Is Dipeptidyl Peptidase-4 Inhibitor a Risk Factor to Develop Permanent Hypothyroidism in Subacute Thyroiditis in Patients with Type 2 Diabetes Mellitus?

Abstract

Abstract Introduction: Permanent hypothyroidism rationale is presented in 5 - 26% of the subacute thyroiditis patients. In the last decade, three cases of Subacute Thyroiditis (SAT) were treated with Dipeptidyl Peptidase-4 Inhibitor (DPP-4i) in patients with Type 2 Diabetes Mellitus (T2DM). Case Presentation: Case 1:52-year-old woman presented with T2DM on tolbutamide and sitagliptin. She was diagnosed with SAT and managed with loxoprofen sodium hydrate while maintaining her antidiabetic agents. Three months later, the thyroid function returned to euthyroid condition. Case 2: 74-year-old man T2DM patient on metformin, glimepiride, and sitagliptin. He was diagnosed with SAT and managed with loxoprofen sodium hydrate while maintaining ongoing antidiabetic management. One month later, his thyroid function deteriorated to hypothyroidism and further nine months later, the thyroid returned to euthyroid function. Case 3: 69-year-old-man T2DM patient on vildagliptin. He was diagnosed with SAT and managed with prednisolone (10mg/ day) with cessation of vildagliptin and introduction of insulin therapy. One month later, the thyroid function returned to euthyroid function. Conclusions: We experienced SAT during the administration of DPP-4i in three T2DM patients. Although one of them experienced transient hypothyroidism, none developed permanent hypothyroidism. DPP-4i may not be a risk factor of permanent hypothyroidism in SAT patients with T2DM. Keywords DPP4 inhibitors; Subacute thyroiditis; Type 2 diabetes mellitus Abbreviations DPP-4i: Dipeptidyl Peptidase-4 Inhibitor; TSH: Thyroid Stimulating Hormone; FT3: Free Triiodothyronine; FT4: Free Thyroxine; Tg: Thyroglobulin; CRP: C-Reactive Protein; Trab: TSH Receptor Antibody; Anti-Tg-Ab: Anti-Thyroglobulin Antibody