Fasting plasma glucose as a screening test for diabetes and its relationship with cardiovascular risk factors in Hong Kong Chinese

OBJECTIVE - To evaluate the use of fasting plasma glucose (FPG) in the diagnosis of diabetes and the relationship between FPG and various cardiovascular risk factors in a community-based Hong Kong Chinese population. RESEARCH DESIGN AND METHODS - The results of 1,470 oral glucose tolerance tests from a prevalence sun ey for glucose intolerance and lipid abnormality in a Hong Kong Chinese working population were examined. Our previous report showed that an FPG of 5.7 mmol/l corresponded to a 2-h plasma glucose (PG) of 11.1 mmol/l, and we used this value as a cutoff value and examined the relationship between FPG and various cardiovascular risk factors in nondiabetic subjects. RESULTS - An FPG cutoff value of 7.8 mmol/l gave a sensitivity of 20.0% and a specificity of 100% in the diagnosis of diabetes (defined as 2-h PG greater than or equal to 11.1 mmol/l). We divided the nondiabetic subjects (FPG < 7.8 mmol/l and 2-h PG < 11.1 mmol/l) into two groups: subjects with FPG < 5.7 mmol/l and those with FPG greater than or equal to 5.7 mmol/l and <7.8 mmol/l. Subjects in the latter group were older, had higher blood pressure, BMI, waist-to-hip ratio, 2-h PG, fasting and 2-h insulin, fasting serum triglyceride, VLDL cholesterol, apolipoprotein B, and urinary albumin concentrations, as well as lower plasma HDL cholesterol and HDL(2) cholesterol concentrations. CONCLUSIONS - These findings suggest that an FPG cutoff value of 7.8 mmol/l, as recommended by the World Health Organization, was too high when applied to Chinese populations. As in the case of hyperlipidemia, plasma glucose concentration should be viewed as a continuum in terms of its relationship with cardiovascular risk.