Prevalence of pancreatic autoantibodies in non-diabetic patients with autoimmune thyroid disease and its relation to insulin secretion and glucose tolerance

Abstract

Objective: We evaluated the prevalence of glutamic acid decarboxylase (GADA) and tyrosine phosphatase-protein antibodies (IA2A), their titers and their relation to first phase insulin response (FPIR) and glucose tolerance in autoimmune thyroid diseases (ATDs) patients. Subjects and methods: Graves' disease (GD; n = 181) and Hashimoto's thyroiditis (HT; n = 143) patients in addition to healthy controls (n = 93) were studied. Secondly, FPIR and oral glucose tolerance tests (OGTT) were performed in 11 anti-pancreatic islet-cell (+) and in 20 anti-pancreatic-cell (-) patients. Results: There was a non significant trend for higher prevalence of GADA positivity in GD vs HT (7.2% vs 2% p = 0.06), but the GADA titers were higher in HT. We also did not find a significant difference in IA2 prevalence (0.7% vs 0.0%) between these two groups or compared to the control group. In the subsequent analysis, low FPIR was found in 10% of these patients but without statistical difference for OGTT between pancreatic antibody-positive and -negative patients. Conclusion: A trend for greater prevalence of GADA was observed for GD patients than for HT or control. However, the titers of these autoantibodies were higher in HT patients, but there was no significant relation to insulin secretion and glucose tolerance at that moment and stage of autoimmune diseases. Arch Endocrinol Metab. 2017;61(3):361-6.

Prevalence of diabetes and presence of autoantibodies against zinc transporter 8 and glutamic decarboxylase at diagnosis and at follow up of Graves’ disease

“…We additionally found that 8.3% of the patients were positive for GADA at GD diagnosis, confirming studies in similar cohorts with reported prevalence of 7.2–13% [ 9 , 10 , 21 ]. Interestingly, GADA positivity appear to be more specific for GD than Hashimoto’s thyroiditis when studied in both phenotypes of autoimmune thyroid disease as studies on adult patients diagnosed with either GD or Hashimoto’s thyroiditis find GADA more often in GD patients.…”

“…It would therefore have been interesting to investigate glucose metabolism in the subjects, to identify patients with pre-diabetes or stage 2 autoimmune T1D; positive islet autoantibodies and dysglycemia without symptoms [ 20 ], but since this study was performed without continuous collection of plasma samples, it was not possible. In a recent study, first phase insulin response was tested in subjects with GD, finding no significant difference between those with positive autoantibodies for GADA or IA-2A and the ones with negative islet autoantibodies [ 21 ]. The islet autoantibodies might not uniquely represent risk for autoimmune T1D, but may instead be an unspecific sign of autoimmune disease.…”

Autoimmune thyroid disease correlates to islet autoimmunity on zinc transporter 8 autoantibody

“…Many studies have showed the prevalence rate of thyroid autoantibodies ranging from 3.7–35% in T1DM patients, some of which suggested the associations between thyroid autoantibodies and islet autoantibodies ( 10 , 11 , 12 , 13 , 14 ). However, little work has been done on the anti-islet autoimmune status in non-diabetic patients with AITD ( 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ). As summarized in Supplementary Table 1 (see section on supplementary materials given at the end of this article), the prevalence rates of glutamic acid decarboxylase autoantibodies (GADA), islet cell autoantibodies (ICA), insulinoma-associated antigen 2 autoantibodies (IA-2A) and insulin autoantibodies (IAA) in patients with AITD were either slightly or significantly higher than those in healthy controls (HC), indicating the distinct value of studying islet immune status in AITD.…”