ISSN: 1301-2193 E-ISSN: 1308-9846
  • Turkish Journal of
    Endocrinology and Metabolism
ORIGINAL ARTICLE

Comparison of Triiodothyronine Level in Patients Treated with Levothyroxine for Different Causes of Hypothyroidism
Farklı Hipotiroidizm Nedenleri Dolayısıyla Levotiroksin ile Tedavi Edilen Hastalarda Triiyodotironin Seviyesinin Karşılaştırılması
Received Date : 13 Oct 2019
Accepted Date : 24 Mar 2020
Available Online : 12 Apr 2020
Doi: 10.25179/tjem.2019-71845 - Makale Dili: EN
Turk J Endocrinol Metab. 2020;24:138-143
Bu makale, CC BY-NC-SA altında lisanslanmış açık erişim bir makaledir.
ABSTRACT
Objective: Several lines of evidence suggest that the symptoms of hypothyroidism, including psychological symptoms and metabolic effects, persist in a significant percentage of patients treated with levothyroxine (L-T4). A hypothesis to explain this phenomenon is that the triiodothyronine (L-T3) serum levels may not be completely normalized. This study aimed to compare the level of serum free T3 (FT3) in patients who are biochemically euthyroid after L-T4 monotherapy with different underlying causes of hypothyroidism. Material and Methods: This cross-sectional study was conducted on patients with hypothyroidism who received L-T4 monotherapy and were biochemically euthyroid. The serum levels of thyroid-stimulating hormone (TSH), free T4 (FT4), FT3, and FT3/FT4 ratio were measured in these patients. Patients were divided into three groups based on the cause of hypothyroidism (radioiodine therapy, thyroidectomy and Hashimoto), and the results of biochemical tests of the thyroid were compared in three groups. Results: Of the 78 patients studied, 12 (15.4%) cases were male, and 66 (84.6%) cases were female. Among the variables studied, only the mean value of FT3 was significantly different in the three groups (p=0.006), where the highest mean value was seen in the Hashimoto group, and the lowest mean value was seen in the radioiodine therapy group. Conclusion: The results of this study showed that although hypothyroidism patients can be optimally treated with L-T4 alone, in many of these patients, the level of FT3 will not be in therapeutic range, and the mean serum FT3 levels in these patients could be related to their hypothyroidism causes.
ÖZET
Amaç: Çeşitli kanıtlar, levotiroksin (L-T4) ile tedavi edilen hastaların önemli bir kısmında, psikolojik semptomlar ve metabolik etkiler dâhil olmak üzere hipotiroidizm semptomlarının sebat ettiğini göstermektedir. Bu fenomeni açıklamak üzere öne sürülen bir hipotez, triiyodotironin (L-T3) serum seviyelerinin tamamen normalleştirilememesidir. Bu çalışmada, altta yatan hipotiroidizm nedenleri farklı olup L-T4 monoterapisi sonrası biyokimyasal olarak ötiroid olan hastalarda serum serbest T3 (sT3) düzeylerini karşılaştırmak amaçlanmıştır. Gereç ve Yöntemler: Kesitsel tipteki bu çalışma, L-T4 monoterapisi alan ve biyokimyasal olarak ötiroid olan hipotiroidili hastalarda gerçekleştirildi. Bu hastalarda tiroid uyarıcı hormon (TSH), serbest T4 (sT4), sT3 serum düzeyleri ve sT3/sT4 oranı ölçüldü. Hastalar, hipotiroidizmin nedenine göre üç gruba ayrıldı (radyoiyot tedavisi, tiroidektomi ve Hashimoto) ve tiroid biyokimyasal testlerinin sonuçları bu üç grupta karşılaştırıldı. Bulgular: Çalışmaya alınan 78 hastanın 12 (%15,4)'si erkek, 66 (%84,6)'sı kadındı. İncelenen değişkenler içinde, sadece ortalama sT3 değeri üç grup arasında anlamlı olarak farklıydı (p=0,006) ve en yüksek ortalama değer Hashimoto grubunda, en düşük ortalama değer ise radyoiyot tedavisi grubunda görüldü. Sonuç: Bu çalışmanın sonuçları, hipotiroidizm hastaları tek başına L-T4 ile optimal şekilde tedavi edilebilmesine rağmen, bu hastaların çoğunda sT3 seviyesinin terapötik aralıkta olmayacağını göstermiştir ve bu hastalardaki ortalama serum sT3 düzeyleri hipotiroidizmin nedeni ile ilişkili olabilir.
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