgang Christian Dietrich
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum, Alexandrinenstr. 5, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Witten/Herdecke University, Alexandrinenstr. 5, Bochum, Germany
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Hoermann R, Midgley JEM, Dietrich JW, Larisch R. Dual control of pituitary thyroid stimulating hormone secretion by thyroxine and triiodothyronine in athyreotic patients. Ther Adv Endocrinol Metab 2017; 8:83-95. [PMID: 28794850 PMCID: PMC5524252 DOI: 10.1177/2042018817716401] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/29/2017] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Patient responses to levothyroxine (LT4) monotherapy vary considerably. We sought to differentiate contributions of FT4 and FT3 in controlling pituitary thyroid stimulating hormone (TSH) secretion. METHODS We retrospectively assessed the relationships between TSH and thyroid hormones in 319 patients with thyroid carcinoma through 2914 visits on various LT4 doses during follow-up for 5.5 years (median, IQR 4.2, 6.9). We also associated patient complaints with the relationships. RESULTS Under varying dose requirements (median 1.84 µg/kg, IQR 1.62, 2.11), patients reached TSH targets below 0.4, 0.1 or 0.01 mIU/l at 73%, 54% and 27% of visits. While intercept, slope and fit of linearity of the relationships between lnTSH and FT4/FT3 varied between individuals, gender, age, LT4 dose and deiodinase activity influenced the relationships in the cohort (all p < 0.001). Deiodinase activity impaired by LT4 dose significantly affected the lnTSH-FT4 relationship. Dose increase and reduced conversion efficiency displaced FT3-TSH equilibria. In LT4-treated patients, FT4 and FT3 contributed on average 52% versus 38%, and by interaction 10% towards TSH suppression. Symptomatic presentations (11%) accompanied reduced FT3 concentrations (-0.23 pmol/l, p = 0.001) adjusted for gender, age and BMI, their relationships being shifted towards higher TSH values at comparable FT3/FT4 levels. CONCLUSIONS Variation in deiodinase activity and resulting FT3 levels shape the TSH-FT4 relationship in LT4-treated athyreotic patients, suggesting cascade control of pituitary TSH production by the two hormones. Consequently, measurement of FT3 and calculation of conversion efficiency may identify patients with impaired biochemistry and a resulting lack of symptomatic control.
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Affiliation(s)
- Rudolf Hoermann
- Department of Nuclear Medicine, Klinikum Lüdenscheid, Paulmannshoeher Str 14, D-58515 Luedenscheid, Germany
| | | | - Johannes W. Dietrich
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum and Witten/Herdecke University, Bochum, Germany
| | - Rolf Larisch
- Department of Nuclear Medicine, Klinikum Lüdenscheid, Lüdenscheid, Germany
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Hoermann R, Midgley JEM, Larisch R, Dietrich JW. Relational Stability in the Expression of Normality, Variation, and Control of Thyroid Function. Front Endocrinol (Lausanne) 2016; 7:142. [PMID: 27872610 PMCID: PMC5098235 DOI: 10.3389/fendo.2016.00142] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 10/21/2016] [Indexed: 12/31/2022] Open
Abstract
Thyroid hormone concentrations only become sufficient to maintain a euthyroid state through appropriate stimulation by pituitary thyroid-stimulating hormone (TSH). In such a dynamic system under constant high pressure, guarding against overstimulation becomes vital. Therefore, several defensive mechanisms protect against accidental overstimulation, such as plasma protein binding, conversion of T4 into the more active T3, active transmembrane transport, counter-regulatory activities of reverse T3 and thyronamines, and negative hypothalamic-pituitary-thyroid feedback control of TSH. TSH has gained a dominant but misguided role in interpreting thyroid function testing in assuming that its exceptional sensitivity thereby translates into superior diagnostic performance. However, TSH-dependent thyroid disease classification is heavily influenced by statistical analytic techniques such as uni- or multivariate-defined normality. This demands a separation of its conjoint roles as a sensitive screening test and accurate diagnostic tool. Homeostatic equilibria (set points) in healthy subjects are less variable and do not follow a pattern of random variation, rather indicating signs of early and progressive homeostatic control across the euthyroid range. In the event of imminent thyroid failure with a reduced FT4 output per unit TSH, conversion efficiency increases in order to maintain FT3 stability. In such situations, T3 stability takes priority over set point maintenance. This suggests a concept of relational stability. These findings have important implications for both TSH reference limits and treatment targets for patients on levothyroxine. The use of archival markers is proposed to facilitate the homeostatic interpretation of all parameters.
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Affiliation(s)
- Rudolf Hoermann
- Department of Nuclear Medicine, Klinikum Luedenscheid, Luedenscheid, Germany
| | | | - Rolf Larisch
- Department of Nuclear Medicine, Klinikum Luedenscheid, Luedenscheid, Germany
| | - Johannes W. Dietrich
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum, Bochum, Germany
- Ruhr Center for Rare Diseases (CeSER), Witten/Herdecke University, Bochum, Germany
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