Theodora Pappa1, Maria Alevizaki2. 1. Endocrine Unit, Department of Clinical Therapeutics, Alexandra Hospital, Athens University School of Medicine, Athens, Greece. 2. Endocrine Unit, Department of Clinical Therapeutics, Alexandra Hospital, Athens University School of Medicine, Athens, Greece ; Department of Endocrinology, Metabolism and Diabetes, Evgenideion Hospital, Athens University School of Medicine, Athens, Greece.
Abstract
BACKGROUND: Metformin is one of the most widely prescribed antidiabetic medications with a favorable safety profile. In the last decade, several studies have reported a TSH-lowering effect of metformin in patients with diabetes mellitus. OBJECTIVE: To review literature data on the role of metformin use on thyroid function tests and the course of thyroid cancer. METHODS: WE PERFORMED A SEARCH IN THE PUBMED DATABASE USING THE TERMS: 'metformin', 'thyroid', 'TSH', 'diabetes', 'polycystic ovarian syndrome (PCOS)' and 'thyroid cancer'. RESULTS: The majority of available evidence suggests that metformin therapy results in a modest reduction of TSH levels in diabetic and/or PCOS patients with thyroid disorder, while thyroid hormone levels remain unaltered. It appears that this effect is independent of thyroid autoimmunity and thyroxine treatment. However, metformin use in subjects with an intact thyroid axis is not associated with a significant change of TSH levels. Concerning thyroid cancer, there is experimental evidence showing antimitogenic properties of metformin in differentiated and medullary thyroid cancer cells. On the other hand, there is also data supporting that metformin administration inhibits iodine uptake by thyroid cells and thus may limit the effectiveness of radioactive iodine treatment. CONCLUSIONS: Most studies suggest a TSH suppressive action of metformin in subjects with overt or subclinical thyroid dysfunction, while this is not apparent in euthyroid individuals. It appears that metformin has antimitogenic properties against various thyroid cancer types; however, experimental evidence of reduced efficacy of radioactive iodine treatment following metformin administration may limit its use in the management of differentiated thyroid cancer.
BACKGROUND:Metformin is one of the most widely prescribed antidiabetic medications with a favorable safety profile. In the last decade, several studies have reported a TSH-lowering effect of metformin in patients with diabetes mellitus. OBJECTIVE: To review literature data on the role of metformin use on thyroid function tests and the course of thyroid cancer. METHODS: WE PERFORMED A SEARCH IN THE PUBMED DATABASE USING THE TERMS: 'metformin', 'thyroid', 'TSH', 'diabetes', 'polycystic ovarian syndrome (PCOS)' and 'thyroid cancer'. RESULTS: The majority of available evidence suggests that metformin therapy results in a modest reduction of TSH levels in diabetic and/or PCOSpatients with thyroid disorder, while thyroid hormone levels remain unaltered. It appears that this effect is independent of thyroid autoimmunity and thyroxine treatment. However, metformin use in subjects with an intact thyroid axis is not associated with a significant change of TSH levels. Concerning thyroid cancer, there is experimental evidence showing antimitogenic properties of metformin in differentiated and medullary thyroid cancer cells. On the other hand, there is also data supporting that metformin administration inhibits iodine uptake by thyroid cells and thus may limit the effectiveness of radioactive iodine treatment. CONCLUSIONS: Most studies suggest a TSH suppressive action of metformin in subjects with overt or subclinical thyroid dysfunction, while this is not apparent in euthyroid individuals. It appears that metformin has antimitogenic properties against various thyroid cancer types; however, experimental evidence of reduced efficacy of radioactive iodine treatment following metformin administration may limit its use in the management of differentiated thyroid cancer.
Entities:
Keywords:
Diabetes; Metformin; Polycystic ovarian syndrome; TSH; Thyroid; Thyroid cancer
Authors: Bruno M Andrade; Renata L Araujo; Robert L S Perry; Elaine C L Souza; Juliana M Cazarin; Denise P Carvalho; Rolando B Ceddia Journal: Am J Physiol Cell Physiol Date: 2011-03-09 Impact factor: 4.249
Authors: Miguel López; Luis Varela; María J Vázquez; Sergio Rodríguez-Cuenca; Carmen R González; Vidya R Velagapudi; Donald A Morgan; Erik Schoenmakers; Khristofor Agassandian; Ricardo Lage; Pablo Blanco Martínez de Morentin; Sulay Tovar; Rubén Nogueiras; David Carling; Christopher Lelliott; Rosalía Gallego; Matej Oresic; Krishna Chatterjee; Asish K Saha; Kamal Rahmouni; Carlos Diéguez; Antonio Vidal-Puig Journal: Nat Med Date: 2010-08-29 Impact factor: 53.440
Authors: Lawrence Blonde; George E Dailey; Serge A Jabbour; Charles A Reasner; Donna J Mills Journal: Curr Med Res Opin Date: 2004-04 Impact factor: 2.580
Authors: Mostafa A Al-Alusi; Lin Du; Ning Li; Michael W Yeh; Xuemei He; Lewis E Braverman; Angela M Leung Journal: Thyroid Date: 2015-08-17 Impact factor: 6.568
Authors: Eun Kyung Jang; Won Gu Kim; Hyemi Kwon; Yun Mi Choi; Min Ji Jeon; Tae Yong Kim; Young Kee Shong; Won Bae Kim; Eui Young Kim Journal: Eur Thyroid J Date: 2015-08-20
Authors: Yvette J E Sloot; Marcel J R Janssen; Antonius E van Herwaarden; Robin P Peeters; Romana T Netea-Maier; Johannes W A Smit Journal: Sci Rep Date: 2019-04-01 Impact factor: 4.379