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Oefele M, Hau M, Ruuskanen S, Casagrande S. Mitochondrial function is enhanced by thyroid hormones during zebra finch development. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240417. [PMID: 39086825 PMCID: PMC11288688 DOI: 10.1098/rsos.240417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 08/02/2024]
Abstract
An organism's response to its environment is largely determined by changes in the energy supplied by aerobic mitochondrial metabolism via adenosine triphosphate (ATP) production. ATP is especially important under energy-demanding conditions, such as during rapid growth. It is currently poorly understood how environmental factors influence energy metabolism and mitochondrial functioning, but recent studies suggest the role of thyroid hormones (TH). TH are key regulators of growth and metabolism and can be flexibly adjusted to environmental conditions, such as environmental temperature or food availability. To test whether TH enhancement is causally linked to mitochondrial function and growth, we provided TH orally at physiological concentrations during the main growth phase in zebra finch (Taeniopygia guttata) nestlings reared in a challenging environment. TH treatment accelerated maximal mitochondrial working capacity-a trait that reflects mitochondrial ATP production, without affecting growth. To our knowledge, this is the first study to characterize the regulation of mitochondria by TH during development in a semi-naturalistic context and to address implications for fitness-related traits, such as growth.
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Affiliation(s)
- Marlene Oefele
- Evolutionary Physiology Research Group, Max Planck Institute for Biological Intelligence, Eberhard-Gwinner-Strasse, Seewiesen82319, Germany
| | - Michaela Hau
- Evolutionary Physiology Research Group, Max Planck Institute for Biological Intelligence, Eberhard-Gwinner-Strasse, Seewiesen82319, Germany
- Department of Biology, University of Konstanz, KonstanzD-78464, Germany
| | - Suvi Ruuskanen
- Environmental Physiology Research Group, University of Jyväskylä, Seminaarinkatu 15, University of Jyväskylä, JyväskyläFI-40014, Finland
| | - Stefania Casagrande
- Evolutionary Physiology Research Group, Max Planck Institute for Biological Intelligence, Eberhard-Gwinner-Strasse, Seewiesen82319, Germany
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2
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Abstract
Levothyroxine (LT4) is effective for most patients with hypothyroidism. However, a minority of the patients remain symptomatic despite the normalization of serum thyrotropin levels. Randomized clinical trials including all types of patients with hypothyroidism revealed that combination levothyroxine and liothyronine (LT4+LT3) therapy is safe and is the preferred choice of patients versus LT4 alone. Many patients who do not fully benefit from LT4 experience improved quality of life and cognition after switching to LT4+LT3. For these patients, new slow-release LT3 formulations that provide stable serum T3 levels are being tested. In addition, progress in regenerative technology has led to the development of human thyroid organoids that restore euthyroidism after being transplanted into hypothyroid mice. Finally, there is a new understanding that, under certain conditions, T3 signaling may be compromised in a tissue-specific fashion while systemic thyroid function is preserved. This is seen, for example, in patients with metabolic (dysfunction)-associated fatty liver disease, for whom liver-selective T3-like molecules have been utilized successfully in clinical trials.
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Affiliation(s)
- Antonio C Bianco
- Section of Adult and Pediatric Endocrinology, Diabetes, and Metabolism, University of Chicago School of Medicine, Chicago, Illinois, USA;
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3
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Premawardhana LD, Taylor PN, Okosieme OE, Adlan MA, Obuobie EK, Dayan CM. Designing a combined liothyronine (LT3), L- thyroxine (LT4) trial in symptomatic hypothyroid subjects on LT4 - the importance of patient selection, choice of LT3 and trial design. Front Endocrinol (Lausanne) 2023; 14:1282608. [PMID: 38034018 PMCID: PMC10687631 DOI: 10.3389/fendo.2023.1282608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
Approximately 10%-15% of subjects with hypothyroidism on L-thyroxine (LT4) alone have persistent symptoms affecting their quality of life (QoL). Although the cause is unclear, there is evidence that "tissue T3 lack" may be responsible. If so, combining liothyronine (LT3) with LT4 would be helpful. However, randomized controlled trials (RCT), have not established greater efficacy for the LT3 + LT4 combination in these subjects than for LT4 alone. While the trial design may have been responsible, the use of unphysiological, short-acting LT3 preparations and non-thyroid-specific patient-reported outcome measures (PROMs) may have contributed. We recommend attention to the following aspects of trial design for future RCTs of LT3 + LT4 compared to LT4 alone: (a) Subject selection-(i) measurable symptoms (disadvantages should be recognized); (ii) using a validated thyroid specific PROM such as ThyPRO39 or the Composite scale derived from it; (iii) those taking over 1.2 μg/day or 100 μg/day (for pragmatic reasons) of LT4 defining a population likely without intrinsic thyroid activity who depend on exogenous LT4; (iv) recruiting a preponderance of subjects with autoimmune thyroiditis increasing generalisability; and (v) those with a high symptom load with a greater response to combination therapy e.g. those with the deiodinase 2 polymorphism. (b) The use of physiological LT3 preparations producing pharmacokinetic similarities to T3 profiles in unaffected subjects: two long-acting LT3 preparations are currently available and must be tested in phase 2b/3 RCTs. (c) The superiority of a crossover design in limiting numbers and costs while maintaining statistical power and ensuring that all subjects experienced the investigative medication.
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Affiliation(s)
- Lakdasa D. Premawardhana
- Thyroid Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Peter Nicholas Taylor
- Thyroid Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Onyebuchi E. Okosieme
- Thyroid Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Mohamed A. Adlan
- Section of Endocrinology, Ysbyty Ystrad Fawr and Royal Gwent Hospitals, Aneurin Bevan University Health Board, Newport, United Kingdom
| | - Emmanuel K. Obuobie
- Section of Endocrinology, Ysbyty Ystrad Fawr and Royal Gwent Hospitals, Aneurin Bevan University Health Board, Newport, United Kingdom
| | - Colin Mark Dayan
- Thyroid Research Group, Division of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
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Murdoch SÓ, Aiello EM, Doyle FJ. Pharmacokinetic Model-Based Control across the Blood-Brain Barrier for Circadian Entrainment. Int J Mol Sci 2023; 24:14830. [PMID: 37834278 PMCID: PMC10573769 DOI: 10.3390/ijms241914830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
The ability to shift circadian phase in vivo has the potential to offer substantial health benefits. However, the blood-brain barrier prevents the absorption of the majority of large and many small molecules, posing a challenge to neurological pharmaceutical development. Motivated by the presence of the circadian molecule KL001, which is capable of causing phase shifts in a circadian oscillator, we investigated the pharmacokinetics of different neurological pharmaceuticals on the dynamics of circadian phase. Specifically, we developed and validated five different transport models that describe drug concentration profiles of a circadian pharmaceutical at the brain level under oral administration and designed a nonlinear model predictive control (MPC)-based framework for phase resetting. Performance of the novel control algorithm based on the identified pharmacokinetic models was demonstrated through simulations of real-world misalignment scenarios due to jet lag. The time to achieve a complete phase reset for 11-h phase delay ranged between 48 and 72 h, while a 5-h phase advance was compensated in 30 to 60 h. This approach provides mechanistic insight into the underlying structure of the circadian oscillatory system and thus leads to a better understanding of the feasibility of therapeutic manipulations of the system.
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Affiliation(s)
- Síofra Ó. Murdoch
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA 02134, USA; (S.Ó.M.); (E.M.A.)
| | - Eleonora M. Aiello
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA 02134, USA; (S.Ó.M.); (E.M.A.)
- Sansum Diabetes Research Institute, Santa Barbara, CA 93105, USA
| | - Francis J. Doyle
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA 02134, USA; (S.Ó.M.); (E.M.A.)
- Sansum Diabetes Research Institute, Santa Barbara, CA 93105, USA
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5
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Biondi B, Celi FS, McAninch EA. Critical Approach to Hypothyroid Patients With Persistent Symptoms. J Clin Endocrinol Metab 2023; 108:2708-2716. [PMID: 37071856 PMCID: PMC10686697 DOI: 10.1210/clinem/dgad224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/07/2023] [Accepted: 04/13/2023] [Indexed: 04/20/2023]
Abstract
Hypothyroidism is a common condition, and numerous studies have been published over the last decade to assess the potential risks associated with this disorder when inappropriately treated. The standard of care for treatment of hypothyroidism remains levothyroxine (LT4) at doses to achieve biochemical and clinical euthyroidism. However, about 15% of hypothyroid patients experience residual hypothyroid symptoms. Some population-based studies and international population-based surveys have confirmed dissatisfaction with LT4 treatment in some hypothyroid patients. It is well established that hypothyroid patients treated with LT4 exhibit higher serum thyroxine:triiodothyronine ratios and can have a persistent increase in cardiovascular risk factors. Moreover, variants in deiodinases and thyroid hormone transporter genes have been associated with subnormal T3 concentrations, persistent symptoms in LT4-treated patients, and improvement in response to the addition of liothyronine to LT4 therapy. The American (ATA) and European Thyroid Association (ETA) guidelines have recently evolved in their recognition of the potential limitations of LT4. This shift is reflected in prescribing patterns: Physicians' use of combination therapy is prevalent and possibly increasing. Randomized clinical trials have recently been published and, while they have found no improvement in treating hypothyroid patients, a number of important limitations did not allow generalizability. Meta-analyses have reported a preference rate for combination therapy in 46.2% hypothyroid patients treated with LT4. To promote discussions about an optimal study design, the ATA, ETA, and British Thyroid Association have recently published a consensus document. Our study provides a useful counterpoint on the controversial benefits of treating hypothyroid patients with combination therapy.
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Affiliation(s)
- Bernadette Biondi
- Division of Internal Medicine and Cardiovascular Endocrinology, Department of Clinical Medicine and Surgery, University Federico II of Naples, 80131 Naples, Italy
| | - Francesco S Celi
- Division of Endocrinology and Metabolism, Department of Medicine UConn Health, Farmington, CT 06030-8075, USA
| | - Elizabeth A McAninch
- Division of Endocrinology, Metabolism and Gerontology, Stanford University Medical Center, Stanford, CA 94305, USA
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Mehran L, Amouzegar A, Foroutan SM, Masoumi S, Tohidi M, Abdi H, Aghaei A, Saghafinia AE, Azizi F. Pharmacodynamic and pharmacokinetic properties of the combined preparation of levothyroxine plus sustained- release liothyronine; a randomized controlled clinical trial. BMC Endocr Disord 2023; 23:182. [PMID: 37641049 PMCID: PMC10463362 DOI: 10.1186/s12902-023-01434-y] [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: 12/26/2022] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Understanding pharmacokinetics (PK) and pharmacodynamics (PD) of the sustained-release liothyronine (SR-T3) is of paramount importance to design therapeutic regimens that are able to simulate normal thyroid hormone secretion while avoiding excursions in the T3 serum concentration. Here, we designed a parallel randomized clinical trial to characterize the PK and PD of the combined preparations of LT4 + SR-T3 in hypothyroid patients. METHODS Radioiodine-treated hypothyroid patients over 20 years of age, who attained euthyroidism with LT4 monotherapy were recruited from the Endocrine Clinic in Tehran. The patients were allocated to two intervention groups of group A: 9 µg SR-T3 plus 68.5 μg LT4 (ratio 1:7.5) and group B: 12 µg SR-T3 plus 60 µg LT4 (ratio 1:5), and a control group with LT4 monotherapy. For PD study, thyroid hormone profile was evaluated at 8 and 12 weeks intervals after intervention. To assess PK properties of SR-T3, T3-Cmax, T3-Tmax and AUC0 - 24 were calculated at the last visit. RESULTS Serum T4 and FT4 concentrations decreased in the intervention groups after 3 months. No significant difference was observed in serum T3 and FT3 concentrations before and after intervention. Serum T3/T4 ratio increased significantly in the intervention groups after intervention, with the highest increase in group B from 8.6 ± 2.03 at baseline to 12.2 ± 1.6. Comparison of trial groups at follow-up showed no differences in serum TSH, T4, T3 and T3/T4 concentrations among different groups. During 24 h, minimal variation in serum T3 concentration was observed in group B with mean ∆T3 of 15.4 ± 10.5 ng/dl. T3-Tmax, T3-Cmax and AUC0 - 24 in the combined sustained-release preparation were 4.38 ± 1.1 h., 101.0 ± 5.7 ng/dl and 2257 ± 110 ng.h/L, respectively which were significantly different from the control group. CONCLUSION Combined treatment with a single dose of SR-T3 plus LT4 is associated with increased serum T3/T4 ratio and minimal excursions in serum T3 concentration during 24 h; however, it was not significantly different from the control group. To incorporate sustained-release T3 in the management of hypothyroidism, a higher ratio of SR-T3 to LT4 than that of the previously recommended by the international organizations is suggested. IRCT REGISTRATION NUMBER IRCT20100922004794N13. https://www.irct.ir/search/result?query=IRCT20100922004794N13 . Registration date: 08/12/2021.
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Affiliation(s)
- Ladan Mehran
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Amouzegar
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Mohsen Foroutan
- Department of Pharmaceutics, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Protein Technology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Safdar Masoumi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Tohidi
- Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hengameh Abdi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Aghaei
- Noor Research & Educational Institute (TAVAN), Tehran, Iran
| | | | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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7
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Jonklaas J. Role of Levothyroxine/Liothyronine Combinations in Treating Hypothyroidism. Endocrinol Metab Clin North Am 2022; 51:243-263. [PMID: 35662440 DOI: 10.1016/j.ecl.2021.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Diverse causes potentially underlie decreased quality of life in biochemically euthyroid patients treated for hypothyroidism with levothyroxine. Once these contributing factors are addressed, if symptoms persist, there may be benefit to personalized use of combination therapy adding liothyronine. This approach should be carefully monitored: avoiding overtreatment and ensuring that therapy is only continued if it improves patient-reported quality of life. Most randomized clinical trials have not shown benefits, perhaps because of not targeting the most symptomatic patients. Sustained-release liothyronine preparations may soon be available for optimally designed studies assessing whether combination therapy provides superior therapy for hypothyroidism in select patients.
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Affiliation(s)
- Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University, Washington, DC 20007, USA.
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8
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Changes in Thyroid Metabolites after Liothyronine Administration: A Secondary Analysis of Two Clinical Trials That Incorporated Pharmacokinetic Data. Metabolites 2022; 12:metabo12060476. [PMID: 35736409 PMCID: PMC9227779 DOI: 10.3390/metabo12060476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/21/2022] [Accepted: 05/22/2022] [Indexed: 12/04/2022] Open
Abstract
We examined relationships between thyroid hormone (TH) metabolites in humans by measuring 3,5-diiodothyronine (3,5-T2) and 3-iodothyronamine (3-T1AM) levels after liothyronine administration. In secondary analyses, we measured 3,5-T2 and 3-T1AM concentrations in stored samples from two clinical trials. In 12 healthy volunteers, THs and metabolites were documented for 96 h after a single dose of 50 mcg liothyronine. In 18 patients treated for hypothyroidism, levothyroxine therapy was replaced by daily dosing of 30–45 mcg liothyronine. Analytes were measured prior to the administration of liothyronine weekly for 6 weeks, and then hourly for 8 h after the last liothyronine dose of the study. In the weekly samples from the hypothyroid patients, 3,5-T2 was higher by 0.033 nmol/L with each mcg/dL increase in T4 and 0.24 nmol/L higher with each ng/dL increase in FT4 (p-values = 0.007, 0.0365). In hourly samples after the last study dose of liothyronine, patients with T3 values higher by one ng/dL had 3-T1AM values that were lower by 0.004 nmol/L (p-value = 0.0473); patients with 3,5-T2 higher by one nmol/L had 3-T1AM values higher by 2.45 nmol/L (p-value = 0.0044). The positive correlations between weekly trough levels of 3,5-T2 and T4/FT4 during liothyronine therapy may provide insight into 3,5-T2 production, possibly supporting some production of 3,5-T2 from endogenous T4, but not from exogenous liothyronine. In hourly sampling after liothyronine administration, the negative correlation between T3 levels and 3-T1AM, but positive correlation between 3,5-T2 levels and 3-T1AM could support the hypothesis that 3-T1AM production occurs via 3,5-T2 with negative regulation by T3.
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9
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Abstract
Hypothyroidism is a common endocrinopathy, and levothyroxine is frequently prescribed. Despite the basic tenets of initiating and adjusting levothyroxine being agreed on, there are many nuances and complexities to consistently maintaining euthyroidism. Understanding the impact of patient weight and residual thyroid function on initial levothyroxine dosage and consideration of age, comorbidities, thyrotropin goal, life stage, and quality of life as levothyroxine is adjusted can be challenging and continually evolving. Because levothyroxine is a lifelong medication, it is important to avoid risks from periods of overtreatment or undertreatment. For the subset of patients not restored to baseline health with levothyroxine, causes arising from all aspects of the patient's life (coexistent medical conditions, stressors, lifestyle, psychosocial factors) should be broadly considered. If such factors do not appear to be contributing, and biochemical euthyroidism has been successfully maintained, there may be benefit to a trial of combination therapy with levothyroxine and liothyronine. This is not supported by the majority of randomized clinical trials, but may be supported by other studies providing lower-quality evidence and by animal studies. Given this discrepancy, it is important that any trial of combination therapy be continued only as long as a patient benefit is being enjoyed. Monitoring for adverse effects, particularly in older or frail individuals, is necessary and combination therapy should not be used during pregnancy. A sustained-release liothyronine preparation has completed phase 1 testing and may soon be available for better designed and powered studies assessing whether combination therapy provides superior therapy for hypothyroidism.
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10
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Tawfik I, Gottschalk B, Jarc A, Bresilla D, Rost R, Obermayer-Pietsch B, Graier WF, Madreiter-Sokolowski CT. T3-induced enhancement of mitochondrial Ca 2+ uptake as a boost for mitochondrial metabolism. Free Radic Biol Med 2022; 181:197-208. [PMID: 35091061 DOI: 10.1016/j.freeradbiomed.2022.01.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/13/2022] [Accepted: 01/24/2022] [Indexed: 12/15/2022]
Abstract
Thyroid hormones act as master regulators of cellular metabolism. Thereby, the biologically active triiodothyronine (T3) induces the expression of genes to enhance mitochondrial metabolic function. Notably, Ca2+ ions are necessary for the activity of dehydrogenases of the tricarboxylic acid cycle and, thus, mitochondrial respiration. We investigated whether treating HeLa cells with T3 causes alterations in mitochondrial Ca2+ ([Ca2+]mito) levels. Real-time measurements by fluorescence microscopy revealed that treatment with T3 for 3 h induces a significant increase in basal [Ca2+]mito levels and [Ca2+]mito uptake upon the depletion of the endoplasmic reticulum (ER) Ca2+ store, while cytosolic Ca2+ levels remained unchanged. T3 incubation was found to upregulate mRNA expression levels of uncoupling proteins 2 and 3 (UCP2, UCP3) and of protein arginine methyltransferase 1 (PRMT1). Live-cell imaging revealed that T3-induced enhancement of mitochondrial Ca2+ uptake depends on the mitochondrial Ca2+ uniporter (MCU), UCP2, and PRMT1 that are essential for increased mitochondrial ATP ([ATP]mito) production after T3 treatment. Besides, increased [Ca2+]mito and [ATP]mito levels correlated with enhanced production of reactive oxygen species (ROS) in mitochondria. Notably, ROS scavenging causes mitochondrial Ca2+ elevation and outplays the impact of T3 on [Ca2+]mito homeostasis. Based on these results, we assume that thyroid hormones adjust [Ca2+]mito homeostasis by modulating the UCP2- and PRMT1-balanced [Ca2+]mito uptake via MCU in case of physiological ROS levels to convey their impact on mitochondrial ATP and ROS production.
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Affiliation(s)
- Ines Tawfik
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Angelo Jarc
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Doruntina Bresilla
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Rene Rost
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Barbara Obermayer-Pietsch
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Endocrinology Lab Platform, Medical University of Graz, Auenbruggerplatz 15, 8010, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria; BioTechMed, Graz, Austria
| | - Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria.
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Dumitrescu AM, Hanlon EC, Arosemena M, Duchon O, Ettleson M, Giurcanu M, Bianco AC. Extended Absorption of Liothyronine from Poly-Zinc-Liothyronine: Results from a Phase 1, Double-Blind, Randomized, and Controlled Study in Humans. Thyroid 2022; 32:196-205. [PMID: 34641706 PMCID: PMC8861912 DOI: 10.1089/thy.2021.0304] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Background: L-triiodothyronine (LT3) has been increasingly used in combination with levothyroxine in the treatment of hypothyroidism. A metal coordinated form of LT3, known as poly-zinc-liothyronine (PZL), avoided in rats the typical triiodothyronine (T3) peak seen after oral administration of LT3. Objectives: To evaluate in healthy volunteers (i) the pharmacokinetics (PK) of PZL-derived T3 after a single dose, (ii) the pharmacodynamics of PZL-derived T3, (iii) incidence of adverse events, and (iv) exploratory analysis of the sleep patterns after LT3, PZL, or placebo (PB) administration. Methods: Twelve healthy volunteers 18-50 years of age were recruited for a Phase 1, double-blind, randomized, single-dose PB-controlled, crossover study to compare PZL against LT3 or PB. Subjects were admitted three separate times to receive a randomly assigned capsule containing PB, 50 μg LT3, or 50 μg PZL, and were observed for 48 hours. A 2-week washout period separated each admission. Results: LT3-derived serum T3 levels exhibited the expected profile, with a Tmax at 2 hours and return to basal levels by 24-36 hours. PZL-derived serum T3 levels exhibited ∼30% lower Cmax that was 1 hour delayed and extended into a plateau that lasted up to 6 hours. This was followed by a lower but much longer plateau; by 24 hours serum T3 levels still exceeded ½ of Cmax. Thyrotropin levels were similarly reduced in both groups. Conclusion: PZL possesses the necessary properties to achieve a much improved T3 PK. PZL is on track to provide hypothyroid patients with stable levels of serum T3.
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Affiliation(s)
- Alexandra M. Dumitrescu
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
- Address correspondence to: Alexandra M. Dumitrescu, MD, PhD, Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago Medical Center, 5841 S. Maryland Avenue, MC1027, Room M267, Chicago, IL 60637, USA
| | - Erin C. Hanlon
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
| | - Marilyn Arosemena
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
| | - Olga Duchon
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
| | - Matthew Ettleson
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
| | - Mihai Giurcanu
- Department of Public Health Sciences, University of Chicago, Chicago, Illinois, USA
| | - Antonio C. Bianco
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, Chicago, Illinois, USA
- Antonio C. Bianco, MD, PhD, Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago Medical Center, 5841 S. Maryland Avenue, MC1027, Room M267, Chicago, IL 60637, USA
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12
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Jing L, Zhang Q. Intrathyroidal feedforward and feedback network regulating thyroid hormone synthesis and secretion. Front Endocrinol (Lausanne) 2022; 13:992883. [PMID: 36187113 PMCID: PMC9519864 DOI: 10.3389/fendo.2022.992883] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Thyroid hormones (THs), including T4 and T3, are produced and released by the thyroid gland under the stimulation of thyroid-stimulating hormone (TSH). The homeostasis of THs is regulated via the coordination of the hypothalamic-pituitary-thyroid axis, plasma binding proteins, and local metabolism in tissues. TH synthesis and secretion in the thyrocytes-containing thyroid follicles are exquisitely regulated by an elaborate molecular network comprising enzymes, transporters, signal transduction machineries, and transcription factors. In this article, we synthesized the relevant literature, organized and dissected the complex intrathyroidal regulatory network into structures amenable to functional interpretation and systems-level modeling. Multiple intertwined feedforward and feedback motifs were identified and described, centering around the transcriptional and posttranslational regulations involved in TH synthesis and secretion, including those underpinning the Wolff-Chaikoff and Plummer effects and thyroglobulin-mediated feedback regulation. A more thorough characterization of the intrathyroidal network from a systems biology perspective, including its topology, constituent network motifs, and nonlinear quantitative properties, can help us to better understand and predict the thyroidal dynamics in response to physiological signals, therapeutic interventions, and environmental disruptions.
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Affiliation(s)
- Li Jing
- Department of Toxicology and Hygienic Chemistry, School of Public Health, Capital Medical University, Beijing, China
- *Correspondence: Li Jing, ; Qiang Zhang,
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
- *Correspondence: Li Jing, ; Qiang Zhang,
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13
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Bjerkreim BA, Hammerstad SS, Gulseth HL, Berg T, Omdal LJ, Lee-Ødegård S, Eriksen EF. Effect of Liothyronine Treatment on Quality of Life in Female Hypothyroid Patients With Residual Symptoms on Levothyroxine Therapy: A Randomized Crossover Study. Front Endocrinol (Lausanne) 2022; 13:816566. [PMID: 35273566 PMCID: PMC8902821 DOI: 10.3389/fendo.2022.816566] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/27/2022] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE The effects of levothyroxine (LT4)/liothyronine (LT3) combination therapy on quality of life (QoL) in hypothyroid patients former on LT4 monotherapy have been disappointing. We therefore wanted to test the effects of LT3 monotherapy on QoL in hypothyroid patients with residual symptoms despite thyroid stimulating hormone (TSH) values within the reference range. DESIGN Female hypothyroid patients with residual symptoms on LT4 monotherapy or combination LT4/LT3 therapy received LT3 and LT4 monotherapy, respectively for 12 weeks in a non-blinded randomized crossover study. METHODS Fifty-nine patients aged 18-65 years were included. QoL was assessed using one disease-specific questionnaire (ThyPRO) and two generic questionnaires (Fatigue Questionnaire and SF-36) at baseline and at the end of the two treatment periods. Clinical indices of cardiovascular health (resting heart rate and blood pressure), as well as thyroid tests, were assessed at baseline and at the end of the two treatment periods. RESULTS After 12 weeks of LT3 treatment, 12 of the 13 domains of the ThyPRO questionnaire (physical, mental and social domains) showed significant improvements. The most pronounced improvements were less tiredness (mean -21 ± 26; P<0.0001) and cognitive complaints (mean -20 ± 20; P<0.0001). LT4 monotherapy exerted minor effects on two domains only (cognitive complaints and impaired daily life). All three dimensions' scores in the Fatigue Questionnaire (physical, mental and total fatigue) improved after LT3 treatment compared to baseline (P<0.001), and in the SF-36 questionnaire 7 of 8 scales showed significantly better scores after LT3 treatment compared to baseline. There were no differences in blood pressure or resting heart rate between the two treatment groups. TSH in patients on LT3 was slightly higher (median 1.33 mU/L (interquartile range (IQR) 0.47-2.26)) than in patients on LT4 (median 0.61 mU/L (IQR 0.25-1.20; P<0.018). Five patients on LT3 dropped out of the study due to subjectively reported side effects, compared to only one on LT4. CONCLUSIONS LT3 treatment improved QoL in women with residual hypothyroid symptoms on LT4 monotherapy or LT4/LT3 combination therapy. Short-term LT3 treatment did not induce biochemical or clinical hyperthyroidism, and no cardiovascular adverse effects were recorded. Further studies are needed to assess the long-term safety and efficacy of LT3 monotherapy. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, identifier NCT03627611.
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Affiliation(s)
- Betty Ann Bjerkreim
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- *Correspondence: Betty Ann Bjerkreim,
| | - Sara Salehi Hammerstad
- Department of Endocrinology, Pilestredet Park Specialist Center, Oslo, Norway
- Department of Pediatrics, Oslo University Hospital, Oslo, Norway
| | - Hanne Løvdal Gulseth
- Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health, Oslo, Norway
| | - Tore Julsrud Berg
- Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | | | - Erik Fink Eriksen
- Department of Endocrinology, Pilestredet Park Specialist Center, Oslo, Norway
- The Faculty of Dentistry, University of Oslo, Oslo, Norway
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Chen S, Wohlford GF, Vecchie’ A, Carbone S, Yavuz S, Van Tassell B, Abbate A, Celi FS. Acute Effects of Liothyronine Administration on Cardiovascular System and Energy Metabolism in Healthy Volunteers. Front Endocrinol (Lausanne) 2022; 13:843539. [PMID: 35295986 PMCID: PMC8919711 DOI: 10.3389/fendo.2022.843539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 02/02/2022] [Indexed: 11/26/2022] Open
Abstract
CONTEXT The pharmacokinetics of liothyronine causes concerns for cardiovascular toxicity. While the effects of sustained increase in serum T3 concentrations are well described, little is known on the effects of acute changes in T3 concentrations due to rapid action of thyroid hormone. OBJECTIVE To assess the clinical relevance of transient increase of T3 levels on cardiovascular system and energy metabolism. SETTING Double-blind, three arms, placebo controlled, cross-over study (ClinicalTrials.gov Identifier: NCT03098433). STUDY PARTICIPANTS Twelve volunteers (3 females, 9 males), age 27.7 ± 5.1 years. INTERVENTION Oral administration of liothyronine 0.7 mcg/kg, equimolar dose of levothyroxine (0.86 mcg/kg), or placebo in three identical study visits. Blood samples for total T3, free T4 were collected at times 0', 60' 120' 180' 240'. Continuous recording of heart rate, blood pressure, and hemodynamic data was performed using the volume clamp method. Resting energy expenditure was measured by indirect calorimetry. An echocardiogram was performed on each study visit at baseline and after the last blood sampling. MAIN OUTCOME MEASURES Changes in cardiovascular function and energy expenditure. RESULTS Following the administration of liothyronine, serum T3 reached a Cmax of 421 ± 57 ng/dL with an estimated Tmax of 120 ± 26 minutes. No differences between study arms were observed in heart rate, blood pressure, hemodynamics parameters, energy expenditure, and in echocardiogram parameters. CONCLUSIONS The absence of measurable rapid effects on the cardiovascular system following a high dose of liothyronine supports the rationale to perform long-term studies to assess its safety and effectiveness in patients affected by hypothyroidism.
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Affiliation(s)
- Shanshan Chen
- Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, Richmond, VA, United States
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA, United States
| | - George F. Wohlford
- Department of Pharmacotherapy and Outcomes Sciences, Virginia Commonwealth University, Richmond, VA, United States
| | - Alessandra Vecchie’
- Division of Cardiology, Virginia Commonwealth University, Richmond, VA, United States
- Department of Internal Medicine, ASST Sette Laghi, Varese, Italy
| | - Salvatore Carbone
- Department of Kinesiology and Health Sciences, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA, United States
| | - Sahzene Yavuz
- Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, Richmond, VA, United States
| | - Benjamin Van Tassell
- Department of Pharmacotherapy and Outcomes Sciences, Virginia Commonwealth University, Richmond, VA, United States
| | - Antonio Abbate
- Division of Cardiology, Virginia Commonwealth University, Richmond, VA, United States
| | - Francesco S. Celi
- Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, Richmond, VA, United States
- *Correspondence: Francesco S. Celi,
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Gottwald-Hostalek U, Kahaly GJ. Triiodothyronine alongside levothyroxine in the management of hypothyroidism? Curr Med Res Opin 2021; 37:2099-2106. [PMID: 34553643 DOI: 10.1080/03007995.2021.1984219] [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] [Indexed: 10/20/2022]
Abstract
The current guideline-based management of hypothyroidism recommends monotherapy with levothyroxine (LT4), titrated to maintain the level of thyrotropin within a euthyroid reference range. This has been successful for most people with hypothyroidism, but a substantial minority still report symptoms of hypothyroidism unexplained by a comorbid medical condition. LT4 is essentially a prodrug for triiodothyronine (T3), the thyroid hormone that acts on target tissues in the brain and the periphery. Thyroid hormone replacement with LT4 alone does not restore physiological tissue levels of thyroid hormones, particularly T3. During the last two decades, much interest has focussed on the potential of combinations of LT4 and T3 to provide a superior outcome to LT4 monotherapy for people with hypothyroidism, especially those with residual symptoms despite thyrotropin-optimized LT4. This review seeks to provide an overview of currently available evidence on combination (LT4 + T3) therapy to be used for personalized medicine in patients with hypothyroidism. A number of randomized, controlled trials (RCTs) have failed to demonstrate superiority for the combination therapy approach, largely due to non-physiological T3 doses. However, patients with hypothyroidism are highly heterogeneous in terms of their residual thyroid function, individual set points for optimal thyroid homeostasis and for the presence or absence of polymorphisms in deiodinase enzymes in tissues that activate and deactivate circulating thyroid hormones. Accordingly, these RCTs may have failed to demonstrate benefits of combination therapy in individual hypothyroid phenotypes. The pharmacokinetics of LT4 and T3 also differ, which is a barrier to their co-administration. Future clinical trials using LT4 + T3 tablets better suited for combination therapy will resolve the outstanding research questions relating to the place of LT4 + T3 combination therapy in the management of hypothyroidism.
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Affiliation(s)
| | - George J Kahaly
- Department of Medicine I, Johannes Gutenberg-University Medical Centre, Mainz, Germany
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Abstract
Background: The basis for the treatment of hypothyroidism with levothyroxine (LT4) is that humans activate T4 to triiodothyronine (T3). Thus, while normalizing serum thyrotropin (TSH), LT4 doses should also restore the body's reservoir of T3. However, there is evidence that T3 is not fully restored in LT4-treated patients. Summary: For patients who remain symptomatic on LT4 therapy, clinical guidelines recommend, on a trial basis, therapy with LT4+LT3. Reducing the LT4 dose by 25 mcg/day and adding 2.5-7.5 mcg liothyronine (LT3) once or twice a day is an appropriate starting point. Transient episodes of hypertriiodothyroninemia with these doses of LT4 and LT3 are unlikely to go above the reference range and have not been associated with adverse drug reactions. Trials following almost a 1000 patients for almost 1 year indicate that similar to LT4, therapy with LT4+LT3 can restore euthyroidism while maintaining a normal serum TSH. An observational study of 400 patients with a mean follow-up of ∼9 years did not indicate increased mortality or morbidity risk due to cardiovascular disease, atrial fibrillation, or fractures after adjusting for age when compared with patients taking only LT4. Desiccated thyroid extract (DTE) is a form of combination therapy in which the LT4/LT3 ratio is ∼4:1; the mean daily dose of DTE needed to normalize serum TSH contains ∼11 mcg T3, but some patients may require higher doses. The DTE remains outside formal FDA oversight, and consistency of T4 and T3 contents is monitored by the manufacturers only. Conclusions: Newly diagnosed hypothyroid patients should be treated with LT4. A trial of combination therapy with LT4+LT3 can be considered for those patients who have unambiguously not benefited from LT4.
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Affiliation(s)
- Thaer Idrees
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, Illinois, USA
| | - Scott Palmer
- Department of Medicine, Rush University Medical Center, Chicago, Illinois, USA
| | - Rui M.B. Maciel
- Division of Endocrinology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Antonio C. Bianco
- Section of Adult and Pediatric Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, Illinois, USA
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17
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Zutinic A, Blauw GJ, Pijl H, Ballieux BE, Westendorp RGJ, Roelfsema F, van Heemst D. Circulating Thyroid Hormone Profile in Response to a Triiodothyronine Challenge in Familial Longevity. J Endocr Soc 2020; 4:bvaa117. [PMID: 32964174 PMCID: PMC7491925 DOI: 10.1210/jendso/bvaa117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 08/12/2020] [Indexed: 02/02/2023] Open
Abstract
Context Familial longevity is associated with higher circulating levels of thyrotropin (TSH), in the absence of differences in circulating thyroid hormones, and a lower thyroid responsivity to TSH, as previously observed in the Leiden Longevity Study (LLS). Further mechanisms underlying these observations remain unknown. Objective We hypothesized that members from long-lived families (offspring) have higher thyroid hormone turnover or less negative feedback effect on TSH secretion compared to controls. Methods In a case-control intervention study, 14 offspring and 13 similarly aged controls received 100 µg 3,5,3′-triiodothyronine (T3) orally. Their circulating T3, free T3 (fT3), and TSH levels were measured during 5 consecutive days. We compared profiles of circulating T3, fT3, and TSH between offspring and controls using general linear modeling (GLM) and calculated the percentage decline in TSH following T3 administration. Results Circulating T3 and fT3 levels increased to supraphysiologic values and normalized over the course of 5 days. There were no serious adverse events. T3 and fT3 concentration profiles over 5 days were similar between offspring and controls (T3 GLM P = .11, fT3 GLM P = .46). TSH levels decreased in a biphasic manner and started returning to baseline by day 5. The TSH concentration profile over 5 days was similar between offspring and controls (GLM P = .08), as was the relative TSH decline (%). Conclusions Members of long-lived families have neither higher T3 turnover nor diminished negative feedback of T3 on TSH secretion. The cause and biological role of elevated TSH levels in familial longevity remain to be elucidated.
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Affiliation(s)
- Ana Zutinic
- Department of Internal Medicine, Division of Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, ZA, the Netherlands
| | - Gerard J Blauw
- Department of Internal Medicine, Division of Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, ZA, the Netherlands
| | - Hanno Pijl
- Department of Internal Medicine, Division of Endocrinology and Metabolic Diseases, Leiden University Medical Centre, Leiden, the Netherlands
| | - Bart E Ballieux
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Centre, Leiden, the Netherlands
| | - Rudi G J Westendorp
- Public Health and Centre for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Ferdinand Roelfsema
- Department of Internal Medicine, Division of Endocrinology and Metabolic Diseases, Leiden University Medical Centre, Leiden, the Netherlands
| | - Diana van Heemst
- Department of Internal Medicine, Division of Gerontology and Geriatrics, Leiden University Medical Centre, Leiden, ZA, the Netherlands
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Köhrle J, Lehmphul I, Pietzner M, Renko K, Rijntjes E, Richards K, Anselmo J, Danielsen M, Jonklaas J. 3,5-T2-A Janus-Faced Thyroid Hormone Metabolite Exerts Both Canonical T3-Mimetic Endocrine and Intracrine Hepatic Action. Front Endocrinol (Lausanne) 2020; 10:787. [PMID: 31969860 PMCID: PMC6960127 DOI: 10.3389/fendo.2019.00787] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022] Open
Abstract
Over the last decades, thyroid hormone metabolites (THMs) received marked attention as it has been demonstrated that they are bioactive compounds. Their concentrations were determined by immunoassay or mass-spectrometry methods. Among those metabolites, 3,5-diiodothyronine (3,5-T2), occurs at low nanomolar concentrations in human serum, but might reach tissue concentrations similar to those of T4 and T3, at least based on data from rodent models. However, the immunoassay-based measurements in human sera revealed remarkable variations depending on antibodies used in the assays and thus need to be interpreted with caution. In clinical experimental approaches in euthyroid volunteers and hypothyroid patients using the immunoassay as the analytical tool no evidence of formation of 3,5-T2 from its putative precursors T4 or T3 was found, nor was any support found for the assumption that 3,5-T2 might represent a direct precursor for serum 3-T1-AM generated by combined deiodination and decarboxylation from 3,5-T2, as previously documented for mouse intestinal mucosa. We hypothesized that lowered endogenous production of 3,5-T2 in patients requiring T4 replacement therapy after thyroidectomy or for treatment of autoimmune thyroid disease, compared to production of 3,5-T2 in individuals with intact thyroid glands might contribute to the discontent seen in a subset of patients with this therapeutic regimen. So far, our observations do not support this assumption. However, the unexpected association between high serum 3,5-T2 and elevated urinary concentrations of metabolites related to coffee consumption requires further studies for an explanation. Elevated 3,5-T2 serum concentrations were found in several situations including impaired renal function, chronic dialysis, sepsis, non-survival in the ICU as well as post-operative atrial fibrillation (POAF) in studies using a monoclonal antibody-based chemoluminescence immunoassay. Pilot analysis of human sera using LC-linear-ion-trap-mass-spectrometry yielded 3,5-T2 concentrations below the limit of quantification in the majority of cases, thus the divergent results of both methods need to be reconciliated by further studies. Although positive anti-steatotic effects have been observed in rodent models, use of 3,5-T2 as a muscle anabolic, slimming or fitness drug, easily obtained without medical prescription, must be advised against, considering its potency in suppressing the HPT axis and causing adverse cardiac side effects. 3,5-T2 escapes regular detection by commercially available clinical routine assays used for thyroid function tests, which may be seriously disrupted in individuals self-administering 3,5-T2 obtained over-the counter or from other sources.
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Affiliation(s)
- Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ina Lehmphul
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Maik Pietzner
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Kostja Renko
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Eddy Rijntjes
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Keith Richards
- Institut für Experimentelle Endokrinologie, Charité Campus Virchow-Klinikum, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - João Anselmo
- Endocrinology Department, Hospital Divino Espirito Santo, Ponta Delgada, Portugal
| | - Mark Danielsen
- Division of Endocrinology, Georgetown University, Washington, DC, United States
| | - Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University, Washington, DC, United States
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Madan R, Celi FS. Combination Therapy for Hypothyroidism: Rationale, Therapeutic Goals, and Design. Front Endocrinol (Lausanne) 2020; 11:371. [PMID: 32733377 PMCID: PMC7360670 DOI: 10.3389/fendo.2020.00371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/11/2020] [Indexed: 12/28/2022] Open
Abstract
Hypothyroidism is a common condition with a wide spectrum of etiologies and clinical manifestations. While the majority of patients affected by hypothyroidism respond well to levothyroxine, some patients do not and complain of symptoms despite adequate replacement. There is evidence in experimental models of hypothyroidism that levothyroxine alone may not be able to deliver an adequate amount of T3 to all the tissues targeted by the hormonal action, while liothyronine/levothyroxine combination therapy can. The results of clinical studies directed to assess the effectiveness of liothyronine/levothyroxine combination therapy on the amelioration of hypothyroid symptoms have been disappointing. Most of the trials have been short and underpowered, with several shortcomings in the study design. There is consensus that an adequately powered clinical trial should be developed to prove or disprove the efficacy and effectiveness of therapies other than LT4 alone for the treatment of hypothyroidism, and to assess which group of patients would benefit from them. Here we present some considerations on the technical aspects and necessary tradeoffs in designing such a study with a particular focus on study population selection, choice of endpoints, and study drugs formulation and regimen.
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Ucci S, Renzini A, Russi V, Mangialardo C, Cammarata I, Cavioli G, Santaguida MG, Virili C, Centanni M, Adamo S, Moresi V, Verga-Falzacappa C. Thyroid Hormone Protects from Fasting-Induced Skeletal Muscle Atrophy by Promoting Metabolic Adaptation. Int J Mol Sci 2019; 20:ijms20225754. [PMID: 31731814 PMCID: PMC6888244 DOI: 10.3390/ijms20225754] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 02/07/2023] Open
Abstract
Thyroid hormones regulate a wide range of cellular responses, via non-genomic and genomic actions, depending on cell-specific thyroid hormone transporters, co-repressors, or co-activators. Skeletal muscle has been identified as a direct target of thyroid hormone T3, where it regulates stem cell proliferation and differentiation, as well as myofiber metabolism. However, the effects of T3 in muscle-wasting conditions have not been yet addressed. Being T3 primarily responsible for the regulation of metabolism, we challenged mice with fasting and found that T3 counteracted starvation-induced muscle atrophy. Interestingly, T3 did not prevent the activation of the main catabolic pathways, i.e., the ubiquitin-proteasome or the autophagy-lysosomal systems, nor did it stimulate de novo muscle synthesis in starved muscles. Transcriptome analyses revealed that T3 mainly affected the metabolic processes in starved muscle. Further analyses of myofiber metabolism revealed that T3 prevented the starvation-mediated metabolic shift, thus preserving skeletal muscle mass. Our study elucidated new T3 functions in regulating skeletal muscle homeostasis and metabolism in pathological conditions, opening to new potential therapeutic approaches for the treatment of skeletal muscle atrophy.
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Affiliation(s)
- Sarassunta Ucci
- Pasteur Institute, 00161 Rome, Italy; (S.U.); (V.R.); (C.M.); (I.C.); (C.V.-F.)
| | - Alessandra Renzini
- DAHFMO Unit of Histology and Medical Embryology, Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy; (A.R.); (G.C.); (S.A.)
| | - Valentina Russi
- Pasteur Institute, 00161 Rome, Italy; (S.U.); (V.R.); (C.M.); (I.C.); (C.V.-F.)
| | - Claudia Mangialardo
- Pasteur Institute, 00161 Rome, Italy; (S.U.); (V.R.); (C.M.); (I.C.); (C.V.-F.)
| | - Ilenia Cammarata
- Pasteur Institute, 00161 Rome, Italy; (S.U.); (V.R.); (C.M.); (I.C.); (C.V.-F.)
| | - Giorgia Cavioli
- DAHFMO Unit of Histology and Medical Embryology, Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy; (A.R.); (G.C.); (S.A.)
| | - Maria Giulia Santaguida
- Department of Medico-Surgical Sciences and Biotechnologies Sapienza University of Rome, 04100 Latina, Italy; (M.G.S.); (C.V.); (M.C.)
| | - Camilla Virili
- Department of Medico-Surgical Sciences and Biotechnologies Sapienza University of Rome, 04100 Latina, Italy; (M.G.S.); (C.V.); (M.C.)
| | - Marco Centanni
- Department of Medico-Surgical Sciences and Biotechnologies Sapienza University of Rome, 04100 Latina, Italy; (M.G.S.); (C.V.); (M.C.)
| | - Sergio Adamo
- DAHFMO Unit of Histology and Medical Embryology, Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy; (A.R.); (G.C.); (S.A.)
| | - Viviana Moresi
- DAHFMO Unit of Histology and Medical Embryology, Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy; (A.R.); (G.C.); (S.A.)
- Correspondence:
| | - Cecilia Verga-Falzacappa
- Pasteur Institute, 00161 Rome, Italy; (S.U.); (V.R.); (C.M.); (I.C.); (C.V.-F.)
- Department of Medico-Surgical Sciences and Biotechnologies Sapienza University of Rome, 04100 Latina, Italy; (M.G.S.); (C.V.); (M.C.)
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Lehmann S, Thomas A, Schiwy-Bochat KH, Geyer H, Thevis M, Glenewinkel F, Rothschild MA, Andresen-Streichert H, Juebner M. Death after misuse of anabolic substances (clenbuterol, stanozolol and metandienone). Forensic Sci Int 2019; 303:109925. [DOI: 10.1016/j.forsciint.2019.109925] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/18/2019] [Accepted: 08/02/2019] [Indexed: 02/06/2023]
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Abstract
Guidelines on T4 + T3 combination therapy were published in 2012. This review investigates whether the issue is better understood 7 years later. Dissatisfaction with the outcome of T4 monotherapy remains high. Persistent symptoms consist mostly of fatigue, weight gain, problems with memory and thinking and mood disturbances. T4 monotherapy is associated with low serum T3 levels, which often require TSH-suppressive doses of L-T4 for normalization. Peripheral tissue thyroid function tests during T4 treatment indicate mild hyperthyroidism at TSH < 0.03 mU/L and mild hypothyroidism at TSH 0.3-5.0 mU/L; tissues are closest to euthyroidism at TSH 0.03-0.3 mU/L. This is explained by the finding that whereas T4 is usually ubiquinated and targeted for proteasomal degradation, hypothalamic T4 is rather stable and less sensitive to ubiquination. A normal serum TSH consequently does not necessarily indicate a euthyroid state. Persistent symptoms in L-T4 treated patients despite a normal serum TSH remain incompletely understood. One hypothesis is that a SNP (Thr92Ala) in DIO2 (required for local production of T3 out of T4) interferes with its kinetics and/or action, resulting in a local hypothyroid state in the brain. Effective treatment of persistent symptoms has not yet realized. One may try T4 + T3 combination treatment in selected patients as an experimental n = 1 study. The 2012 ETA guidelines are still valid for this purpose. More well-designed randomized clinical trials in selected patients are key in order to make progress. In the meantime the whole issue has become rather complicated by commercial and political overtones, as evident from skyrocketing prices of T3 tablets, aggressive pressure groups and motions in the House of Lords.
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Affiliation(s)
- Wilmar M Wiersinga
- Department of Endocrinology & Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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23
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Van Tassell B, Wohlford GF, Linderman JD, Smith S, Yavuz S, Pucino F, Celi FS. Pharmacokinetics of L-Triiodothyronine in Patients Undergoing Thyroid Hormone Therapy Withdrawal. Thyroid 2019; 29:1371-1379. [PMID: 31364488 PMCID: PMC6797066 DOI: 10.1089/thy.2019.0101] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background: L-triiodothyronine (LT3) is a substitute for levothyroxine (LT4) for thyroid cancer (TC) patients during the preparation for nuclear medicine procedures, and it is used in combination with LT4 in patients who do not respond to the standard treatment for hypothyroidism. This therapy is commonly done by using fixed doses, potentially resulting in supraphysiologic levels of triiodothyronine (T3). A good understanding of the LT3 pharmacokinetics (PK) is necessary to design combination treatment schemes that are able to maintain serum T3 levels within the reference range, but data on the PK of LT3 are conflicting. Here, we present a study designed to characterize the PK of LT3 in patients devoid of endogenous thyroid hormone production, and not receiving LT4 therapy. Methods: We performed an open-label, PK study in patients undergoing thyroid hormone withdrawal in preparation for nuclear medicine procedures for the evaluation and treatment of follicular-derived TC. LT3 was substituted for LT4 at a 1:3 mcg/mcg dosage ratio thrice daily for at least 30 days. PK of the last LT3 dose while at steady state and terminal elimination was assessed over 11 days. Thereafter, a PK study was performed following the nuclear medicine procedure in patients who volunteered for a second study. Results: Fourteen patients age 48.5 ± 16.0 years completed the last dose study and five completed the second PK study. PK analysis indicates a time to maximum serum concentration of 1.8 ± 0.32 hours and two distinct phases of linear elimination, with a fast distribution phase and slow elimination phases with half-lives of 2.3 ± 0.11 hours and 22.9 ± 7.7 hours, supporting a two-compartment model. PK modeling predicts that a twice-daily administration of low-dose LT3 (0.07 mcg/kg twice daily) in combination with LT4 can predictably increase the serum T3 concentration without significant peaks above the reference range. Conclusions: The PK of LT3 is well described by a two-compartment model that assumes elimination only from the sampling compartment, with a rapid distribution phase and a slow elimination phase. This information will contribute to design therapeutic strategies for LT3/LT4 combination therapies directed to maintain stable T3 serum levels.
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Affiliation(s)
- Benjamin Van Tassell
- Department of Pharmacotherapy and Outcomes Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - George F. Wohlford
- Department of Pharmacotherapy and Outcomes Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Joyce D. Linderman
- Diabetes, Endocrinology and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sheila Smith
- Diabetes, Endocrinology and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sahzene Yavuz
- Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, Richmond, Virginia
| | - Frank Pucino
- Food and Drug Administration, Silver Spring, Maryland
| | - Francesco S. Celi
- Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, Richmond, Virginia
- Address correspondence to: Francesco S. Celi, MD, MHSc, Division of Endocrinology Diabetes and Metabolism, Virginia Commonwealth University, 1101 East Marshall Street, PO Box 980111, Sanger Hall, Room 7-007, Richmond, VA 23298-0111
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24
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Hoermann R, Midgley JEM, Larisch R, Dietrich JW. Individualised requirements for optimum treatment of hypothyroidism: complex needs, limited options. Drugs Context 2019; 8:212597. [PMID: 31516533 PMCID: PMC6726361 DOI: 10.7573/dic.212597] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/21/2022] Open
Abstract
Levothyroxine (LT4) therapy has a long history, a well-defined pharmacological profile and a favourable safety record in the alleviation of hypothyroidism. However, questions remain in defining the threshold for the requirement of treatment in patients with subclinical hypothyroidism, assessing the dose adequacy of the drug, and selecting the best treatment mode (LT4 monotherapy versus liothyronine [LT3]/LT4 combinations) for subpopulations with persisting complaints. Supplied as a prodrug, LT4 is enzymatically converted into the biologically more active thyroid hormone, triiodothyronine (T3). Importantly, tetraiodothyronine (T4) to T3 conversion efficiency may be impaired in patients receiving LT4, resulting in a loss of thyroid-stimulating hormone (TSH)-mediated feed-forward control of T3, alteration of the interlocking equilibria between serum concentrations of TSH, free thyroxine (FT4), and free triiodothyonine (FT3), and a decrease in FT3 to FT4 ratios. This downgrades the value of the TSH reference system derived in thyroid health for guiding the replacement dose in the treatment situation. Individualised conditionally defined setpoints may therefore provide appropriate biochemical targets to be clinically tested, together with a stronger focus on clinical presentation and future endpoint markers of tissue thyroid state. This cautionary note encompasses the use of aggregated statistical data from clinical trials which are not safely applicable to the individual level of patient care under these circumstances.
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Affiliation(s)
- Rudolf Hoermann
- Department for Nuclear Medicine, Klinikum Lüdenscheid, Paulmannshöherstr. 14, 58515 Lüdenscheid, Germany
| | | | - Rolf Larisch
- Department for Nuclear Medicine, Klinikum Lüdenscheid, Paulmannshöherstr. 14, 58515 Lüdenscheid, Germany
| | - Johannes W Dietrich
- Medical Department I, Endocrinology and Diabetology, Bergmannsheil University Hospitals, Ruhr University of Bochum, Buerkle-de-la-Camp-Platz 1, 44789 Bochum, Germany.,Ruhr Center for Rare Diseases (CeSER), Ruhr University of Bochum and Witten/Herdecke University, Alexandrinenstr. 5, 44791 Bochum, Germany
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Idrees T, Price JD, Piccariello T, Bianco AC. Sustained Release T3 Therapy: Animal Models and Translational Applications. Front Endocrinol (Lausanne) 2019; 10:544. [PMID: 31456749 PMCID: PMC6700330 DOI: 10.3389/fendo.2019.00544] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
The standard of care to treat hypothyroidism is daily administration of levo-thyroxine (LT4). This is based on the understanding that deiodinases can restore production of T3 and compensate for the small amounts of T3 that are normally produced by the thyroid gland. However, pre-clinical and clinical evidence indicating that deiodinases fall short of restoring T3 production is accumulating, opening the possibility that liothyronine (LT3) might have a role in the treatment of some hypothyroid patients. LT3 tablets taken orally result in a substantial peak of circulating T3 that is dissipated during the next several hours, which is markedly distinct from the relative stability of T3 levels in normal individuals. Thus, the effort to developing new delivery strategies for LT3, including slow release tablets, liquid formulations, use of T3-related/hybrid molecules such as T3 sulfate, poly-zinc-T3 and glucagon-T3, nanoparticles containing T3, subcutaneous implant of T3-containing matrices, and stem cells for de novo development of the thyroid gland. This article reviews these strategies, their applicability in animal models and translatability to humans.
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Affiliation(s)
- Thaer Idrees
- Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, United States
| | | | - Thomas Piccariello
- Synthonics Inc., Blacksburg, VA, United States
- Department of Chemistry, Virginia Tech, Blacksburg, VA, United States
| | - Antonio C. Bianco
- Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, United States
- *Correspondence: Antonio C. Bianco
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26
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Perros P. A decade of thyroidology. Hormones (Athens) 2018; 17:491-495. [PMID: 30306416 PMCID: PMC6294812 DOI: 10.1007/s42000-018-0068-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 07/18/2018] [Indexed: 11/26/2022]
Abstract
Significant scientific progress has been achieved in the past decade in thyroidology driven by scholarly enquiry, unmet patient needs, and investment by the pharmaceutical and diagnostics industry. In this review, nine publications have been selected for their impact in pushing the frontiers of knowledge and understanding. They include new perspectives in the diagnosis, pathophysiology, epidemiology and management of thyroid cancer, understanding of thyroid hormone physiology, and new treatments for Graves' orbitopathy.
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Affiliation(s)
- Petros Perros
- Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle University, Newcastle upon Tyne, UK.
- Department of Endocrinology, Level 6, Leazes Wing, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK.
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Goede SL, Latham KR, Leow MKS, Jonklaas J. High Resolution Free Triiodothyronine-Thyrotropin (FT3-TSH) Responses to a Single Oral Dose of Liothyronine in Humans: Evidence of Distinct Inter-Individual Differences Unraveled Using an Electrical Network Model. J BIOL SYST 2017; 25:119-143. [PMID: 28989211 DOI: 10.1142/s0218339017500073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of a single oral dose of liothyronine (L-T3) on thyroid stimulating hormone (TSH) and other related thyroid system parameters are partly understood despite therapeutic use of this hormone over many decades. We characterize individualized responses of the hypothalamus-pituitary-thyroid (HPT) axis and its related temporal hormonal profile using an electrical network model. Based on thyroid hormone responses from blood samples using a single 50 μg oral dose of liothyronine in healthy persons with a normal operating euthyroid feedback HPT system, we derived an equivalent electrical circuit model for the system's responses. The mathematical model was tested with a circuit simulator and validated with individualized clinical data. This signal processing technique makes the evaluation of bioequivalence and bioavailability of various preparations of liothyronine at an individualized level a feasible endeavor for clinical application.
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Affiliation(s)
- Simon L Goede
- Systems Research, Oterlekerweg 4, 1841, GP Stompetoren, The Netherlands
| | - Keith R Latham
- ITL Pharma, 100 Coley Street, LIAS Campus, Bldg. B Kingsport, TN 37660
| | - Melvin Khee-Shing Leow
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore, Yong Loo Lin School of Medicine, National University of Singapore, Lee Kong Chian School of Medicine, Nanyang, Technological University, Singapore
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Trimboli P, Centanni M, Virili C. Liquid liothyronine to obtain target TSH in differentiated thyroid cancer patients. Endocr J 2016; 63:563-7. [PMID: 27000530 DOI: 10.1507/endocrj.ej16-0040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In the last ten years a liquid formulation of liothyronine (L-T3) became available. To date, no studies on its systematic use have been reported. This study is aimed at assessing the reliability of liquid L-T3 in achieving target TSH in patients with differentiated thyroid cancers (DTC). Twenty-one high risk DTC patients in whom levothyroxine treatment up to 2.0 μg/kg/day did not suppress TSH levels (i.e. >0.1 mIU/L) were selected. Maintaining the same L-T4 dose, they started to assume liquid L-T3 at an initial fixed dose of 3.55 μg (5 drops). Further adjustments of L-T3 dose were tailored according to individual assessment. Initial serum TSH ranged from 0.8 to 12.0 mIU/L, when patients assumed high dose of L-T4 alone. Following the addition of a daily single dose of 3.55 μg L-T3, the target TSH was attained in five patients (23.8%). After increasing L-T3 dose up to a mean of 7.3±3.4 μg/day all patients reached target serum TSH (<0.1 mIU/L). The mean individual L-T3 dose was significantly correlated with the body weight and was 0.11±0.04 μg/kg/day (p=0.013). Mean L-T4:L-T3 ratio was 21:1. No patients showed skewed free-T3 or free-T4 values, neither experienced discomfort nor reported adverse events. Liquid L-T3 can be useful to achieve optimal TSH suppression in high risk DTC with not suppressed TSH on L-T4 alone. This formulation allows an individual tailoring of L-T3, minimizing risks of side effects as well as of overtreatment in these clinical conditions.
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Affiliation(s)
- Pierpaolo Trimboli
- Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
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29
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Jonklaas J, Burman KD. Daily Administration of Short-Acting Liothyronine Is Associated with Significant Triiodothyronine Excursions and Fails to Alter Thyroid-Responsive Parameters. Thyroid 2016; 26:770-8. [PMID: 27030088 PMCID: PMC4913511 DOI: 10.1089/thy.2015.0629] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Although most studies of levothyroxine-liothyronine combination therapy employ once-daily hormone administration, the kinetics of once-daily liothyronine have been studied infrequently. The aim of this study was to document both the peak and trough serum triiodothyronine (T3) levels that occur with once-daily liothyronine administration, along with changes in thyroid-responsive parameters. METHODS Participants with hypothyroidism were studied prospectively at an academic institution. Patients were switched from levothyroxine monotherapy to liothyronine monotherapy with 15 μg liothyronine for two weeks, and then continued liothyronine at doses of 30-45 μg for a further four weeks in an open-label, single-arm study. Weekly trough levels of T3 were documented. In addition, hourly T3 concentrations immediately following liothyronine tablet administration were documented for eight hours during the sixth week of therapy. Serum thyrotropin (TSH) and free thyroxine (fT4) concentrations were documented. Biochemical markers, markers of energy metabolism, anthropometric parameters, well-being, and hyperthyroid symptoms were also assessed. RESULTS Mean serum TSH levels increased from 1.56 ± 0.81 mIU/L at baseline to 5.90 ± 5.74 mIU/L at two weeks and 3.84 ± 3.66 mIU/L at six weeks. Trough T3 levels decreased from 99.5 ± 22.9 to 91.9 ± 40.2 at two weeks and recovered to 96.1 ± 32.2 at six weeks. The peak T3 concentration after dosing of liothyronine during week 6 was 292.8 ± 152.3 ng/dL. fT4 levels fell once levothyroxine was discontinued and plateaued at 0.44 ng/dL at week 4. The sex hormone binding globulin (SHBG) concentration decreased at week 2 (p = 0.002). Hyperthyroid symptoms and SF36-PCS scores increased significantly at weeks 4-5 of liothyronine therapy (p = 0.04-0.005). Preference for liothyronine therapy increased from 6% to 39% over the study period. CONCLUSIONS Once-daily dosing of liothyronine at doses of 30-45 μg did not return serum TSH to the values seen during levothyroxine therapy. There were significant excursions in serum total and free T3 concentrations with once-daily therapy. Trials of combination therapy are likely to be associated with similar excursions, albeit of a lesser magnitude. Only the physical component score of the SF36 questionnaire and hyperthyroid symptoms changed significantly with conversion to liothyronine monotherapy. Sustained release preparations with stable serum T3 profiles may have entirely different outcomes.
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Affiliation(s)
- Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University Medical Center, Washington, DC
| | - Kenneth D. Burman
- Endocrine Section, MedStar Washington Hospital Center, Washington, DC
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Abstract
INTRODUCTION Hypothyroidism is currently a condition that can be treated, but not cured. Although levothyroxine reverses stigmata of hypothyroidism in most individuals, some patients feel dissatisfied with 'monotherapy', and this has stimulated interest in 'combination therapy' with both levothyroxine and liothyronine. AREAS COVERED A search of PubMed was conducted using terms including hypothyroidism, treatment, benefits, risks, and safety. Based on the articles identified, the body of evidence regarding the efficacy of traditional levothyroxine is reviewed. Concerns with levothyroxine therapy including impaired quality of life in treated patients, thyroxine-predominant hormone ratios, and inadvertent iatrogenic thyroid disease are discussed. The trials of combination therapy performed since 1999 were reviewed. The heterogeneity of these trials, both in terms of design and results, is discussed. The potential for new trials to determine whether combination therapy can reverse the dissatisfaction associated with monotherapy, while avoiding non-physiologic hormone ratios, inadvertent thyrotoxicosis, and unacceptable side effects is discussed. Expert commentary: Research regarding which therapy fully reverses hypothyroidism at a tissue and cellular level is ongoing. The field would be advanced by the development of an extended release preparation of liothyronine. In the future regeneration of functional thyroid follicles from stem cells may offer hope for curing hypothyroidism.
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