Though diabetes is common worldwide, the proportion of cases diagnosed is not high. Nearly fifty percent of patients with diabetes mellitus (DM) in US are undiagnosed.1 The ratio might be higher in China. It has been suggested that diabetes may be present 4 to 7 years before diagnosis.2 Many of the complications appear to be present at the time of diagnosis of the diabetic status.1 Screening for diabetes in early stage of diabetes is thus a worthwhile exercise.