Polymorphisms in type 2 deiodinase are not associated with well-being, neurocognitive functioning, and preference for combined thyroxine/3, 5, 3′-triiodothyronine …
BC Appelhof, RP Peeters, WM Wiersinga… - The Journal of …, 2005 - academic.oup.com
BC Appelhof, RP Peeters, WM Wiersinga, TJ Visser, EM Wekking, J Huyser, AH Schene…
The Journal of Clinical Endocrinology & Metabolism, 2005•academic.oup.comIntroduction: Some patients on levothyroxine replacement display significant impairment in
psychological well-being, compared with sex-and age-matched controls. Levothyroxine-
treated patients can be assumed to derive T3 exclusively from deiodination of T4, which, in
the central nervous system, is regulated by type II deiodinase (DII). Objective: We
investigated whether two recently identified polymorphisms in the DII gene (DII-ORFa-
Gly3Asp and DII-Thr92Ala) are determinants of well-being and neurocognitive functioning …
psychological well-being, compared with sex-and age-matched controls. Levothyroxine-
treated patients can be assumed to derive T3 exclusively from deiodination of T4, which, in
the central nervous system, is regulated by type II deiodinase (DII). Objective: We
investigated whether two recently identified polymorphisms in the DII gene (DII-ORFa-
Gly3Asp and DII-Thr92Ala) are determinants of well-being and neurocognitive functioning …
Abstract
Introduction: Some patients on levothyroxine replacement display significant impairment in psychological well-being, compared with sex- and age-matched controls. Levothyroxine-treated patients can be assumed to derive T3 exclusively from deiodination of T4, which, in the central nervous system, is regulated by type II deiodinase (DII).
Objective: We investigated whether two recently identified polymorphisms in the DII gene (DII-ORFa-Gly3Asp and DII-Thr92Ala) are determinants of well-being and neurocognitive functioning and associated with a preference for replacement with a combination of T3 and T4.
Methods: Genotypes for both polymorphisms were determined in 141 patients with primary autoimmune hypothyroidism, adequately treated with levothyroxine monotherapy and participating in a randomized clinical trial comparing T4 therapy with T4/T3 combination therapy. Questionnaires on well-being and neurocognitive tests were performed at baseline.
Results: Allele frequencies in patients with primary hypothyroidism were similar to those of healthy blood bank donors (32.0 vs. 33.9% for DII-ORFa-Gly3Asp and 40.4 vs. 38.8% for DII-Thr92Ala). DII polymorphisms were not associated with measures of well-being, neurocognitive functioning, or preference for combined T4/T3 therapy.
Conclusion: The DII-ORFa-Gly3Asp and DII-Thr92Ala polymorphisms do not explain differences in well-being, neurocognitive functioning, or appreciation of T4/T3 combination therapy in patients treated for hypothyroidism.
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