Diabetes is becoming an epidemic in Hong Kong, affecting over 10% of population and causing a major burden to the health care system. Over 30-40% of patients admitted to the medical wards of the Hospital Authority hospitals have diabetes as a contributory factor. It was estimated that thirty to fifty percent of patients with stroke, heart failure or acute myocardial infarction have diabetes as a key causative factor. However, the exact prevalence rate of diabetes, including asymptomatic undiagnosed glucose intolerance, among subjects with coronary heart disease is still unknown in Hong Kong. Many heart disease patients with undiagnosed diabetes remained being untreated on their abnormal glycemic status, which will further aggravate the heart disease and impair the prognosis.