Adverse Impact of Hashimoto's Thyroiditis on Pancreatic Beta-Cell Function in Type 2 Diabetic Patients

Abstract

Background: Hashimoto’s thyroiditis (HT) is an autoimmune disease and often complicated with other metabolic disorders. It has been shown that HT patients have higher levels of antibodies against proinsulin than controls. The incidence of HT in T2DM patients is unclear and has never been studied whether beta cell function differ between T2DM patients alone and complexed with HT. Methods: 8T2DM patients who were recruited between November 2015 till June 2016 to Endocrinology Center in Lu He hospital were analyzed. HT was diagnosed if either serum TPO antibody or TG antibody exceeded the normal range. After a 12-hour overnight fast, venous blood samples were obtained to measure total cholesterol, triglyceride, HDL-c, FBG, insulin and Scr. Oral glucose tolerance test (OGTT) was examined in the patients and serum c-peptide levels were quantified at 0, 1, 2, and 3 hours after glucose administration. Results: 8T2DM patients were included in the study. 249 patients were diagnosed HT.Compared with non-HT subjects, T2DM with HT were more males (44.7% vs. 35.2%, p=0.02) and had higher values of systolic blood pressure (133.8 mm Hg vs. 131.1 mmHg, p=0.03). Although age, body mass index, HbA1c, serum cholesterol and serum triglyceride did not differ between two groups (p≥0.17 for all), fasting C-peptide levels were lower in T2DM complicated with HT than T2DM alone (1.09 ±0.90 nmol/L vs. 1.28±0.98 nmol/L, p=0.004). To further compare beta cell function, patients were performed OGTT test. Serum C-peptide levels remained lower at 1 and 2 hours after oral administration of 75-g glucose in T2DM with HT than T2DM alone (1 hour: 2.10±1.77 nMol/L vs. 2.33 ±1.84 nMol/L, p=0.03; 2 hours: 3.04±2.56 vs. 3.47±2.77 nmol/L, p=0.02). Serum C-peptide levels were comparable three hours after 75-g glucose intake (3.16±2.45 nmol/L vs. 3.50±2.78 nMol/L, p=0.49). Conclusion: The prevalence of HT is relatively high in T2DM patients, which was associated with reduced beta cell function. Disclosure Y. Zhang: None. R. Sun: None. L. Zhang: None. Y. Fang: None. C. Yu: None. S. Yuan: None. Y. Feng: None. D. Zhao: None.