Metabolic parameters are associated with thyroid volume and free T3 levels in euthyroid individuals: a cross-sectional study

Year 2026, Volume: 8 Issue: 2, 231 - 237, 10.03.2026

Adile Begüm Bahçecioğlu , Bağdagül Yüksel Güler , Berna İmge Aydoğan , Alptekin Gürsoy

https://doi.org/10.38053/acmj.1838783

https://izlik.org/JA88JS66HN

Abstract

Aims: Our study aimed to investigate the impact of metabolic parameters, specifically insulin level and body-mass index (BMI), on the thyroid gland, considering both morphological and functional aspects. For this purpose, we performed a cross-sectional analysis with euthyroid participants.
Methods: One hundred euthyroid adults without thyroid autoimmunity or nodules were included. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), fasting insulin levels (FPI), and glucose/insulin values from a 2-hour OGTT were recorded. Anthropometric measures, including BMI and waist circumference (WC), were obtained, and thyroid volume (TV) was measured by ultrasound. The relationship between TV, hormone levels, and metabolic parameters was analyzed.
Results: A significant positive relationship was observed between TV and multiple parameters, including BMI, HOMA-IR, HbA1c, FPG, and FPI. Regression modeling identified OGTT 2nd-hour insulin and WC as significant predictors of thyroid volume. Furthermore, FT3 concentrations correlated positively with BMI, WC, HOMA-IR, and FPI measurements.
Conclusion: Increased TV appears to be associated with obesity and higher HOMA-IR, whereas FT3 levels show a positive correlation with both. These findings imply a significant interplay between insulin level, adiposity, thyroid gland morphology, and thyroid hormone metabolism.

Keywords

Thyrotropin , triiodothyronine , glucose tolerance test , ultrasonography , glycated hemoglobin

Metabolik parametreler, ötiroid bireylerde tiroid hacmi ve serbest T3 seviyeleri ile ilişkilidir: kesitsel bir çalışma

https://izlik.org/JA88JS66HN

Abstract

Amaç: Çalışmamız, metabolik parametrelerin—özellikle insülin düzeyi ve vücut kitle indeksi (VKİ)—tiroid bezi üzerindeki etkisini, hem morfolojik hem de fonksiyonel açıdan incelemeyi amaçlamıştır. Bu amaçla, ötiroid katılımcılarla kesitsel bir analiz yapılmıştır.
Yöntemler: Tiroid otoimmünitesi veya nodülü olmayan 100 ötiroid erişkin çalışmaya dahil edildi. Tiroid uyarıcı hormon (TSH), serbest triiyodotironin (FT3), serbest tiroksin (FT4), açlık plazma glukozu (APG), glike hemoglobin (HbA1c), açlık insülini (FPI) ve 2 saatlik OGTT’den elde edilen glukoz/insülin değerleri kaydedildi. VKİ ve bel çevresi (BÇ) dahil antropometrik ölçümler alındı ve tiroid hacmi (TH) ultrasonografi ile değerlendirildi. TH, hormon düzeyleri ve metabolik parametreler arasındaki ilişki analiz edildi.
Bulgular: TH ile VKİ, HOMA-IR, HbA1c, APG ve FPI dahil birçok parametre arasında anlamlı pozitif ilişki bulundu. Regresyon analizinde OGTT 2. saat insülin düzeyi ve BÇ, tiroid hacminin anlamlı belirleyicileri olarak ortaya çıktı. Ayrıca FT3 düzeyleri, VKİ, BÇ, HOMA-IR ve FPI ölçümleri ile pozitif korelasyon gösterdi.
Sonuç: Artmış tiroid hacmi, obezite ve daha yüksek HOMA-IR ile ilişkili görünmektedir; FT3 düzeyleri ise her ikisiyle pozitif korelasyon göstermektedir. Bu bulgular, insülin düzeyi, adipozite, tiroid bezi morfolojisi ve tiroid hormon metabolizması arasında anlamlı bir etkileşim olduğunu düşündürmektedir.

Keywords

Tirotropin , triiyodotironin , glukoz tolerans testi , ultrasonografi , glike hemoglobin

References

• Ayturk S, Gursoy A, Kut A, Anil C, Nar A, Tutuncu NB. Metabolic syndrome and its components are associated with increased thyroid volume and nodule prevalence in a mild-to-moderate iodine-deficient area. Eur J Endocrinol. Oct 2009;161(4):599-605. doi:10.1530/eje-09-0410
• Rendina D, De Filippo G, Mossetti G, et al. Relationship between metabolic syndrome and multinodular non-toxic goiter in an inpatient population from a geographic area with moderate iodine deficiency. J Endocrinol Invest. 2012;35(4):407-412. doi:10.3275/7842
• Lass N, Barth A, Reinehr T. Thyroid volume and thyroid function parameters are independently associated with weight status in overweight children. Horm Res Paediatr. 2020;93(5):279-286. doi:10. 1159/000509786
• Gómez JM, Maravall FJ, Gumà A, Abós R, Soler J, Fernández-Castañer M. Thyroid volume as measured by ultrasonography in patients with type 1 diabetes mellitus without thyroid dysfunction. Horm Metab Res. 2003;35(8):486-491. doi:10.1055/s-2003-41806
• Okten A, Akcay S, Cakir M, Girisken I, Kosucu P, Deger O. Iodine status, thyroid function, thyroid volume and thyroid autoimmunity in patients with type 1 diabetes mellitus in an iodine-replete area. Diabetes Metab. 2006;32(4):323-329. doi:10.1016/s1262-3636(07)70286-0
• Rezzonico J, Rezzonico M, Pusiol E, Pitoia F, Niepomniszcze H. Introducing the thyroid gland as another victim of the insulin resistance syndrome. Thyroid. 2008;18(4):461-464. doi:10.1089/thy.2007.0223
• De Pergola G, Ciampolillo A, Paolotti S, Trerotoli P, Giorgino R. Free triiodothyronine and thyroid stimulating hormone are directly associated with waist circumference, independently of insulin resistance, metabolic parameters and blood pressure in overweight and obese women. Clin Endocrinol (Oxf). 2007;67(2):265-269. doi:10.1111/j.1365- 2265.2007.02874.x
• Schäffler A, Binart N, Schölmerich J, Büchler C. Hypothesis paper brain talks with fat--evidence for a hypothalamic-pituitary-adipose axis? Neuropeptides. 2005;39(4):363-367. doi:10.1016/j.npep.2005.06.003
• Feldt-Rasmussen U. Thyroid and leptin. Thyroid. 2007;17(5):413-419. doi:10.1089/thy.2007.0032
• Knudsen N, Laurberg P, Rasmussen LB, et al. Small differences in thyroid function may be important for body mass index and the occurrence of obesity in the population. J Clin Endocrinol Metab. 2005;90(7):4019-4024. doi:10.1210/jc.2004-2225
• Fox CS, Pencina MJ, D'Agostino RB, et al. Relations of thyroid function to body weight: cross-sectional and longitudinal observations in a community-based sample. Arch Intern Med. 24 2008;168(6):587-592. doi:10.1001/archinte.168.6.587
• Tarcin O, Abanonu GB, Yazici D, Tarcin O. Association of metabolic syndrome parameters with TT3 and FT3/FT4 ratio in obese Turkish population. Metab Syndr Relat Disord. 2012;10(2):137-142. doi:10.1089/met.2011.0098
• Sechi LA, Catena C, Zingaro L, De Carli S, Bartoli E. Hypertension and abnormalities of carbohydrate metabolism possible role of the sympathetic nervous system. Am J Hypertens. 1997;10(6):678-682. doi: 10.1016/s0895-7061(97)00062-9
• Purves RD. Optimum numerical integration methods for estimation of area-under-the-curve (AUC) and area-under-the-moment-curve (AUMC). J Pharmacokinet Biopharm. 1992;20(3):211-226. doi:10.1007/bf01062525
• Brunn J, Block U, Ruf G, Bos I, Kunze WP, Scriba PC. Volumetrie der Schilddrüsenlappen mittels Real-time-Sonographie [volumetric analysis of thyroid lobes by real-time ultrasound (author's transl)]. Dtsch Med Wochenschr. 1981;106(41):1338-1340. doi:10.1055/s-2008-1070506
• Xiao Y, Mao J, Mao X, et al. Metabolic syndrome and its components are associated with thyroid volume in adolescents. BMC Endocr Disord. 2021;21(1):176. doi:10.1186/s12902-021-00833-3
• Michalaki MA, Vagenakis AG, Leonardou AS, et al. Thyroid function in humans with morbid obesity. Thyroid. 2006;16(1):73-78. doi:10.1089/thy.2006.16.73
• Yang L, Sun X, Tao H, Zhao Y. The association between thyroid homeostasis parameters and obesity in subjects with euthyroidism. J Physiol Pharmacol. 2023;74(1):10.26402/jpp.2023.1.07 doi:10.26402/jpp. 2023.1.07
• Reinehr T. Obesity and thyroid function. Mol Cell Endocrinol. 2010;316 (2):165-171. doi:10.1016/j.mce.2009.06.005
• Zimmermann-Belsing T, Brabant G, Holst JJ, Feldt-Rasmussen U. Circulating leptin and thyroid dysfunction. Eur J Endocrinol. Oct 2003; 149(4):257-271. doi:10.1530/eje.0.1490257
• Blanc E, Ponce C, Brodschi D, et al. Association between worse metabolic control and increased thyroid volume and nodular disease in elderly adults with metabolic syndrome. Metab Syndr Relat Disord. 2015;13(5):221-226. doi:10.1089/met.2014.0158
• Feng S, Zhang Z, Xu S, et al. The prevalence of thyroid nodules and their association with metabolic syndrome risk factors in a moderate iodine intake area. Metab Syndr Relat Disord. 2017;15(2):93-97. doi:10.1089/met.2016.0077
• Lomtadze N, Giorgadze E, Janjgava S, Kacharava T, Taboridze I. The relationship between insulin resistance and thyroid volume in Georgia. Endocr Metab Immune Disord Drug Targets. 2023;23(10):1318-1325. doi:10.2174/1871530323666230220093432
• Olgun ME, Pire G, Güney İB. Effects of metformin therapy on thyroid volume and functions in patients with newly diagnosed type 2 diabetes mellitus: a single-center prospective study. Endocr Metab Immune Disord Drug Targets. 2024;24(15):1842-1855. doi:10.2174/0118715303307313240315162000
• Walker E. Area under the (learning) curve. Diabetes Spectrum. 1994; 7:148.
• Allison DB, Paultre F, Maggio C, Mezzitis N, Pi-Sunyer FX. The use of areas under curves in diabetes research. Diabetes Care. 1995;18(2):245-250. doi:10.2337/diacare.18.2.245
• Van Keymeulen A, Dumont JE, Roger PP. TSH induces insulin receptors that mediate insulin costimulation of growth in normal human thyroid cells. Biochem Biophys Res Commun. 2000;279(1):202-207. doi:10.1006/bbrc.2000.3910