Thyroid autoimmunity has no negative impact on insulin dynamics in prediabetic patients with normal thyroid function

Abstract

Introduction. The association of autoimmune thyroid disease (AITD) with diabetes mellitus type-1 (DM1) has been previously documented. However, limited data exist regarding the association of AITD and diabetes mellitus type-2 (DM2). The objective of the study was to expose the role of AITD on DM2 and the impact of AITD in euthyroid patients with pre-diabetes. Euthyroid prediabetic patients were defined by impaired fasting glucose and/or glucose intolerance. Material and methods. We assessed static and dynamic insulin resistance (IRI) and insulin secretion indices (ISI), and the disposition index (DI). Results. Out of 166 patients studied, 31.9% had AITD; impaired fasting glucose (IFG) prevalence was the same with non-AITD patients. In contrast, impaired glucose tolerance (IGT) was less prevalent in AITD compared to non-AITD patients (9.4% versus 28.3%, p=0.008). IRI did not differ between the two groups. The dynamic ISI, 1st phase and 2nd phase insulin release, and the DI showed a worse insulin secretion in non-AITD compared to AITD patients (0.54 versus 0.45, p=0.029; 1029.3 versus 864.3, p=0.033; 354.8 versus 286.5, p=0.035; 0.09 versus 0.07, p=0.02, respectively). On the other hand, hsCRP was higher in AITD versus non-AITD individuals (p=0.008). Conclusions. Although individuals with pre-diabetes and AITD presented with higher levels of low-grade inflammation, their dynamic ISI and the DI, were less impaired.

Keywords

• insulin resistance indices
• quicki
• homa
• disposition index
• glucose-to-insulin ratio