A method for detecting whether glucose metabolism is abnormal comprises: detecting GPx2 gene expression, GPx2 protein expression or the activity of GPx2 protein in a test body, and making comparisons with GPx2 expression amount of a normal individual, when the GPx2 expression of the individual is significantly lower than that of the normal individual, indicating that the carbohydrate metabolism of the individual is in an abnormal state. Applications of GPx2 in the preparation of a medical composition for the treatment and prevention of type II diabetes.