In patients with type 2 diabetes the presence of Hashimoto’s thyroiditis reduces the beneficial effect of dipeptidyl peptidase–4 inhibitor on plasma glucose control

Abstract

In this study, we compared the efficacy of a dipeptidyl peptidase-4 inhibitor (DPP4i) to improve glucose control in patients with type 2 diabetes mellitus (T2DM) with or without Hashimoto's thyroiditis (HT). First, we compared the change in glycated hemoglobin (HbA1c) between the hypothyroid condition (before levothyroxine sodium hydrate [LT4] treatment) and euthyroid condition (after LT4 treatment when patients had achieved euthyroidism for at least six months) in patients with T2DM and HT. Next, we compared the change in HbA1c levels before and six months of DPP4i treatment in patients with T2DM with and without HT. In hypothyroid condition the change in HbA1c after six months of DPP4i treatment was 0.13% ± 0.86%. The change in HbA1c levels from when patients first achieved euthyroidism to after six months in the euthyroid condition was 0.26% ± 0.90%. DPP4i efficacy in patients with T2DM and HT was reduced compared to patients with T2DM but without HT (-0.40 ± 0.90 vs. -0.99 ± 0.5, p = 0.0032). These data suggest that hypothyroidism does not impact on DPP4i efficacy. However, the effect of DPP4i in patients with T2DM and HT was reduced compared to that in T2DM patients without HT. An estimation of thyroid function before prescribing DPP4i may be useful tool for predicting the efficacy of DPP4i, allowing the ruling out complications from HT.

Prediction models constructed for Hashimoto’s thyroiditis risk based on clinical and laboratory factors

“…In our study, the levels of FPG, TAG, and TC were all significantly decreased while LDL-C was significantly increased in HT patients compared to controls. Blood glucose and blood lipid, including FPG, TAG, TC, and LDL-C are indeed found to be decreased in HT patients (24)(25)(26).…”

“…In general, the average BMI of HT patients tends to be lower than controls (53). Also, patients with an endocrine disorder, such as diabetes, also have a potential HT risk (25). However, many other autoimmune disorders are associated to HT, such as rheumatic disorders, autoimmune hemolytic anemia, and immune thrombocytopenic purpura, which may become potential risk factors for HT development (54)(55)(56)(57).…”

“…Also, the proper levels of inherent hormone metabolism, such as free thyroxine (FT4) and free triiodothyronine (FT3), along with fatty acid intake play important roles in the course of HT and thyroid cancer ( 19 , 23 ). It is reported that other endocrine diseases, such as diabetes and hyperlipemia, are often concurrent in HT patients whose fasting plasma glucose (FPG) may be disordered ( 24 , 25 ), while triglyceride (TAG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) may be significantly lower than in healthy people ( 26 ).…”