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 survey 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 > or = 11.1 mmol/l). We divided the non-diabetic 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 > or = 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 HDL2 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.