Islet Cell and Thyroid Autoimmunity in Chinese Patients With IDDM

Abstract

Letters tion (ADA) recommends that screening be confined to individuals with more than one risk factor for diabetes (4). The ADA Diabetes Risk Test (5) is a tool that is used to educate people about diabetes and encourage individuals at "high risk" of diabetes to seek further diagnostic testing.Two research groups have recently investigated the usefulness of the ADA Diabetes Risk Test and the ADA Diabetes Screening Position Statement. Using the Risk Test, Burden and Burden (6) found poor test sensitivity (46%) and specificity (59.5%) in England. In a U.S. Study (7), 8.3% of participants without risk factors were found to have abnormal screening glucose tests, and 9.2% of those with more than one risk factor were found to have abnormal screening glucose tests (NS).As part of a diabetes education and intervention project, we used the ADA Risk Test as an initial screening tool for finding individuals with undiagnosed diabetes. A revised version of the ADA Diabetes Risk Test was sent to all households occupied by individuals >60 years of age in the Everett, WA, area. These individuals were asked to complete and return the test. Test results were scored using the ADA Diabetes Risk Test scoring guidelines (5). All individuals in the high risk category were asked to have their fasting plasma glucose (FPG) tested. All FPG tests were done through our laboratory using the hexokinase-ultraviolet method. Individuals with FPG levels >6.38 mmol/1 were advised to visit their physicians for further diagnostic testing.We received 349 completed returns (return rate 4.7%). One hundred and eighty-one Risk Tests were classified as high risk by ADA criteria. One hundred and ten (61%) of those people with high risk test scores had FPG testing. Eleven of these people (10%) had FPG tests that exceeded 6.38 mmol/1. Of these 11,7 had FPG levels >7.77 mmol/1. Six new cases of diabetes were diagnosed.Results from individuals with known diabetes were eliminated from data analysis. We compared revised ADA Diabetes Risk Test total scores with FPG values using ^ and Fisher's exact tests.The revised ADA Diabetes Risk Test total scores were not significantly related to FPG results (P = 0.961). The ADA Diabetes Risk Test positive predictive value was 9.8% when an FPG level of 6.38 mmol/1 was used and 6.3% when a FPG level oil.11 mmol/1 was used.The revised ADA Diabetes Risk Test did not prove to be a useful instrument for detecting undiagnosed diabetes in our population of older, primarily Caucasian individuals.We recommend that ADA convert the ADA Diabetes Risk Test to an educational tool that lists common symptoms of diabetes and supports work to analyze the predictive value of various diabetes risk factors with an emphasis on changes that occur with aging and with relative occurrence of each risk factor.

Serum Thyrotropin is a Better Predictor of Future Thyroid Dysfunction Than Thyroid Autoantibody Status in Biochemically Euthyroid Patients with Diabetes: Implications for Screening

“…More modern assays may prove to be better predictors of thyroid dysfunction. The overall prevalence of thyroid autoantibodies was 22%, which is compatible with previous reports (6)(7)(8)(9)(10)(11)(12)(13)(14)(15).…”

“…Thyroid autoantibodies are more common in people with diabetes than in the general population; prevalences from 15% to 31% have been reported in type 1 diabetes mellitus (T1DM) (6)(7)(8)(9)(10)(11)(12)(13)(14)(15), and of 15% in type 2 diabetes mellitus (T2DM) (11). The presence of thyroid autoantibodies at the time of diagnosis of T1DM also increases the likelihood of concurrent thyroid dysfunction (6,8,9,14).…”

Differentially methylated and expressed genes in familial type 1 diabetes

“…ICA1: This gene is involved in membrane trafficking at the Golgi complex, including transport of insulin in immature secretory granules 17,18 . ICA1 is an autoantigen in insulin-dependent diabetes mellitus [19][20][21] ; however, it has a low number of detectable ICA in Chinese patients compared to Caucasians 22 . The expression of ICA1 is high in human pancreatic islets 23 and is upregulated in pancreatic tissue at the clinical onset of T1D (Table 2).…”

ICA1 is differentially methylated and expressed in familial type 1 diabetes

“…This gene is involved in membrane tra cking at the Golgi complex, including transport of insulin in immature secretory granules (17,18). ICA1 is an autoantigen in insulin-dependent diabetes mellitus (19,20,21); however, it has a low number of detectable ICA in Chinese patients compared to Caucasians (22). Expression of ICA1 is high in human pancreatic islets (23) and is upregulated in pancreatic tissue at the clinical onset of T1D (Table 2).…”