V Eligar1, P N Taylor1, O E Okosieme2, G P Leese3, C M Dayan1. 1. Thyroid Research Group, Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff, UK. 2. Thyroid Research Group, Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff, UK Endocrine and Diabetes, Department Prince Charles Hospital, Cwm Taf University Health Board Merthyr Tydfil, UK OkosiemeOE@Cardiff.ac.uk. 3. Department of Medicine, University of Dundee, Ninewells Hospital, Dundee, UK.
Abstract
BACKGROUND: Hypothyroidism affects 2-5% of the general population. Patients with uncorrected disease suffer significant morbidity and have an increased risk of cardiovascular disease and neurocognitive impairment. Levothyroxine, the treatment of choice, is inexpensive, easy to administer and in most cases restores well-being while normalizing thyroid function. However, 30-50% of individuals on levothyroxine are either over-treated or under-treated and others remain dissatisfied with treatment despite achieving thyroid hormone concentrations within the laboratory reference interval. METHODS: This review is based on a systematic search of the literature for controlled trials, systematic reviews, guideline papers and cohort studies addressing best practice in thyroid hormone replacement. RESULTS: Recent decades have seen improvements in patient management strategies driven by a better appreciation of levothyroxine pharmacokinetics. However, aspects of therapy such as the optimal timing of medication, strategies to overcome treatment non-adherence and target thyroid stimulating hormone concentrations in pregnancy and in patients with differentiated thyroid cancer remain challenging. Furthermore, there is now a substantial body of literature on common genetic variations in the deiodinases and thyroid hormone transporters and their role in the local regulation of thyroid hormone delivery. The benefits of combination therapy with liothyronine and levothyroxine are uncertain, and while it is theoretically probable that subsets of genetically predisposed individuals will benefit from combination therapy the existing evidence is as yet limited. CONCLUSION: Despite the availability of thyroid hormone replacement for more than a century, there are still substantial challenges in practice and opportunities to improve treatment outcomes.
BACKGROUND:Hypothyroidism affects 2-5% of the general population. Patients with uncorrected disease suffer significant morbidity and have an increased risk of cardiovascular disease and neurocognitive impairment. Levothyroxine, the treatment of choice, is inexpensive, easy to administer and in most cases restores well-being while normalizing thyroid function. However, 30-50% of individuals on levothyroxine are either over-treated or under-treated and others remain dissatisfied with treatment despite achieving thyroid hormone concentrations within the laboratory reference interval. METHODS: This review is based on a systematic search of the literature for controlled trials, systematic reviews, guideline papers and cohort studies addressing best practice in thyroid hormone replacement. RESULTS: Recent decades have seen improvements in patient management strategies driven by a better appreciation of levothyroxine pharmacokinetics. However, aspects of therapy such as the optimal timing of medication, strategies to overcome treatment non-adherence and target thyroid stimulating hormone concentrations in pregnancy and in patients with differentiated thyroid cancer remain challenging. Furthermore, there is now a substantial body of literature on common genetic variations in the deiodinases and thyroid hormone transporters and their role in the local regulation of thyroid hormone delivery. The benefits of combination therapy with liothyronine and levothyroxine are uncertain, and while it is theoretically probable that subsets of genetically predisposed individuals will benefit from combination therapy the existing evidence is as yet limited. CONCLUSION: Despite the availability of thyroid hormone replacement for more than a century, there are still substantial challenges in practice and opportunities to improve treatment outcomes.
Authors: Peter N Taylor; Diana Albrecht; Anna Scholz; Gala Gutierrez-Buey; John H Lazarus; Colin M Dayan; Onyebuchi E Okosieme Journal: Nat Rev Endocrinol Date: 2018-03-23 Impact factor: 43.330
Authors: Peter N Taylor; Vinay Eligar; Ilaria Muller; Anna Scholz; Colin Dayan; Onyebuchi Okosieme Journal: Front Endocrinol (Lausanne) Date: 2019-10-22 Impact factor: 5.555
Authors: Chae Won Chung; Eun Young Mo; Gyung Seo Jung; Yoo Hyung Kim; Sun Wook Cho; Do Joon Park; Jeong Mo Bae; Young Joo Park Journal: Front Endocrinol (Lausanne) Date: 2021-05-26 Impact factor: 5.555