1. Introduction
Diabetes mellitus is a group of metabolic diseases, which causes high blood sugar to a person, due to the functional problems of the pancreas or the metabolism. The pancreas produces insulin, which is a kind of hormone to control the level of glucose in the blood, however for a person with diabetes, glucose would not be used properly in the metabolic cycle, and cause health problems, such as polyphagia, polyuria and polydipsia, since glucose is the main source of energy for the body cells. Diabetes mellitus is mainly divided into two types; the pancreas does not make enough insulin (type 1 diabetes), and the calls cannot respond normally to the insulin that is produced (type 2 diabetes). In the medical diagnosis of diabetes, the level of plasma glucose and the value of glycated hemoglobin (Hb A1C) are referred by frequently collecting blood.