Diabetes mellitus type 1 According to the current definition, two fasting glucose measurements above 126 mg/dl (7.0 mmol/l) is considered diagnostic for diabetes mellitus. In type 1, pancreatic beta cells in the islets of Langerhans are destroyed, decreasing endogenous insulin production. This distinguishes type 1's origin from type 2. Type 2 diabetes is characterized by insulin resistance, while type 1 diabetes is characterized by insulin deficiency, generally without insulin resistance. Another hallmark of type 1 diabetes is islet autoreactivity, which is generally measured by the presence of autoantibodies directed towards the beta cells. The appearance of diabetes-related autoantibodies has been shown to be able
Epigenetics of diabetes Type 2 found that there was an approximately twofold increase in DNA methylation of the PPARGC1A promoter of human islet cells from diabetics as compared to non-diabetic human islet cells. This means that expression from the PPARGC1A genes were turned down in the diabetic patients. Further testing revealed that the more PPARGC1A was expressed, the more insulin was released from the islets, and as expected, in diabetic patients there was less PPARGC1A expressed and also less insulin secreted. This data supports the idea that PPARGC1A expression is reduced in animal models of diabetes and human diabetes and is associated with impaired insulin